Hi Pranab, As per RFC 3261- section 12.2.1.1 Generating the Request Requests within a dialog MUST contain strictly monotonically increasing and contiguous CSeq sequence numbers (increasing-by-one) in each direction (excepting ACK and CANCEL of course, whose numbers equal the requests being acknowledged or cancelled). Therefore, 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.
In your scenario,A sends Invite to B to keep B on hold with Incremented CSeq. Regards, Alok Tiwari Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of pranab sahoo Sent: Thursday, May 10, 2012 5:00 PM To: sip-implementors Subject: [Sip-implementors] query in sip Hi all, I have a doubt on cseq. Lets consider a case INVITE A---------------------->B 180 Ringing A<----------------------B 200ok A<---------------------->B again A sends Invite to B to keep B on hold. IS in this case there is increment in cseq value or it will same as previous one? What will be cseq value if B sends Invite to A? In RFC 5359 I checked cseq value which remain same in Invite(hold). But in some voip product like Ekiga there is increment in cseq in Invite(hold). Can anybody help in this regards? Waiting for quick clarification. thanks and regards 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
