Internet DRAFT - draft-ietf-ccamp-rsvp-te-eth-oam-ext
draft-ietf-ccamp-rsvp-te-eth-oam-ext
Network Working Group A. Takacs
Internet-Draft B. Gero
Intended status: Standards Track Ericsson
Expires: January 23, 2015 H. Long
Huawei
July 22, 2014
GMPLS RSVP-TE Extensions for Ethernet OAM Configuration
draft-ietf-ccamp-rsvp-te-eth-oam-ext-13
Abstract
The GMPLS controlled Ethernet Label Switching (GELS) work extended
GMPLS RSVP-TE to support the establishment of Ethernet LSPs. IEEE
Ethernet Connectivity Fault Management (CFM) specifies an adjunct OAM
flow to check connectivity in Ethernet networks. CFM can be also
used with Ethernet LSPs for fault detection and triggering recovery
mechanisms. The ITU-T Y.1731 specification builds on CFM and
specifies additional OAM mechanisms, including Performance
Monitoring, for Ethernet networks. This document specifies
extensions of GMPLS RSVP-TE protocol to support the setup of the
associated Ethernet OAM entities of Ethernet LSPs, and defines the
Ethernet technology specific TLVs based on the GMPLS OAM
Configuration Framework. This document supports, but does not
modify, the IEEE and ITU-T OAM mechanisms.
Requirements Language
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 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on January 23, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Background . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Overview of Ethernet OAM operation . . . . . . . . . . . . . 3
3. GMPLS RSVP-TE Extensions . . . . . . . . . . . . . . . . . . 5
3.1. Operation overview . . . . . . . . . . . . . . . . . . . 5
3.2. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 7
3.3. Ethernet OAM Configuration Sub-TLV . . . . . . . . . . . 8
3.3.1. MD Name Sub-TLV . . . . . . . . . . . . . . . . . . . 8
3.3.2. Short MA Name Sub-TLV . . . . . . . . . . . . . . . . 9
3.3.3. MEP ID Sub-TLV . . . . . . . . . . . . . . . . . . . 10
3.3.4. Continuity Check (CC) Sub-TLV . . . . . . . . . . . . 11
3.4. Pro-active Performance Monitoring . . . . . . . . . . . . 12
3.5. Summary of Ethernet OAM configuration errors . . . . . . 13
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
4.1. RSVP-TE OAM Configuration Registry . . . . . . . . . . . 13
4.2. Ethernet Sub-TLVs Sub-Registry . . . . . . . . . . . . . 14
4.3. RSVP Error Code . . . . . . . . . . . . . . . . . . . . . 14
5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Normative References . . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Background
Provider Backbone Bridging - Traffic Engineering (PBB-TE)
[IEEE.802.1Q-2011] decouples the Ethernet data and control planes,
and allows external control and management mechanisms to create
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explicitly routed Ethernet connections. In addition, PBB-TE defines
mechanisms for protection switching of bidirectional Ethernet
connections. Ethernet Connectivity Fault Management (CFM) defines an
adjunct connectivity monitoring OAM flow to check the liveliness of
Ethernet networks [IEEE.802.1Q-2011], including the monitoring of
specific explicitly routed Ethernet connections. The ITU-T
Recommendation Y.1731 [ITU-T.Y.1731-2011] extended CFM and specified
additional OAM functionality.
In IETF, the GMPLS controlled Ethernet Label Switching (GELS) work
extended the GMPLS control plane to support the establishment of
explicitly routed Ethernet connections [RFC5828][RFC6060]. We refer
to GMPLS established Ethernet connections as Ethernet LSPs. GELS
enables the application of MPLS-TE and GMPLS provisioning and
recovery features in Ethernet networks.
The use of GMPLS RSVP-TE to support the establishment and
configuration of OAM entities with LSP signaling is defined in a
technology agnostic way in [RFC7260]. The purpose of this document
is to specify the additional technology specific OAM entities to
support Ethernet connections.
2. Overview of Ethernet OAM operation
For the purposes of this document, we only discuss Ethernet OAM
aspects that are relevant for proactive connectivity monitoring of
Ethernet LSPs. On-demand OAM functions for the purposes of this
document will be supported by Management Plane operations.
PBB-TE defines point-to-point Ethernet Switched Paths (ESPs) as a
provisioned traffic engineered unidirectional connectivity,
identified by the 3-tuple [ESP-MAC DA, ESP-MAC SA, ESP-VID], where
the ESP-MAC DA is the destination address of the ESP, the ESP-MAC SA
is the source address of the ESP, and the ESP-VID is a VLAN
identifier allocated for explicitly routed connections. To form a
bidirectional PBB-TE connection, two co-routed point-to-point ESPs
are combined. The combined ESPs must have the same ESP-MAC addresses
but may have different ESP-VIDs. The formed co-routed bidirectional
path is a path where the forward and backward directions follow the
same route (links and nodes) across the network.
Note that although it would be possible to use GMPLS to setup a
single unidirectional ESP, the Ethernet OAM mechanisms are only fully
functional when bidirectional connections are established with co-
routed ESPs. Therefore, the scope of this document only covers
bidirectional point-to-point PBB-TE connections.
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At both ends of the bidirectional point-to-point PBB-TE connection,
one Maintenance Endpoint (MEP) is configured. The MEPs monitoring a
PBB-TE connection must be configured with the same Maintenance Domain
Level (MD Level) and Maintenance Association Identifier (MAID). Each
MEP has a unique identifier, the MEP ID. Besides these identifiers,
a MEP monitoring a PBB-TE connection must be provisioned with the
3-tuples [ESP-MAC DA, ESP-MAC SA, ESP-VID] of the two ESPs.
In the case of point-to-point VLAN connections, the connection may be
identified with a single VLAN, or with two VLANs, one for each
direction. Therefore, instead of the 3-tuples of the PBB-TE ESPs,
MEPs must be provisioned with the proper VLAN identifiers.
MEPs exchange Connectivity Check Messages (CCMs) periodically with
fixed intervals. Eight distinct intervals are defined in
[IEEE.802.1Q-2011]:
+---+--------------------+----------------+
| # | CCM Interval (CCI) | 3 bit encoding |
+---+--------------------+----------------+
| 0 | Reserved | 000 |
| | | |
| 1 | 3 1/3 ms | 001 |
| | | |
| 2 | 10 ms | 010 |
| | | |
| 3 | 100 ms | 011 |
| | | |
| 4 | 1 s | 100 |
| | | |
| 5 | 10 s | 101 |
| | | |
| 6 | 1 min | 110 |
| | | |
| 7 | 10 min | 111 |
+---+--------------------+----------------+
Table 1: CCM Interval encoding
If 3 consecutive CCM messages are lost; connectivity failure is
declared. The MEP detecting the failure will signal the defect to
the remote MEP in the subsequent CCM messages it emits, by setting
the Remote Defect Indicator (RDI) bit in the CCM message. If a MEP
receives a CCM message with RDI bit set it immediately declares
failure. The detection of a failure may trigger protection switching
mechanisms or may be signaled to a management system.
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At each transit node, Maintenance Intermediate Points (MIPs) may be
established to help failure localization, e.g., using link trace and
loop back functions. MIPs need to be provisioned with a subset of
the MEP identification parameters described above.
3. GMPLS RSVP-TE Extensions
3.1. Operation overview
To simplify the configuration of connectivity monitoring, when an
Ethernet LSP is signaled, the associated MEPs should be automatically
established. To monitor an Ethernet LSP, a set of parameters must be
provided to setup a Maintenance Association and related MEPs.
Optionally, MIPs may be created at the transit nodes of the Ethernet
LSP. The LSP Attribute Flags: "OAM MEP entities desired" and "OAM
MIP entities desired", as described in [RFC7260], are used to signal
that the respective OAM entities must be established. An OAM
Configuration TLV, as described in [RFC7260], is added to the
LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES Objects specifying that
Ethernet OAM is to be setup for the LSP. Ethernet OAM specific
information, as described below, is carried in the new Ethernet OAM
Configuration Sub-TLV (see Section 3.3) within the OAM Configuration
TLV.
o A unique MAID must be allocated for the PBB-TE connection and both
MEPs must be configured with the same information. The MAID
consists of an optional Maintenance Domain Name (MD Name) and a
mandatory Short Maintenance Association Name (Short MA Name).
Various formatting rules for these names have been defined in
[IEEE.802.1Q-2011]. Since this information is also carried in all
CCM messages, the combined length of the Names is limited to 44
bytes, see [IEEE.802.1Q-2011] for the details of the message
format. How these parameters are determined is out of scope of
this document.
o Each MEP must be provisioned with a MEP ID. The MEP ID uniquely
identifies a given MEP within a Maintenance Association. That is,
the combination of MAID and MEP ID must uniquely identify a MEP.
How the value of the MEP ID is determined is out of scope of this
document.
o The Maintenance Domain Level (MD Level) allows hierarchical
separation of monitoring entities. [IEEE.802.1Q-2011] allows
differentiation of 8 levels. How the value of the MD Level is
determined is out of scope of this document. Note that probably
for all Ethernet LSPs a single (default) MD Level will be used
within a network domain.
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o The desired CCM Interval must be specified by the management
system based on service requirements or operator policy. The same
CCM Interval must be set in each of the MEPs monitoring a given
Ethernet LSP. How the value of the CCM Interval is determined is
out of scope of this document.
o The desired forwarding priority to be set by MEPs for the CCM
frames may be specified. The same CCM priority must be set in
each of the MEPs monitoring a given Ethernet LSP. How CCM
priority is determined is out of scope of this document. Note
that the highest priority should be used as the default CCM
priority.
o MEPs must be aware of the reachability parameters of their own and
that of the remote MEP. In the case of bidirectional point-to-
point PBB-TE connections, this requires that the 3-tuples [ESP-MAC
A, ESP-MAC B, ESP-VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are
configured in each MEP, where the ESP-MAC A is the same as the
local MEP's MAC address and ESP-MAC B is the same as remote MEP's
MAC address. The GMPLS Ethernet Label format, as defined in
[RFC6060], consists of the ESP-MAC DA and ESP-VID. Hence the
necessary reachability parameters for the MEPs can be obtained
from the Ethernet Labels (i.e., carried in the downstream and
upstream labels). In the case of point-to-point VLAN connections,
MEPs need to be provisioned with the VLAN identifiers only, which
can be derived similarly from the Ethernet Labels.
Based on the procedures described in [RFC6060] for bidirectional PBB-
TE Ethernet LSP establishment, the Ethernet OAM configuration
procedures are as follows:
When the RSVP-TE signaling is initiated for the bidirectional
Ethernet LSP the local node generates a Path message and:
o Allocates an Upstream Label formed by combining its MAC address
(ESP-MAC A) and locally selected VID (ESP-VID1), which will be
used to receive traffic;
o MUST include the OAM Configuration TLV with OAM Type set to
Ethernet OAM in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES
Object;
o MUST include the OAM Function Flags Sub-TLV in the OAM
Configuration TLV and set the OAM function flags as needed;
o MUST include an Ethernet OAM Configuration Sub-TLV in the OAM
Configuration TLV that specifies the CCM Interval and MD Level;
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o MAY add an MD Name Sub-TLV (optional) and MUST add a Short MA Name
Sub-TLV (required) to the Ethernet OAM Configuration Sub-TLV, that
will unambiguously identify a Maintenance Association for this
specific PBB-TE connection. Note that values for these parameters
may be derived from the GMPLS LSP identification parameters;
o MUST include a MEP ID Sub-TLV in the Ethernet OAM Configuration
Sub-TLV and select two distinct integer values to identify the
local and remote MEPs within the Maintenance Association created
for monitoring of the point-to-point PBB-TE connection.
Once the remote node receives the Path message, it can use the
UPSTREAM_LABEL to extract the reachability information of the
initiator. Then it allocates a Label by selecting a local MAC
address (ESP-MAC B) and VID (ESP-VID2) that will be used to receive
traffic. These parameters determine the reachability information of
the local MEP. That is, the 3-tuples [ESP-MAC A, ESP-MAC B, ESP-
VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are derived from the
Ethernet Labels. In addition, the information received in the
Ethernet OAM Configuration TLV is used to configure the local MEP.
Once the Resv message successfully arrives to the initiator, this end
can extract the remote side's reachability information from the Label
Object and therefore it has all the information needed to properly
configure its local MEP.
3.2. OAM Configuration TLV
This TLV is specified in [RFC7260] and is used to select which OAM
technology/method should be used for the LSP. In this document, a
new OAM Type: Ethernet OAM is defined. IANA is requested to allocate
OAM Type 1 for Ethernet OAM in the RSVP-TE OAM Configuration
Registry.
RSVP-TE OAM Configuration Registry
OAM Type Description
------------ ------------------
TBA1 Ethernet OAM
The receiving node, when the Ethernet OAM Type is requested, should
look for the corresponding technology specific Ethernet OAM
Configuration Sub-TLV.
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3.3. Ethernet OAM Configuration Sub-TLV
The Ethernet OAM Configuration Sub-TLV (depicted below) is defined
for Ethernet OAM specific configuration parameters. The Ethernet OAM
Configuration Sub-TLV, when used, MUST be carried in the OAM
Configuration TLV. This new sub-TLV accommodates Ethernet OAM
information and carries sub-TLVs.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBA2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version |MD L.| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type: the Ethernet OAM Configuration Sub-TLV.
IANA is requested to assign a value from the "Sub-TLV" space in the
"RSVP-TE OAM Configuration Registry".
Length: indicates the total length of the TLV including padding and
including the Type and Length fields.
Version: identifies the CFM protocol version according to
[IEEE.802.1Q-2011]. If a node does not support a specific CFM
version an error MUST be generated: "OAM Problem/Unsupported OAM
Version"
MD L. (MD Level): indicates the desired MD Level. Possible values
are defined according to [IEEE.802.1Q-2011]. If a node does not
support a specific MD Level an error MUST be generated: "OAM Problem/
Unsupported MD Level".
3.3.1. MD Name Sub-TLV
The optional MD Name Sub-TLV is depicted below, it MAY be used for MD
naming.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (1) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Format | Name Length | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ MD Name ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 1, MD Name Sub-TLV. IANA is requested to maintain an Ethernet
TLV Type space in the "RSVP-TE OAM Configuration Registry" for the
sub-TLV types carried in the Ethernet OAM Configuration Sub-TLV.
Length: indicates the total length of the TLV including padding and
including the Type and Length fields.
Format: according to [IEEE.802.1Q-2011].
Name Length: the length of the MD Name field in bytes. This is
necessary to allow non 4 byte padded MD Name lengths.
MD Name: variable length field, formatted according to the format
specified in the Format field.
If an undefined Format is specified an error MUST be generated: "OAM
Problem/Unknown MD Name Format". Also the combined length of MD Name
and Short MA Name MUST be less or equal to 44bytes, if this is
violated an error MUST be generated: "OAM Problem/Name Length
Problem". Note it is allowed to have no MD Name, therefore the MD
Name Sub-TLV is optional. In this case the MA Name must uniquely
identify a Maintenance Association.
3.3.2. Short MA Name Sub-TLV
The Short MA Name Sub-TLV is depicted below. This sub-TLV MUST be
present in the Ethernet OAM Configuration Sub-TLV.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Format | Name Length | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Short MA Name ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 2, Short MA Name Sub-TLV. IANA is requested to maintain an
Ethernet TLV Type space in the "RSVP-TE OAM Configuration Registry"
for the sub-TLV types carried in the Ethernet OAM Configuration Sub-
TLV.
Length: indicates the total length of the TLV including padding and
including the Type and Length fields.
Format: according to [IEEE.802.1Q-2011].
Name Length: the length of the MA Name field in bytes. This is
necessary to allow non 4 byte padded MA Name lengths.
Short MA Name: variable length field formatted according to the
format specified in the Format field.
If an undefined Format is specified an error MUST be generated: "OAM
Problem/Unknown MA Name Format". Also the combined length of MD Name
and Short MA Name MUST be less or equal to 44bytes, if this is
violated an error MUST be generated: "OAM Problem/Name Length
Problem". Note it is allowed to have no MD Name, in this case the MA
Name MUST uniquely identify a Maintenance Association.
3.3.3. MEP ID Sub-TLV
The MEP ID Sub-TLV is depicted below. This sub-TLV MUST be present
in the Ethernet OAM Configuration Sub-TLV.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (3) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local MEP ID |T|R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote MEP ID |T|R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 3, MEP ID Sub-TLV. IANA is requested to maintain an Ethernet
TLV Type space in the "RSVP-TE OAM Configuration Registry" for the
sub-TLV types carried in the Ethernet OAM Configuration Sub-TLV.
Length: indicates the total length of the TLV including padding and
including the Type and Length fields.
Local MEP ID: a 16 bit integer value in the range 1-8191 of the MEP
ID on the initiator side.
Remote MEP ID: a 16 bit integer value in the range 1-8191 of the MEP
ID to be set for the MEP established at the receiving side. This
value is determined by the initiator node. This is possible, since a
new MAID is assigned to each PBB-TE connection, and MEP IDs must be
only unique within the scope of the MAID.
Two flags are defined Transmit (T) and Receive (R). When T is set
the corresponding MEP MUST send OAM packets. When R is set the
corresponding MEP MUST expect to receive OAM packets. These flags
are used to configure the role of MEPs.
3.3.4. Continuity Check (CC) Sub-TLV
The Continuity Check (CC) Sub-TLV is depicted below. This sub-TLV
MUST be present in the Ethernet OAM Configuration Sub-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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (4) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prio | CCM I | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 4, Continuity Check (CC) Sub-TLV. IANA is requested to
maintain an Ethernet TLV Type space in the "RSVP-TE OAM Configuration
Registry" for the sub-TLV types carried in the Ethernet OAM
Configuration Sub-TLV.
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Length: indicates the total length of the TLV including padding and
including the Type and Length fields.
Prio: Indicates the priority to be set for CCM frames. In Ethernet,
3 bits carried in VLAN TAGs identify priority information. Setting
the priority is optional. If the most significant bit is set to
zero, the subsequent 3 priority bits will be ignored, and priority
bits of the Ethernet CCM frame will be set based on default values
specified in the Ethernet nodes. If the most significant bit is set
to 1, the subsequent 3 bits will be used to set the priority bits of
the Ethernet CCM frame.
CCM I (CCM Interval): CCM Interval, it MUST be set according to the 3
bit encoding [IEEE.802.1Q-2011] shown in Table 1. As a consequence
the most significant bit will be set to 0. Four bits are allocated
to support the configuration of CCM intervals that may be specified
in the future. If a node does not support the requested CCM Interval
an error MUST be generated: "OAM Problem/Unsupported CC Interval".
3.4. Pro-active Performance Monitoring
Ethernet OAM functions for Performance Monitoring (PM) allow
measurements of different performance parameters including Frame Loss
Ratio, Frame Delay and Frame Delay variation as defined in
[ITU-T.Y.1731-2011]. Only a subset of PM functions are operated in a
pro-active fashion to monitor the performance of the connection
continuously. Pro-active PM supports Fault Management functions, by
providing an indication of decreased service performance and as such
may provide triggers to initiate recovery procedures.
While on demand PM functions are, for the purposes of this document,
always initiated by management commands, for pro-active PM, it may be
desirable to utilize the control plane for configuration and
activation together with Fault Management functions such as the
Continuity Check.
[ITU-T.Y.1731-2011] defines dual-ended Loss Measurement as pro-active
OAM for performance monitoring and as a PM function applicable to
fault management. For dual-ended Loss Measurement each MEP piggy-
backs transmitted and received frame counters on CC messages; to
support and synchronize bidirectional Loss Measurements at the MEPs.
Dual-ended Loss Measurement is supported by setting the Performance
Monitoring/Loss OAM Function Flag and the Continuity Check Flag in
the OAM Function Flags Sub-TLV [RFC7260], and configuring the
Continuity Check functionality by including the Ethernet OAM
Configuration Sub-TLV. No additional configuration is required for
this type of Loss Measurement.
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3.5. Summary of Ethernet OAM configuration errors
In addition to error values specified in [RFC7260] this document
defines the following values for the "OAM Problem" Error Code.
o If a node does not support a specific CFM version, an error MUST
be generated: "OAM Problem/Unsupported OAM Version".
o If a node does not support a specific MD Level, an error MUST be
generated: "OAM Problem/Unsupported MD Level".
o If an undefined MD name format is specified, an error MUST be
generated: "OAM Problem/Unknown MD Name Format".
o If an undefined MA name format is specified, an error MUST be
generated: "OAM Problem/Unknown MA Name Format".
o The combined length of MD Name and Short MA Name must be less or
equal to 44bytes, if this is violated an error MUST be generated:
"OAM Problem/Name Length Problem".
o If a node does not support the requested CCM Interval, an error
MUST be generated: "OAM Problem/Unsupported CC Interval".
4. IANA Considerations
4.1. RSVP-TE OAM Configuration Registry
IANA maintains the "RSVP-TE OAM Configuration Registry". IANA is
requested to assign an "OAM Type" from this registry as follows.
Allocate the value TBA1 for "Ethernet OAM" from the "OAM Type Sub-
Registry" of the "RSVP-TE OAM Configuration Registry". Allocate type
TBA2 for the "Ethernet OAM Configuration Sub-TLV" from the
technology-specific range of the "OAM Sub-TLVs Sub-Registry" of the
"RSVP-TE OAM Configuration Registry".
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RSVP-TE OAM Configuration Registry
OAM Types Sub-Registry
OAM Type Number | Description | Reference
-------------------------------------------------
TBA1 | Ethernet OAM | [This.ID]
OAM Sub-TLVs Sub-Registry
Sub-TLV Type | Description | Ref.
----------------------------------------------------------
TBA2 |Ethernet OAM Configuration Sub-TLV|[This.ID]
The value of 1 is suggested for TBA1. The value of 32 is suggested
for TBA2.
4.2. Ethernet Sub-TLVs Sub-Registry
IANA is requested to maintain an Ethernet Sub-TLVs Sub-Registry in
the "RSVP-TE OAM Configuration Registry" for the sub-TLV types
carried in the Ethernet OAM Configuration Sub-TLV. This document
defines the following types.
Ethernet Sub-TLVs Sub-Registry
Range | Registration Procedures
------------+----------------------------
0-65534 | IETF Review
65535-65536 | Experimental
Sub-TLV Type | Description | Ref.
---------------------------------------------------
0 | Reserved | [This.ID]
1 | MD Name Sub-TLV | [This.ID]
2 | Short MA Name Sub-TLV | [This.ID]
3 | MEP ID Sub-TLV | [This.ID]
4 | Continuity Check Sub-TLV | [This.ID]
5-65536 | Unassigned | [This.ID]
4.3. RSVP Error Code
IANA maintains an Error Code, "OAM Problem" in the "Error Codes and
Globally-Defined Error Value Sub-Codes" sub-registry of the "Resource
Reservation Protocol (RSVP) Parameters" registry. [RFC7260] defines
a set of Error Value sub-codes for the "OAM Problem" Error Code.
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This document defines additional Error Values sub-codes for the "OAM
Problem" Error Code as summarized below.
Value | Description | Reference
-------+---------------------------+--------------
TBA | Unsupported OAM Version | [This.ID]
TBA | Unsupported MD Level | [This.ID]
TBA | Unknown MD Name Format | [This.ID]
TBA | Unknown MA Name Format | [This.ID]
TBA | Name Length Problem | [This.ID]
TBA | Unsupported CC Interval | [This.ID]
5. Security Considerations
This document does not introduce any additional security issue to
those discussed in [RFC7260] and [RFC6060].
The signaling of OAM-related parameters and the automatic
establishment of OAM entities based on RSVP-TE messages add a new
aspect to the security considerations discussed in [RFC3473]. In
particular, a network element could be overloaded if a remote
attacker targeted that element by sending frequent periodic messages
requesting liveliness monitoring of a high number of LSPs. Such an
attack can efficiently be prevented when mechanisms for message
integrity and node authentication are deployed. Since the OAM
configuration extensions rely on the hop-by-hop exchange of exiting
RSVP-TE messages, procedures specified for RSVP message security in
[RFC2747] can be used to mitigate possible attacks.
For a more comprehensive discussion of GMPLS security and attack
mitigation techniques, please see the Security Framework for MPLS and
GMPLS Networks [RFC5920].
6. Acknowledgements
The authors would like to thank Francesco Fondelli, Adrian Farrel,
Loa Andersson, Eric Gray and Dimitri Papadimitriou for their useful
comments.
7. Contributors
- Don Fedyk, don.fedyk@hp.com
- Dinesh Mohan, dinmohan@hotmail.com
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8. References
8.1. Normative References
[IEEE.802.1Q-2011]
IEEE, "IEEE Standard for Local and metropolitan area
networks -- Media Access Control (MAC) Bridges and Virtual
Bridged Local Area Networks", IEEE Std 802.1Q, 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC6060] Fedyk, D., Shah, H., Bitar, N., and A. Takacs,
"Generalized Multiprotocol Label Switching (GMPLS) Control
of Ethernet Provider Backbone Traffic Engineering (PBB-
TE)", RFC 6060, March 2011.
[RFC7260] Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE
Extensions for Operations, Administration, and Maintenance
(OAM) Configuration", RFC 7260, June 2014.
8.2. Informative References
[ITU-T.Y.1731-2011]
ITU, "ITU-T Recommendation Y.1731: OAM functions and
mechanisms for Ethernet based networks", ITU-T
Recommendation Y.1731, 2011.
[RFC2747] Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
Authentication", RFC 2747, January 2000.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC5828] Fedyk, D., Berger, L., and L. Andersson, "Generalized
Multiprotocol Label Switching (GMPLS) Ethernet Label
Switching Architecture and Framework", RFC 5828, March
2010.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
Authors' Addresses
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Attila Takacs
Ericsson
Konyves Kalman krt. 11.
Budapest 1097
Hungary
Email: attila.takacs@ericsson.com
Balazs Peter Gero
Ericsson
Konyves Kalman krt. 11.
Budapest 1097
Hungary
Email: balazs.peter.gero@ericsson.com
Hao Long
Huawei
PR China
Email: lonho@huawei.com
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