Hi Priya , Session timer is restarted for each update request.
Regards, Sumit Jindal On Mon, Nov 8, 2010 at 10:48 AM, Tarun2 Gupta <tarun2.gu...@aricent.com> wrote: > > Hi Priya > > IMO, the version number in the 'o' line of SDP can be used to determine > whether the SDP is a new offer or a session refresh request. > > Consider the following excerpt from RFC 3264, > > Modifying the Session > > The offer MAY be identical to the last SDP provided to the other > party (which may have been provided in an offer or an answer), or it > MAY be different. We refer to the last SDP provided as the "previous > SDP". If the offer is the same, the answer MAY be the same as the > previous SDP from the answerer, or it MAY be different. If the > offered SDP is different from the previous SDP, some constraints are > placed on its construction, discussed below. > > Nearly all aspects of the session can be modified. New streams can > be added, existing streams can be deleted, and parameters of existing > streams can change. When issuing an offer that modifies the session, > the "o=" line of the new SDP MUST be identical to that in the > previous SDP, except that the version in the origin field MUST > increment by one from the previous SDP. If the version in the origin > line does not increment, the SDP MUST be identical to the SDP with > that version number. The answerer MUST be prepared to receive an > offer that contains SDP with a version that has not changed; this is > effectively a no-op. > > Thus > - If UPDATE is received with SDP having the same version in 'o' line, you can > consider it as a session refresh request. > - If the version number is incremented by 1, consider it as a new offer. > > Regards, > Tarun Gupta > Aricent > > -----Original Message----- > From: sip-implementors-boun...@lists.cs.columbia.edu > [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Priya > Arya > Sent: Monday, November 08, 2010 9:33 AM > To: sip-implementors@lists.cs.columbia.edu > Subject: [Sip-implementors] Identifying Session Refresh UPDATE > > Hi, > > I have one query regarding the Session Refresh UPDATE. > > - Just by looking at PDU of UPDATE in a session, can it be idenitified that > if this UPDATE is for session refresh or for updating the SDP parameters in > the session. > > Actually RFC 4028 recommends the following : > " It is RECOMMENDED that the UPDATE request not contain an offer > [4<http://tools.ietf.org/html/rfc4028#ref-4>], but a re-INVITE SHOULD contain > one, even if the details of the session have not changed." > > But if UPDATE is received from UAS containing SDP in it, then can the session > version number in the "o-line" be used to identify if this UPDATE is for > updating the SDP parameters only. > > Thanks in advance. > > Regards > Priya Arya > > ________________________________ > "DISCLAIMER: This message is proprietary to Aricent and is intended solely > for the use of the individual to whom it is addressed. It may contain > privileged or confidential information and should not be circulated or used > for any purpose other than for what it is intended. If you have received this > message in error, please notify the originator immediately. If you are not > the intended recipient, you are notified that you are strictly prohibited > from using, copying, altering, or disclosing the contents of this message. > Aricent accepts no responsibility for loss or damage arising from the use of > the information transmitted by this email including damage from virus." > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > "DISCLAIMER: This message is proprietary to Aricent and is intended solely > for the use of the individual to whom it is addressed. It may contain > privileged or confidential information and should not be circulated or used > for any purpose other than for what it is intended. If you have received this > message in error, please notify the originator immediately. If you are not > the intended recipient, you are notified that you are strictly prohibited > from using, copying, altering, or disclosing the contents of this message. > Aricent accepts no responsibility for loss or damage arising from the use of > the information transmitted by this email including damage from virus." > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > -- Regards, Sumit Jindal _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
