Avaya B179 SIP Installation And Administration Manual page 26

Avaya B179 SIP Conference Phone
possible to replace the IP address in the SIP requests with the address shown on the other
side of the firewall.
Note that in some cases NAT traversal is not necessary. Some public service providers of IP
telephony keep track of the actual IP address used to register a phone, and the one used in
the SIP requests from the same phone, and then replaces the addresses in the SIP messages.
 NAT is not supported for SIP line clients in CS1000 server environment.
STUN
STUN host
Offer ICE
TURN
TURN User
TURN host
Password
STUN (Simple Traversal of UDP through NATs) is a protocol that assists
devices behind a NAT firewall or router with their packet routing.
STUN is commonly used in real-time voice, video,
messaging, and other interactive IP communication applications.
The protocol allows applications operating through a NAT to
discover the presence and specific type of NAT and obtain the
mapped (public) IP address (NAT address) and port number that the
NAT has allocated for the application's User Datagram Protocol (UDP)
connections to remote hosts. The protocol requires assistance from a
3rd-party network server (STUN server).
STUN should be activated if an external SIP server cannot connect
to the Avaya B179 behind a firewall NAT function and the SIP server
supports STUN. A suitable STUN server is usually provided by the VoIP
service provider.
Note: STUN might also be referred to as Session Traversal Utilities for
NAT.
The IP address or public name of the STUN server.
ICE (Interactive Connectivity Establishment), is a STUN addition that
provides various techniques to allow SIP-based VoIP devices to suc-
cessfully traverse the variety of firewalls that may exist between the
devices. The protocol provides a mechanism for both endpoints to
identify the most optimal path for the media traffic to follow.
TURN (Traversal Using Relay NAT) TURN is an extension of the STUN
protocol that enables NAT traversal when both endpoints are behind
symmetric NAT. With TURN, media traffic for the session will have to
go to a relay server. Since relaying is expensive, in terms of bandwidth
that must be provided by the provider, and additional delay for the
media traffic, TURN is normally used as a last resort when endpoints
cannot communicate directly.
User authentication name on the TURN server.
The IP address or public name of the TURN server.
User authentication password on the TURN server.
Installation and Administration Guide
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