> Does Record-Route header has any significance in a 4xx response? No.
However many years and rfc2543bis drafts ago, some thought that it could help with resolving HERFP. Thus the reason why draft-ietf-sip-rfc2543bis-04 indicates allowing Record-Route within 401 and 484 responses. > Is it ok if a UA adds the same while rejecting an incoming > INVITE with a 4xx response? RFC 3261 section 20 accommodates expansion (and backwards compatibility) of where headers can be included. It does this by indicating that non applicable headers (such as no 4xx column for Record-Route) MUST NOT be sent; however if they are received, they MUST be ignored. Thus don't send it unless you have a reason; the receiver MUST tolerate it being sent. Since there was some discussion concerning rfc3261 tables 2 and 3 earlier this year, the following are few emails from Adam that may be of interest to sip-implementors. http://www.ietf.org/mail-archive/web/sipcore/current/msg01979.html http://www.ietf.org/mail-archive/web/sipcore/current/msg01990.html http://www.ietf.org/mail-archive/web/sipcore/current/msg02230.html _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
