Internet DRAFT - draft-eastlake-trill-cn
draft-eastlake-trill-cn
TRILL Working Group Donald Eastlake
INTERNET-DRAFT Huawei
Intended status: Proposed Standard Manoj Wadekar
Updates: 6325 QLogic
Anoop Ghanwani
Dell
Puneet Agarwal
Broadcom
Tal Mizrahi
Marvell
Expires: July 3, 2013 January 4, 2013
TRILL: Support of IEEE 802.1 Congestion Notification
<draft-eastlake-trill-cn-00.txt>
Abstract
This document briefly explains the IEEE 802.1 Congestion Notification
standard and specifies the support of this standard in TRILL switches
(devices that implement the IETF TRILL protocol standard). It updates
RFC 6325.
Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent
to the authors.
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Table of Contents
1. Introduction............................................3
1.1 Overview of These Standards............................3
1.2 Terminology............................................4
2. Congestion Notification.................................5
2.1 Congestion Notification Domains........................7
2.2 Congestion Notification Tag Details....................9
2.3 Congestion Notification Message Details................9
3 Addition to TRILL to Support Congestion Notification....11
3.1 TRILL Switch Ingress Details..........................12
3.2 Transit TRILL Switch Details..........................15
3.2.1 Transit TRILL Switch Input Port.....................15
3.2.2 Transit TRILL Switch Output Port....................15
3.3 TRILL Switch Egress Details...........................16
4. Management Considerations..............................17
5. IANA Considerations....................................17
6. Security Considerations................................17
7. References.............................................18
7.1 Normative References..................................18
7.2 Informative References................................18
Authors' Addresses........................................20
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1. Introduction
IEEE 802.1 has developed various standards as part of its Data Center
Bridging (DCB) activity. The intent of thee of these standards is (1)
to efficiently minimize data loss due to queue overflow for selected
classes of traffic within Local Area Networks (LANs) meeting certain
conditions and (2) to provide limited means to allocate the available
bandwidth to different classes of traffic. Those three standards are
Priority Based Flow Control (IEEE [802.1Qbb]), Enhanced Tramission
Selection (IEEE [802.1Qaz]), and the Congestion Notification (CN)
feature in the IEEE [802.1Q] standard. Intended uses include the
support of loss sensitive services, such as Fiber Channel over
Ethernet [FCoE], in data centers.
PFC and ETS and their support in TRILL, which requires no changes to
TRILL, are described in [PfcEts].
This document concerns the Congestion Notification (CN) feature in
the IEEE [802.1Q] standard. To support CN, a change to TRILL is
required as specified herein and for that reason this document
updates [RFC6325].
The existing optional PAUSE feature of IEEE 802.3 (Annex 31B of
[802.3]) can, with appropriate engineering, also provide Ethernet
service without loss of frames due to queue overflow. However, PAUSE
has problems as described in [PfcEts].
1.1 Overview of These Standards
An overview of the CN standard covered herein is given below.
Congestion Notification (CN) provides signaling of congestion on a
per flow basis to the end station source of the flow as specified in
[802.1Q]. As a part of CN, participating end stations are required to
implement per flow rate limiting. CN is enabled on a per priority
basis and, with appropriate engineering, minimizes frame drops due to
queue overflow in a LAN Congestion Notification Domain within which
all switches and end stations implement it. CN and Priority-based
Flow Control (PFC, see [PfcEts]) complement each other to help
eliminate such frame drops. CN reduces congestion by proactively
reducing frame ingress rates at the source end station(s) involved in
the congestion. For some congestion cases this may be insufficient to
stop buffer overflow at a congestion point. PFC provides an emergency
brake for such cases and avoids frame loss. Frames that require drops
due to congestion for flow control, such as those using TCP [RFC793]
can be assigned a priority for which CN is not enabled. CN is not
normally used to limit priorities 6 and 7 to avoid interfering with
time sensitive control frames that commonly use such priorities. And
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CN acts by restraining end station flow sources rather than blocking
transmission on intermediate switch ports, which avoids congestion
spreading as discussed in [PfcEts]. Section 2 below provides
additional information on CN and specifies additions to the TRILL
protocol to support it.
The PFC, ETS, and CN standards may be implemented independently or in
any combination except that implementation of any of them implies
implementation of DCBX, specified in IEEE [802.1Qaz] and discussed in
[PfcEts].
1.2 Terminology
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].
The following acronyms are used in this document in addition to those
defined in [RFC6325].
CN - Congestion Notification [802.1Q]
CNM - Congestion Notification Message
CNtag - Congestion Notification tag
DCB - Data Center Bridging [802.1Qaz]
DCBX - DCB Exchange protocol [802.1Qaz]
ETS - Enhanced Transmission Selection [802.1Qaz] [PfcEts]
FCoE - Fiber Channel over Ethernet [FCoE]
LLDP - Link Layer Discovery Protocol [802.1AB]
PFC - Priority-based Flow Control [802.1Qbb] [802.3bd] [PfcEts]
RBridge - "Routing Bridge", an alternative name for a TRILL switch
TRILL Switch - A device implementing the TRILL protocol [RFC6325]
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2. Congestion Notification
Congestion Notification (CN) can limit flows to minimize frame loss
by having congestion points that detect congestion send Congestion
Notification Messages (CNMs) back to reaction points in end stations
that can limit flows. See [802.1Q] for the specification of the CN
algorithms to perform at congestion and reaction points. Congestion
Notification is designed to operate best in minimizing frame loss of
unicast flows in a LAN composed of point-to-point physical links
where all switches have implemented Congestion Notification.
A TRILL switch that implements Congestion Notification may act as an
end point, for example when sourcing or sinking SNMP management
frames, and thus may contain one or more reaction points, as well as
implementing congestion points at its output queues.
Reaction points are in end stations where flows originate and are the
mechanism to limit flows. The granularity of reaction point flows is
beyond the scope of CN and this document but cannot be larger than a
priority at a source MAC address. If the granularity is smaller and
there are multiple reaction points in an end station for a given
priority, then the end station must label outgoing frames with a
Congestion Notification tag (CNtag) that includes an end station flow
ID. This flow ID is an opaque field to the rest or the network.
+-----------------------------------------------+
| Ethernet Header (possibly including VLAN Tag) |
+-----------------------------------------------+
| Optional CNtag |
+-----------------------------------------------+
| Ethernet Payload |
+-----------------------------------------------+
| Ethernet FCS |
+-----------------------------------------------+
Figure 1: Native Ethernet Frame in a CN Domain
Congestion points are at queues in forwarding devices, normally port
output queues. The functions of a congestion point are (1) to
conditionally send Congestion Notification Messages (CNMs) to the
source of a frame and (2) to conditionally strip Congestion
Notification tags (CNtags) out of a frame being forwarded, for
example if it is being forwarded out of a congestion notification
domain.
When a frame is to be inserted into an output queue with a congestion
point, the procedures specified in IEEE [802.1Q] are used to
determine if a CNM should be sent to the frame's source and if so to
determine various fields in that CNM. When a frame is to be inserted
D. Eastlake, et al [Page 5]
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into an output queue with a congestion point, the congestion point
may remove any CNtag in the frame as discussed in Section 2.1.
Congestion points are implemented within the logic associated with a
port and require no changes to TRILL for the output of native frames,
as TRILL is implemented above such port logic as described in
[RFC6325]; however, when outputting a TRILL Data frame, any CNM
generated needs to be for the TRILL encapsulated frame rather than
for the entire TRILL Data frame. In that case there are some
differences between the details of the creation of a CNM at an TRILL
switch output port and at a bridge output port. This CNM also needs
to be TRILL encapsulated but this will happen automatically as the
CNM is specified by [802.1Q] to be treated as a native frame arriving
at the port.
+-----------------------------------------------+
| Ethernet Header (possibly including VLAN Tag) |
+-----------------------------------------------+
| CNtag |
+-----------------------------------------------+
| Congestion Notification Message Fixed Fields |
+ - - - - - - - - - - - - - - - - - - - - - - -+
| Initial bytes of frame causing CNM |
+-----------------------------------------------+
| Ethernet FCS |
+-----------------------------------------------+
Figure 2: Native Congestion Notification Message
Within a contiguous part of the TRILL campus where Congestion
Notification is enabled (see Section 2.1), you would see the same
frames with the same tags as in a similar bridged LAN except that
those frames will be TRILL encapsulated as shown in Figures 3 and 4.
The exception is when a TRILL-ignorant bridge within the campus
produces a CNM in response to a TRILL data frame as shown in Figure
6. The resulting CNM is corrected by the first TRILL switch it
encounters, which will be the previous-hop TRILL switch.
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+-----------------------------------------------+
| Link Header |
+-----------------------------------------------+
| TRILL Header |
+-----------------------------------------------+
| CNtag |
+-----------------------------------------------+
| Rest of Native Payload |
+-----------------------------------------------+
| Link Trailer |
+-----------------------------------------------+
Figure 3. TRILL Data Form of CNtagged Native Frame
+-----------------------------------------------+
| Link Header |
+-----------------------------------------------+
| TRILL Header |
+-----------------------------------------------+
| CNtag |
+-----------------------------------------------+
| Congestion Notification Message Fixed Fields |
+ - - - - - - - - - - - - - - - - - - - - - - -+
| Initial bytes of frame causing CNM |
+-----------------------------------------------+
| Link Trailer |
+-----------------------------------------------+
Figure 4: TRILL Data Form of Congestion Notification Message
2.1 Congestion Notification Domains
Congestion Notification (CN) reduces frame drops due to output queue
overflow in a Congestion Notification Domain. There could be many
such domains, each specified for a particular priority and contiguous
set of network stations (end stations, TRILL switches, or bridges),
within a TRILL campus. For example, two Congestion Notification
Domains, one at priority X and one at priority Y, could cover the
same set of contiguous stations, overlapping but different sets of
such stations, or completely disjoint sets of such stations, in a
campus.
CN includes mechanisms to "defend" Congestion Notification Domains,
that is, make sure only congestion managed flows of frames enter
congestion point queues. The edge of a domain, i.e. the set of
station ports in the domain directly connected to a station not in
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the domain, is determined by a combination of auto-detection using
LLDP (see Section 4 of [PfcEts]) and management configuration.
Bridges that implement Congestion Notification defend a domain by the
following:
1. Prohibiting priority mapping inside the domain.
2. Mapping the priority of any frame entering the domain from a
station outside the domain to a priority that is not a congestion
managed priority.
3. Prohibiting the mapping of the priority of any frame entering the
domain from a station outside the domain to the domain's priority.
The station containing the reaction-point-equipped source of a flow
must be part of a Congestion Notification Domain at the flow's
priority along with all stations along the path to the flow's
destination and all of the queues involved with the flow must be
congestion-point-equipped in order for CN to be able to meet its
goals.
Because of item 2 in the list above, a station can be a member of no
more than 7 different Congestion Notification Domains because there
must be at least one priority that is not congestion managed for use
as the mapped priority of entering frames from outside the domain and
which are therefore not part of a congestion managed flow. As a
practical matter, it is unlikely that a station would be a member of
more than 4 or 5 different Congestion Notification Domains as
priorities 6 and 7 are normally used for high priority control frames
that are not congestion controlled and at least one low priority is
kept non-congestion managed for mapping as above.
The per port per priority state of a switch or end station will be
one of the following four values, which have the effects indicated:
o Disabled:
- On native frame input, frame priority can be mapped to or from
this priority.
- If this is an end-station output port, CNtags are not added.
- If this is a switch output port, CNtags are not stripped.
o Edge:
- On native frame input, a frame with this priority is mapped to
a non-CN priority and no native frame can be mapped to this
priority, regardless of the priority-mapping table at the port.
For TRILL Data frames, this also applies to the Inner.VLAN
priority.
- If this is an end-station output port, CNtags are not added.
- If this is a switch output port, CNtags are stripped including
any CNtag in the encapsulated frame if a TRILL Data frame is
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being output.
o Interior:
- On frame input, a frame in this priority is not mapped to
another priority and no frame can be mapped to this priority,
regardless of the priority-mapping table at this port. For
TRILL Data frames, this also applies to the Inner.VLAN
priority.
- If this is an end-station output port, CNtags are not added.
- If this is a switch output port, CNtags are stripped including
any CNtag in the encapsulated frame if a TRILL Data frame is
being output.
o InteriorReady:
- On frame input, a frame in this priority is not mapped to
another priority and no frame can be mapped to this priority,
regardless of the priority-mapping table at this port. For
TRILL Data frames, this also applies to the Inner.VLAN
priority.
- If this is an end-station output port, CNtags may be added.
- If this is a switch output port, CNtags are not stripped.
Note that when the priority of a TRILL encapsulated frame is mapped,
the priority field in the Inner.VLAN tag MUST be changed.
2.2 Congestion Notification Tag Details
An end station originating a native frame may add a Congestion
Notification tag (CNtag) to identify the native frame's reaction
point in that end station, if the end station and the next hop device
are part of a Congestion Notification Domain. A CNtag is 4 bytes
long, consisting of a 2 bytes Ethertype (0x22E9) followed by a 2
bytes flow ID, and appears after any VLAN tag but before the frame
body. This CNtag flow ID is an opaque quantity only meaningful to the
originating end station. The inclusion of a CNtag is optional as the
originating end station may be able to identify the corresponding
reaction point from other information returned in a Congestion
Notification Message such as the priority.
As described in Section 2.3, CNtags are always added to Congestion
Notification Messages (CNM) when they are created.
2.3 Congestion Notification Message Details
A Congestion Notification Message (CNM) is, under certain
circumstances, created by a congestion point, as described in IEEE
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[802.1Q], when a frame is entered into the queue associated with that
congestion point. The CNM frame always includes a Congestion
Notification tag (CNtag, see Section 2.2). The CNtag includes a zero
flow ID if the frame provoking the CNM did not have a CNtag. The body
of the CNM itself, after the CNtag, starts with the CNM Ethertype
(0x22E7) followed by the information below:
- CNM version information, currently zero
- Quantized congestion feedback information as specified in
[802.1Q]
- An 8 byte opaque ID of the congestion point generating the CNM
- The priority of the frame causing the CNM
- The destination MAC address of the frame causing the CNM
- The number of bytes included from the beginning of the body of
the frame causing the CNM
- The first up to 64 bytes of the body of the frame causing the
CNM
Except that input bytes/frame counters are not incremented, a CNM
generated at an output queue for a port is treated as if it had been
received on that port. CNMs are considered to be in the same VLAN as
the frame that provoked them and have configurable priority that
defaults to priority 6.
It is undesirable, but not an error, for a CNM to be sent in response
to a CNM frame which encounters congestion. This is normally avoided
by sending CNM frames with a priority which does not have congestion
notification enabled.
As described in Section 3.1.3 below, when a CNM is generated by an
TRILL switch when queuing a TRILL data frame, it is generated for the
enclosed frame, not for the entire TRILL data frame. This will cause
the CNM to be addressed to the source end station of the data.
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3 Addition to TRILL to Support Congestion Notification
The figure below is used in the discussion in this section. The
assumption is that a frame is generated at End Station "a" (ESa)
destined for End Station "b" (ESb) and this frame is forwarded
through the sequence of 802.1 bridges (Bn) and TRILL switches
(RBridges, RBn) shown. For native frames from ESa, RB1 acts as the
ingress TRILL switch, encapsulating and directing them to egress
TRILL switch RB3 for decapsulation and delivery to ESb. The arrows
indicate the flow of a data frame. Any resulting CNM would flow in
the opposite direction; however, such a CNM would be independently
routed towards ESa and would not be constrained to follow the same
sequence of switches shown below.
+-----+ +-----+ +-----+ +-----+
| ESa +-->--+ B1 | + RB3 |-->--+ B3 +
+-----+ +--+--+ +--+--+ +--+--+
| | |
V ^ V
| | |
+--+--+ +-----+ +--+--+ +--+--+
| RB1 +-->--+ RB2 +-->--+ B2 + | ESb |
+-----+ +-----+ +-----+ +-----+
Figure 5: Example Frame Path
TRILL can make no change to the actions at any reaction points in ESa
or any congestion points at the output queues of B1, B2, or B3, since
they are not TRILL switches. Any CNM generated at B2 will be in
response to a TRILL frame and will need to be corrected by the
previous hop TRILL switch. The situation at the output queue of RB3
is actually the same as B3 since, as egress, RB3 will have
decapsulated any traffic for ESb before it tries to insert it in an
output queue. Thus the frame RB3 is enqueuing will be a native frame,
a congestion point at the RB3 output can act, for such a frame,
exactly as an IEEE 802.1 congestion point, and any CNM generated in
the RB3 output from that native frame will be treated as if it was
received by the RB3 port.
A CNM created at the RB1 or RB2 output queue is straightforward.
Assume the CNM is created in response to TRILL Data frame 1 (TDF1)
and the TDF1 encapsulates native frame 1 (NF1). The CNM would be
created as a TRILL encapsulated CNM with the ingress TRILL switch of
NF1 as its egress. The Inner.MacDA would be ESa. The Inner.MacSA
would be the MAC address of the port on which the TRILL encapsulated
CNM was initially sent, that is, the same as the Outer.MacSA. The
encapsulated CNM itself would be filled in as if in response to NF1,
not TDF1.
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Similarly, a CNM created at B3 would have ESa as its destination
address and would be TRILL encapsulated when it arrived at RB3 as RB3
would be its ingress TRILL switch.
3.1 TRILL Switch Ingress Details
This section specifies special actions for CN at a TRILL switch input
port receiving a native frame, that is, the TRILL switch ingress
function. The usual processing on the priority of the input TRILL
data frame, modified as described in Section 2.1, is done. Special
actions are required only when the native frame received is a CNM.
The ingress process at a TRILL switch, say RB2, supporting CN MUST
detect the case of a native CNM created by a bridge in response to a
TRILL frame, say by B2 in Figure 4, and transform or discard it as
described below. No other changes are needed in the TRILL switch
ingress process. If such a CNM was generated in response to a TRILL
control (IS-IS) frame, it is discarded.
A native CNM requiring special actions is easily recognized on
ingress as it's MAC destination address will be the TRILL switch and
it will have the CNM Ethertype. (A CNM not addressed to the TRILL
switch must have been generated in response to an unencapsulated
native frame, for example at B3 in the diagram above, and can be
encapsulated by its Ingress TRILL switch and generally forwarded by
transit TRILL switches in the same way as other native frame.)
Such a native CNM resulting from a TRILL data frame at B2 has the
contents generally shown in Figure 6 and listed further below.
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+-----------------------------------------------+
| Ethernet Header (possibly including VLAN Tag} |
+-----------------------------------------------+
| CNtag |
+-----------------------------------------------+
| CNM Ethertype and Fixed Fields |
+ - - - - - - - - - - - - - - - - - - - - - - -+
| Up to 64 initial bytes of the following: |
| +-----------------------------------------+ |
| | TRILL Ethertype and Header | |
| +-----------------------------------------+ |
| | Optional CNtag | |
| +-----------------------------------------+ |
| | Native Payload | |
| +-----------------------------------------+ |
| |
+-----------------------------------------------+
| Ethernet FCS |
+-----------------------------------------------+
Figure 6: Native CNM Caused by a TRILL Data Frame
1 + Outer.MacDA, MAC address of RB2
2 + Outer.MacSA, MAC address of port on which B2, the bridge
generating this CNM, sent the CNM
3 + Outer.VLAN tag for the designated VLAN on the RB2 to RB3 link
with the priority configured at B2 for CNMs (default priority 6)
4 + CNtag (CNtag Ethertype 0x22E9 followed by Flow ID of zero)
+ CNM
5 o CNM Ethertype 0x22E7
6 o CNM version information, quantized congestion feedback
information, and an 8 byte opaque ID of the congestion
point generating the CNM
7 o The priority of the TRILL encapsulated frame causing the
CNM
8 o The destination MAC address of the TRILL encapsulation
frame causing the CNM, RB3 in this case
9 o The number of bytes included below from the beginning of
the body of the TRILL encapsulation frame causing the CNM
+ Initial bytes of body of TRILL encapsulation Data frame causing
the CNM
o TRILL Header of the frame causing the CNM
10 - TRILL Ethertype 0x22F3
11 - Flags, hop count, options length
12 - Egress nickname, RB3 in this case
13 - Ingress nickname, RB1 in this case
14 - Options, if any
15 o Inner.MacDA, MAC address of ESb
16 o Inner.MacSA, MAC address of ESa
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17 o Inner.VLAN tag of the TRILL encapsulated frame causing the
CNM
18 o Optional CNtag
19 o Encapsulated native frame body
The ingressing TRILL switch RB2 transforms this CNM above into the
following TRILL encapsulated CNM.
+ Outer.MacDA, MAC address of next hop RBridge (RB1) toward
originating end station
+ Outer.MacSA, MAC address of RB2 port on which this TRILL
encapsulated CNM frame is to be sent
+ Outer.VLAN tag for the designated VLAN on the RB2 to RB1 link
with priority copied from incoming Outer.VLAN, field #3 above
+ TRILL Header to get the CNM to the right end station
o TRILL Ethertype 0x22F3
o Flags, hop count, options length
o Egress nickname, RB1 in this case, from ingress nickname in
the TRILL header in the received CNM, field #13 above
o Ingress nickname, RB2 in this case, the nickname of the
RBridge doing this transformation
o Options, if any
+ Inner.MacDA, MAC address of ESa, field #16 above
+ Inner.MacSA, MAC address of B2, field #2 above
+ Inner.VLAN Tag with VLAN ID from field #17 above and priority
from field #3 above
+ CNtag, with flow ID from field #18 above, if #18 is present,
otherwise flow ID of zero
+ CNM
o CNM Ethertype 0x22E7
o CNM version information, quantized congestion feedback
information, and an 8 byte opaque ID of the congestion
point generating the CNM, field #6 above
o The priority of the native frame who's encapsulated form
caused the CNM, from Inner.VLAN, field #17 above
o The destination MAC address of the frame whose encapsulated
form caused the CNM, the Inner.MacDA, field #15 above
o The number of bytes included below from the beginning of
the body of the frame whose encapsulated form caused the
CNM. This will be 24 smaller (but not less than zero) than
the same field (#9) in the CNM tag received due to dropping
the TRILL Header (8 bytes), MAC addresses (12 bytes), and
Inner.VLAN (4 bytes).
+ Initial bytes of the body of the frame whose encapsulated form
caused the CNM, field #19 above
Because of the reduction in the number of bytes of the body of the
frame that would have caused the CNM if it weren't TRILL
encapsulated, it is RECOMMENDED that bridges and TRILL switches
implementing Congestion Notification in a TRILL campus be configured
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to include the maximum (64) number of bytes when generating a CNM.
3.2 Transit TRILL Switch Details
The subsections below describe transit TRILL switch support of
Congestion Notification at input and output ports. As this is a TRILL
switch in its transit role, only the handling of TRILL Data frames is
discussed. If the TRILL switch is receiving a native frame, it will
be an ingress as described in Section 3.1 and if it is sending a
native frame, it will be an egress as described in Section 3.3.
However, this section does apply to the output of an encapsulated
frame that was ingressed at a TRILL switch and to the input, in TRILL
encapsulated form, of a frame to be egressed at a TRILL switch.
3.2.1 Transit TRILL Switch Input Port
The usual 802.1Q processing on the priority of the input TRILL data
frame, modified as described in Section 2.1, is done.
3.2.2 Transit TRILL Switch Output Port
As discussed in Section 2.1, a CNtag is stripped under some
circumstances; however, such a CNtag will appear as part of the
encapsulated frame, not on the outside of the TRILL data frame, so
the CNtag is stripped from deeper in the frame. When there is a
Congestion Point enabled at a TRILL switch output queue, a CNM is not
generated as the result of trying to queue a TRILL control (IS-IS)
frame for output at a TRILL switch port. A TRILL encapsulated CNM is
generated in response to a TRILL Data frame composed as below, when
to do so is specified by [802.1Q]. The TRILL Data frame causing the
CNM is referred to as TDF1 and its encapsulated native frame as NF1.
+ Outer.MacDA - MAC address of the next hop RBridge towards the
egress nickname used in the TRILL Header (see below)
+ Outer.MacSA - MAC address of the output port on which the TRILL
encapsulated CNM is to be sent
+ Outer.VLAN - Designated VLAN of the link on which the TRILL
encapsulated CNM is to be sent
+ TRILL Header
o TRILL Ethertype 0x22F3
o Flags, hop count, options length
o Egress nickname, from ingress nickname in TDF1
o Ingress nickname, a nickname of the RBridge generating the
CNM
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o Options, if any
+ Inner.MacDA - set to the Inner.MacSA of TDF1, that is, the
source MAC address of NF1
+ Inner.MacSA - same as Outer.MacSA of TDF1
+ Inner.VLAN - same as the Inner.VLAN of TDF1, that is, the VLAN
tag of NF1
+ CNtag - with flow ID from the CNtag of NF1 or zero if NF1 did
not have a CNtag
+ CNM - message generated for NF1
3.3 TRILL Switch Egress Details
After decapsulation, processing of the decapsulated native frame is
the same as at any CN equipped output port. As discussed in Section
5.1, any CNtag present is stripped under some circumstances. If the
output queue is congested, then a native CNM may be generated in
response to the decapsulated native frame. This native CNM will then
be treated as if it had been received on the port.
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4. Management Considerations
---TBD---
5. IANA Considerations
This document requires no IANA actions. RFC Editor: Please delete
this section before publication.
6. Security Considerations
See [RFC6325] for general RBridge Security Considerations.
---more TBD---
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7. References
Normative and informational references for this document are given
below.
7.1 Normative References
[802.1Q] - IEEE, "IEEE Standard for Local and metropolitan area
networks / Virtual Bridged Local Area Networks", IEEE
802.1Q-2011, May 2011.
[RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997
[RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
Ghanwani, "Routing Bridges (RBridges): Base Protocol
Specification", RFC 6325, July 2011.
7.2 Informative References
[802.1Qaz] - IEEE, "Draft Standard for Local and Metropolitan Area
Networks / Virtual Bridged Local Area Networks / Amendment XX:
Enhanced Transmission Selection for Bandwidth Sharing Between
Traffic Classes", IEEE Std 802.1Qaz-2011, June 2011.
[802.1Qbb] - IEEE, "Draft Standard for Local and Metropolitan Area
Networks / Virtual Bridged Local Area Networks / Amendment:
Priority-based Flow Control", IEEE Std 802.1Qbb-2011, June
2011.
[802.3] IEEE, "IEEE Standard for Information technology /
Telecommunications and information exchange between systems /
Local and metropolitan area networks / Specific requirements
Part 3: Carrier sense multiple access with collision detection
(CSMA/CD) access method and physical layer specifications",
IEEE 802.3-2008, 26 December 2008.
[802.3bd] - IEEE 802.3, "Draft Standard for Information technology /
Telecommunications and information exchange between systems /
Local and Metropolitan Area Networks / Specific requirements
Part 3: Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) Access Method and Physical Layer Specifications /
Amendment: MAC Control Frame for Priority-based Flow Control",
IEEE Std 802.3bd-2011, June 2011.
[FCoE] - http://fcoe.com/
D. Eastlake, et al [Page 18]
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[RFC793] - Postel, J., "Transmission Control Protocol", STD 7, RFC
793, September 1981
[PfcEts] - draft-eastlake-trill-pfc-ets, work in progress.
D. Eastlake, et al [Page 19]
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Authors' Addresses
Donald Eastlake 3rd
Huawei Technologies
155 Beaver Street
Milford, MA 01757 USA
Tel: +1-508-333-2270
Email: d3e3e3@gmail.com
Manoj Wadekar
QLogic Corporation
26650 Aliso Viejo Pkwy
Aliso Viejo, CA 92656 USA
Tel: +1-949-389-6000
Email: manoj.wadekar@qlogic.com
Anoop Ghanwani
Dell
350 Holger Way
San Jose, CA 95134 USA
Phone: +1-408-571-3500
Email: anoop@alumni.duke.edu
Puneet Agarwal
Broadcom
3975 Freedom Circle
Santa Clara, CA 95054 USA
Phone: +1-949-926-5000
Email: pagarwal@broadcom.com
Tal Mizrahi
Marvell
6 Hamada Street
Yokneam, 20692 Israel
Email: talmi@marvell.com
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D. Eastlake, et al [Page 21]
