Operation Manual

SIP
SIP Software Release 6-0-0
J613-M0524-00
47
SIP Messages
A SIP request message consists of three elements:
Request Line
Header
Message Body
A SIP response message consists of three elements:
Status Line
Header
Message Body
The Request line and header field define the nature of the call in terms of
services, addresses and protocol features. The message body is independent
of the SIP protocol and can contain anything.
SIP defines the following methods (SIP uses the term ‘method’ to describe
the specification areas):
Invite – invites a user to join a call.
Bye – terminates the call between two of the users on a call
Options – requests information on the capabilities of a server
Ack – confirms that a client has received a final response to an INVITE
Register – provides the map for address resolution, letting a server
know the location of other users.
Cancel – ends a pending request, but does not end the call
The INFO method, for mid-session signalling, is also being added
Related Standards Activity.
AT-RG213 Call Processes
The AT-RG213 can communicate with the following devices:
 Another terminal on the IP network such as the AT-RG213.
 Any LAN SIP endpoint on the IP network, for instance:
o a Soft Phone
o an IP phone directly connected to the IP network
 A PSTN phone or fax. However, the AT-RG213 would need to contact a PSTN
gateway
Calls Involving Another Terminal
The following example described in Figure 12 illustrates how to reach a
phone or fax on another AT-RG213 terminal.