"P Vinod" <[EMAIL PROTECTED]> wrote: > Hi, > > The following is a quote from section 14.1 of RFC 3261: > > <Begin quote> > > If a UAC receives a 491 response to a re-INVITE, it SHOULD start a > timer with a value T chosen as follows: > 1. If the UAC is the owner of the Call-ID of the dialog ID > (meaning it generated the value), T has a randomly chosen value > between 2.1 and 4 seconds in units of 10 ms. > 2. If the UAC is not the owner of the Call-ID of the dialog ID, T > has a randomly chosen value of between 0 and 2 seconds in units > of 10 ms. > > <End Quote> > > Does anyone know the design logic behind the difference in the timer values?
After the guys wrote the first SIP RFC, RFC 2543, they discovered a "glare" condition, where both sides attempted to alter the session description at the same time. Here's a nice write-up of the problem: http://www.atm.tut.fi/list-archive/sip/msg01970.html Notice how the intervals of the UAC's and UAS's retry times don't overlap? That's to help prevent another glare condition. frank _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
