Cisco Unified IP Phone 7940G Specification Guide

For the Cisco IP Phone to successfully operate as a Cisco IP Phone endpoint in
your network, your network must meet the following requirements:

Working VoIP Network

Voice over IP (VoIP) configured on your Cisco routers and gateways

Cisco CallManager Release 4.0 or higher installed in your network and
configured to handle call processing

IP network that supports DHCP or manual assignment of IP address, gateway,
and subnet mask

The Cisco IP Phone requires Cisco CallManager to handle call processing. Refer
to Cisco CallManager Administration Guide or context-sensitive help in the
Cisco CallManager application to ensure that Cisco CallManager is set up
properly to manage the phone and to properly route and process calls.

If you plan to use auto-registration, verify that it is enabled and properly
configured in Cisco CallManager before connecting any Cisco IP Phone to the
network. See the

 for details.

You must use Cisco CallManager to configure and assign telephony features to the
Cisco IP Phones. See the

In Cisco CallManager, you can add users to the database and associate them with
specific phones. In this way, users gain access to web pages that allow them to
configure phone items such as call forwarding, speed dialing, and voice
messaging system options. See the

 for details.