HI Oviaprasad D, I guess the question was after UAC has sent the RPACK but UAS didn't receive it. The quote "The UAC MAY acknowledge reliable provisional responses received after the final response or MAY discard them." is applicable only before PRACK has been sent meaning, when reliable provisional was received by UAC, it may ack with PRACK. But in this case PRACK has already been sent. Here question remains: what happen to PRACK transaction? I think Initiated transaction must be committed or roll-backed.
Thanks and regards Nabam Serbang -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, December 16, 2008 5:13 PM To: [email protected] Cc: [email protected] Subject: Re: [Sip-implementors] INVITE Behaviour When PRACK is notrespondedwith 2xx Hi Tamal, Please find the quote from RFC 3262 sec 4. "The UAC MAY acknowledge reliable provisional responses received after the final response or MAY discard them." The PRACK is required and to be waited for the 2xx to the PRACK which quoted bellow from sec 5. "If the UAS receives a PRACK with an offer, it MUST place the answer in the 2xx to the PRACK" also "If the UAS had placed a session description in any reliable provisional response that is unacknowledged when the INVITE is accepted, the UAS MUST delay sending the 2xx until the provisional response is acknowledged. Otherwise, the reliability of the 1xx cannot be guaranteed, and reliability is needed for proper operation of the offer/answer exchange" My view point is your question is applicable for sec 4 quote on this email. Regards Oviaprasad D ESN: 6-877-7352 ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, December 16, 2008 3:56 PM To: [email protected] Subject: [Sip-implementors] INVITE Behaviour When PRACK is not respondedwith 2xx Dear all, Could you please let me know the behaviour of UAC in the following scenario (RFC3262 doesn't seem to address this behaviour). Scenario 1: UAC UAS ----INV-------> <---180-------- ---PRACK-----> (Peer didnt respond to PRACK because of some problem) <---200 INV---- ----ACK-------> ----PRACK-----> ?? Should UAC retransmit PRACK ? or Should the PRACK retransmissions stop after receiving 200OK to INVITE? Scenario 2: UAC UAS ----INV-------> <---180-------- ----PRACK-----> (Peer didnt respond to PRACK because of some problem) ----CANCEL----> <---200 CAN---- <---487 INV---- ----ACK-------> ----PRACK-----> ?? Should UAC retransmit PRACK ? or Should the PRACK retransmissions stop after receiving 487 to INVITE? Thanks & Regards Tamal Tanu Biswas Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
