Cisco Unified IP Phone 7940G Specification Guide

The back of the Cisco IP Phones models 7960G and 7940G have two RJ-45 ports
labelled 10/100 SW and 10/100 PC. Each port supports 10/100 Mbps half- or
full-duplex connections to external devices. You can use either Category 3 or 5
cabling for 10-Mbps connections, but you must use Category 5 for 100 Mbps
connections. On both the network port and access port, use full-duplex mode to
avoid collisions.

Use the 10/100 SW port to connect the phone to the network. You must use a
straight-through cable on these ports. The phone can also obtain inline power
from the Cisco Catalyst switch over these connections. See the

Use the 10/100 PC port to connect a network device, such as a computer, to the
phone. You must use a straight-through cable on this port.

The handset is designed especially for use with a Cisco IP Phone. It includes a
light strip that indicates incoming calls and voice messages waiting.

You can use a headset with the Cisco IP Phone. To connect a headset, plug it into
the Headset port on the back of the phone. Press the Headset button on your
phone to place and answer calls using the headset.

You can use the headset with all of the features on your Cisco IP Phone, including
the Volume and Mute buttons. Use these buttons to adjust the ear piece volume
and to mute the speech path from the headset microphone.

The Cisco IP Phone supports four- or six-wire headset jacks. For information
about some suggested models, refer to the following URL:

To disable the headset on a Cisco IP Phone models 7960G and 7940G, choose
Device > Phone from the Cisco CallManager Administration application, locate
the phone you want to modify, and check the Disable Speakerphone and
Headset check box.