Hi all,

I'm having an issue with ACK's being proxied. When an INVITE first comes in 
(new transaction, new dialog), I do a 'www_challenge(...)'. This makes the 
proxy send a '401 Unauthorized' reply. The client acknowledges this reply with 
"ACK". This ACK is 'absorbed' by the proxy.

When during an established call/dialog the client sends an INVITE to set the 
call on hold, this is an in dialog INVITE (with to-tag etc). Although 
authentication for this INVITE isn't very necessary, my script does 
'www_challenge' anyway. The proxy sends '401 Unauthorized', the client responds 
with 'ACK'. This ACK however is not 'absorbed' as it should be, but 
forwarded/proxied (or at least handed over to the routing script). Is this 
intended behaviour? If so, how can I recognize this ACK to be able to drop it?

I found some related info in this email thread: 
http://lists.kamailio.org/pipermail/devel/2008-December/017246.html but doesn't 
discuss this exact issue.

Though this isn't a big problem for me (the upstream gateway ignores the ack, 
and I can disable authentication for re-invite's), I'm curious why the proxy 
behaves this way. Hopefully someone can enlighten me.


regards,
Egbert.


_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users@lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users

Reply via email to