Subject: [Sip] Manyfolks: the segmented approach

From: [email-masked]
Date: Fri, 15 Mar 2002 09:38:32 +0100

Hello,

The segmented approach defines two tags: local and remote. Are they both
really needed ?
I have the feeling that a single value should be enough, let's say "local".

For the desired-status, you only need to say "I'm using the segmented
model", that is, I will not send you e2e resource reservation messages, and
therefore each of us has to solve the reservation question independently in
its own access network.

For the current-status, using a single value means: when I send a
current-status, I'm telling you about what *I did* in *my* access network
for resource reservation. When I receive a current-status, I'm learning
what *you did* in *your* access network for resource reservation.

By the way, the example in section 9 seems to me a little bit strange. I
agree that you can have several preconditions on the same media stream
(even if for complexity reasons, I guess that most people will use only one
precondition), but can you still use at the same time the e2e approach
*and* the segmented approach for the same media? Can you please explain me
how this can work ?

Best regards
Juan Carlos

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From: Gonzalo Camarillo <[email-masked]>
Date: Fri, 15 Mar 2002 19:27:44 +0200

Hi,

inline:

> I have the feeling that a single value should be enough, let's say "local".

Yours is a valid point of view. However, the point of view of the draft
is slightly different. Let's say that I am in a 3G network. I know that
the backbone is not a problem, but the radio interface is. Therefore, I
want the callee to establish the proper PDP context for this call. I can
ask him to do that by using the remote tag.

In the next call I migh care only about my access, but it is OK if the
callee does not reserve resources in his access network. In this case,
as you suggest, you would only need the local tag.

Therefore, your proposal would cover the second call, but not the first.
And I believe that I have the right to say that if the other end does
not reserve resources in his access I do not want to talk to him... you
could claim, that the other end could tell you that he has reserved
resources when he ha not really done so, but, as I said, that would be a
non-compliant UAS.

> *and* the segmented approach for the same media? Can you please explain me

For example, I want to make sure that there are enough resources in the
access networks (where the bottlenecks typically are), and I would find
desirable, although not essential, to have resources in the backbone as
well.

Regards,

Gonzalo

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