Subject: RE: [Sip] Manyfolks: e2e meaning

From: "Chen, Xin (Xin)" <[email-masked]>
Date: Fri, 15 Mar 2002 10:53:43 -0000

Agree! I think the e2e is really useless here. The impression I got from the
manyfolks draft is that the only way you can get end to end is using RSVP,
because getting a RSVP RESV message is the detection point that end to end
is achieved. What happen that one terminal uses RSVP and another terminal
uses a protocol called "banana" to do end to end? for sure, this will not
work in manyfolks. Therefore, the e2e here simply mandates that it works
only if both terminals using the same QoS reservation protocol. 
So my suggestion is to change the "e2e" parameter to "rsvp", then all the
SIP terminal will have to implement RSVP and we all get end to end QoS.

By the way, manyfolks says:

		"B receives RESV messages conforming the reservation." 

This is WRONG. Any router will route RESV packets even it is not rsvp aware,
don't be cheated when getting the RESV message! Therefore, the "e2e" just
gives the terminal a chance to be cheated, a terminal can never be sure
whether the end to end QoS achieved unless you are in charge of the RSVP
admission control for all the routers in the path between UAC and UAS, in
other words, all the routers on the path are in your local network, in
another words "e2e" = "local". So, please not to introduce any status type
in manyfolks, they just can not achieve what they want to achieve. 

Xin Chen

Lucent Technologies
Tel: +44 1793 883137
Mobile: +44 7799 034668

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: 15 March 2002 8:18
To: [email-masked]
Cc: [email-masked]
Subject: [Sip] Manyfolks: e2e meaning

Hello,

In manyfolks-05, it is said that "status type: ...: The end-to-end status
reflects the status of the end-to-end resource reservation"
In fact, end-to-end means that both end-users will exchange end-to-end some
messages using some protocol in order to reserve resources (this could be
added for clarification, as it is never said in the draft).

My question: Does "end-to-end" mean here RSVP ?
If the answer is yes, this is not a very future safe approach for the SDP
extensions, as other protocols could be defined also.
If the answer is no, how can I know which protocol will be used for
end-to-end resource reservation ?

Best regards
Juan Carlos

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_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

---

From: Brian Williams <[email-masked]>
Date: 15 Mar 2002 22:11:12 +1100

Hi.
> SIP terminal will have to implement RSVP and we all get end to end QoS.
I would not agree with chaging e2e to be RSVP. This would mean the
manyfolks draft needs to be updated every time a new protocol is
created. Manyfolks should not depend on the actual protocol in use.

It would work if A uses RSVP and B uses "banana", as long as there is
some point within the network where RSVP interworks with "banana". If
there is no interworking, then of course the qos preconditions will not
be met because there will be no reply to the RSVP (or the "banana").
/brian