When you send the CANCEL, won't the branch be the same as in the INVITE? So I can't see what extra advantage is offered by the CSeq. Can you explain.
________________________________ From: Somesh S. Shanbhag [mailto:[email protected]] Sent: 02 March 2009 08:25 To: Attila Sipos; priyank luthra; [email protected] Subject: RE: [Sip-implementors] Branch parameter as transaction identifierv/sCseq CSeq method is used to identify the transaction along with branch, when a CANCEL request is processed. Somesh * Please do not take print out of this e-mail unless its absolutely necessary * -----Original Message----- From: [email protected] on behalf of Attila Sipos Sent: Mon 3/2/2009 1:53 PM To: priyank luthra; [email protected] Subject: Re: [Sip-implementors] Branch parameter as transaction identifierv/sCseq Simply: 1. transaction instance is created and a branch parameter is associated with it 2. the branch parameter is placed into a request 3. response is received with the same branch parameter 4. transaction instance can be destroyed As far as I can tell, you don't need to use CSeq to identify a transaction. I believe branch was not used by UA's in the orignal SIP RFC (RFC2543) so CSeq and Method was originally used to match transactions. However in RFC3261, branch is used by UA's so CSeq is not now needed for transaction matching. Regards, Attila -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of priyank luthra Sent: 02 March 2009 06:50 To: [email protected] Subject: [Sip-implementors] Branch parameter as transaction identifier v/sCseq Hi all, I would like to know why and how is a branch parameter in Via header able to identify a transaction, and if so, why do we need CSeq header to identify a transaction? -- Regards, Priyank _______________________________________________ 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 ________________________________ EMAIL DISCLAIMER : This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Any unauthorised distribution or copying is strictly prohibited. If you receive this transmission in error, please notify the sender by reply email and then destroy the message. Opinions, conclusions and other information in this message that do not relate to official business of Mascon shall be understood to be neither given nor endorsed by Mascon. Any information contained in this email, when addressed to Mascon clients is subject to the terms and conditions in governing client contract. Whilst Mascon takes steps to prevent the transmission of viruses via e-mail, we can not guarantee that any email or attachment is free from computer viruses and you are strongly advised to undertake your own anti-virus precautions. Mascon grants no warranties regarding performance, use or quality of any e-mail or attachment and undertakes no liability for loss or damage, howsoever caused. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
