ICE with Policy Authorization, Slide 2 Alice Bob FW-B FW-A 13 14 16 SIP 183 or 200From: BobTo: AliceIP=Z, UDP=z, Token=B1 15 STUNResponse Bob's Call Controller Alice's Call Controller No external authorization check is necessary because the same STUN transaction-id and (flipped) 5-tuple are in STUN Request and Response |