Cisco Systems 2950, 2955 Overriding the CoS Priority of Incoming Data Frames, Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames

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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide

OL-10101-02

Chapter 18 Configuring Voice VLAN

Configuring Voice VLAN

Overriding the CoS Priority of Incoming Data Frames

You can connect a PC or other data device to a Cisco 7960 IP Phone port. The PC can generate packets

with an assigned CoS value. You can configure the switch to override the priority of frames arriving on

the IP phone port from connected devices.

Beginning in privileged EXEC mode, follow these steps to override the CoS priority received from the

nonvoice port on the Cisco 7960 IP Phone:

Use the no switchport priority extend interface configuration command or the switchport priority

extend cos 0 interface configuration command to return the port to its default setting.

Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames

You can connect a PC or other data device to a Cisco 7960 IP Phone port. The PC can generate packets

with an assigned CoS value. You can configure the switch to trust the priority of frames arriving on the

IP phone port from connected devices.

Beginning in privileged EXEC mode, follow these steps to trust the CoS priority received from the

nonvoice port on the Cisco 7960 IP Phone:

Command Purpose

Step 1 configure terminal Enter global configuration mode.

Step 2 interface interface-id Enter interface configuration mode, and specify the interface connected to

the IP phone.

Step 3 switchport priority extend

cos value

Set the IP phone access port to override the priority received from the PC or

the attached device.

The CoS value is a number from 0 to 7. Seven is the highest priority. The

default is 0.

Step 4 end Return to privileged EXEC mode.

Step 5 show interfaces interface-id

switchport

Verify your entries.

Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.