Normally in B2B UA (which follows the sip standard), there is a 32 seconds timer which kicks in while waiting for ACK. If ACK isn't received, the call is terminated with a BYE. I've seen a BYE getting terminated with 481 (doesn't exists) ;
Some B2B agents have a small timer on top of the normal 32 seconds timer to disconnect the call (especially for ACME products); -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of ext Manolis Katsidoniotis Sent: Wednesday, February 11, 2015 12:24 PM To: sip-implementors Subject: [Sip-implementors] ACK issue Hello folks My apologies if this has been asked in the past but is this call flow correct? B2BUA IMS B2BUA | | | ------> | ------> | | INVITE | INVITE | | | | | | | ------> | ------> | | INVITE | INVITE | | | | | <------ | <------ | | 200OK | 200OK <------ | <------ | | 200OK | 200OK | | | | | (retransmit) | | | 200OK (INV) | | | | | | (ACK timeout) | | <------ | <------ | | BYE | BYE <------ | <------ | | BYE | BYE | | | | | ------> | ------> | | 200OK | 200OK | | | | ------> | ------> | | 200OK | 200OK | | | | <------ | <------ | ??????? | 200OK(INV) | 200OK(INV) | | | | | | | | | | | | | I think it's an error but I'm getting confused from the rfc ... The UAS MUST still respond to any pending requests received for that dialog. It is RECOMMENDED that a 487 (Request Terminated) response be generated to those pending requests. 2nd question If the B2BUA sends BYE and then incorrectly repeats the 200 for INVITE should IMS forward it? thanks Manolis _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
