Samsung Ubigate iBG2016 Configuration Manual page 397

How SIP Works with a Redirect Server
If a redirect server is used, the caller user agent sends an INVITE request to
the redirect server, the redirect server contacts the location server to determine
the path to the called party, and then the redirect server sends that information
back to the caller. The caller then acknowledges receipt of the information.
The caller then sends a request to the device indicated in the redirection
information(which could be the callee or another server that forwards the
request). Once the request reaches the called party, it sends back a response
and the caller acknowledges the response. RTP is used for the communication
between the caller and the callee. Figure 28.5 and Figure 28.6 illustrate the
SIP works with a Redirect Server.
Server
User agents
© SAMSUNG Electronics Co., Ltd.
Client
Figure 3.5 SIP Session Through a Redirect Server
Ubigate iBG2016 Configuration Guide/Ed.00
Invite
200 OK
Ack
RTP
IP-based
network
Proxy Redirect
Client
Server
User agents
343