Liaison statement
LS out Reply to "Reply LS to 3GPP TSG CT4 on support of ECN"

3GPP TSG CT4 Meeting #52	C4-111025
Salt Lake City, US
21st  – 25th February 2011


Title:	LS out Reply to "Reply LS to 3GPP TSG CT4 on support of ECN"
Response to:	LS (C4-110519, COM 16 – LS 203 – E) on Reply LS to 3GPP TSG CT4
on support of ECN from ITU-T Q3/16
Release:	Rel-10
Work Item:	ECSRA_LAA-CN

Source:	3GPP TSG CT4
To:	ITU-T Q3/16
Cc:	TSG CT, IETF AVTCORE

Contact Person:	
Name:	Phil Hodges
Tel. Number:	+61 404069546
E-mail Address:	Philip . hodges @ Ericsson . com

Attachments:	C4-111026


1. Overall Description:
CT4 thanks ITU-T Q3/16 for their reply liaison regarding Explicit Congestion
Notification support in H.248 and is pleased to read that a new WI has been
initiated to develop a solution that can be used by 3GPP.

CT4 has agreed a stage 3 solution which aims to satisfy the requirements in
3GPP Rel-10 but it is envisaged that some additional work will be required to
support interworking to non-3GPP ECN networks.

The attached CR includes the stage 3 solution embodied in two packages
described in Annexes. CT4 is aware that the CR contains a number of errors
which will be corrected in a later revision. The CR was agreed by majority in
order to progress the work but it was not agreed by consensus as it was
questioned whether the solution should be a single H.248 package or as
proposed: a generic package and an additional 3GPP specific package. What is
agreed by consensus is that a single ECN solution (whether it consists of
multiple packages or not) is desired by 3GPP. Hence despite proposing the
second package as a 3GPP package CT4 prefer this being part of a generic ITU-T
solution.

CT4 asks ITU-T Q3/16 if the solution described in 3GPP Annexes can be
developed as a single generic solution, i.e. if the scenarios required by 3GPP
can be solved by the generic package(s) and still support all other
scenarios.

2. Actions:
To ITU-T Q3/16 group.
ACTION: 	CT4 kindly asks ITU-T Q3/16 to consider the CT4 agreed stage 3
solution as input to their generic work on H.248.ECN, consider the above
question and provide CT4 with any output drafts on this work from Q3/16.

3. Date of Next CT4 Meetings:

CT4#53	9th – 13th May 2011		Tallinn, Estonia 
CT4#54	22nd – 26th August 2011		Malta