Administrator’s Guide for Yealink Video Conferencing Systems884. Enter the port of the STUN server in the Port field.5. Press the Save soft key to accept the change.To configure STUN server for SIP IP call via the remote control:1. Select Menu->Advanced (default password: 0000) ->SIP IP Call.2. Select STUN from the pull-down list of NAT Traversal.3. Press the Save soft key to accept the change.NAT TypesFull Cone:A full cone NAT is one where all requests from the same internal IP address and port aremapped to the same external IP address and port. Furthermore, any external host can send apacket to the internal host, by sending a packet to the mapped external address.Restricted Cone:A restricted cone NAT is one where all requests from the same internal IP address and port aremapped to the same external IP address and port. Unlike a full cone NAT, an external host (withIP address X) can send a packet to the internal host only if the internal host had previously senta packet to IP address X.Port Restricted Cone:A port restricted cone NAT is like a restricted cone NAT, but the restriction includes portnumbers. Specifically, an external host can send a packet, with source IP address X and sourceport P, to the internal host only if the internal host had previously sent a packet to IP address Xand port P.Symmetric:A symmetric NAT is one where all requests from the same internal IP address and port, to aspecific destination IP address and port, are mapped to the same external IP address and port. Ifthe same host sends a packet with the same source address and port, but to a differentdestination, a different mapping is used. Furthermore, only the external host that receives apacket can send a UDP packet back to the internal host.RportRport in RFC 3581, allows a client to request that the server sends the response back to thesource port from which the request came. Rport feature depends on support from a SIP server.
