CHAPTER
16-1
Catalyst 2950 Desktop Switch Software Configuration Guide
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16

Configuring Voic e VLAN

This chapter describes how to configure the voice VLAN feature on your switch. Voice VLAN is referred
to as an auxiliary VLAN in the Catalyst 6000 family switch documentation.
Note For comple te syntax and us age inform ation for the co mmands used in this chapter, refer to th e command
refere nce fo r thi s r ele ase.
This chapter consists of these sections:
Understa ndin g Voi ce V LAN, p age 16- 1
Configuring Vo ice VLA N, page 1 6- 2
Displaying Voice VLAN, page 16-6

Understandin g Vo ice VLAN

The v oic e VLAN feat ure en ables ac cess po rts to carry IP voice traffi c from an IP phone. The switch can
connect to a Cisco 7960 IP Phone and carry IP voice traffic. Because the sound quality of an IP phone
call can deteriorate if the data is unevenly sent, the switch supports quality of service (QoS) based on
IEEE 802.1P class of service (CoS). QoS uses classification and scheduling to send netw ork tr affic from
the switch in a predictable manner. For more information on QoS, see Chapter 26, Configuring
QoS.The Cisco 7960 IP Phone is a configurable device, and you can configure it to forward traf fic with
an 802.1P priority. You can configure the switch to trust or override the traffic priority assigned by an
IP phone.
The Cisc o 7960 IP Phone contains an in tegrated three-port 10/100 switch as shown in Figure 16-1. The
ports provide dedicat ed connec tions to th ese devices:
Port 1 conne cts to the sw itch or other voice-over-IP (VoIP) device.
Port 2 is an intern al 10/10 0 inter face that ca rries the IP phone traffic.
Port 3 (acce ss port) c onnec ts to a PC or other device.