> Is it OK to include Require header with 100rel > in the re-INVITE, UA1 has already showed that > it supports this extension.
Yes; however you might receive a 420. > Why should UA1 reject this message with 420 response. Among other potential reasons, a B2BUA is involved and re-INVITE reached a different UAS which doesn't support 100rel. And for completeness since you are attempting to use 100rel for re-INVITE, be aware that RFC 6141 updates RFC 3261. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
