Subject: [Sip] About maintaing reliable connections according to bis05

From: [email-masked]
Date: Fri, 7 Dec 2001 11:34:28 +0530

Hi,
bis-05 states under "section 19 on TRANSPORT" as below

"It is RECOMMENDED that connections be kept open for some implementation
defined time after the last message
was sent or received over that connection. This time SHOULD be at least 16
seconds in order to ensure with
high probability that responses can be sent over the same connection a
request was sent."

This recomendation will have problems with the clients already implemented
according to RFC2543.
These clients will see the connection closure as Server Error which is not
desirable, when there are transactions initiated
by them are still not complete.

backword compatibility is lost because of this recommendation,
Suggestion is that "this recommendation must be applicable only on the
transactions that have been completed."

can this be clarified in the forthcoming drafts as suggested?

with regards,
Shetti

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---

From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 19 Dec 2001 15:59:54 -0500

> transactions that have been completed."

No. The point of the 16s is to guarantee exactly this. Thats why it says 
" ensure with high probability that responses can be sent over the same 
connection a request was sent.".

However, we absolutely do not want to say to wait until all transactions 
have been completed, since this requires coupling of transport layer 
behavior with transaction behavior, and is an unholy nightmare to 
implement properly. A timer captures the essence of the requirement 
without the hassle.

I will, though, clarify that the timer is aimed at ensure transactions 
complete over the same connection, since its not just responses, but ack 
(for non-2xx) that you want over that connection.

-Jonathan R.

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