-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Kyzivat (pkyzivat) Sent: Friday, August 11, 2006 12:18 PM To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: [Sip-implementors] Incrementation of Cseq inside dialogs
[EMAIL PROTECTED] wrote: > From: sudhagar NAGARAJAN <[EMAIL PROTECTED]> > > Can anyone clarify whether Cseq is always incremented by 1 inside a > dialog? for all new requests inside the dialog. > > At some place in the RFC, it says that the CSeq should be incremented > by 1. > > But -- if the UA incremented the CSeq by more than 1, the other UA > would behave the same way, as it is required to presume that an > intermediate request had been lost by the network. > > But -- incrementing the CSeq by more than 1 would not be useful, and > would tend to consume the available CSeq space. Admittedly, a dialog > has a minimum of 2^31 (IIRC) CSeq numbers available, but if the UA > decides to increment by 2^28, it might run out of numbers. The received CSeq can increase by more than one due to lost messages. Will the lost messages not create a problem for the dialog? If client is using UDP, it will keep retransmitting that request and the transaction layer will return a 408 response which will create the dialog to be terminated. So how does UAC send another request on that dialog with higher cseq? Cases where I have seen received Cseq at UAS increasing by 1 is when a proxy in route list, authenticates that request. Sanjay. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
