[Ekiga-list] Invalid Contact header field, or bug in ekiga.net?

[Stuart Gathman <stuart gathman org>]

I am new at SIP, but I got tired of googling to try and find why I keep getting 606 from ekiga.net, and dived into the protocol myself with wireshark and RFC3261.  So feel free to correct me.

STUN is used, and returns the correct public IP and port.  Ekiga doesn't use the port (assuming consumer nat with port forwarding, I guess).

The REGISTER packet contains this Contact header field:

Contact: <sip:SDGathman 72 209 xxx xxx>;q=1, <sip:SDGathman 192 168 1 105>;q=0.500

RFC3261 section 8.1.1.8 says there can be only one sip uri, but that seems to be for INVITE only (and 10.3 talks about iterating over all sip uris).  So I believe that ekiga.net is barfing on the private ip in the 2nd contact.  Other services seem to ignore it, including ekiga call-out (sip.diamondcard.us).  ekiga.net gives this response:

Status-Line: SIP/2.0 606 Not Acceptable