Liaison statement
Interim Comments on IETF PhoneBCP Draft

State Posted
Submitted Date 2009-07-21
From Group 3GPP
From Contact Susanna Kooistra
To Group IETF
To Contacts
Purpose For information
Attachments (None)
3GPP TSG SA WG2 Meeting #74                     S2-094882
06 – 10 July, 2009, Sophia Antipolis, France

Title:  Interim Comments on IETF PhoneBCP Draft

Source: 3GPP TSG SA WG2
To:     Hannes Tschofenig (, Chairman IETF Ecrit
        Marc Linsner (, Chairman IETF Ecrit
        Cullen Jennings (, IETF Real-time Applications and
        Infrastructure Area Director
Cc:     IETF Ecrit Working Group
        3GPP TSG CT WG1

Contact Person:
Name:   Stephen Edge
Tel. Number:    +1-858-651-6234
E-mail Address:

Attachments:    none

1. Overall Description:
3GPP TSG SA WG2 along with 3GPP TSG CT WG1 were requested by the TSG CT Chair
on behalf of IETF Ecrit on May 6 to provide any feedback on the issue of
applicability of the phoneBCP draft to a cellular environment. The immediate
issue at the time was inclusion of an applicability statement in the draft but
we assume that the question of applicability itself would also be of concern.

The Email request was as follows:

From: Hannu Hietalahti [mailto:hannu.hietalahti@NOKIA.COM]
Sent: Wednesday, May 06, 2009 4:48 AM
Subject: Question on draft-ietf-ecrit-phonebcp

Dear CT1, SA2,

in the 3GPP - IETF telco earlier this week a question was brought up on whether
the phonebcp IETF draft could be applicable on cellular systems or not:

We have got no dependency from 3GPP specifications and I am not saying that we
should have. In the 3GPP - IETF telco I promised to ping the 3GPP groups
working in the area of VoIP and emergency calls just in case someone might be
able to help in this question.

The question seems to be whether it would be justified or not to restrict the
applicability area of the draft by excluding the use of it in cellular
environment. Even if we are currenlty not directly referencing to the draft,
for me it sounds a bit odd if IETF needs to start categorising SIP extensions
to those that are applicable in cellular environment and to those that are not.

If you think you can help to solve this, please keep the CC'd Cullen Jennings
and Hannes Tschofenig in the discussion.

Hannu Hietalahti
3GPP TSG CT Chairman
tel: +358 40 5021724

Up to this point, there have been no comments on the SA WG2 Email reflector and
no meeting contributions on this issue. But the work items within SA WG2 that
could normally address comments related to this and to which any contributions
might have been directed are not on the agenda in this SA WG2 meeting and hence
a definitive response is not possible at this time. However, the subject areas
are back on the agenda in our next meeting on August 31 to September 4.

We therefore plan to provide a definitive response to IETF Ecrit from our next
meeting and hope that this may be of use in completing this draft.

2. Actions:
3. Date of Next TSG-SA WG2 Meetings:
TSG-SA2 Meeting #75     31st Aug – 4th Sep 2009 Kyoto, Japan
TSG-SA2 Meeting #76     16th – 20th November 2009       San Jose Del Cabo,