> While sending BYE for the initial INVITE is prohibited > by RFC 3261 before an ACK is received, I guess this > does not hold for RE-INVITEs since the dialog is > already established. Is this correct, as re-invites > are not mentioned at all in sec. 15?
RFC 3261 does not generically require the called party to wait for ACK before sending re-INVITE. However if the 2xx contains an offer SDP, you should wait for the ACK containing the answer SDP before generating another offer. If called party is unsure that the caller is aware of the dialog, waiting for ACK avoids re-INVITE 481 response caused by race conditions and dropped packets. If you want to avoid receiving a 500 or 491 response, waiting for ACK may be desirable when interworking with some devices. See RFC 5407 sections 3.1.4, 3.1.5, 3.3.1 and 3.3.2 for these and other race conditions. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
