Subject: [L2tpext] [Fwd: [PWE3] CEP IESG comments]

From: Carlos Pignataro <[email-masked]>
Date: Sun, 12 Nov 2006 21:29:24 -0500

Group,

FYI.

Thanks,

--Carlos.

-------- Original Message --------
Subject: [PWE3] CEP IESG comments
Date: Fri, 10 Nov 2006 19:21:34 +0200
From: Ron Cohen <[email-masked]>
To: <[email-masked]>

Hi,

Please find below resolutions to several comments raised during the IESG
review of the SONET PW draft (draft-ietf-pwe3-sonet-13.txt). Please let
us know of any objections or comments to these resolutions.

The modifications are:

1. Limiting the draft scope to transport of CEP over MPLS and L2TP.
Transport over UDP/IP will be left out of scope of this draft.

One comment concerned the security mechanims needed to support UDP/IP.
To address this we need to include a detailed description of the use of
IPsec, including the mechanisms needed to exchange keys. As far as the
authors have been able to determine, there is no planned use of CEP over
UDP/IP. The authors therefore recommend limiting the draft scope to
transport of CEP over MPLS and L2TP. Transport over UDP/IP will be left
out of scope of this draft and the associated sections removed from the
text.

2. Clarification on the use of RTP for CEP. Clarifications include

- Add the following sentence:

     Although CEP MAY employ an RTP
     header when explicit transfer of timing information is
     required, this is purely formal reuse of the header format.
     RTP mechanisms, such as header extensions, CSRC list, padding,
     RTCP, RTP header compression, SRTP, etc. are not applicable to
pseudowires.

- Change Figure 1 to indicate RTP header location between CEP header and
SONET fragement.
  This is consistent with L2TP and MPLS PSN encapsulation of other TDM
drafts.

                +-----------------------------------+
                |   PSN and Multiplexing Layer      |
                |             Headers               |
                +-----------------------------------+
                |           CEP Header              |
                +-----------------------------------+
                |           RTP Header              |
                |           (RFC3550)               |
                +-----------------------------------+                |
|
                |                                   |
                |           SONET/SDH               |
                |            Fragment               |
                |                                   |
                |                                   |
                +-----------------------------------+

                   Figure 1: Basic CEP Packet

3. Clarifications on security section that include adding the following
sentences:

    Although CEP MAY employ an RTP header when explicit transfer of
timing information
    is required, SRTP [RFC3711] mechanisms are not a substitute for PW
layer security.

    CEP transport over L2TPv3 is subject to the security considerations
discussed in
    section 4.1.3 of [LT2Pv3]. In particular, CEP over L2TP may be
secured using IPsec
    as described in [RFC3193].

If this approach is acceptable to the working group we will forward the
changes to the RFC editor.

Best
Ron (on behalf of CEP Authors)

Ron Cohen
Resolute Networks

_______________________________________________
pwe3 mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/pwe3

-- 
--Carlos Pignataro.
Escalation RTP - cisco Systems

_______________________________________________
L2tpext mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/l2tpext