User's Manual

Chapter 15 VoIP
B222s User’s Guide
138
2 The SI P proxy server forwards the call invit ation t o C.
Figure 77 SI P Proxy Server
SIP Redirect Server
A SI P redirect server accept s SI P requests, t ranslat es the destinat ion address t o an I P address and
sends t he t ranslat ed I P address back t o t he device that sent t he request . Then t he client device t hat
originally sent t he request can send request s t o the I P address that it received back from the
redirect server. Redirect servers do not init iate SI P request s.
I n t he following exam ple, you want t o use client device A to call som eone w ho is using client device
C.
1 Client device A sends a call invit at ion for C to t he SI P redirect server B.
2 The SI P redirect server sends t he invitat ion back t o A wit h C’s I P address ( or dom ain nam e) .
B
A
C
1
2