In the current scenario UAC had sent an offer in INVITE and still UAC has not received any answer and UAC created one more offer in PRACK. Now UAC can't send an offer in PRACK until unless it has received an Answer in provisional response, here it is 180. So AFAIK UAC cant send an offer in PRACK in the scenario you have mentioned.
Regards Ajit -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kavita Rai Sent: Thursday, December 01, 2005 11:33 AM To: '[EMAIL PROTECTED]' Cc: Seshu; [EMAIL PROTECTED]; '[email protected]'; Vibhuti V Natraj Subject: RE: [Sip-implementors] Prack Queries Hi thangarajan, Thanks for the reply. Sorry to have mistakenly drawn the sip call flow for the second query. Redrawing it : Q) Section 3 of RFC 3262 mentions "The UAS MAY send a final response to the initial request before having received PRACKs for all unacknowledged reliable provisional responses, unless the final response is 2xx and any of the unacknowledged reliable provisional responses contained a session description." In a scenario the reliable 1xx did not have SDP and we go ahead and send 2xx for Invite without waiting for Prack. What if the Prack for the relaible 1xx we receive has an offer? Invite (SDP)------> <------- 180 (no SDP) <------- 200 Ok for Invite (No SDP) Prack (SDP)------> <------ 200 OK(SDP) By sending the offer in PRACK user wanted to re-negotiate the parameters, but in this case we have already sent 2xx for invite and other side will respond with ACK and the session will be eatablished as per SDP exchange in Invite and 1xx. Hoe does above statement from the RFC take care of this scenario?? Regards, Kavita -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, December 01, 2005 9:10 AM To: Kavita Rai Cc: Seshu; '[email protected]'; [EMAIL PROTECTED]; Vibhuti V Natraj Subject: Re: [Sip-implementors] Prack Queries Hi Kavita, 1) When PRACK times out, Transaction layer: If Timer F fires while the client transaction is still in the "Trying" state, the client transaction SHOULD inform the TU about the timeout, and then it SHOULD enter the "Terminated" state. UAC core: When a timeout error is received from the transaction layer, it MUST be treated as if a 408 (Request Timeout) status code has been received. Action: If the response for a request within a dialog is a 481 (Call/Transaction Does Not Exist) or a 408 (Request Timeout), the UAC SHOULD terminate the dialog. A UAC SHOULD also terminate a dialog if no response at all is received for the request 2) Invite (SDP)------> <------- 180 (no SDP) Prack (no SDP) -----> (no SDP) <-------200 OK for Invite (SDP) Prack (SDP)------> <------ 200 OK(SDP) SIP trapezoid is not clear. In SIP trapezoid there are 2 PARCK [one is with SDP and other is with out SDP]. But only one RPR is there. Regards, Thangarajan. Kavita Rai <[EMAIL PROTECTED] ch.com> To Sent by: "'[email protected]' sip-implementors- " [EMAIL PROTECTED] <[email protected]> ia.edu cc Seshu <[EMAIL PROTECTED]>, Vibhuti V Natraj 11/30/2005 05:17 <[EMAIL PROTECTED]> PM Subject [Sip-implementors] Prack Queries Hi, 1) In a situation where we send 2xx for Invite before receiving Prack for a reliable 1xx which does not have session description and session gets established, how should we handle Prack time out ? Does it affect the connected session? Invite (SDP)------> <------- 180 (no SDP) Prack (no SDP) -----> (no SDP) <-------200 OK for Invite (SDP) ACK------> ---------------------Session Established------------------- Prack---> ... ... Prack TimeOut() happens what happens to the session state or what action should be taken at UAC for Prack Timeout? 2) Section 3 of RFC 3262 mentions "The UAS MAY send a final response to the initial request before having received PRACKs for all unacknowledged reliable provisional responses, unless the final response is 2xx and any of the unacknowledged reliable provisional responses contained a session description." In a scenario where the reliable 1xx did not have SDP and we go ahead and send 2xx for Invite without waiting for Prack. What if the Prack we receive has an offer? Invite (SDP)------> <------- 180 (no SDP) Prack (no SDP) -----> (no SDP) <-------200 OK for Invite (SDP) Prack (SDP)------> <------ 200 OK(SDP) Regards, Kavita Rai, [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors *********************** FSS-Private *********************** "DISCLAIMER: This message is proprietary to Hughes Software Systems Limited (HSS) 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. 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