On Oct 19, 2011, at 8:18 PM, Kevin P. Fleming wrote: > On 10/19/2011 12:50 PM, Pavesi, Valdemar (NSN - US/Irving) wrote: > >> The 100-trying will be used to stop the timer T1 (500MSEC) , If any >> subsequent response 18x will take longer than 500msec than 100trying >> will >> Be send back to stop the timer T1. Check the timestamp when 180ringing >> was send. > > This is incorrect; Timer T1 is just a base value for other timers, it > never 'fires' on its own. It would be completely impractical to require > a provisional response to appear before Timer T1 expired (and thus cause > a retransmission). > > The '100 Trying' response (or any other provisional response) stops > Timer B, which defaults to 64 * Timer T1 (so nominally it is 32 seconds). >
IIRC timer B is set for transaction timeout. Timer A controls request retransmissions, and in case of an unreliable transport it defaults to T1. -- Saúl Ibarra Corretgé AG Projects _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
