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Cisco IE 2000 Switch Software Configuration Guide
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Configuring Voice VLAN
Finding Feature Information
Your software release may not support all the features documented in this chapter. For the latest feature
information and caveats, see the release notes for your platform and software release.
Use Cisco Feature Navigator to find information about platform support an d Cisco software image
support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on
Cisco.com is not required.

Information About Configuring Voice VLAN

Voice VLAN

The voice VLAN feature enables access ports to carry IP voice traffic from an IP phone. When the switch
is connected to a Cisco 7960 IP Phone, the phone sends voice traffic with Layer 3 IP precedence and
Layer 2 class of service (CoS) values, which are both set to 5 by default. Because the sound quality of a
Cisco IP phone call can deteriorate if the data is unevenly sent, the swit ch supports quality of service
(QoS) based on IEEE 802.1p CoS. QoS uses classification and scheduling to send network traffic from
the switch in a predictable manner. Voice VLAN is referred to as an auxiliary VLAN in some Catalyst
6500 family switch documentation.
The Cisco 7960 IP Phone is a configurable device, and you can configure it to forward traffic with an
IEEE 802.1p priority. You can configure the switch to trust or override the traffic priority assigned by a
Cisco IP phone.
The Cisco IP phone contains an integrated three-port 10/100 switch as shown in Fig ure 19-1. The ports
provide dedicated connections to these devices:
Port 1 connects to the switch or other voice-over-IP (VoIP) device.
Port 2 is an internal 10/100 interface that carries the IP phone traffic.
Port 3 (access port) connects to a PC or other device.