Subject: Another draft liaison to SG15: Call/Connection Separation

From: "Adrian Farrel" <[email-masked]>
Date: Thu, 29 Mar 2007 15:53:41 +0100

Hi,

A small liaison just to close down on a technical point.

Comments by end of Tuesday 3rd April, please.

Adrian and Deborah

===

To: ITU-T SG15
Cc: Stephen Trowbridge; Kam Lam; Ross Callon; Dave Ward; Scott Bradner
Subject: Call/Connection Separation in ASON and GMPLS
For Comment
Deadline: 11th May 2007

The CCAMP working group of the IETF thanks you for your liaison "Liaison

Statement to CCAMP responding to ccamp liaison of 21 February 2007"
(Q14/15 - LS 1 - E) dated March 2007.

This liaison continues a discussion on the logical separation of calls and
connections. The substance of this conversation is as follows:

SG15 to CCAMP
COM 15 - LS 126 - E dated November 2006
     1. Call/Connection architecture and realization approaches
         Attachment 2 below provides further elaboration of application
         scenarios that illustrate G.8080 call/connection control
         component interactions.  The G.8080 architecture may be
         employed to support various call control realization
         approaches.  It should be noted that the architecture does not
         dictate any particular implementation and we would request that
         any solution not impose such limitations.  We observe that
         Section 3.2 of <draft-ietf-ccamp-gmpls-rsvp-te-call-01.txt>
         explicitly prohibits logical call/connection control
         separation; i.e., call communications "piggy-backing" on
         connection communications.

CCAMP to SG15
Dated 21st February 2007
     Regarding your comments on 2.0
     It is important to recognize that [this draft] introduces Call
     mechanisms into GMPLS as a generic tool. As noted in
     Section 2, while the mechanisms of this document meet
     the requirements in RFC 4139, they are intended to have
     wider applicability than ASON. RFC 4139 details the
     requirements for ASON.

     The application of the GMPLS Call to the ASON
     architecture in order to satisfy the requirements for
     conveying ASON Call information across a GMPLS
     interface and for managing ASON Calls at a GMPLS UNI or
     GMPLS ENNI will require a new Applicability Draft.

     Thus, section 3.2 of this document does not imply
     anything about ASON, and certainly not that ASON
     requires full and logical call/connection separation.

     We understand that ASON Calls may be implemented
     through full call/connection separation (as in
     G.7713.3) or call/connection 'piggybacking' as in
     G.7713.2. Please confirm that our interpretation of
     G.8080 and G.7713 is correct.

SG15 to CCAMP
Q14/15-LS1-E dated March 2007
     Regarding call and connection separation the liaison states:
     "We understand that ASON Calls may be implemented
     through full call/connection separation (as in G.7713.3) or
     call/connection 'piggybacking' as in G.7713.2. Please
     confirm that our interpretation of G.8080 and G.7713 is
     correct."  ASON requires full logical separation of the call
     and connection which may be implemented with separate
     or piggybacked call and connection signalling.

We would like to complete this discussion by reiterating that
draft-ietf-ccamp-gmpls-rsvp-te-call-04.txt defines mechanisms that
provide full and logical Call/Connection separation. Your initial
interpretation of section 3.2 of draft-ietf-ccamp-gmpls-rsvp-te-call-01.txt
was incorrect and the text states now (and stated then) that "Full and
logical Call and Connection separation is required."

If you have any further concerns about how call and connection separation is
achieved in this work, please do not hesitate to contact us.

Best regards,
Adrian Farrel and Deborah Brungard
Co-chairs, IETF CCAMP working group