RFC 3261 section 17.2.3 discusses transaction matching using Via branch and sent-by. It also discusses importance of sent-by to avoid "accidental or malicious duplication"; however it might only protect against "accidental" duplication since RFC indicates to use Via sent-by instead of Via received.
> -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of VYANKTESH TADKOD > Sent: Tuesday, February 03, 2009 4:10 AM > To: [email protected] > Subject: [Sip-implementors] Question on Branch parameter usage > > Hi All, > > I am straightaway jumping to the question here > > If there are 2 UA (UAC's) talking to another UA (UAS) ... > > a> can both the UAC's use the same branch parameter value in the via > header at the same time across different SIP message(s) ? > > I have a situation where one UA is sending a branch value say A in the > top via header of the BYE message and after let say 3-4 sec later I have > a INVITE message from another UA with the top via header having the same > branch value A. Is this correct? Pls advice. > > b> In the same context, if the BYE is received by a UA, should the UA > (underlying SIP stack) respond to BYE and immediately remove it from > transaction table? I see that few of the SIP stack remove the > transaction immediately from the transaction table and few of the stack > keep the transaction for few secs (~32 sec) before they remove it from > the transaction table. > > Few questions > > 1> What is purpose of keeping the transaction data (i.e branch ID) > in transaction table once the BYE is processed? > > 2> Is there any standard which mentions about how long it should > keep the transaction in the table after it has processed BYE? > > > > > > Thanks and Regards > > -venkat > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
