Table of Contents
Advertisement
In the following example, you want to use client device A to call someone who is
using client device C.
The client device (A in the figure) sends a call invitation to the SIP proxy server
1
(B).
The SIP proxy server forwards the call invitation to C.
2
Figure 65 SIP Proxy Server
STUN
STUN (Simple Traversal of User Datagram Protocol (UDP) through Network
Address Translators) allows the MAX208M2W Series to find the presence and
types of NAT routers and/or firewalls between it and the public Internet. STUN
also allows the MAX208M2W Series to find the public IP address that NAT
assigned, so the MAX208M2W Series can embed it in the SIP data stream. STUN
does not work with symmetric NAT routers or firewalls. See RFC 3489 for details
on STUN.
The following figure shows how STUN works.
The MAX208M2W Series (A) sends SIP packets to the STUN server (B).
1
The STUN server (B) finds the public IP address and port number that the NAT
2
router used on the MAX208M2W Series's SIP packets and sends them to the
MAX208M2W Series.
MAX208M2W Series User's Guide
B
1
A
Chapter 10 The VoIP Account Screens
2
C
141
Advertisement
Table of Contents
