Hello, On Mon, Aug 07, 2017 at 04:52:23PM -0700, NK wrote:
> 1) Is that really mandatory to send ACK for 200 OK to start the call? > Because once my switch sent the 200 OK then logically the billing is > started from my end, doesn't matter whether I received ACK or not? Without an end-to-end ACK from the caller, it will be terminated after 64*T1 seconds by the callee (as a practical matter, 32 seconds in most implementations). So, yes, sending the end-to-end ACK to fully confirm the session is mandatory. > 2) Even though if my understanding is not correct on point 1, but then > client UA replied to BYE message immediately then how my switch will > treat this, is that treat this as a connected call with duration? How this should be treated from a billing perspective is a matter of some philosophical debate. The call is answered with the 2xx reply, and two-way media flows are possible henceforth, so my inclination is to say that yes, this is a connected call with billable duration. > 3) Do we have any document, I did research but cannot find any clear > document who can state this along with 5407 etc. Not sure what you are referring to here, but RFC 3261 ยง 13.2.2.4 is quite clear on this subject: The UAC core MUST generate an ACK request for each 2xx received from the transaction layer. -- Alex -- Alex Balashov | Principal | Evariste Systems LLC Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/ _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
