HP MSR SERIES User Manual

631
Figure 655 Message exchange for a UA to register with a Registrar
Call setup
SIP operates in the Client/Server mode and sets up calls through communication between UA and proxy
server.
Figure 656 Network diagram
In the previous figure, Telephone A wants to call Telephone B, and Router A and Router B work as SIP
endpoints (UAs).
The following is the procedure for connecting a call from Telephone A to Telephone B:
1. Telephone A sends the number of Telephone B.
2. Upon receipt of the call, Router A sends a session request (INVITE) to the proxy server.
3. The proxy server consults its database for information corresponding to the number of Telephone
B. If such information is available, it forwards the request to Router B.
4. Router B, after receiving the request, responds to the proxy server and makes Telephone B ring if
Telephone B is available.
5. The proxy server forwards the response to Router A. The response discussed here includes two
provisional response messages (100 Trying and 180 Ringing) and one success response (200
OK).
Figure 657 sh
ows the complete call setup procedure.

HP MSR SERIES Specifications

General

Product Series	MSR Series
Manufacturer	HP
Category	Network Router
Ports	Varies by model
WAN Interfaces	Varies by model
LAN Interfaces	Varies by model
VPN Support	Yes
Firewall	Yes
Dimensions	Varies by model
Weight	Varies by model
Wireless Support	Varies by model
Management	Web-based, CLI
Power Supply	Varies by model
Operating Temperature	0°C to 45°C
Storage Temperature	-40°C to 70°C
Humidity	5% to 95% non-condensing