Hi
If you intended to ask whether UAS can send another reliable provisional response before receiving PRACK for the previous one, the answer is negative. Following text on Pg 5 of RFC 3262 will help: After the first reliable provisional response for a request has been acknowledged, the UAS MAY send additional reliable provisional responses. The UAS MUST NOT send a second reliable provisional response until the first is acknowledged. After the first, it is RECOMMENDED that the UAS not send an additional reliable provisional response until the previous is acknowledged. The first reliable provisional response receives special treatment because it conveys the initial sequence number. If additional reliable provisional responses were sent before the first was acknowledged, the UAS could not be certain these were received in order. Regards Rohit Aggarwal Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Radha Krishna Sent: Monday, January 19, 2009 11:31 AM To: [email protected] Cc: [email protected] Subject: [Sip-implementors] Doubt About Prack..... Hi, Can anyone pls clarify the following call flow doubt? UAC UAS --------------INV-----------> STEP1 <-------------100----------- STEP2 <-----180(with 100rel) ----- Rseq: 1 STEP3 --------------Prack----------> RACK 1 STEP4 <-----180(with 100rel) ----- Rseq: 2 STEP5 --------------Prack----------> RACK 2 STEP6 Questions: 1. Is it possible that UAS can send an 180 with Rseq 2(STEP5) before receiving final response for 1st PRACK (STEP4) 2. If STEP5 is possible then can UAC send one more PRACK request (STEP6) with RACK2? Thanks, RadhaKrishna _______________________________________________ Sip-implementors mailing list [email protected] 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 [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
