Hi Taisto,
Timer C simply makes sure that things end eventually. If it takes too long,
the UAC can CANCEL the process at any time. Each INVITE client transaction
has its own timer C associated with it ("Timer C MUST be set for each client
transaction when an INVITE request is proxied"). So a series of attempts
trying a list of IP addresses from DNS (as you describe) would start a timer
C for each.
Regards,
Jeroen
----- Original Message -----
From: "Taisto Qvist" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, September 07, 2005 8:17 AM
Subject: [Sip-implementors] restarting timer c on failures
Hi folks,
The rfc says to restart timer C on every provisional response received,
but what about the failures according to rfc3263.
Chapter 4.3 says that on fatal transport error, or reception of a 503,
or txntimeout w/o any provisionals, one should create a new txn and
send the request to the next server selected from the DNS-data available.
Do I update Timer C, when I create this new txn?
If I do, this could keep a proxy going for a very long time, if a lot of
the servers dns is pointing to, answer very slowly with 503s. Or just a
lot of consequtive transaction timeouts to each server in the DNS-list.
Naturally it would require a big list of choices in the DNS, since txns
timeout after normally 32s, but I always saw the timer C as a protection
for making sure the proxy doesnt keep trying to long, so I wouldnt want to
restart it in these
cases.
Regards
Taisto Qvist
IP-Solutions AB
_______________________________________________
Sip-implementors mailing list
[email protected]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
_______________________________________________
Sip-implementors mailing list
[email protected]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
