Subject: [MMUSIC] RE: [Sipping] What role (if any) for IMS/SIP in a StreamingService:IMS/SIP - RTSP interworking

From: "Pascal Dore" <[email-masked]>
Date: Wed, 2 Nov 2005 13:47:03 -0500

Hi Henry,

I completely agree with what you're saying.

The only point I intend to do was that currently, it seems that there is
an ongoing effort to standardize the Content-On-Demand delivery and
control mechanisms which can be RTSP, SIP with RTSP or anything else
because there is a need for that in every market space (DSL, Cable,
Satellite, ...).  

My opinion is that an agreement like RFC 3113 (3GPP-IETF Standardization
Collaboration) should be extend between all other stakeholders before
each walled garden goes too far in their own requirements &
specifications to be effectively sure that new specifications will be
_OPEN_ and interoperable. 

Thanks,

Pascal.D

________________________________

From: [email-masked] [mailto:[email-masked]] On
Behalf Of Henry Sinnreich
Sent: 2 novembre 2005 12:17
To: Pascal Dore; [email-masked]; [email-masked];
[email-masked]
Subject: RE: [Sipping] What role (if any) for IMS/SIP in a
StreamingService:IMS/SIP - RTSP interworking

Since the IETF works for the _OPEN_ Internet, there seems to be no
rationale in a partnership with organizations that promote walled
gardens, such as 3GPP or Packet Cable. Closed systems can deploy
anything they want.

It would be regrettable IMHO if the IETF would legitimize walled gardens
in any shape or form, since they are the very opposite of the Internet.
There is no way to gloss over this fact.

Thanks, Henry

________________________________

From: [email-masked] [mailto:[email-masked]] On
Behalf Of Pascal Dore
Sent: Tuesday, November 01, 2005 12:34 PM
To: [email-masked]; [email-masked]; [email-masked]
Subject: RE: [Sipping] What role (if any) for IMS/SIP in a Streaming
Service:IMS/SIP - RTSP interworking

Hi Steven,

Maybe this link could be interesting to look:

Internet Streaming Media Alliance:

http://www.isma.tv/ <http://www.isma.tv/> 

I think there is a need for a partnership between IETF, 3GPP, Packet
Cable 2.0 effort and ISMA for that particuliar service definition of
Content-On-Demand.  Same kind of work that have been done to define the
IMS architecture. ISMA could be the place to drive this requirement (NGN
Streaming Services Architecture) with links to other working groups.

- Pascal.D

________________________________

From: [email-masked] [mailto:[email-masked]] On
Behalf Of [email-masked]
Sent: 1 novembre 2005 11:49
To: [email-masked]; [email-masked]
Cc: [email-masked]
Subject: [Sipping] What role (if any) for IMS/SIP in a Streaming
Service: IMS/SIP - RTSP interworking

Is there a prevailing view in the IETF/SIP/MMUSIC community on what role
(if any) IMS/SIP should play in a NGN (Video) Streaming Services
architecture? Or alternatively, how should IMS/SIP interwork (if at all)
with RTSP for streaming services in an NGN architecture?

Most discussions of Streaming Services use RTSP as the signaling
protocol (e.g., 3GPP's PSS architecture). But RTSP alone dosen't bring
with it all the supporting infrastructure that IMS does (nor should it).
Because IMS is SIP-based, and becuse SIP is oriented toward "interactive
communication" services, does that preclude IMS from being used for
streaming services like video on demand or pay-per-view TV?

At a minimum, IMS brings with it:

            - an authentication/authorization framework & assoc
standards

            - an accounting framework & assoc standards

            - a network resource management scheme (at least for QOS
authorization & CAC)

            - and of course a session setup/management protocol

If I want to deploy a commercial VOD service, I'd like support for this
functionality as well. If I'm designing a 'next-generation' services
architecture, a logical question is: Can I use my IMS infrastrcture for
my "communication" services as well as my "streaming" services? And if
so how? How does RTSP fit into an IMS world?

Here's the problem:

            IMS alone, isn't enough for Streaming services, because I
need a stream control protocol (RTSP) to provide start, pause, skip,
stop, etc control. RTSP alone isn't sufficient because I need
infrastructure for authentication, authorization, accounting, resource
management, etc. (Stuff I get with IMS).

A combination of IMS/RTSP seems like it could be made to work, but there
appears to be overlap in the session setup-signaling. In the most
straightforard approach you could for example first use SIP to establish
a session between a client and server -- exchanging SDP that describes
the media streams AND the control stream (rtsp), then followup with an
RTSP session that again proceeds through the "setup phase" and on to
playing and media control. The redundancy is in the duplication of the
"session setup" that occurs.

Is there a consensus view on if/how these two should interwork? Am I
barking up the wrong tree here? Just totally confused? 

One approach that appeals to me is to use IMS/SIP to establish the
session (and all is associated baggage -- AAA, resource management,
media negotiation) and then use RTSP as a kind of "application layer"
control protocol that would be used to manage the media stream (but not
necessarily be used to set it up, since IMS would have already done
that). A similar type of two layer control design might also make sense
for gaming applications.

Thoughts? Insights?

My apologies if this question is well known by all but me, but alas I've
found scant discussion of it on the web and in recent mailing list
archives -- perhaps I'm looking in the wrong place.  

Thanks,

-Steve

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