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Protocol Extensions for Header Compression over MPLS
RFC 4901

Revision differences

Document history

Date Rev. By Action
2015-10-14
08 (System) Notify list changed from avt-chairs@ietf.org, pwe3-chairs@ietf.org, Andy.Malis@tellabs.com, jameshand@att.com, gash@att.com, townsley@cisco.com to pwe3-chairs@ietf.org, townsley@cisco.com
2007-06-18
08 Amy Vezza State Changes to RFC Published from RFC Ed Queue by Amy Vezza
2007-06-18
08 Amy Vezza [Note]: 'RFC 4901' added by Amy Vezza
2007-06-15
08 (System) RFC published
2007-04-16
08 (System) IANA Action state changed to RFC-Ed-Ack from Waiting on RFC Editor
2007-04-16
08 (System) IANA Action state changed to Waiting on RFC Editor from Waiting on Authors
2007-03-26
08 (System) IANA Action state changed to Waiting on Authors from In Progress
2007-03-14
08 Amy Vezza State Changes to RFC Ed Queue from Approved-announcement sent by Amy Vezza
2007-03-13
08 (System) IANA Action state changed to In Progress
2007-03-12
08 Amy Vezza IESG state changed to Approved-announcement sent
2007-03-12
08 Amy Vezza IESG has approved the document
2007-03-12
08 Amy Vezza Closed "Approve" ballot
2007-03-09
08 (System) Removed from agenda for telechat - 2007-03-08
2007-03-08
08 Amy Vezza State Changes to Approved-announcement to be sent from IESG Evaluation by Amy Vezza
2007-03-08
08 Ross Callon [Ballot Position Update] New position, No Objection, has been recorded by Ross Callon
2007-03-08
08 Mark Townsley [Ballot Position Update] New position, No Objection, has been recorded by Mark Townsley
2007-03-08
08 Jon Peterson [Ballot Position Update] New position, No Objection, has been recorded by Jon Peterson
2007-03-08
08 Jari Arkko [Ballot Position Update] New position, No Objection, has been recorded by Jari Arkko
2007-03-08
08 Bill Fenner [Ballot Position Update] New position, No Objection, has been recorded by Bill Fenner
2007-03-07
08 David Kessens [Ballot Position Update] New position, No Objection, has been recorded by David Kessens
2007-03-07
08 Russ Housley [Ballot Position Update] New position, No Objection, has been recorded by Russ Housley
2007-03-07
08 Magnus Westerlund
[Ballot comment]
I think one should consider switching the reference to RFC 3095 to that of the approved document: draft-ietf-rohc-rfc3095bis-framework

Nits:

Section 2:
compressed Real …
[Ballot comment]
I think one should consider switching the reference to RFC 3095 to that of the approved document: draft-ietf-rohc-rfc3095bis-framework

Nits:

Section 2:
compressed Real Time Protocol (cRTP)

Should be:

compressed Real-time Transport Protocol (cRTP)

Enhanced Compressed Real Time Porotocol (ECRTP)

Should be:

Enhanced Compressed Real-time Transport Protocol (ECRTP)

Section 2:
  Label Switching Router (LSR): an MPLS node which is capable of
  forwarding native L3 packets label stack an ordered set of labels

It seems another definition for "Label stack" has been sucked into this definition.
2007-03-07
08 Magnus Westerlund [Ballot Position Update] New position, No Objection, has been recorded by Magnus Westerlund
2007-03-07
08 Dan Romascanu [Ballot Position Update] New position, No Objection, has been recorded by Dan Romascanu
2007-03-06
08 Sam Hartman [Ballot Position Update] New position, No Objection, has been recorded by Sam Hartman
2007-03-05
08 Ted Hardie [Ballot Position Update] New position, No Objection, has been recorded by Ted Hardie
2007-03-05
08 Brian Carpenter
[Ballot comment]
One author response to Spencer Dawkins' Gen-ART review remains open.
This would be an improvement:

If you prefer I could replace the phrasing …
[Ballot comment]
One author response to Spencer Dawkins' Gen-ART review remains open.
This would be an improvement:

If you prefer I could replace the phrasing "These sub-options do not
occur together" with the following text: "These sub-options MUST NOT
occur together, if they do (e.g., if misconfigured) a decompressor MUST
reject this option and send an explicit error message to the compressor
[RFC3544]."
2007-03-05
08 Brian Carpenter [Ballot Position Update] New position, No Objection, has been recorded by Brian Carpenter
2007-03-02
08 Lars Eggert [Ballot Position Update] New position, No Objection, has been recorded by Lars Eggert
2007-02-25
08 Cullen Jennings [Ballot Position Update] New position, Yes, has been recorded for Cullen Jennings
2007-02-25
08 Cullen Jennings Ballot has been issued by Cullen Jennings
2007-02-25
08 Cullen Jennings Created "Approve" ballot
2007-02-25
08 Cullen Jennings Placed on agenda for telechat - 2007-03-08 by Cullen Jennings
2007-02-25
08 Cullen Jennings State Changes to IESG Evaluation from Waiting for AD Go-Ahead by Cullen Jennings
2007-02-19
08 (System) State has been changed to Waiting for AD Go-Ahead from AD Followup by system
2007-02-16
08 (System) Sub state has been changed to AD Follow up from New Id Needed
2007-02-16
08 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-08.txt
2007-02-13
08 Cullen Jennings State Changes to In Last Call::Revised ID Needed from In Last Call by Cullen Jennings
2007-02-13
08 Cullen Jennings Will rev 08 version after last call
2007-02-12
08 Samuel Weiler Request for Last Call review by SECDIR Completed. Reviewer: Radia Perlman.
2007-02-05
08 Amy Vezza Last call sent
2007-02-05
08 Amy Vezza State Changes to In Last Call from Last Call Requested by Amy Vezza
2007-02-03
08 Cullen Jennings Last Call was requested by Cullen Jennings
2007-02-03
08 Cullen Jennings State Changes to Last Call Requested from In Last Call by Cullen Jennings
2007-02-01
08 Samuel Weiler Request for Last Call review by SECDIR is assigned to Radia Perlman
2007-02-01
08 Samuel Weiler Request for Last Call review by SECDIR is assigned to Radia Perlman
2007-01-31
08 Yoshiko Fong
IANA Last Call Comments:

IANA understands that there are three actions required
upon approval of this document.

First, in the Pseudo Wires Name Spaces registry …
IANA Last Call Comments:

IANA understands that there are three actions required
upon approval of this document.

First, in the Pseudo Wires Name Spaces registry located at:

http://www.iana.org/assignments/pwe3-parameters

in the subregistry named MPLS Pseudowire Types Registry,
the following values will be added:

PW type Description Reference
------- ----------------------------------------------- ---------
0x001A ROHC Transport Header-compressed Packets [RFC3095]
0x001B ECRTP Transport Header-compressed Packets [RFC3545]
0x001C IPHC Transport Header-compressed Packets [RFC2507]
0x001D cRTP Transport Header-compressed Packets [RFC2508]

Second, also in the Pseudo Wires Name Spaces registry
located at:

http://www.iana.org/assignments/pwe3-parameters

in the subregistry named, Pseudowire Interface Parameters
Sub-TLV type Registry the following values will be added:

Parameter ID Length Description References
--------- --------------- ----------------------------- -----------
0x0D up to 256 bytes ROHC over MPLS configuration RFC 3241
0x0F up to 256 bytes CRTP/ECRTP/IPHC HC over MPLS RFC 3544
configuration

Finally, also in the Pseudo Wires Name Spaces registry
located at:

http://www.iana.org/assignments/pwe3-parameters

a new subregistry will be created called Header
Compression Over MPLS PW Control Word Packet Type.

Header Compression Over MPLS PW Control Word Packet Type
Registration Rules for values 11 to 15 - Expert Review

Packet
Type Description
-------- --------------------------------------------------
0 ROHC Small-CIDs
1 ROHC Large-CIDs
2 FULL_HEADER
3 COMPRESSED_TCP
4 COMPRESSED_TCP_NODELTA
5 COMPRESSED_NON_TCP
6 COMPRESSED_RTP_8
7 COMPRESSED_RTP_16
8 COMPRESSED_UDP_8
9 COMPRESSED_UDP_16
10 CONTEXT_STATE

IANA understands that these are the only IANA Actions
required for this document.
2007-01-24
08 Amy Vezza State Changes to In Last Call from Last Call Requested by Amy Vezza
2007-01-24
08 Cullen Jennings The refernce to 3985 seems to be a downref.
2007-01-24
08 Cullen Jennings Last Call was requested by Cullen Jennings
2007-01-24
08 Cullen Jennings State Changes to Last Call Requested from AD Evaluation by Cullen Jennings
2007-01-24
08 (System) Ballot writeup text was added
2007-01-24
08 (System) Last call text was added
2007-01-24
08 (System) Ballot approval text was added
2007-01-24
08 Cullen Jennings
2007-01-24
08 Cullen Jennings
Please consider the following as an IETF LC comment that needs to be addressed

This document defines a new Control Word for PWs. Section 4: …
Please consider the following as an IETF LC comment that needs to be addressed

This document defines a new Control Word for PWs. Section 4:
In addition to the PW label and PSN label(s), HC over MPLS packets
  also carry a PW control word.  The control word contains both a
  packet type field and a packet length field.  The packet type field
  is needed because each HC scheme supported by this specification
  defines multiple packet types, for example "full header" packets,
And 5.3:

5.3 Encapsulation of Header Compressed Packets

  The PW control word is used to identify the packet types for IPHC
  [RFC2507], cRTP [RFC2508], and ECRTP [RFC3545], as shown in Figure 4:

                                    1
                0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
              +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              |0 0 0 0|Pkt Typ|  Length  |Res|
              +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 4 - PW Control Word

  where:

  "Packet Type" encoding:
  0: ROHC Small-CIDs
  1: ROHC Large-CIDs
  2: FULL_HEADER
  3: COMPRESSED_TCP
                  :
                  :

This is a 16-bit "Word" rather than the 32-bit length one typically considers a "Word." RFC 4385, which defines how MPLS PW Control Words are to be specified, states that an MPLS Control Word MUST follow the format in Figure 1 of said document, and SHOULD follow the format in Figure 2. The HC PW completely dismisses the SHOULD, which I suppose is acceptable, but it is also dismissing the MUST as control words clearly need to be the size of a 32-bit word based on what we see in that document.

When the WG defined the Control Word in RFC4385, it tried hard to make it possible for future PWs to include things like a "Channel Type" and such multiplexed into the PW. You will see in Figure 5 of RFC 4385 that there is a Control Word defined explicitly for carriage of an "Associated Channel" to the PW - the case it was defined for was for carrying OAM (VCCV) packets associated with a given PW. Perhaps the WG could consider using this format, though I am afraid that the large number of "Reserved" bits would give someone paranoid about header sizes heartburn.

At a minimum, this is going to require consensus from the PWE3/MPLS community to allow a 16-bit "Control Word" into the PW ranks. If approved, an explicit acknowledgment of the deviation from RFC4385 would be in order in this document (with perhaps an RFC4385-bis in the works for the MPLS/PWE3 folks as well).

- Mark

PS. It would also be *much* clearer if this document referred to the new control word it is defining as the "HC PW Control Word" rather than just "PW Control Word" - people use the latter to refer to the canonical control word in figure 2 of RFC4385
2007-01-24
08 Cullen Jennings Version 6 of this document was WG last called in AVT, MPLS and PWE3 on the 4th of May.
2006-09-07
08 Cullen Jennings [Note]: 'PROTO Shepherd is Colin Perkins<br>' added by Cullen Jennings
2006-09-07
08 Cullen Jennings
2006-09-07
08 Cullen Jennings State Change Notice email list have been change to avt-chairs@tools.ietf.org, Andy.Malis@tellabs.com, jameshand@att.com, gash@att.com, townsley@cisco.com, townsley@cisco.com from avt-chairs@tools.ietf.org
2006-09-07
08 Cullen Jennings State Changes to AD Evaluation from Publication Requested by Cullen Jennings
2006-09-07
08 Mark Townsley Mark Townsley agreed to review and/or delegate review.
2006-07-10
08 Dinara Suleymanova
PROTO Write-up

> 1.a) Have the chairs personally reviewed this version of the ID and
> do they believe this ID is sufficiently baked to …
PROTO Write-up

> 1.a) Have the chairs personally reviewed this version of the ID and
> do they believe this ID is sufficiently baked to forward to
> the
> IESG for publication?

Yes.

> 1.b) Has the document had adequate review from both key WG members
> and key non-WG members? Do you have any concerns about the
> depth or breadth of the reviews that have been performed?

The document has had extensive reviewed in AVT, and follows from an
earlier requirements effort [RFC 4247]. I have no concerns.

> 1.c) Do you have concerns that the document needs more review
> from a
> particular (broader) perspective (e.g., security, operational
> complexity, someone familiar with AAA, etc.)?

I have no concerns. The document has been reviewed by the PWE3, ROHC
and MPLS working groups, in addition to AVT.

> 1.d) Do you have any specific concerns/issues with this document
> that
> you believe the ADs and/or IESG should be aware of? For
> example, perhaps you are uncomfortable with certain parts
> of the
> document, or have concerns whether there really is a need for
> it, etc. If your issues have been discussed in the WG and the
> WG has indicated it wishes to advance the document anyway,
> note
> if you continue to have concerns.

I have no technical concerns.

> 1.e) How solid is the WG consensus behind this document? Does it
> represent the strong concurrence of a few individuals, with
> others being silent, or does the WG as a whole understand and
> agree with it?

There is reasonable consensus.

> 1.f) Has anyone threatened an appeal or otherwise indicated extreme
> discontent? If so, please summarise what are they upset
> about.

No.

> 1.g) Have the chairs verified that the document adheres to _all_ of
> the ID nits? (see http://www.ietf.org/ID-Checklist.html).

Yes, although idnits 1.103 erroneously gives a missing reference
warning (which has been reported as a bug).

> 1.h) Does the document a) split references into normative/
> informative, and b) are there normative references to IDs,
> where
> the IDs are not also ready for advancement or are otherwise in
> an unclear state? (Note: the RFC editor will not publish an
> RFC
> with normative references to IDs, it will delay publication
> until all such IDs are also ready for publication as RFCs.)

References have been split. There is an incorrect normative reference
to the draft on "PWE3 Control Word for use over an MPLS PSN", which
should refer to RFC 4385.

> 1.i) For Standards Track and BCP documents, the IESG approval
> announcement includes a writeup section with the following
> sections:
>
>
> * Technical Summary

This specification defines how to use Multi-Protocol Label Switching
(MPLS) to route Header-Compressed (HC) packets over an MPLS label
switched path. HC can significantly reduce packet-header overhead
and, in combination with MPLS, can also increases bandwidth
efficiency and processing scalability in terms of the maximum number
of simultaneous compressed flows that use HC at each router). Here
we define how MPLS pseudowires are used to transport the HC context
and control messages between the ingress and egress MPLS label
switching routers. This is defined for a specific set of
existing HC
mechanisms that might be used, for example, to support voice over
IP.
This specification also describes extension mechanisms to allow
support for future, as yet to be defined, HC protocols. In this
specification, each HC protocol operates independently over a single
pseudowire instance very much as it would over a single
point-to-point link.

> * Working Group Summary

This draft has been in development for several years, with the
initial proposal being refined significantly in the course of the
discussion, to provide a solid framework for header compression over
MPLS pseudo-wires.

> * Protocol Quality

This draft is a product of the AVT working group, with input from
MPLS, ROHC and PWE3. Extensive working group last call comments were
provided by Kristofer Sandlund and Eric Gray. PROTO write-up by Colin
Perkins.
2006-07-10
08 Dinara Suleymanova Draft Added by Dinara Suleymanova in state Publication Requested
2006-05-31
07 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-07.txt
2006-05-25
06 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-06.txt
2006-05-03
05 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-05.txt
2006-03-07
04 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-04.txt
2006-02-13
03 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-03.txt
2005-12-28
02 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-02.txt
2005-09-27
01 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-01.txt
2005-08-10
00 (System) New version available: draft-ietf-avt-hc-over-mpls-protocol-00.txt