Internet DRAFT - draft-ietf-pwe3-iccp
draft-ietf-pwe3-iccp
Internet Engineering Task Force Luca Martini
Internet Draft Samer Salam
Intended status: Standards Track Ali Sajassi
Expires: September 27, 2014 Cisco
Matthew Bocci Satoru Matsushima
Alcatel-Lucent Softbank
Thomas Nadeau
Brocade
March 27, 2014
Inter-Chassis Communication Protocol for L2VPN PE Redundancy
draft-ietf-pwe3-iccp-16.txt
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Abstract
This document specifies an inter-chassis communication protocol
(ICCP) that enables Provider Edge (PE) device redundancy for Virtual
Private Wire Service (VPWS) and Virtual Private LAN Service (VPLS)
applications. The protocol runs within a set of two or more PEs,
forming a redundancy group, for the purpose of synchronizing data
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amongst the systems. It accommodates multi-chassis attachment circuit
as well as pseudowire redundancy mechanisms.
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Table of Contents
1 Specification of Requirements ........................ 5
2 Introduction ......................................... 5
3 ICCP Overview ........................................ 5
3.1 Redundancy Model & Topology .......................... 5
3.2 ICCP Interconnect Scenarios .......................... 7
3.2.1 Co-located Dedicated Interconnect .................... 7
3.2.2 Co-located Shared Interconnect ....................... 8
3.2.3 Geo-redundant Dedicated Interconnect ................. 8
3.2.4 Geo-redundant Shared Interconnect .................... 9
3.3 ICCP Requirements .................................... 10
4 ICC LDP Protocol Extension Specification ............. 12
4.1 LDP ICCP Capability Advertisement .................... 13
4.2 RG Membership Management ............................. 13
4.2.1 ICCP Connection State Machine ........................ 14
4.3 Redundant Object Identification ...................... 17
4.4 Application Connection Management .................... 17
4.4.1 Application Versioning ............................... 18
4.4.2 Application Connection State Machine ................. 19
4.5 Application Data Transfer ............................ 22
4.6 Dedicated Redundancy Group LDP session ............... 22
5 ICCP PE Node Failure / Isolation Detection Mechanism . 23
6 ICCP Message Formats ................................. 24
6.1 Encoding ICC into LDP Messages ...................... 24
6.1.1 ICC Header ........................................... 24
6.1.2 ICC Parameter Encoding ............................... 26
6.1.3 Redundant Object Identifier Encoding ................. 27
6.2 RG Connect Message ................................... 28
6.2.1 ICC Sender Name TLV .................................. 29
6.3 RG Disconnect Message ................................ 29
6.4 RG Notification Message .............................. 32
6.4.1 Notification Message TLVs ............................ 32
6.5 RG Application Data Message .......................... 36
7 Application TLVs ..................................... 36
7.1 Pseudowire Redundancy (PW-RED) Application TLVs ...... 36
7.1.1 PW-RED Connect TLV ................................... 36
7.1.2 PW-RED Disconnect TLV ................................ 37
7.1.2.1 PW-RED Disconnect Cause TLV .......................... 38
7.1.3 PW-RED Config TLV .................................... 39
7.1.3.1 Service Name TLV ..................................... 41
7.1.3.2 PW ID TLV ............................................ 42
7.1.3.3 Generalized PW ID TLV ................................ 43
7.1.4 PW-RED State TLV ..................................... 44
7.1.5 PW-RED Synchronization Request TLV ................... 45
7.1.6 PW-RED Synchronization Data TLV ...................... 47
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7.2 Multi-chassis LACP (mLACP) Application TLVs .......... 48
7.2.1 mLACP Connect TLV .................................... 48
7.2.2 mLACP Disconnect TLV ................................. 49
7.2.2.1 mLACP Disconnect Cause TLV ........................... 50
7.2.3 mLACP System Config TLV .............................. 50
7.2.4 mLACP Aggregator Config TLV .......................... 51
7.2.5 mLACP Port Config TLV ................................ 53
7.2.6 mLACP Port Priority TLV .............................. 55
7.2.7 mLACP Port State TLV ................................. 57
7.2.8 mLACP Aggregator State TLV ........................... 59
7.2.9 mLACP Synchronization Request TLV .................... 61
7.2.10 mLACP Synchronization Data TLV ....................... 63
8 LDP Capability Negotiation ........................... 64
9 Client Applications .................................. 65
9.1 Pseudowire Redundancy Application Procedures ......... 65
9.1.1 Initial Setup ........................................ 66
9.1.2 Pseudowire Configuration Synchronization ............. 66
9.1.3 Pseudowire Status Synchronization .................... 67
9.1.3.1 Independent Mode ..................................... 68
9.1.3.2 Master/Slave Mode .................................... 69
9.1.4 PE Node Failure or Isolation ......................... 69
9.2 Attachment Circuit Redundancy Application Procedures . 70
9.2.1 Common AC Procedures ................................. 70
9.2.1.1 AC Failure ........................................... 70
9.2.1.2 Remote PE Node Failure or Isolation .................. 70
9.2.1.3 Local PE Isolation ................................... 70
9.2.1.4 Determining Pseudowire State ......................... 71
9.2.2 Multi-chassis LACP (mLACP) Application Procedures .... 71
9.2.2.1 Initial Setup ........................................ 71
9.2.2.2 mLACP Aggregator and Port Configuration .............. 73
9.2.2.3 mLACP Aggregator and Port Status Synchronization ..... 74
9.2.2.4 Failure and Recovery ................................. 76
10 Security Considerations .............................. 77
11 Manageability Considerations ......................... 78
12 IANA Considerations .................................. 78
12.1 MESSAGE TYPE NAME SPACE .............................. 78
12.2 TLV TYPE NAME SPACE .................................. 78
12.3 ICC RG Parameter Type Space .......................... 79
12.4 STATUS CODE NAME SPACE ............................... 80
13 Acknowledgments ...................................... 80
14 Normative References ................................. 80
15 Informative References ............................... 81
16 Author's Addresses ................................... 81
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1. Specification of Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119.
2. Introduction
Network availability is a critical metric for service providers as it
has a direct bearing on their profitability. Outages translate not
only to lost revenue but also to potential penalties mandated by
contractual agreements with customers running mission-critical
applications that require tight SLAs. This is true for any carrier
network, and networks employing Layer 2 Virtual Private Network
(L2VPN) technology are no exception. Network high-availability can
be achieved by employing intra and inter-chassis redundancy
mechanisms. The focus of this document is on the latter. The document
defines an Inter-Chassis Communication Protocol (ICCP) that allows
synchronization of state and configuration data between a set of two
or more Provider Edge nodes (PEs) forming a Redundancy Group (RG).
The protocol supports multi-chassis redundancy mechanisms that can be
employed on either the attachment circuits or pseudowires. A formal
definition of the term chassis can be found in [RFC2922]. For the
purpose of this document, a chassis is an L2VPN PE node.
This document assumes that it is normal to run the Label Distribution
Protocol (LDP) between the PEs in the RG, and that LDP components
will in any case be present on the PEs to establish and maintain
pseudowires. Therefore, ICCP is built as a secondary protocol running
within LDP and taking advantage of the LDP session mechanisms and the
underlying TCP and TCP-based security mechanisms already necessary
for LDP operation.
3. ICCP Overview
3.1. Redundancy Model & Topology
The focus of this document is on PE node redundancy. It is assumed
that a set of two or more PE nodes are designated by the operator to
form a Redundancy Group (RG). Members of a Redundancy Group fall
under a single administration (e.g. service provider) and employ a
common redundancy mechanism towards the access (attachment circuits
or access pseudowires) and/or towards the core (pseudowires) for any
given service instance. It is possible, however, for members of an RG
to make use of disparate redundancy mechanisms for disjoint services.
The PE devices may be offering any type of L2VPN service, i.e. VPWS
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or VPLS. As a matter of fact, the use of ICCP may even be applicable
for Layer 3 service redundancy, but this is considered to be outside
the scope of this document.
The PEs in an RG offer multi-homed connectivity to either individual
devices (e.g. CE, DSLAM, etc...) or entire networks (e.g. access
network). Figure 1 below depicts the model.
+=================+
| |
Mutli-homed +----+ | +-----+ |
Node ------------> | CE |-------|--| PE1 ||<------|---Pseudowire-->|
| |--+ -|--| ||<------|---Pseudowire-->|
+----+ | / | +-----+ |
| / | || |
|/ | || ICCP |--> Towards Core
+-------------+ / | || |
| | /| | +-----+ |
| Access |/ +----|--| PE2 ||<------|---Pseudowire-->|
| Network |-------|--| ||<------|---Pseudowire-->|
| | | +-----+ |
| | | |
+-------------+ | Redundancy |
^ | Group |
| +=================+
|
Multi-homed Network
Figure 1: Generic Multi-chassis Redundancy Model
In the topology of Figure 1, the redundancy mechanism employed
towards the access node/network can be one of a multitude of
technologies, e.g. it could be IEEE 802.1AX Link Aggregation Groups
with Link Aggregation Control Protocol (LACP), or SONET APS. The
specifics of the mechanism are out of the scope of this document.
However, it is assumed that the PEs in the RG are required to
communicate amongst each other in order for the access redundancy
mechanism to operate correctly. As such, it is required to run an
inter-chassis communication protocol among the PEs in the RG in order
to synchronize configuration and/or running state data.
Furthermore, the presence of the inter-chassis communication channel
allows simplification of the pseudowire redundancy mechanism. This is
primarily because it allows the PEs within an RG to run some
arbitration algorithm to elect which pseudowire(s) should be in
active or standby mode for a given service instance. The PEs can then
advertise the outcome of the arbitration to the remote-end PE(s), as
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opposed to having to embed a hand-shake procedure into the pseudowire
redundancy status communication mechanism, and every other possible
Layer 2 status communication mechanism.
3.2. ICCP Interconnect Scenarios
When referring to 'interconnect' in this section, we are concerned
with the links or networks over which Inter-Chassis Communication
Protocol messages are transported, and not normal data traffic
between PEs. The PEs which are members of an RG may be either
physically co-located or geo-redundant. Furthermore, the physical
interconnect between the PEs over which ICCP is to run may comprise
of either dedicated back-to-back links or a shared connection through
the packet switched network (PSN); for e.g., MPLS core network. This
gives rise to a matrix of four interconnect scenarios, described
next.
3.2.1. Co-located Dedicated Interconnect
In this scenario, the PEs within an RG are co-located in the same
physical location, e.g. point of presence (POP) or central office
(CO). Furthermore, dedicated links provide the interconnect for ICCP
among the PEs.
+=================+ +-----------------+
|CO | | |
| +-----+ | | |
| | PE1 |________|_____| |
| | | | | |
| +-----+ | | |
| || | | |
| || ICCP | | Core |
| || | | Network |
| +-----+ | | |
| | PE2 |________|_____| |
| | | | | |
| +-----+ | | |
| | | |
+=================+ +-----------------+
Figure 2: ICCP Co-located PEs Dedicated Interconnect Scenario
Given that the PEs are connected back-to-back in this case, it is
possible to rely on Layer 2 redundancy mechanisms to guarantee the
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robustness of the ICCP interconnect. For example, if the interconnect
comprises of IEEE 802.3 Ethernet links, it is possible to provide
link redundancy by means of IEEE 802.1AX Link Aggregation Groups.
3.2.2. Co-located Shared Interconnect
In this scenario, the PEs within an RG are co-located in the same
physical location (POP, CO). However, unlike the previous scenario,
there are no dedicated links between the PEs. The interconnect for
ICCP is provided through the core network to which the PEs are
connected. Figure 3 depicts this model.
+=================+ +-----------------+
|CO | | |
| +-----+ | | |
| | PE1 |________|_____| |
| | |<=================+ |
| +-----+ ICCP | | || |
| | | || |
| | | || Core |
| | | || Network |
| +-----+ | | || |
| | PE2 |________|_____| || |
| | |<=================+ |
| +-----+ | | |
| | | |
+=================+ +-----------------+
Figure 3: ICCP Co-located PEs Shared Interconnect Scenario
Given that the PEs in the RG are connected over the packet switched
network (PSN), then PSN Layer mechanisms can be leveraged to ensure
the resiliency of the interconnect against connectivity failures. For
example, it is possible to employ RSVP LSPs with Fast Re-Route (FRR)
and/or end-to-end backup LSPs.
3.2.3. Geo-redundant Dedicated Interconnect
In this variation, the PEs within a Redundancy Group are located in
different physical locations to provide geographic redundancy. This
may be desirable, for example, to protect against natural disasters
or the like. A dedicated interconnect is provided to link the PEs,
which is a costly option, especially when considering the possibility
of providing multiple such links for interconnect robustness. The
resiliency mechanisms for the interconnect are similar to those
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highlighted in the co-located interconnect counterpart.
+=================+ +-----------------+
|CO 1 | | |
| +-----+ | | |
| | PE1 |________|_____| |
| | | | | |
| +-----+ | | |
+=====||==========+ | |
|| ICCP | Core |
+=====||==========+ | Network |
| +-----+ | | |
| | PE2 |________|_____| |
| | | | | |
| +-----+ | | |
|CO 2 | | |
+=================+ +-----------------+
Figure 4: ICCP Geo-redundant PEs Dedicated Interconnect Scenario
3.2.4. Geo-redundant Shared Interconnect
In this scenario, the PEs of an RG are located in different physical
locations and the interconnect for ICCP is provided over the PSN
network to which the PEs are connected. This interconnect option is
more likely to be the one used for geo-redundancy as it is more
economically appealing compared to the geo-redundant dedicated
interconnect. The resiliency mechanisms that can be employed to
guarantee the robustness of the ICCP transport are PSN Layer
mechanisms as has been described in the "Co-located Shared
Interconnect" section above.
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+=================+ +-----------------+
|CO 1 | | |
| +-----+ | | |
| | PE1 |________|_____| |
| | |<=================+ |
| +-----+ ICCP | | || |
+=================+ | || |
| || Core |
+=================+ | || Network |
| +-----+ | | || |
| | PE2 |________|_____| || |
| | |<=================+ |
| +-----+ | | |
|CO 2 | | |
+=================+ +-----------------+
Figure 5: ICCP Geo-redundant PEs Shared Interconnect Scenario
3.3. ICCP Requirements
The requirements for the Inter-chassis Communication Protocol are as
follows:
-i. ICCP MUST Provide a control channel for communication
between PEs in a Redundancy Group (RG). PE nodes may be co-
located or remote (refer to "Interconnect Scenarios" section
above). Client applications which make use of ICCP services
MUST only use this channel to communicate control
information and not data-traffic. As such the protocol
SHOULD cater for relatively low bandwidth, low-delay and
highly reliable message transfer.
-ii. ICCP MUST accommodate multiple client applications (e.g.
multi-chassis LACP, PW redundancy, SONET APS, etc...). This
implies that the messages SHOULD be extensible (e.g. TLV-
based) and the protocol SHOULD provide a robust application
registration and versioning scheme.
-iii. ICCP MUST provide reliable message transport and in-order
delivery between nodes in a RG with secure authentication
mechanisms built into the protocol. The redundancy
applications that are clients of ICCP expect reliable
message transfer, and as such will assume that the protocol
takes care of flow-control and retransmissions. Furthermore,
given that the applications will rely on ICCP to communicate
data used to synchronize state-machines on disparate nodes,
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it is critical that ICCP guarantees in-order message
delivery. Loss of messages or out-of-sequence messages would
have adverse side-effects to the operation of the client
applications.
-iv. ICCP MUST provide a common mechanism to actively monitor the
health of PEs in an RG. This mechanism will be used to
detect PE node failure (or isolation from the MPLS network
in case of shared interconnect), and inform the client
applications. The applications require this to trigger
failover according to the procedures of the employed
redundancy protocol on the AC and PW. The solution SHOULD
achieve sub-second detection of loss of remote node (~ 50 -
150 msec) in order to give the client applications
(redundancy mechanisms) enough reaction time to achieve
sub-second service restoration time.s
-v. ICCP SHOULD provide asynchronous event-driven state update,
independent of periodic messages, for immediate notification
of client applications' state changes. In other words, the
transmission of messages carrying application data SHOULD be
on-demand rather than timer-based to minimize inter-chassis
state synchronization delay.
-vi. ICCP MUST accommodate multi-link and multi-hop interconnect
between nodes. When the devices within an RG are located in
different physical locations, the physical interconnect
between them will comprise of a network rather than a link.
As such, ICCP MUST accommodate the case where the
interconnect involves multiple hops. Furthermore, it is
possible to have multiple (redundant) paths or interconnects
between a given pair of devices. This is true for both the
co-located and geo-redundant scenarios. ICCP MUST handle
this as well.
-vii. ICCP MUST ensure transport security between devices in an
RG. This is especially important in the scenario where the
members of an RG are located in different physical locations
and connected over a shared network (e.g. PSN). In
particular, ICCP MUST NOT accept connections arbitrarily
from any device; otherwise, the state of client applications
might be compromised. Furthermore, even if an ICCP
connection request appears to come from an eligible device,
its source address may have been spoofed. Therefore, some
means of preventing source address spoofing MUST be in
place.
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-viii. ICCP MUST allow the operator to statically configure members
of RG. Auto-discovery may be considered in the future.
-ix. ICCP SHOULD allow for flexible RG membership. It is expected
that only two nodes per an RG will cover most of the
redundancy applications for common deployments. ICCP SHOULD
NOT preclude supporting more than two nodes in an RG by
virtue of design. Furthermore, ICCP MUST allow a single node
to be member of multiple RGs simultaneously.
4. ICC LDP Protocol Extension Specification
To address the requirements identified in the previous section, ICCP
is modeled to comprise of three layers:
-i. Application Layer: This provides the interface to the
various redundancy applications that make use of the
services of ICCP. ICCP is concerned with defining common
connection management procedures and the formats of the
messages exchanged at this layer; however, beyond that, it
does not impose any restrictions on the procedures or
state-machines of the clients, as these are deemed
application-specific and lie outside the scope of ICCP.
This guarantees implementation inter-operability without
placing any unnecessary constraints on internal design
specifics.
-ii. Inter Chassis Communication (ICC) Layer: This layer
implements the common set of services which ICCP offers to
the client applications. It handles protocol versioning, RG
membership, Redundant Object identification, PE node
identification and ICCP connection management.
-iii. Transport Layer: This layer provides the actual ICCP message
transport. It is responsible for addressing, route
resolution, flow-control, reliable and in-order message
delivery, connectivity resiliency/redundancy and finally PE
node failure detection. The Transport layer may differ
depending on the Physical Layer of the inter-connect.
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4.1. LDP ICCP Capability Advertisement
When an RG is enabled on a particular PE, an LDP session MUST be
created to every remote PE in that RG, if one does not already exist.
Then, the capability of supporting ICCP MUST be advertised to all
those LDP peers in that RG. This is achieved by using the methods in
[RFC5561] and advertising the ICCP LDP capability TLV. If an LDP peer
supports the dynamic capability advertisement, this can be done by
sending a new capability message with the S bit set for the ICCP
capability TLV when the first RG is enabled on the PE. If the peer
does not support dynamic capability advertisement, then the ICCP TLV
MUST be included in the LDP initialization procedures in the
capability parameter [RFC5561].
4.2. RG Membership Management
ICCP defines a mechanism that enables PE nodes to manage their RG
membership. When a PE is configured to be a member of an RG, it will
first advertise the ICCP capability to its peers. Subsequently, the
PE sends an RG Connect message to the peers that have also advertised
ICCP capability. The PE then waits for the peers to send their own RG
Connect messages, if they haven't done so already. For a given RG,
the ICCP connection between two devices is considered to be
operational only when both have sent and received ICCP RG Connect
messages for that RG.
If a PE that has sent a particular RG Connect message doesn't receive
a corresponding RG Connect (or a Notification message rejecting the
connection) from a destination, it will remain in a state expecting
the corresponding RG Connect message (or Notification message). The
RG will not become operational until the corresponding RG Connect
Message has been received. If a PE that has sent an RG Connect
message receives a Notification message rejecting the connection,
with a NAK TLV (section 6.4.1), it will stop attempting to bring up
the ICCP connection immediately.
A device MUST reject an incoming RG Connect message if at least one
of the following conditions is satisfied:
-i. the PE is not a member of the RG;
-ii. the maximum number of simultaneous ICCP connections that the
PE can handle is exceeded.
Otherwise, the PE MUST bring up the connection by responding to the
incoming RG Connect message with an appropriate RG Connect.
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A PE sends an RG Disconnect message to tear down the ICCP connection
for a given RG. This is a unilateral operation and doesn't require
any acknowledgement from the other PEs. Note that the ICCP connection
for an RG MUST be operational before any client application can make
use of ICCP services in that RG.
4.2.1. ICCP Connection State Machine
A PE maintains an ICCP Connection State Machine instance for every
ICCP connection with a remote peer in the RG. This state machine is
separate from any Application Connection State Machine (section
4.4.2). The ICCP Connection State Machine reacts only to RG Connect,
RG Disconnect and RG Notification messages that do not contain any
Application TLVs. Actions and state transitions in the Application
Connection state machines have no effect on the ICCP Connection State
Machine.
The ICCP Connection state machine is defined to have six states as
follows:
-NON EXISTENT: This state is the starting point for the state
machine.It indicates that no ICCP connection exists and that
there's no LDP session established between the PEs.
-INITIALIZED: This state indicates that an LDP session exists between
the PEs but LDP ICCP Capabilitiy have not yet been exchanged between
them.
-CAPSENT: This state indicates that an LDP session exists between the
PEs and that the local PE has avertized LDP ICCP Capability to its
peer.
-CAPREC: This state indicates that an LDP session exists between the
PEs and that the local PE has both received and avertized LDP ICCP
Capability from/to its peer.
-CONNECTING: This state indicates that the local PE has initiated
an ICCP connection to its peer, and is awaiting its response.
-OPERATIONAL: This state indicates that the ICCP connection is
operational.
The state transition table and state transition diagram follow.
ICCP Connection State Transition Table
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STATE EVENT NEW STATE
NON EXISTENT LDP session established INITIALIZED
INITIALIZED Transmit LDP ICCP Capability CAPSENT
Receive LDP ICCP Capability CAPREC
Action: Transmit LDP ICCP Capability
LDP session torn down NON EXISTENT
CAPSENT Receive LDP ICCP Capability CAPREC
LDP session torn down NON EXISTENT
CAPREC Transmit RG Connect Message CONNECTING
Receive acceptable RG Connect Message OPERATIONAL
Action: Transmit RG Connect Message
Receive any other ICCP Message CAPREC
Action: Transmit NAK TLV in RG
Notification Message
LDP session torn down NON EXISTENT
CONNECTING Receive acceptable RG Connect Message OPERATIONAL
Receive any other ICCP Message CAPREC
Action: Transmit NAK TLV in RG
Notification Message
LDP session torn down NON EXISTENT
OPERATIONAL Receive acceptable RG Disconnect Message CAPREC
Transmit RG Disconnect Message CAPREC
LDP session torn down NON EXISTENT
ICCP Connection State Transition Diagram
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+------------+
| |
+------------------>|NON EXISTENT| LDP session torn down
| | |<--------------------------+
| +------------+ |
| LDP session | ^ LDP session |
| established | | torn down |
| V | |
| +-----------+ |
LDP | | | Tx LDP ICCP |
session| |INITIALIZED| capability |
torn | +---| |---------------+ |
down | Rx other | +-----------+ | |
| ICCP msg/ |Rx LDP ICCP | |
| Tx NAK TLV | capability/ | |
| +---+ |Tx LDP ICCP capability | |
| | | | | |
| V | V V |
| +-----------+ Rx LDP ICCP +--------+ |
+---| | capability | | |
|CAPREC |<----------------------|CAPSENT |---------->+
+---| |-------------------+ | | |
| +-----------+ | +--------+ |
| ^ ^ | |
Tx | | | | |
RG | | |Rx RG Disconnect msg | |
Connect| | | or |Rx RG Connect msg / |
Msg | | |Tx RG Disconnect msg | Tx RG Connect msg |
| | | V |
| | | +------------+ |
| | +--------------------| | |
| | |OPERATIONAL |------------>+
| | | | |
| |Rx other ICCP msg/ +------------+ |
| | Tx NAK TLV ^ |
| | | |
| +----------+ Rx RG Connect msg | |
| | |---------------------+ |
+----->|CONNECTING| |
| |----------------------------------------->+
+----------+
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4.3. Redundant Object Identification
ICCP offers its client applications a uniform mechanism for
identifying links, ports, forwarding constructs and more generally
objects (e.g. interfaces, pseudowires, VLANs, etc...) that are being
protected in a redundant setup. These are referred to as Redundant
Objects (RO). An example of an RO is a multi-chassis link-aggregation
group that spans two PEs. ICCP introduces a 64-bit opaque identifier
to uniquely identify ROs in an RG. This identifier, referred to as
Redundant Object ID (ROID), MUST match between RG members for the
protected object in question. That allows separate systems in an RG
to use a common handle to reference the protected entity irrespective
of its nature (e.g. physical or virtual) and in a manner that is
agnostic to implementation specifics. Client applications that need
to synchronize state pertaining to a particular RO SHOULD embed the
corresponding ROID in their TLVs.
4.4. Application Connection Management
ICCP provides a common set of procedures by which applications on one
PE can connect to their counterparts on another PE, for purpose of
inter-chassis communication in the context of a given RG. The
prerequisite for establishing an application connection is to have an
operational ICCP RG connection between the two endpoints. It is
assumed that the association of applications with RGs is known a
priori, e.g. by means of device configuration. ICCP then sends an
Application-specific Connect TLV (carried in RG Connect message), on
behalf of each client application, to each remote PE within the RG.
The client may piggyback application-specific information in that
Connect TLV, which for example can be used to negotiate parameters or
attributes prior to bringing up the actual application connection.
The procedures for bringing up the application connection are similar
to those of the ICCP connection: An application connection between
two nodes is up only when both nodes have sent and received RG
Connect Messages with the proper Application-specific Connect TLVs. A
PE MUST send a Notification Message to reject an application
connection request if one of the following conditions is encountered:
-i. the application doesn't exist or is not configured for that
RG;
-ii. the application connection count exceeds the PE's
capabilities.
When a PE receives such a rejection notification, it MUST stop
attempting to bring up the application connection until it receives a
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new application connection request from the remote PE. This is done
by responding to the incoming RG Connect message (carrying an
Application-specific Connect TLV) with an appropriate RG Connect
message (carrying a corresponding Application-specific Connect TLV).
When an application is stopped on a device or it is no longer
associated with an RG, it MUST signal ICCP to trigger sending an
Application-specific Disconnect TLV (in the RG Disconnect message).
This is a unilateral notification to the other PEs within an RG, and
as such doesn't trigger any response.
4.4.1. Application Versioning
During application connection setup time, a given application on one
PE can negotiate with its counterpart on a peer PE the proper
application version to use for communication. If no common version is
agreed upon, then the application connection is not brought up. This
is achieved through the following set of rules:
- If an application receives an Application-specific Connect TLV
with a version number that is higher than its own, it MUST send a
Notification message with a NAK TLV indicating status code
"Incompatible Protocol Version" and supplying the version that is
locally supported by the PE.
- If an application receives an Application-specific Connect TLV
with a version number that is lower than its own, it MAY respond
with an RG Connect that has an Application-specific Connect TLV
using the same version that was received. Alternatively, the
application MAY respond with a Notification message to reject the
request using the "Incompatible Protocol Version" code, and
supplying the version that is supported. The above allows an
application to operate in either backwards compatible or
incompatible mode.
- If an application receives an Application-specific Connect TLV
with a version that is equal to its own, then the application
MUST honor or reject the request based on whether the application
is configured for the RG in question, and whether or not the
application connection count has been exceeded.
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4.4.2. Application Connection State Machine
A PE maintains an Application Connection State Machine instance per
ICCP application for every ICCP connection with a remote PE in the
RG. Each application's state machine reacts only to the RG Connect,
RG Disconnect and RG Notification messages that contain an
Application TLV specifying that particular application.
The Application Connection state machine has six states as follows:
-NON EXISTENT: This state indicates that the Application Connection
does not exist since there is no ICCP connection between the PEs.
-RESET: This state indicates that an ICCP connection is operational
between the PEs, but that the Application Connection has not been
initialized yet or has been resent.
-CONNSENT: This state indicates that the local PE has requested
initiation of an Application Connection with its peer, but has not
received a response yet.
-CONNREC: This state indicates that the local PE has received a
request to initiate an Application Connection from its peer but has
not responded yet.
-CONNECTING: This state indicates that the local PE has transmitted
to its peer an Application Connection message with the A-bit set
to 1, and is awaiting the peer's response
-OPERATIONAL: This state indicates that the Application Connection is
operational.
The state transition table and diagram follow.
ICCP Application Connection State Transition Table
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STATE EVENT NEW STATE
NON EXISTENT ICCP connection established RESET
RESET ICCP connection torn down NON EXISTENT
Transmit Application Connect TLV CONNSENT
Receive Application Connect TLV CONNREC
Receive any other Application TLV RESET
Action: Transmit NAK TLV
CONNSENT Receive NAK TLV RESET
Receive Application Connect TLV OPERATIONAL
with A-bit=1
Action: Transmit Application Connect
TLV with A-bit=1
Receive any other Application TLV RESET
Action: Transmit NAK TLV
ICCP connection torn down NON EXISTENT
CONNREC Transmit NAK TLV RESET
Transmit Application Connect TLV CONNECTING
with A-bit=1
Receive Application Connect TLV CONNREC
Receive any Application TLV except RESET
Connect
Action: Transmit NAK TLV
ICCP connection torn down NON EXISTENT
CONNECTING Receive Application Connect TLV OPERATIONAL
with A-bit=1
Receive any other Application TLV RESET
Action: Transmit NAK TLV
ICCP connection torn down NON EXISTENT
OPERATIONAL Receive Application Disconnect TLV RESET
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Transmit Applicaton Disconnect TLV RESET
ICCP connection torn down NON EXISTENT
ICCP Application Connection State Transition Diagram
+------------+
| |
+---------------->|NON EXISTENT| ICCP connection torn down
| | |<--------------------------+
| +------------+ |
| ICCP connection| ^ ICCP connection |
| established | | torn down |
| | | |
| V | Rx other App TLV/ |
| +-----------+<-----+ Tx NAK TLV |
ICCP | Rx App | | | |
connect| Connect TLV | RESET |------+ |
torn | +-------------| |---------------+ |
down | | +-----------+ Tx App | |
| | ^ ^ ^ ^ Connect TLV| |
| | Tx NAK | | | | | |
| | or | | | | | |
| | Rx non | | | | | |
| | Connect | | | | | |
| V TLV/Tx NAK | | |Rx NAK TLV V |
| +-----------+ | | | |or +--------+ |
+-| |---+ | | +---------| | |
|CONNREC | | | Rx other |CONNSENT|---------->+
+-| |-+ | | App TLV/ | | |
| +-----------+ | | | Tx NAK +--------+ |
| ^---+ | | |Rx App Connect |
| Rx App | | |TLV (A=1) / |
| Connect TLV | |Rx App Disconn | Tx App |
| | |or | Connect TLV |
| Tx App Connect | |Tx App Disconn V (A=1) |
| TLV (A=1) | | +------------+ |
| | +------| | |
| Rx other App | |OPERATIONAL |------------>+
| TLV / Tx NAK | | | |
| +------+ +------------+ |
| | ^ Rx App Connect |
| +----------+ | TLV (A=1) |
| | |---------------------+ |
+--->|CONNECTING| |
| |----------------------------------------->+
+----------+
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4.5. Application Data Transfer
When an application has information to transfer over ICCP it triggers
the transmission of an Application Data message. ICCP guarantees in-
order and loss-less delivery of data. An application may reject a
message or a set of one or more TLVs within a message by using the
Notification Message with NAK TLV. Furthermore, an application may
implement its own ACK mechanism, if deemed required, by defining an
application-specific TLV to be transported in an Application Data
message. Note that this document does not define a common ACK
mechanism for applications.
It is left up to the application to define the procedures to handle
the situation where a PE receives a NAK TLV in response to a
transmitted Application Data message. Depending on the specifics of
the application, it may be favorable to have the PE, which sent the
NAK, explicitly request retransmission of data. On the other hand,
for certain applications it may be more suitable to have the original
sender of the Application Data message handle retransmissions in
response to a NAK. ICCP supports both models.
4.6. Dedicated Redundancy Group LDP session
For certain ICCP applications, it is required to exchange a fairly
large amount of RG information in a very short period of time. In
order to better distribute the load in a multiple processor system,
and to avoid head of line blocking to other LDP applications, it may
be required to initiate a separate TCP/IP session between the two LDP
speakers.
This procedure is OPTIONAL, and does not change the operation of LDP
or ICCP.
A PE that requires a separate LDP session will advertise a separate
LDP adjacency with a non-zero label space identifier. This will cause
the remote peer to open a separate LDP session for this label space.
No labels need to be advertised in this label space, as it is only
used for one or a set of ICCP RGs. All relevant LDP and ICCP
procedures still apply as described in the relevant documents.
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5. ICCP PE Node Failure / Isolation Detection Mechanism
ICCP provides its client applications a notification when a remote PE
that is member of the RG is no longer reachable. In the case of
dedicated interconnect, this indicates that the remote PE node has
failed. Whereas, in the case of shared interconnect, this indicates
that either the remote PE node has failed or that it has become
isolated from the MPLS network. This is used by the client
applications to trigger failover according to the procedures of the
employed redundancy protocol on the AC and PW. To that end, ICCP does
not define its own Keep-Alive mechanism for purpose of monitoring the
health of remote PE nodes, but rather reuses existing fault detection
mechanisms. The following mechanisms may be used by ICCP to detect PE
node failure:
- BFD
Run a BFD session [RFC5880] between the PEs that are members of a
given RG, and use that to detect PE node failure. This assumes
that resiliency mechanisms are in place to protect connectivity
to the remote PE nodes, and hence loss of BFD periodic messages
from a given PE node can only mean that the node itself has
failed.
- IP Reachability Monitoring
It is possible for a PE to monitor IP layer connectivity to other
members of an RG that are participating in IGP/BGP. When
connectivity to a given PE is lost, the local PE interprets that
to mean loss of the remote PE node. This assumes that resiliency
mechanisms are in place to protect the route to the remote PE
nodes, and hence loss of IP reachability to a given node can only
mean that the node itself has failed.
It is worth noting here that loss of the LDP session with a PE in an
RG is not a reliable indicator that the remote PE itself is down. It
is possible, for e.g. that the remote PE encounters a local event
that leads to resetting the LDP session, while the PE node remains
operational for purpose of traffic forwarding.
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6. ICCP Message Formats
This section defines the messages exchanged at the Application and
ICC layers.
6.1. Encoding ICC into LDP Messages
ICCP requires reliable, in-order, state-full message delivery, as
well as capability negotiation between PEs. The LDP protocol offers
all these features, and is already in wide use in the applications
that would also require the ICCP protocol extensions. For these
reasons, ICCP takes advantage of the already defined LDP protocol
infrastructure.
[RFC5036] Section 3.5 defines a generic LDP message structure. A new
set of LDP message types is defined to communicate the ICCP
information. LDP message types in the range 0x700 to 0x70F will be
used for ICCP.
Message types are allocated by IANA, and requested in the IANA
section below.
6.1.1. ICC Header
Every ICCP message comprises of an ICC specific LDP Header followed
by message data. The format of the ICC Header is as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U| Message Type | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x0005 (ICC RG ID) | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICC RG ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Mandatory ICC Parameters |
~ ~
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Optional ICC Parameters |
~ ~
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U-bit
Unknown message bit. Upon receipt of an unknown message, if U is
clear (=0), a notification is returned to the message originator;
if U is set (=1), the unknown message is silently ignored. The
following sections which define messages specify a value for the
U-bit.
- Message Type
Identifies the type of the ICCP message, must be in the range of
0x0700 to 0x070F.
- Message Length
Two octet integer specifying the total length of this message in
octets, excluding the U-bit, Message Type and Length fields.
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- Message ID
Four octet value used to identify this message. Used by the
sending PE to facilitate identifying RG Notification messages
that may apply to this message. A PE sending an RG Notification
message in response to this message SHOULD include this Message
ID in the "NAK TLV" of the RG Notification message; see Section
6.4 "RG Notification Message".
- ICC RG ID TLV
A TLV of type 0x0005, length 4, containing 4 octets unsigned
integer designating the Redundancy Group which the sending device
is member of. RG ID value 0x00000000 is reserved by the protocol.
- Mandatory ICC Parameters
Variable length set of required message parameters. Some
messages have no required parameters.
For messages that have required parameters, the required
parameters MUST appear in the order specified by the individual
message specifications in the sections that follow.
- Optional ICC Parameters
Variable length set of optional message parameters. Many
messages have no optional parameters.
For messages that have optional parameters, the optional
parameters may appear in any order.
6.1.2. ICC Parameter Encoding
The generic format of an ICC parameter is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV(s) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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- U-bit
Unknown TLV bit. Upon receipt of an unknown TLV, if U is clear
(=0), a notification MUST be returned to the message originator
and the entire message MUST be ignored; if U is set (=1), the
unknown TLV MUST be silently ignored and the rest of the message
processed as if the unknown TLV did not exist. The sections
following that define TLVs specify a value for the U-bit.
- F-bit
Forward unknown TLV bit. This bit applies only when the U-bit is
set and the LDP message containing the unknown TLV is to be
forwarded. If F is clear (=0), the unknown TLV is not forwarded
with the containing message; if F is set (=1), the unknown TLV is
forwarded with the containing message. The sections following
that define TLVs specify a value for the F-bit. By setting both
the U- and F-bits, a TLV can be propagated as opaque data through
nodes that do not recognize the TLV.
- Type
Fourteen bits indicating the ICC Parameter type.
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- TLV(s): A set of 0 or more TLVs, that vary according to the
message type.
6.1.3. Redundant Object Identifier Encoding
The Redundant Object Identifier (ROID) is a generic opaque handle
that uniquely identifies a Redundant Object (e.g. link, bundle, VLAN,
etc...) which is being protected in an RG. It is encoded as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ROID |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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where: ROID is an 8 octets field encoded as an unsigned integer. The
ROID value of 0 is reserved.
The ROID is carried within application specific TLVs.
6.2. RG Connect Message
The RG Connect Message is used to establish the ICCP RG connection in
addition to individual Application connections between PEs in an RG.
An RG Connect message with no "Application-specific connect TLV"
signals establishment of the ICCP RG connection. Whereas, an RG
Connect message with a valid "Application-specific connect TLV"
signals the establishment of an Application connection, in addition
to the ICCP RG connection if the latter is not already established.
An implementation MAY send a dedicated RG Connect message to set up
the ICCP RG connection and a separate RG Connect message per client
application. However, all implementations MUST support the receipt of
an RG Connect message that triggers the setup of the ICCP RG
connection as well as a single Application connection simultaneously.
A PE sends an RG Connect Message to declare its membership in a
Redundancy Group. One such message should be sent to each PE that is
member of the same RG. The set of PEs to which RG Connect Messages
should be transmitted is known via configuration or an auto-discovery
mechanism that is outside the scope of this specification. If a
device is member of multiple RGs, it MUST send separate RG Connect
Messages for each RG even if the receiving device(s) happen to be the
same.
The format of the RG Connect Message is as follows:
-i. ICC header with Message type = "RG Connect Message" (0x0700)
-ii. ICC Sender Name TLV
-iii. Zero or one Application-specific connect TLV
The currently defined Application-specific connect TLVs are:
- PW-RED Connect TLV (section 7.1.1)
- mLACP Connect TLV (section 7.2.1)
The details of these TLVs are discussed in the "Application TLVs"
section.
The RG Connect message can contain zero or one Application-specific
connect TLV.
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6.2.1. ICC Sender Name TLV
A TLV that carries the hostname of the sender encoded in UTF-8
[RFC3629]. This is used primarily for purpose of management of the RG
and easing network operations. The specific format is shown below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Name |
+ +-+-+-+-+-+-+-+-+-+
~ ~
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U=F=0
- Type set to 0x0001 (from ICC parameter name space).
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Sender Name
An administratively-assigned name of the sending device encoded
in UTF-8 and limited to a maximum of 80 octets. This field does
not include a terminating null character.
6.3. RG Disconnect Message
The RG Disconnect Message serves dual-purpose: to signal that a
particular Application connection is being closed within an RG, or
that the ICCP RG connection itself is being disconnected because the
PE wishes to leave the RG. The format of this message is:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U| Message Type=0x0701 | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x0005 (ICC RG ID) | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICC RG ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Disconnect Code TLV |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Application-specific Disconnect TLV |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Parameter TLVs |
+ +
| |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U-bit
U=0
- Message Type
The message type for RG Disconnect Message is set to (0x0701)
- Length
Length of the TLV in octets excluding the U-bit, Message Type,
and Message Length fields.
- Message ID
Defined in the "ICC Header" section above.
- ICC RG ID
Defined in the "ICC Header" section above.
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- Disconnect Code TLV
The format of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICCP Status Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U,F Bits
both U and F are set to 0.
- Type
set to "Disconnect Code TLV" (0x0004)
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- ICCP Status Code
A status code that reflects the reason for the disconnect
message. Allowed values are "ICCP RG Removed" and "ICCP
Application Removed from RG".
- Optional Application-specific Disconnect TLV
Zero or one Application-specific Disconnect TLVs which are
defined later in the document. If the RG Disconnect message has
a status code of "RG Removed", then it MUST NOT contain any
Application-specific Disconnect TLVs, as the sending PE is
signaling that it has left the RG and, thus, is disconnecting the
ICCP RG connection, with all associated client application
connections. If the message has a status code of "Application
Removed from RG", then it MUST contain exactly one Application-
specific Disconnect TLV, as the sending PE is only tearing down
the connection for the specified application. Other applications,
and the ICCP RG connection are not to be affected.
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- Optional Parameter TLVs
None are defined for this message in this document. This is
specified to allow for future extensions.
6.4. RG Notification Message
A PE sends an RG Notification Message to indicate one of the
following: to reject an ICCP connection, to reject an application
connection, to reject an entire message or to reject one or more
TLV(s) within a message. The Notification message MUST only be sent
to a PE that is already part of an RG.
The RG Notification Message MUST only be used to reject messages or
TLVs corresponding to a single ICCP application. In other words,
there is a limit of at most a single ICCP application per RG
Notification Message.
The format of the RG Notification Message is:
-i. ICC header with Message type = "RG Notification Message"
(0x0702)
-ii. Notification Message TLVs.
The currently defined Notification message TLVs are:
-i. ICC Sender Name TLV
-ii. Negative-Acknowledgement (NAK) TLV
6.4.1. Notification Message TLVs
The ICC Sender Name TLV uses the same format as in the RG Connect
message, and was described above.
The NAK TLV is defined as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0002 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICCP Status Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Rejected Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional TLV(s) |
+ +
| |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U,F Bits
both U and F are set to 0.
- Type
set to "NAK TLV" (0x0002)
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- ICCP Status Code
A status code that reflects the reason for the NAK TLV. Allowed
values are:
-i. Unknown RG (0x00010001)
This code is used to reject a new incoming ICCP
connection for an RG that is not configured on the local
PE. When this code is used, the Rejected Message ID
field MUST contain the message ID of the rejected "RG
Connect" message.
-ii. ICCP Connection Count Exceeded (0x00010002)
This is used to reject a new incoming ICCP connection
that would cause the local PE's ICCP connection count to
exceed its capabilities. When this code is used, the
Rejected Message ID field MUST contain the message ID of
the rejected "RG Connect" message.
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-iii. Application Connection Count Exceeded (0x00010003)
This is used to reject a new incoming application
connection that would cause the local PE's ICCP
connection count to exceed its capabilities. When this
code is used, the Rejected Message ID field MUST contain
the message ID of the rejected "RG Connect" message and
the corresponding Application Connect TLV MUST be
included in the "Optional TLV".
-iv. Application not in RG (0x00010004)
This is used to reject a new incoming application
connection when the local PE doesn't support the
application, or the application is not configured in the
RG. When this code is used, the Rejected Message ID
field MUST contain the message ID of the rejected "RG
Connect" message and the corresponding Application
Connect TLV MUST be included in the "Optional TLV".
-v. Incompatible Protocol Version (0x00010005)
This is used to reject a new incoming application
connection when the local PE has an incompatible version
of the application. When this code is used, the Rejected
Message ID field MUST contain the message ID of the
rejected "RG Connect" message and the corresponding
Application Connect TLV MUST be included in the
"Optional TLV".
-vi. Rejected Message (0x00010006)
This is used to reject an RG Application Data message,
or one or more TLV(s) within the message. When this code
is used, the Rejected Message ID field MUST contain the
message ID of the rejected "RG Application Data"
message.
-vii. ICCP Administratively Disabled (0x00010007)
This is used to reject any ICCP messages from a peer
from which the PE is not allowed to exchange ICCP
messages due to local administrative policy.
- Rejected Message ID
If non-zero, four octets value that identifies the peer message
to which the NAK TLV refers. If zero, no specific peer message is
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being identified.
- Optional TLV(s)
A set of one or more optional TLVs. If the status code is
"Rejected Message" then this field contains the TLV(s) that were
rejected. If the entire message is rejected, all its TLVs MUST be
present in this field; otherwise, the subset of TLVs that were
rejected MUST be echoed in this field.
If the status code is "Incompatible Protocol Version" then this
field contains the original "Application Connect TLV" sent by the
peer, in addition to the "Requested Protocol Version TLV" defined
below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Connection Reference | Requested Version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0003 for "Requested Protocol Version TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Connection Reference
This field is set to the Type field of the Application specific
Connect TLV that was rejected because of incompatible version.
- Requested Version
The version of the application supported by the transmitting
device. For this version of the protocol it is set to 0x0001.
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6.5. RG Application Data Message
The RG Application Data Message is used to transport application data
between PEs within an RG. A single message can be used to carry data
from only one application. Multiple application TLVs are allowed in a
single message, as long as all of these TLVs belong to the same
application. The format of the Application Data Message is:
-i. ICC header with Message type = "RG Application Data Message"
(0x703)
-ii. "Application specific TLVs"
The details of these TLVs are discussed in the "Application TLVs"
section. All application specific TLVs in one RG Application Data
Message MUST belong to a single application but MAY reference
different ROs.
7. Application TLVs
7.1. Pseudowire Redundancy (PW-RED) Application TLVs
This section discusses the ICCP TLVs for the Pseudowire Redundancy
application.
7.1.1. PW-RED Connect TLV
This TLV is included in the RG Connect message to signal the
establishment of PW-RED application connection.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0010 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol Version |A| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Sub-TLVs |
~ ~
| |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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- U and F Bits
Both are set to 0.
- Type
set to 0x0010 for "PW-RED Connect TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Protocol Version
The version of this particular protocol for the purposes of ICCP.
This is set to 0x0001.
- A bit
Acknowledgement Bit. Set to 1 if the sender has received a PW-RED
Connect TLV from the recipient. Otherwise, set to 0.
- Reserved
Reserved for future use.
- Optional Sub-TLVs
There are no optional Sub-TLVs defined for this version of the
protocol. This document does not impose any resrictions on the
length of the sub-TLVs.
7.1.2. PW-RED Disconnect TLV
This TLV is used in an RG Disconnect Message to indicate that the
connection for the PW-RED application is to be terminated.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0011 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Sub-TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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- U and F Bits
Both are set to 0.
- Type
set to 0x0011 for "PW-RED Disconnect TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Optional Sub-TLVs
The only optional Sub-TLV defined for this version of the
protocol is the "PW-RED Disconnect Cause" TLV defined in Section
7.1.2.1.
7.1.2.1. PW-RED Disconnect Cause TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0019 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Disconnect Cause String |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0019 for "PW-RED Disconnect Cause TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
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- Disconnect Cause String
Variable length string specifying the reason for the disconnect,
encoded in UTF-8. The string does not include a terminating null
character. Used for network management.
7.1.3. PW-RED Config TLV
The PW-RED Config TLV is used in the RG Application Data message and
has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type = 0x0012 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ROID |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW Priority | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Service Name TLV |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW ID TLV or Generalized PW ID TLV |
~ ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0012 for "PW-RED Config TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
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- ROID
As defined in Section 6.1.3.
- PW Priority
Two octets Pseudowire Priority. Used to indicate which PW has
better priority to go into Active state. Numerically lower
numbers are better priority. In case of a tie, the PE with the
numerically lower identifier (i.e. IP Address) has better
priority.
- Flags
Valid values are:
-i. Synchronized (0x01)
Indicates that the sender has concluded transmitting all
pseudowire configuration for a given service.
-ii. Purge Configuration (0x02)
Indicates that the pseudowire is no longer configured
for PW-RED operation.
-iii. Independent Mode (0x04)
Indicates that the pseudowire is configured for
redundancy using the Independent Mode of operation, per
section 5.1 of [RFC6870].
-iv. Independent Mode with Request Switchover (0x08)
Indicates that the pseudowire is configured for
redundancy using the Independent Mode of operation with
the use of the "Request Switchover" bit, per section 6.3
of [RFC6870].
-v. Master Mode (0x10)
Indicates that the pseudowire is configured for
redundancy using the Master/Slave Mode of operation,
with the advertising PE acting as Master, per section
5.2 of [RFC6870].
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-vi. Slave Mode (0x20)
Indicates that the pseudowire is configured for
redundancy using the Master/Slave Mode of operation,
with the advertising PE acting as Slave, per section 5.2
of [RFC6870].
- Sub-TLVs
The "PW-RED Config TLV" includes the following two sub-TLVs:
-i. Service Name TLV
-ii. One of PW ID TLV or Generalized PW ID TLV
The format of the sub-TLVs is defined in Sections 7.1.3.1 through
7.1.3.3.
7.1.3.1. Service Name TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Service Name |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0013 for "Service Name TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
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- Service Name
The name of the L2VPN service instance encoded in UTF-8 format
and up to 80 octets in length. The string does not include a
terminating null character.
7.1.3.2. PW ID TLV
This TLV is used to communicate the configuration of PWs for VPWS.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0014 for "PW ID TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Peer ID
Four octet LDP Router ID of the peer at the far end of the PW.
- Group ID
Same as Group ID in [RFC4447] section 5.2.
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- PW ID
Same as PW ID in [RFC4447] section 5.2.
7.1.3.3. Generalized PW ID TLV
This TLV is used to communicate the configuration of PWs for VPLS.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type = 0x0015 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AGI Type | Length | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ AGI Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AII Type | Length | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ SAII Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AII Type | Length | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ TAII Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F bits
both set to 0.
- Type
set to 0x0015
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- AGI, AII, SAII and TAII
defined in [RFC4447] section 5.3.2.
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7.1.4. PW-RED State TLV
The PW-RED State TLV is used in the RG Application Data Message. This
TLV is used by a device to report its PW status to other members in
the RG.
The format of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0016 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ROID |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local PW State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote PW State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0016 for PW-RED State TLV.
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- ROID
As defined in Section 6.1.3.
- Local PW State
The status of the PW as determined by the sending PE, encoded in
the same format as the "Status Code" field of the "PW Status TLV"
defined in [RFC4447] and extended in [RFC6870].
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- Remote PW State
The status of the PW as determined by the remote peer of the
sending PE. Encoded in the same format as the "Status Code" field
of the "PW Status TLV" defined in [RFC4447] and extended in
[RFC6870].
7.1.5. PW-RED Synchronization Request TLV
The PW-RED Synchronization Request TLV is used in the RG Application
Data message. This TLV is used by a device to request from its peer
to retransmit configuration or operational state. The following
information can be requested:
- configuration and/or state for one or more pseudowires
- configuration and/or state for all pseudowires
- configuration and/or state for all pseudowires in a given service
The format of the TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0017 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Request Number |C|S| Request Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Sub-TLVs |
~ ~
| |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0017 for "PW-RED Synchronization Request TLV"
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- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Request Number
2 octets. Unsigned integer uniquely identifying the request. Used
to match the request with a response. The value of 0 is reserved
for unsolicited synchronization, and MUST NOT be used in the PW-
RED Synchronization Request TLV. Given the use of TCP, there are
no issues associated with the wrap-around of the Request Number.
- C Bit
Set to 1 if request is for configuration data. Otherwise, set to
0.
- S Bit
Set to 1 if request is for running state data. Otherwise, set to
0.
- Request Type
14-bits specifying the request type, encoded as follows:
0x00 Request Data for specified pseudowire(s)
0x01 Request Data for all pseudowires in specified service(s)
0x3FFF Request All Data
- Optional Sub-TLVs
A set of zero or more TLVs, as follows:
If the Request Type field is set to (0x00), then this field
contains one or more PW ID TLV(s) or Generalized PW ID TLV(s). If
the Request Type field is set to (0x01), then this field contains
one or more Service Name TLV(s). If the Request Type field is set
to (0x3FFF), then this field MUST be empty. This document does
not impose any restrictions on the length of the sub-TLVs.
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7.1.6. PW-RED Synchronization Data TLV
The PW-RED Synchronization Data TLV is used in the RG Application
Data mesage. A pair of these TLVs is used by a device to delimit a
set of TLVs that are sent in response to a PW-RED Synchronization
Request TLV. The delimiting TLVs signal the start and end of the
synchronization data, and associate the response with its
corresponding request via the Request Number field.
The PW-RED Synchronization Data TLVs are also used for unsolicited
advertisements of complete PW-RED configuration and operational state
data. In this case, the Request Number field MUST be set to 0.
This TLV has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0018 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Request Number | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0018 for "PW-RED Synchronization Data TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Request Number
2 octets. Unsigned integer identifying the Request Number from
the "PW-RED Synchronization Request TLV" which solicited this
synchronization data response.
- Flags
2 octets, response flags encoded as follows:
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0x00 Synchronization Data Start
0x01 Synchronization Data End
7.2. Multi-chassis LACP (mLACP) Application TLVs
This section discusses the ICCP TLVs for Ethernet attachment circuit
redundancy using the multi-chassis LACP (mLACP) application.
7.2.1. mLACP Connect TLV
This TLV is included in the RG Connect message to signal the
establishment of mLACP application connection.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0030 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol Version |A| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Sub-TLVs |
~ ~
| |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0030 for "mLACP Connect TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Protocol Version
The version of this particular protocol for the purposes of ICCP.
This is set to 0x0001.
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- A Bit
Acknowledgement Bit. Set to 1 if the sender has received an mLACP
Connect TLV from the recipient. Otherwise, set to 0.
- Reserved
Reserved for future use.
- Optional Sub-TLVs
There are no optional Sub-TLVs defined for this version of the
protocol.
7.2.2. mLACP Disconnect TLV
This TLV is used in an RG Disconnect Message to indicate that the
connection for the mLACP application is to be terminated.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0031 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Sub-TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0031 for "mLACP Disconnect TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Optional Sub-TLVs
The only optional Sub-TLV defined for this version of the
protocol is the "mLACP Disconnect Cause" TLV defined in Section
7.2.2.1.
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7.2.2.1. mLACP Disconnect Cause TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x003A | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Disconnect Cause String |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x003A for "mLACP Disconnect Cause TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Disconnect Cause String
Variable length string specifying the reason for the disconnect.
Used for network management.
7.2.3. mLACP System Config TLV
The mLACP System Config TLV is sent in the RG Application Data
message. This TLV announces the local node's LACP System Parameters
to the RG peers.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0032 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| System ID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | System Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Node ID |
+-+-+-+-+-+-+-+-+
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- U and F Bits
Both are set to 0.
- Type
set to 0x0032 for "mLACP System Config TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- System ID
6 octets field encoding the System ID used by LACP as specified
in [IEEE-802.1AX] section 5.3.2.
- System Priority
2 octets encoding the LACP System Priority as defined in [IEEE-
802.1AX] section 5.3.2.
- Node ID
One octet, LACP node ID. Used to ensure that the LACP Port
Numbers are unique across all devices in an RG. Valid values are
in the range 0 - 7. Uniqueness of the LACP Port Numbers across
RG members is ensured by encoding the Port Numbers as follows:
- Most significant bit always set to 1
- The next 3 most significant bits set to Node ID
- Remaining 12 bits freely assigned by the system
7.2.4. mLACP Aggregator Config TLV
The mLACP Aggregator Config TLV is sent in the RG Application Data
message. This TLV is used to notify RG peers about the local
configuration state of an aggregator.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0036 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ROID |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Aggregator ID | MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Actor Key | Member Ports Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Agg Name Len | Aggregator Name |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
~ ~
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0036 for "mLACP Aggregator Config TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- ROID
Defined in the 'ROID Encoding' section above.
- Aggregator ID
Two octets, LACP Aggregator Identifier as specified in [IEEE-
802.1AX] section 5.4.6
- MAC Address
Six octets encoding the Aggregator MAC address.
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- Actor Key
Two octets, LACP Actor Key for the corresponding Aggregator, as
specified in [IEEE-802.1AX] section 5.3.5.
- Member Ports Priority
Two octets, LACP administrative port priority associated with all
interfaces bound to the Aggregator. This field is valid only when
the "Flags" field has "Priority Set" asserted.
- Flags
Valid values are:
-i. Synchronized (0x01)
Indicates that the sender has concluded transmitting all
Aggregator configuration information.
-ii. Purge Configuration (0x02)
Indicates that the Aggregator is no longer configured
for mLACP operation.
-iii. Priority Set (0x04)
Indicates that the "Member Ports Priority" field is
valid.
- Agg Name Len
One octet, length of the "Aggregator Name" field in octets.
- Aggregator Name
Aggregator name encoded in UTF-8 format, up to a maximum of 20
octets. Used for ease of management. The string does not include
a terminating null character.
7.2.5. mLACP Port Config TLV
The mLACP Port Config TLV is sent in the RG Application Data message.
This TLV is used to notify RG peers about the local configuration
state of a port.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0033 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Number | MAC Address |
+-------------------------------+ +
| |
+---------------------------------------------------------------+
| Actor Key | Port Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Speed |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Port Name Len | Port Name |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
~ ~
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0033 for "mLACP Port Config TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Port Number
Two octets, LACP Port Number for the corresponding interface as
specified in [IEEE-802.1AX] section 5.3.4. The Port Number MUST
be encoded with the Node ID as was discussed above.
- MAC Address
Six octets encoding the port MAC address.
- Actor Key
Two octets, LACP Actor Key for the corresponding interface, as
specified in [IEEE-802.1AX] section 5.3.5.
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- Port Priority
Two octets, LACP administrative port priority for the
corresponding interface, as specified in [IEEE-802.1AX] section
5.3.4. This field is valid only when the "Flags" field has
"Priority Set" asserted.
- Port Speed
Four octets integer encoding the port's current bandwidth in
units of 1,000,000 bits per second. This field corresponds to the
ifHighSpeed object of IF-MIB [RFC2863].
- Flags
Valid values are:
-i. Synchronized (0x01)
Indicates that the sender has concluded transmitting all
member link port configurations for a given Aggregator.
-ii. Purge Configuration (0x02)
Indicates that the port is no longer configured for
mLACP operation.
-iii. Priority Set (0x04)
Indicates that the "Port Priority" field is valid.
- Port Name Len
One octet, length of the "Port Name" field in octets.
- Port Name
This field corresponds to the ifName object of IF-MIB [RFC2863]
encoded in UTF-8 format, and truncated to 20 octets. Port Name
does not include a terminating null character.
7.2.6. mLACP Port Priority TLV
The mLACP Port Priority TLV is sent in the RG Application Data
message. This TLV is used by a device to either advertise its
operational Port Priority to other members in the RG, or to
authoritatively request that a particular member of an RG change its
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port priority.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0034 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OpCode | Port Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Aggregator ID | Last Port Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Current Port Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0034 for "mLACP Port Priority TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- OpCode
Two octets identifying the operational code-point for the TLV,
encoded as follows:
0x00 Local Priority Change Notification
0x01 Remote Request for Priority Change
- Port Number
2 octets field representing the LACP Port Number as specified in
[IEEE-802.1AX] section 5.3.4. When the value of this field is 0,
it denotes all ports bound to the Aggregator specified in the
"Aggregator ID" field. When non-zero, the Port Number MUST be
encoded with the Node ID as was discussed above.
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- Aggregator ID
Two octets, LACP Aggregator Identifier as specified in [IEEE-
802.1AX] section 5.4.6
- Last Port Priority
Two octets, LACP port priority for the corresponding interface,
as specified in [IEEE-802.1AX] section 5.3.4. For local ports,
this field encodes the previous operational value of port
priority. For remote ports, this field encodes the operational
port priority last known to the PE via notifications received
from its peers in the RG.
- Current Port Priority
Two octets, LACP port priority for the corresponding interface,
as specified in [IEEE-802.1AX] section 5.3.4. For local ports,
this field encodes the new operational value of port priority
being advertised by the PE. For remote ports, this field
specifies the new port priority being requested by the PE.
7.2.7. mLACP Port State TLV
The mLACP Port State TLV is used in the RG Application Data message.
This TLV is used by a device to report its LACP port status to other
members in the RG.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0035 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Partner System ID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Partner System Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Partner Port Number | Partner Port Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Partner Key | Partner State | Actor State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Actor Port Number | Actor Key |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Selected | Port State | Aggregator ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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- U and F Bits
Both are set to 0.
- Type
set to 0x0035 for "mLACP Port State TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Partner System ID
6 octets, the LACP Partner System ID for the corresponding
interface, encoded as a MAC address as specified in [IEEE-
802.1AX] section 5.4.2.2 item r.
- Partner System Priority
2 octets field specifying the LACP Partner System Priority as
specified in [IEEE-802.1AX] section 5.4.2.2 item q.
- Partner Port Number
2 octets encoding the LACP Partner Port Number as specified in
[IEEE-802.1AX] section 5.4.2.2 item u. The Port Number MUST be
encoded with the Node ID as was discussed above.
- Partner Port Priority
2 octets field encoding the LACP Partner Port Priority as
specified in [IEEE-802.1AX] section 5.4.2.2 item t.
- Partner Key
2 octets field representing the LACP Partner Key as defined in
[IEEE-802.1AX] section 5.4.2.2 item s.
- Partner State
1 octet field encoding the LACP Partner State Variable as defined
in [IEEE-802.1AX] section 5.4.2.2 item v.
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- Actor State
1 octet encoding the LACP Actor's State Variable for the port as
specified in [IEEE-802.1AX] section 5.4.2.2 item m.
- Actor Port Number
2 octets field representing the LACP Actor Port Number as
specified in [IEEE-802.1AX] section 5.3.4. The Port Number MUST
be encoded with the Node ID as was discussed above.
- Actor Key
2 octet field encoding the LACP Actor Operational Key as
specified in [IEEE-802.1AX] section 5.3.5.
- Selected
1 octet encoding the LACP 'Selected' variable, defined in [IEEE-
802.1AX] section 5.4.8, as follows:
0x00 SELECTED
0x01 UNSELECTED
0x02 STANDBY
- Port State
1 octet encoding the operational state of the port as follows:
0x00 Up
0x01 Down
0x02 Administrative Down
0x03 Test (e.g. IEEE 802.3ah OAM Intrusive Loopback mode)
- Aggregator ID
Two octets, LACP Aggregator Identifier to which this port is
bound based on the outcome of the LACP selection logic.
7.2.8. mLACP Aggregator State TLV
The mLACP Aggregator State TLV is used in the RG Application Data
message. This TLV is used by a device to report its Aggregator status
to other members in the RG.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0037 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Partner System ID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Partner System Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Partner Key | Aggregator ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Actor Key | Agg State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0037 for "mLACP Aggregator State TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Partner System ID
6 octets, the LACP Partner System ID for the corresponding
interface, encoded as a MAC address as specified in [IEEE-
802.1AX] section 5.4.2.2 item r.
- Partner System Priority
2 octets field specifying the LACP Partner System Priority as
specified in [IEEE-802.1AX] section 5.4.2.2 item q.
- Partner Key
2 octets field representing the LACP Partner Key as defined in
[IEEE-802.1AX] section 5.4.2.2 item s.
- Aggregator ID
Two octets, LACP Aggregator Identifier as specified in [IEEE-
802.1AX] section 5.4.6
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- Actor Key
2 octet field encoding the LACP Actor Operational Key as
specified in [IEEE-802.1AX] section 5.3.5.
- Agg State
1 octet encoding the operational state of the Aggregator as
follows:
0x00 Up
0x01 Down
0x02 Administrative Down
0x03 Test (e.g. IEEE 802.3ah OAM Intrusive Loopback mode)
7.2.9. mLACP Synchronization Request TLV
The mLACP Synchronization Request TLV is used in the RG Application
Data message. This TLV is used by a device to request from its peer
to re-transmit configuration or operational state. The following
information can be requested:
- system configuration and/or state
- configuration and/or state for a specific port
- configuration and/or state for all ports with a specific LACP key
- configuration and/or state for all mLACP ports
- configuration and/or state for a specific aggregator
- configuration and/or state for all aggregators with a specific
LACP key
- configuration and/or state for all mLACP aggregators
The format of the TLV is as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0038 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Request Number |C|S| Request Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Number / Aggregator ID | Actor Key |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0038 for "mLACP Synchronization Request TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Request Number
2 octets. Unsigned integer uniquely identifying the request. Used
to match the request with a response. The value of 0 is reserved
for unsolicited synchronization, and MUST NOT be used in the
mLACP Synchronization Request TLV.
- C Bit
Set to 1 if request is for configuration data. Otherwise, set to
0.
- S Bit
Set to 1 if request is for running state data. Otherwise, set to
0.
- Request Type
14-bits specifying the request type, encoded as follows:
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0x00 Request System Data
0x01 Request Aggregator Data
0x02 Request Port Data
0x3FFF Request All Data
- Port Number / Aggregator ID
2 octets. When Request Type field is set to 'Request Port Data',
this field encodes the LACP Port Number for the requested port.
When the Request Type field is set to 'Request Aggregator Data',
this field encodes the Aggregator ID of the requested Aggregator.
When the value of this field is 0, it denotes that all ports (or
Aggregators), whose LACP Key is specified in the "Actor Key"
field, are being requested.
- Actor Key
Two octets, LACP Actor key for the corresponding port or
Aggregator. When the value of this field is 0 (and the Port
Number/Aggregator ID field is 0 as well), it denotes that
information for all ports or Aggregators in the system is being
requested.
7.2.10. mLACP Synchronization Data TLV
The mLACP Synchronization Data TLV is used in the RG Application Data
message. A pair of these TLVs is used by a device to delimit a set of
TLVs that are being transmitted in response to an mLACP
Synchronization Request TLV. The delimiting TLVs signal the start and
end of the synchronization data, and associate the response with its
corresponding request via the 'Request Number' field.
The mLACP Synchronization Data TLVs are also used for unsolicited
advertisements of complete mLACP configuration and operational state
data. The 'Request Number' field MUST be set to 0 in this case. For
such unsolicited synchronization, the PE MUST advertise all system,
Aggregator and port information as done during the initialization
sequence.
This TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type=0x0039 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Request Number | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- U and F Bits
Both are set to 0.
- Type
set to 0x0039 for "mLACP Synchronization Data TLV"
- Length
Length of the TLV in octets excluding the U-bit, F-bit, Type, and
Length fields.
- Request Number
2 octets. Unsigned integer identifying the Request Number from
the "mLACP Synchronization Request TLV" which solicited this
synchronization data response.
- Flags
2 octets, response flags encoded as follows:
0x00 Synchronization Data Start
0x01 Synchronization Data End
8. LDP Capability Negotiation
As requited in [RFC5561] the following TLV is defined to indicate the
ICCP capability:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| TLV Code Point=0x700 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| Reserved | Reserved | VER/Maj | Ver/Min |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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where:
- U-bit
SHOULD be 1 (ignore if not understood).
- F-bit
SHOULD be 0 (don't forward if not understood).
- TLV Code Point
The TLV type, which identifies a specific capability. The ICCP
code point is requested in the IANA allocation section below.
- S-bit The State Bit indicates whether the sender is advertising
or withdrawing the ICCP capability. The State bit is used as
follows:
1 - The TLV is advertising the capability specified by the
TLV Code Point.
0 - The TLV is withdrawing the capability specified by the
TLV Code Point.
- Ver/Maj
The major version revision of the ICCP protocol, this document
specifies 1.0. This field is then set to 1
- Ver/Min
The minor version revision of the ICCP protocol, this document
specifies 1.0. This field is then set to 0
ICCP capability is advertised to a LDP peer if there is at least one
RG enabled on the local PE.
9. Client Applications
9.1. Pseudowire Redundancy Application Procedures
This section defines the procedures for the Pseudowire Redundancy
(PW-RED) Application.
It should be noted that the PW-RED application SHOULD NOT be enabled
together with an AC Redundancy application for the same service
instance. This simplifies the operation of the multi-chassis
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redundancy solution (Figure 1) and eliminates the possibility of
deadlock conditions between the AC and PW redundancy mechanisms.
9.1.1. Initial Setup
When an RG is configured on a system and multi-chassis pseudowire
redundancy is enabled in that RG, the PW-RED application MUST send an
"RG Connect" message with "PW-RED Connect TLV" to each PE that is a
member of the same RG. The sending PE MUST set the A bit to 1 if it
has already received a "PW-RED Connect TLV" from its peer; otherwise,
the PE MUST set the A bit to 0. If a PE, that has sent the TLV with
the A bit set to 0, receives a "PW-RED Connect TLV" from a peer, it
MUST repeat its advertisement with the A bit set to 1. The PW-RED
application connection is considered to be operational when both PEs
have sent and received "PW-RED Connect TLVs" with the A bit set to 1.
Once the application connection becomes operational, the two devices
can start exchanging "RG Application Data" messages for the PW-RED
application.
If a system receives an "RG Connect" message with "PW-RED Connect
TLV" that has a differing Protocol Version, it must follow the
procedures outlined in the "Application Versioning" section above.
When the PW-RED application is disabled on the device, or is
unconfigured for the RG in question, the system MUST send an "RG
Disconnect" message with "PW-RED Disconnect TLV".
9.1.2. Pseudowire Configuration Synchronization
A system MUST advertise its local PW configuration to other PEs that
are members of the same RG. This allows the PEs to build a view of
the redundant nodes and pseudowires that are protecting the same
service instances. The advertisement MUST be initiated when the PW-
RED application connection first comes up. To that end, the system
sends "RG Application Data" messages with "PW-RED Config TLVs" as
part of an unsolicited synchronization. A PE MUST use a pair of "PW-
RED Synchronization Data TLVs" to delimit the set of TLVs that are
being sent as part of this unsolicited advertisement.
In the case of a configuration change, a PE MUST re-advertise the
most up to date information for the affected pseudowires.
As part of the configuration synchronization, a PE advertises the
ROID associated with the pseudowire. This is used to correlate the
pseudowires that are protecting each other on different PEs. As well,
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a PE advertises the configured PW redundancy mode. This can be one of
the following four options: Master Mode, Slave Mode, Independent Mode
or Independent Mode with Request Switchover. If the received
redundancy mode does not match the locally configured mode for the
same ROID, then the PE MUST respond with an "RG Notification Message"
to reject the "PW-RED Config TLV". The PE MUST disable the associated
local pseudowire until a satisfactory "PW-RED Config TLV" is received
from the peer. This guarantees that device mis-configuration does not
lead to network wide problems (e.g. by creating forwarding loops).
The PE SHOULD also raise an alarm to alert the operator. If a PE
receives a NAK TLV for an advertised "PW-RED Config TLV", it MUST
disable the associated pseudowire and SHOULD raise an alarm to alert
the operator.
Furthermore, a PE advertises in its "PW-RED Config TLVs" a priority
value that is used to determine the precedence of a given pseudowire
to assume the Active role in a redundant setup. A PE also adverties a
Service Name that is global in the context of an RG and is used to
identify which pseudowires belong to the same service. Finally, a PE
also advertises the pseudowire identifier as part of this
synchronization.
9.1.3. Pseudowire Status Synchronization
PEs, that are member of an RG, synchronize pseudowire status for the
purpose of identifying, on a per ROID basis, which pseudowire will be
actively used for forwarding and which pseudowire(s) will be placed
in standby state.
Synchronization of pseudowire status is done by sending the "PW-RED
State TLV" whenever the pseudowire state changes on a PE. This
includes changes to the local end as well as the remote end of the
pseudowire.
A PE may request that its peer retransmit previously advertised PW-
RED state. This is useful for instance when the PE is recovering from
a soft failure. To request such retransmission, a PE MUST send a set
of one or more "PW-RED Synchronization Request TLVs".
A PE MUST respond to a "PW-RED Synchronization Request TLV" by
sending the requested data in a set of one or more PW-RED TLVs
delimited by a pair of "PW-RED Synchronization Data TLVs". The TLVs
comprising the response MUST be ordered such that the Synchronization
Response TLV with the "Synchronization Data Start" flag precedes the
various other PW-RED TLVs encoding the requested data. These, in
turn, MUST precede the Synchronization Data TLV with the
"Synchronization Data End" flag. It is worth noting that the response
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may span across multiple RG Application Data messages; however, the
above TLV ordering MUST be retained across messages, and only a
single pair of Synchronization Data TLVs must be used to delimit the
response across all Application Data Messages.
A PE MAY re-advertise its PW-RED state in an unsolicited manner. This
is done by sending the appropriate config and state TLVs delimited by
a pair of "PW-RED Synchronization Data TLVs" and using a 'Request
Number' of 0.
While a PE has a pending synchronization request for a pseudowire or
a service, it SHOULD silently ignore all TLVs for said pseudowire or
service that are received prior to the synchronization response and
which carry the same type of information being requested. This saves
the system from the burden of updating state that will ultimately be
overwritten by the synchronization response. Note that TLVs
pertaining to other pseudowires or services are to continue to be
processed per normal in the interim.
If a PE receives a synchronization request for a pseudowire or
service that doesn't exist or is not known to the PE, then it MUST
trigger an unsolicited synchronization of all pseudowire information
(i.e. replay the initialization sequence).
In the subsections that follow, we describe the details of pseudowire
status synchronization for each of the PW redundancy modes defined in
[RFC6870].
9.1.3.1. Independent Mode
This section covers the operation in Independent Mode with or without
Request Switchover capability.
In this mode, the operator must ensure that for a given RO, the PW
Priority values configured for all associated pseudowires on a given
PE are collectively higher (or lower) than those configured on other
PEs in the same RG. If this condition is not satisfied after the PEs
have exchanged "PW-RED State TLVs", a PE MUST disable the associated
pseudowire(s) and SHOULD raise an alarm to alert the operator. Note
that the PW Priority MAY be the same as the PW Precedence defined in
[RFC6870].
For a given RO, after the all the PEs in an RG have exchanged their
"PW-RED State TLVs", the PE with the best PW Priority (i.e. least
numeric value) advertises Active preferential forwarding status in
LDP on all its associated pseudowires. Whereas, all other PEs in the
RG advertise Standby preferential forwarding status in LDP on their
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associated pseudowires.
If the service is VPWS, then only a single pseudowire per service
will be selected for forwarding. This is the pseudowire that is
independently advertised with Active preferential forwarding status
on both endpoints, as described in [RFC6870].
If the service is VPLS, then one or multiple pseudowires per service
will be selected for forwarding. These are the pseudowires that are
independently advertised with Active preferential forwarding status
on both PW endpoints, as described in [RFC6870].
9.1.3.2. Master/Slave Mode
In this mode, the operator must ensure that for a given RO, the PW
Priority values configured for all associated pseudowires on a given
PE are collectively higher (or lower) than those configured on other
PEs in the same RG. If this condition is not satisfied after the PEs
have exchanged "PW-RED State TLVs", a PE MUST disable the associated
pseudowire(s) and SHOULD raise an alarm to alert the operator. Note
that the PW Priority MAY be the same as the PW Precedence defined in
[RFC6870]. In addition, the operator must ensure that, for a given
RO, all the PEs in the RG are consistently configured as Master or
Slave.
In the context of a given RO, if the PEs in the RG are acting as
Master, then the PE with the best PW Priority (i.e. least numeric
value) advertises Active preferential forwarding status in LDP on
only a single pseudowire, following the procedures in sections 5.2
and 6.2 of [RFC6870]. Whereas, all the other pseudowires on other PEs
in the RG are advertised with Standby preferential forwarding status
in LDP.
9.1.4. PE Node Failure or Isolation
When a PE node detects that a remote PE, that is member of the same
RG, is no longer reachable (using the mechanisms of Section 5), the
local PE examines if it has redundant PWs for the affected services.
If the local PE has the highest priority (after the failed PE) then
it becomes the active node for the services in question, and
subsequently activates its associated PW(s).
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9.2. Attachment Circuit Redundancy Application Procedures
9.2.1. Common AC Procedures
This section describes generic procedures for AC Redundancy
applications, independent of the type of the AC (ATM, FR or
Ethernet).
9.2.1.1. AC Failure
When the AC Redundancy mechanism on the Active PE detects a failure
of the AC, it should send an ICCP Application Data message to inform
the redundant PEs of the need to take over. The AC failures can be
categorized into the following scenarios:
- Failure of CE interface connecting to PE
- Failure of CE uplink to PE
- Failure of PE interface connecting to CE
9.2.1.2. Remote PE Node Failure or Isolation
When a PE node detects that a remote PE, that is member of the same
RG, is no longer reachable (using the mechanisms of Section 5), the
local PE examines if it has redundant ACs for the affected services.
If the local PE has the highest priority (after the failed PE) then
it becomes the active node for the services in question, and
subsequently activates its associated ACs.
9.2.1.3. Local PE Isolation
When a PE node detects that is has been isolated from the core
network (i.e. all core facing interfaces/links are not operational),
then it should ensure that its AC Redundancy mechanism will change
the status of any active ACs to Standby. The AC Redundancy
application SHOULD then send ICCP Application Data messages in order
to trigger failover to a standby PE. Note that this works only in the
case of dedicated interconnect (Sections 3.2.1 and 3.2.3) since ICCP
will still have a path to the peer, even though the PE is isolated
from the MPLS core network.
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9.2.1.4. Determining Pseudowire State
If the PEs in an RG are running an AC Redundancy application over
ICCP, then the Independent Mode of PW Redundancy, as defined in
[RFC6870], MUST be used. On a given PE, the Preferential Forwarding
status of the PW (Active or Standby) is derived from the state of the
associated AC(s). This simplifies the operation of the multi-chassis
redundancy solution (Figure 1) and eliminates the possibility of
deadlock conditions between the AC and PW redundancy mechanisms. The
rules by which the PW status is derived from the AC status are as
follows:
- VPWS
For VPWS, there's a single AC per service instance. If the AC is
Active, then the PW status should be Active. If the AC is
Standby, then the PW status should be Standby.
- VPLS
For VPLS, there could be multiple ACs per service instance (i.e.
VFI). If AT LEAST ONE AC is Active, then the PW status should be
Active. If ALL ACs are Standby, then the PW status should be
Standby.
In this case, the PW-RED application is not used to synchronize PW
status between PEs. Rather, the AC Redundancy application should
synchronize AC status between PE, in order to establish which AC (and
subsequently which PE) is Active or Standby for a given service. When
that is determined, each PE will then derive its local PWs state
according to the rules described above. The Preferential Forwarding
status bit, described in [RFC6870], is used to advertise PW status to
the remote peers.
9.2.2. Multi-chassis LACP (mLACP) Application Procedures
This section defines the procedures that are specific to the multi-
chassis LACP (mLACP) application, which is applicable for Ethernet
ACs.
9.2.2.1. Initial Setup
When an RG is configured on a system and mLACP is enabled in that RG,
the mLACP application MUST send an "RG Connect" message with "mLACP
Connect TLV" to each PE that is member of the same RG. The sending PE
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MUST set the A bit to 1 in the said TLV if it has received a
corresponding "mLACP Connect TLV" from its peer PE; otherwise, the
sending PE MUST set the A bit to 0. If a PE receives an "mLACP
Connect TLV" from its peer after sending the said TLV with the A bit
set to 0, it MUST resend the TLV with the A bit set to 1. A system
considers the mLACP application connection to be operational when it
has sent and received "mLACP Connect TLVs" with the A bit set to 1.
When the mLACP application connection between a pair of PEs is
operational, the two devices can start exchanging "RG Application
Data" messages for the mLACP application. This involves having each
PE advertise its mLACP configuration and operational state in an
unsolicited manner. A PE SHOULD subscribe to the following order when
advertising its mLACP state upon initial application connection
setup:
- Advertise system configuration
- Advertise Aggregator configuration
- Advertise port configuration
- Advertise Aggregator state
- Advertise port state
A PE MUST use a pair of "mLACP Synchronization Data TLVs" to delimit
the entire set of TLVs that are being sent as part of this
unsolicited advertisement.
If a system receives an "RG Connect" message with "mLACP Connect TLV"
that has a differing Protocol Version, it MUST follow the procedures
outlined in the "Application Versioning" section above.
After the mLACP application connection has been established, every PE
MUST communicate its system level configuration to its peers via the
use of "mLACP System Config TLV". This allows every PE to discover
the Node ID and the locally configured System ID and System Priority
values of its peers.
If a PE receives an "mLACP System Config TLV" from a remote peer
advertising the same Node ID value as the local system, then the PE
MUST respond with an "RG Notification Message" to reject the "mLACP
System Config TLV". The PE MUST suspend the mLACP application until a
satisfactory "mLACP System Config TLV" is received from the peer. It
SHOULD also raise an alarm to alert the operator. Furthermore, if a
PE receives a NAK TLV for an "mLACP System Config TLV" that it has
advertised, the PE MUST suspend the mLACP application and SHOULD
raise an alarm to alert the network operator of potential device
mis-configuration.
If a PE receives an "mLACP System Config TLV" from a new peer
advertising the same Node ID value as another existing peer with
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which the local system has an established mLACP Application
connection, then the PE MUST respond to the new peer with an "RG
Notification Message" to reject the "mLACP System Config TLV" and
MUST ignore the offending TLV.
If the Node ID of a particular PE changes due to administrative
configuration action, the PE MUST then inform its peers to purge the
configuration of all previously advertised ports and/or aggregators,
and MUST replay the initialization sequence by sending an unsolicited
synchronization of: the system configuration, Aggregator
configuration, port configuration, Aggregator state and port state.
It is necessary for all PEs in an RG to agree upon the System ID and
System Priority values to be used ubiquitously. To achieve this,
every PE MUST use the values for the two parameters that are supplied
by the PE with the numerically lowest value (among RG members) of
System Aggregation Priority. This guarantees that the PEs always
agree on uniform values, which yield the highest System Priority.
When the mLACP application is disabled on the device, or is
unconfigured for the RG in question, the system MUST send an "RG
Disconnect" message with "mLACP Disconnect TLV".
9.2.2.2. mLACP Aggregator and Port Configuration
A system MUST synchronize the configuration of its mLACP enabled
Aggregators and ports with other RG members. This is achieved via the
use of "mLACP Aggregator Config TLVs" and "mLACP Port Config TLVs",
respectively. An implementation MUST advertise the configuration of
Aggregators prior to advertising the configuration of any of their
associated member ports.
The PEs in an RG MUST all agree on the MAC address to be associated
with a given Aggregator. It is possible to achieve this via
consistent configuration on member PEs. However, in order to protect
against possible misconfiguration, a system MUST use, for any given
Aggregator, the MAC address supplied by the PE with the numerically
lowest System Aggregation Priority in the RG.
A system that receives an "mLACP Aggregator Config TLV" with an ROID
to Key association that is different from its local association MUST
reject the corresponding TLV and disable the Aggregator with the same
ROID. Furthermore, it SHOULD raise an alarm to alert the operator.
Similarly, a system that receives a NAK TLV in response to a
transmitted "mLACP Aggregator Config TLV" MUST disable the associated
Aggregator and SHOULD raise an alarm to alert the network operator.
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A system MAY enforce a restriction that all ports that are to be
bundled together on a given PE share the same Port Priority value. If
so, the system MUST advertise this common priority in the "mLACP
Aggregator Config TLV" and assert the "Priority Set" flag in such
TLV. Furthermore, the system in this case MUST NOT advertise
individual Port Priority values in the associated "mLACP Port Config
TLVs" (i.e. the "Priority Set" flag in these TLVs should be 0).
A system MAY support individual Port Priority values to be configured
on ports that are to be bundled together on a PE. If so, the system
MUST advertise the individual Port Priority values in the appropriate
"mLACP Port Config TLVs", and MUST NOT assert the "Priority Set" flag
in the corresponding "mLACP Aggregator Config TLV".
When the configurations of all ports for member links associated with
a given Aggregator have been sent by a device, it asserts that fact
by setting the "Synchronized" flag in the last port's "mLACP Port
Config TLV". If an Aggregator doesn't have any candidate member ports
configured, this is indicated by asserting the "Synchronized" flag in
its "mLACP Aggregator Config TLV".
Furthermore, for a given port/Aggregator, an implementation MUST
advertise the port/Aggregator configuration prior to advertising its
state (via the "mLACP Port State TLV" or "mLACP Aggregator State
TLV"). If a PE receives an "mLACP Port State TLV" or "mLACP
Aggregator State TLV" for a port or Aggregator that it had not
learned of before via an appropriate Port or Aggregator Config TLV,
then the PE MUST request synchronization of the configuration and
state of all mLACP ports as well as all mLACP Aggregators from its
respective peer. If during a synchronization (solicited or
unsolicited), a PE receives a State TLV for a port or Aggregator that
it has not learned of before, then the PE MUST send a NAK TLV for the
offending TLV. The PE MUST NOT request re-synchronization in this
case.
When mLACP is unconfigured on a port/Aggregator, a PE MUST send a
"Port/Aggregator Config TLV" with the "Purge Configuration" flag
asserted. This allows receiving PEs to purge any state maintained for
the decommissioned port/Aggregator. If a PE receives a
"Port/Aggregator Config TLV" with the "Purge Configuration" flag
asserted, and the PE is not maintaining any state for that
port/Aggregator, then it MUST silently discard the TLV.
9.2.2.3. mLACP Aggregator and Port Status Synchronization
PEs within an RG need to synchronize their state-machines for proper
mLACP operation with a multi-homed device. This is achieved by having
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each system advertise its Aggregators and ports running state in
"mLACP Aggregator State TLVs" and "mLACP Port State TLVs",
respectively. Whenever any LACP parameter for an Aggregator or a
port, whether on the Partner (i.e. multi-homed device) or the Actor
(i.e. PE) side, is changed a system MUST transmit an updated TLV for
the affected Aggregator and/or port. Moreover, when the
administrative or operational state of an Aggregator or port changes,
the system MUST transmit an updated Aggregator or port state TLV to
its peers.
If a PE receives an Aggregator or port state TLV where the 'Actor
Key' doesn't match what was previously received in a corresponding
Aggregator or port config TLV, the PE MUST then request
synchronization of the configuration and state of the affected
Aggregator or port. If such a mismatch occurs between the config and
state TLVs as part of a synchronization (solicited or unsolicited),
then the PE MUST send a NAK TLV for the state TLV. Furthermore, if a
PE receives a port state TLV with the 'Aggregator ID' set to a value
that doesn't map to some Aggregator that the PE had learned of via a
previous Aggregator config TLV, then the PE MUST request
synchronization of the configuration and state of all Aggregators and
ports. If the above anomaly occurs during a synchronization, then the
PE MUST send a NAK TLV for the offending port state TLV.
A PE MAY request that its peer retransmit previously advertised
state. This is useful for example when the PE is recovering from a
soft failure and attempting to relearn state. To request such
retransmissions, a PE MUST send a set of one or more "mLACP
Synchronization Request TLVs".
A PE MUST respond to an "mLACP Synchronization Request TLV" by
sending the requested data in a set of one or more mLACP TLVs
delimited by a pair of "mLACP Synchronization Data TLVs". The TLVs
comprising the response MUST be ordered in the RG Application Data
message(s) such that the Synchronization Response TLV with the
"Synchronization Data Start" flag precedes the various other mLACP
TLVs encoding the requested data. These, in turn, MUST precede the
Synchronization Data TLV with the "Synchronization Data End" flag.
Note that the response may span across multiple RG Application Data
messages, for example when MTU limits are exceeded; however, the
above ordering MUST be retained across messages, and only a single
pair of Synchronization Data TLVs MUST be used to delimit the
response across all Application Data Messages.
A PE device MAY re-advertise its mLACP state in an unsolicited
manner. This is done by sending the appropriate Config and State TLVs
delimited by a pair of "mLACP Synchronization Data TLVs" and using a
'Request Number' of 0.
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While a PE has a pending synchronization request for a system,
Aggregator or port, it SHOULD silently ignore all TLVs for said
system, Aggregator or port that are received prior to the
synchronization response and which carry the same type of information
being requested. This saves the system from the burden of updating
state that will utlimately be overwritten by the synchronization
response. Note that TLVs pertaining to other systems, Aggregators or
ports are to continue to be processed per normal in this case.
If a PE receives a synchronization request for an Aggregator, port or
Key that doesn't exist or is not known to the PE, then it MUST
trigger an unsolicited synchronization of all system, Aggregator and
port information (i.e. replay the initialization sequence).
If a PE learns, as part of a synchronization operation from its peer,
that the latter is advertising a Node ID value which is different
from the value previously advertised, then the PE MUST purge all
port/aggregator data previously learnt from that peer prior to the
last synchronization.
9.2.2.4. Failure and Recovery
When a PE that is active for a multi-chassis link aggregation group
encounters a core isolation fault, it SHOULD attempt to fail-over to
a peer PE which hosts the same RO. The default fail-over procedure is
to have the failed PE bring down the link(s) towards the multi-homed
CE (e.g. by bringing down the line-protocol). This will cause the CE
to fail-over to the other member link(s) of the bundle that are
connected to the other PE(s) in the RG. Other procedures for
triggering fail-over are possible, and are outside the scope of this
document.
Upon recovery from a previous fault, a PE MAY reclaim active role for
a multi-chassis link aggregation group if configured for revertive
protection. Otherwise, the recovering PE may assume standby role
when configured for non-revertive protection. In the revertive
scenario, a PE SHOULD assume active role within the RG by sending an
"mLACP Port Priority TLV" to the currently active PE, requesting that
the latter change its port priority to a value that is lower (i.e.
numerically larger) for the Aggregator in question.
If a system is operating in a mode where different ports of a bundle
are configured with different Port Priorities, then the system MUST
NOT advertise or request change of Port Priority values for
aggregated ports collectively (i.e. by using a 'Port Number' of 0 in
the "mLACP Port Priority TLV"). This is to avoid ambiguity in the
interpretation of the 'Last Port Priority' field.
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If a PE receives an "mLACP Port Priority TLV" requesting a priority
change for a port or Aggregator that is not local to the device, then
the PE MUST re-advertise the local configuration of the system, as
well as the configuration and state of all its mLACP ports and
Aggregators.
If a PE receives an "mLACP Port Priority TLV" in which the remote
system is advertising priority change for a port or Aggregator that
the local PE had not learned of before via an appropriate Port or
Aggregator Config TLV, then the PE MUST request synchronization of
the configuration and state of all mLACP ports as well as all mLACP
Aggregators from its respective peer.
10. Security Considerations
ICCP SHOULD only be used in well managed and highly monitored
networks. It ought not be deployed on or over the public Internet.
The ICCP protocol is not intended to be applicable when the
redundancy group spans PE in different administrative domains.
The security considerations described in [RFC5036] and [RFC4447] that
apply to the base LDP specification, and to the PW LDP control
protocol extensions apply to the capability mechanism described in
this document. In particular, ICCP implementations MUST provide a
mechanism to select to which LDP peers the ICCP capability will be
advertised, and from which LDP peers the ICCP messages will be
accepted. Therefore, an incoming ICCP connection request MUST NOT be
accepted unless its source IP address is known to be the source of an
"eligible" ICCP peer. The set of eligible peers could be pre-
configured (either as a list of IP addresses, or as a list of
address/mask combinations), or it could be discovered dynamically via
some secure discovery protocol. The TCP Authentication Option (TCP-
AO), as defined in [RFC5925], SHOULD be used. This provides integrity
and authentication for the ICCP messages and eliminates the
possiblity of source address spoofing. However, for backwards
compatibility and/or to accommodate the ease of migration, the LDP
MD5 authentication key option, as described in section 2.9 of
[RFC5036] MAY be used instead.
The security framework and considerations for MPLS in general, and
LDP in particular, described in [RFC5920] apply to this document.
Moreover, the recommendations of [RFC6952] and mechanisms of [LDP-
CRYPTO] aimed at addressing LDP's vulnerabilities are applicable as
well.
Furthermore, activitiy on the attachment ciruits may cause security
threats or be exploited to create denial of service attackes. For
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example, a malicious CE implementation may trigger continuously
variying LACP messages that lead to excessive ICCP exchanges. Also,
excessive link bouncing of the attachment circuits may lead to the
same effect. Similar arguments apply to the inter-PE MPLS links.
Implementations SHOULD provide mechanisms to perform control-plane
policing and mitigate such types of attacks.
11. Manageability Considerations
Implementations SHOULD generally minimize the number of parameters
required to configure ICCP, as this contributes to the ease of use.
Implementations SHOULD allow the user to control the RGID via
configuration, as this is required to support flexible grouping of
PEs in RGs. Furthermore, implementations SHOULD provide mechanisms to
troubleshoot the correct operation of ICCP, this includes providing
mechanisms to diagnose ICCP as well as Application connections.
Implementations MUST provide a means for the user to indicate the IP
addresses of remote PEs that are to be members of a given RG.
Automatic discovery of RG membership MAY be supported, and is outside
the scope of this specification.
12. IANA Considerations
12.1. MESSAGE TYPE NAME SPACE
This document uses several new LDP message types, IANA already
maintains a registry of name "MESSAGE TYPE NAME SPACE" defined by
[RFC5036]. The following values are suggested for assignment:
Message type Description
0x0700 RG Connect Message
0x0701 RG Disconnect Message
0x0702 RG Notification Message
0x0703 RG Application Data Message
0x0704-0x070F Reserved for future ICCP use
12.2. TLV TYPE NAME SPACE
This document uses a new LDP TLV type, IANA already maintains a
registry of name "TLV TYPE NAME SPACE" defined by [RFC5036]. The
following value is suggested for assignment:
TLV Type Description
0x700 ICCP capability TLV.
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12.3. ICC RG Parameter Type Space
IANA needs to set up a registry of "ICC RG parameter type", to be
added to the list of "Pseudowire Name Spaces (PWE3)" registries. ICC
RG parameter types are 14-bit values. Parameter Type values 1 through
0x003A are specified in this document, Parameter Type values 0x003B
through 0x1FFF are to be assigned by IANA, using the "Expert Review"
policy defined in [RFC5226]. Parameter Type values 0x2000 through
0x2FFF, 0x3FFF, and 0 are to be allocated using the IETF consensus
policy defined in [RFC5226]. Parameter Type values 0x3000 through
0x3FFE are reserved for vendor proprietary extensions and are to be
assigned by IANA, using the "First Come First Served" policy defined
in [RFC5226].
Initial ICC parameter type space value allocations are specified
below:
Parameter Type Description
-------------- ---------------------------------
0x0001 ICC Sender Name
0x0002 NAK TLV
0x0003 Requested Protocol Version TLV
0x0004 Disconnect Code TLV
0x0005 ICC RG ID TLV
0x0006-0x000F Reserved
0x0010 PW-RED Connect TLV
0x0011 PW-RED Disconnect TLV
0x0012 PW-RED Config TLV
0x0013 Service Name TLV
0x0014 PW ID TLV
0x0015 Generalized PW ID TLV
0x0016 PW-RED State TLV
0x0017 PW-RED Synchronization Request TLV
0x0018 PW-RED Synchronization Data TLV
0x0019 PW-RED Disconnect Cause TLV
0x001A-0x002F Reserved
0x0030 mLACP Connect TLV
0x0031 mLACP Disconnect TLV
0x0032 mLACP System Config TLV
0x0033 mLACP Port Config TLV
0x0034 mLACP Port Priority TLV
0x0035 mLACP Port State TLV
0x0036 mLACP Aggregator Config TLV
0x0037 mLACP Aggregator State TLV
0x0038 mLACP Synchronization Request TLV
0x0039 mLACP Synchronization Data TLV
0x003A mLACP Disconnect Cause TLV
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12.4. STATUS CODE NAME SPACE
This document use several new Status codes, IANA already maintains a
registry of name "STATUS CODE NAME SPACE" defined by [RFC5036]. The
following values is suggested for assignment: The "E" column is the
required setting of the Status Code E-bit.
Range/Value E Description
------------- ----- ----------------------
0x00010001 0 Unknown ICCP RG
0x00010002 0 ICCP Connection Count Exceeded
0x00010003 0 ICCP Application Connection
Count Exceeded
0x00010004 0 ICCP Application not in RG
0x00010005 0 Incompatible ICCP Protocol Version
0x00010006 0 ICCP Rejected Message
0x00010007 0 ICCP Administratively Disabled
0x00010010 0 ICCP RG Removed
0x00010011 0 ICCP Application Removed from RG
13. Acknowledgments
The authors wish to acknowledge the important contributions of Dennis
Cai, Neil McGill, Amir Maleki, Dan Biagini, Robert Leger, Sami
Boutros, Neil Ketley and Mark Christopher Sains.
The authors also thank Daniel Cohn, Lizhong Jin and Ran Chen for the
valuable input, discussions and comments.
14. Normative References
[RFC5036] L. Andersson et al, "LDP Specification", RFC 5036,
October 2007.
[RFC5561] "LDP Capabilities", RFC5561, July 2009.
[RFC4447] "Transport of Layer 2 Frames Over MPLS", Martini, L.,
et al., rfc4447 April 2006.
[IEEE-802.1AX] IEEE Std. 802.1AX-2008, "IEEE Standard for Local and
metropolitan area networks- Link Aggregation", IEEE Computer
Society, November 2008.
[RFC2863] K. McCloghrie, F. Kastenholz, "The Interfaces Group MIB",
rfc2863, June 2000.
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[RFC6870] Praveen Muley, Mustapha Aissaoui, "Pseudowire
Preferential Forwarding Status Bit", RFC 6870,
February 2013.
[RFC5920] L. Fang, "Security Framework for MPLS and GMPLS Networks",
rfc5920, July 2010.
[RFC6952] M. Jethanandani et al., "Analysis of BGP, LDP, PCEP, and
MSDP Issues According to the Keying and Authentication for Routing
Protocols (KARP) Design Guide", rfc6952, May 2013.
[RFC5925] J. Touch et al., "The TCP Authentication Option", RFC 5925,
June 2010.
15. Informative References
[RFC2922] Bierman & Jones, "Physical Topology MIB",
RFC2922, September 2000.
[RFC5880] D. Katz, D. Ward, "Bidirectional Forwarding Detection",
RFC5880, June 2010
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations section in RFCs", BCP 26, RFC 5226, May 2008
[RFC3629] F. Yergeau, "UTF-8, a transformation format of ISO 10646",
STD 63, RFC 3629, November 2003.
[LDP-CRYPTO] L. Zheng et al., "LDP Hello Cryptographic Autentication",
draft-ietf-mpls-ldp-hello-crypto-auth-02, work in progress,
August 2013.
16. Author's Addresses
Luca Martini
Cisco Systems, Inc.
9155 East Nichols Avenue, Suite 400
Englewood, CO, 80112
e-mail: lmartini@cisco.com
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Samer Salam
Cisco Systems, Inc.
595 Burrard Street, Suite 2123
Vancouver, BC V7X 1J1
Canada
e-mail: ssalam@cisco.com
Ali Sajassi
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134
e-mail: sajassi@cisco.com
Matthew Bocci
Alcatel-Lucent
Grove House, Waltham Road Rd
White Waltham, Berks, UK. SL6 3TN
e-mail: matthew.bocci@alcatel-lucent.co.uk
Satoru Matsushima
Softbank Telecom
1-9-1, Higashi-Shinbashi, Minato-ku
Tokyo 105-7313, JAPAN
e-mail: satoru.matsushima@gmail.com
Thomas Nadeau
Brocade
e-mail: tnadeau@brocade.com
Copyright Notice
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
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Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
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