User`s guide

Routing Table
Dialogic
®
1000 and 2000 Media Gateway Series User’s Guide 241
Example #6 – Toll Bypass
Toll Bypass allows a company to make interoffice calls using the company’s WAN and without using the
public telephone network – reducing the cost of phone calls.
System Configuration:
The sample system configuration shows three offices. We named them New York City (NYC), Los
Angeles (LA) and Seattle to make the example more real-world. Each office has a number of phones
connected to an internal PBX. The Seattle PBX connects directly to the Central Office and on to the PSTN
(public switched telephone network). The New York City and Los Angeles offices have their PBX
connected to a gateway. Each gateway connects to the company’s WAN and to a Central Office.
Central Office
PBX AT1
. . .
Gateway T1 Central OfficePBX B
. . .
Gateway T1T1
New York City Office Los Angeles Office
WAN
PSTN
Central Office PBX C
. . .
T1
Seattle Office
1
2
12
System Requirements:
• Calls between the New York City office and the Los Angeles office use the WAN.
• Calls between the New York City office and the Seattle office use the PSTN.
• Calls between the Los Angeles office and the Seattle office use the PSTN.
• In New York and Los Angeles all inbound calls from the CO (PSTN) are routed to the local PBX.
• In New York and Los Angeles all inbound calls from the WAN are routed to the local PBX. These
could be calls form other offices or other companies who all use the WAN.
System Setup:
• New York City phones have extensions 1xxx.
• Los Angeles phones have extensions 2xxx.
• Seattle phones have extensions 3xxx.
• New York City gateway is at 172.16.5.4.
• Los Angeles gateway is at 172.16.5.3.