How would the proxy know ahead of time that both
parties actually
support ICE?
easy. when ice capable sip ua registers, it has +sip.ice feature tag in
contact uri. caller's ice support can be detected using sdp_with_ice()
function that i introduced today.
Sorry, I meant the RTP proxy, not the SIP proxy.
rtp proxy does not need to know anything. it just does what it is
explicitly asked for by sip proxy.
-- juha