Samsung Ubigate iBG3026 Configuration Manual page 383

How SIP Works with a Proxy Server
If a proxy server is used, the caller user agent sends an INVITE request to the
proxy server, the proxy server determines the path, and then forwards the
request to the called party. The called party responds to the proxy server,
which in turn, forwards the response to the caller. The proxy server forwards
the acknowledgments of both parties. A session is then established between
the caller and called party. Real-time Transfer Protocol(RTP) is used for the
communication between the caller and the called party. Figure 28.2, Figure
28.3 and Figure 28.4 illustrate the SIP works with a Proxy Server.
Server
User agents
© SAMSUNG Electronics Co., Ltd.
Client
Client
Figure 28.2 SIP Request Through a Proxy Server
Ubigate iBG3026 Configuration Guide/Ed.00
Invite
IP-based
network
Invite
Server
Proxy Redirect
Client
Server
User agents
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