28 Sep
2009
28 Sep
'09
6:18 a.m.
For SIP NAT traversal. Almost all SIP clients are
symmetric
(send/receive SIP on the same port) - thus by always use the "received"
information instead of the provided "Contact" you should not have
negative impacts. Exception: IIRC, I once saw Cisco SIP phones behind a
Cisco PIX which were asymmetric (can't remember if it was SIP or RTP).
I see. So I'll do it the same.
+ some countries require lawful intercept, which
must not be
noticeable by the costumer. As the LI requires a media relay (to record
audio) you do not have a choice and have to activate the media relay
for
all calls anyway.
I have exactly that problem, so I already proxying all rtp-traffic via rtpproxy.