Chapter 1. Introduction
What is a Telecommuting Module?
A Telecommuting Module is a device which processes traffic under the SIP protocol (see RFC 3261). The Telecommuting Module receives SIP requests, processes them according to the rules you have set up, and forwards them to the receiver.
The Telecommuting Module connects to an existing enterprise firewall through a DMZ port, enabling the transmission of
The Telecommuting Module can also be used as an extra gateway to the internal network without connecting to the firewall, transmitting only
Configuration alternatives
The 3Com VCX IP Telecommuting Module can be connected to your network in three different ways, depending on your needs.
Note that if the Standalone type is used, the interface which should receive traffic from the outside must have a public IP address (no NAT).
For a DMZ or DMZ/LAN type which uses a private IP address on the interface connected to the DMZ of the firewall, its corresponding public IP address must be entered on the Interoperability page.
DMZ Configuration
Using this configuration, the Telecommuting Module is located on the DMZ of your firewall, and connected to it with only one interface. The SIP traffic finds its way to the Telecommut- ing Module using DNS or by setting the Telecommuting Module as an outbound proxy on the clients.
This is the most secure configuration, since all traffic goes through both your firewall and your Telecommuting Module. It is also the most flexible, since all networks connected to any of your firewall’s interfaces can be
The drawback is that the SIP traffic will pass the firewall twice, which can decrease perfor- mance.
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