Hi Pranab, As per RFC-3261, section 12.2.1.1,
If the local sequence number is not empty, the value of the local sequence number MUST be incremented by one, and this value MUST be placed into the CSeq header field. If the local sequence number is empty, an initial value MUST be chosen using the guidelines of Section 8.1.1.5. The method field in the CSeq header field value MUST match the method of the request. In your scenario, - A call is connected from A (originating party) to B (Terminating party), CSeq will be 1. - when A want to send video from one way i.e from A to B, the CSeq will be incremented and it will be 2. - When one way video conversion between A to B,B also wants to make video call from B to A, CSeq can be any arbitrary number. Also, Call-ID remains unique throughout the dialog and it cannot be changed. Regards, Alok Tiwari Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of pranab sahoo Sent: Monday, May 07, 2012 5:32 PM To: [email protected] Subject: [Sip-implementors] issue in sip Hi all, Hope you all doing well. I have a doubt regarding cseq. suppose I made a complete audio call between user A and B without disconnecting call.In this case cseq is 1 INVITE. In middle A want to send video from one way i.e from A to B.so in this case cseq value will be 2 INVITE or 1 INVITE. Again after one way video conversion between A to B,B also wants to make video call from B to A.so what will be the value of Cseq in this case? Again call id value will change or not? waiting for quick reply. Thanks in advance. pranab Brazil _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =============================================================================== _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
