![background image](http://html.mh-extra.com/html/cisco/vg200/vg200_using-manual_65000012.webp)
Chapter 1
Using the Cisco Voice Gateway 200
Using a Cisco VG200 Gateway with H.323
1-12
Software Configuration Guide for the Cisco VG200
78-10322-02
Figure 1-7
Using E&M Analog Emulation with T1-CAS
Linking PBX Users with E&M Trunk Lines
The following example shows how to configure VoIP to link PBX users with E&M
trunk lines.
In this example, a company wants to connect two offices: one in San Jose,
California and the other in Salt Lake City, Utah. Each office has an internal
telephone network using PBX, connected to the voice network by an E&M
interface. Both the Salt Lake City and the San Jose offices are using E&M Port
Type II, with four-wire operation and Immediate Start signaling. Each E&M
interface connects to the gateway using two voice interface connections. Users in
San Jose dial “8-569” and then the extension number to reach a destination in Salt
Lake City. Users in Salt Lake City dial “4-527” and then the extension number to
reach a destination in San Jose.
Figure 1-8 illustrates the topology of this connection example.
Cisco CallManager
Simple IP
telephony devices
Voice
10/100BaseT Ethernet
33471
T1-CAS
DS-0 groups 0-23
PBX
E&M emulation
Trunk (tie) line
DS-0 groups 0-23
Port 0
Port 1
1 or 2
T1 ports
Gateway