Cisco Ip Phone Voice Traffic - Cisco Catalyst 4500 Series Software Configuration Manual

Configuring a Port to Connect to a Cisco 7960 IP Phone
Figure 46-1
Catalyst 4500 Series Switch

Cisco IP Phone Voice Traffic

You can configure an access port with an attached Cisco IP phone to use one VLAN for voice traffic and
another VLAN for data traffic from a device attached to the phone. You can configure access ports on
the switch to send Cisco Discovery Protocol (CDP) packets that instruct an attached phone to send voice
traffic to the switch in any of these ways:
•
•
•
In all configurations, the voice traffic carries a Layer 3 IP precedence value (the default is 5 for voice
Note
traffic and 3 for voice control traffic).
Cisco IP Phone Data Traffic
The switch can also process tagged data traffic (traffic in IEEE 802.1Q or IEEE 802.1p frame types) from
the device attached to the access port on the Cisco IP phone. See
access ports on the switch to send CDP packets that instruct the attached phone to configure the phone
access port in one of these modes:
•
•
Note Untagged traffic from the device attached to the Cisco IP phone passes using the phone unchanged,
regardless of the trust state of the access port on the phone.
Configuring a Port to Connect to a Cisco 7960 IP Phone
Because a Cisco 7960 IP Phone also supports connection to a PC or another device, an interface
connecting a Catalyst 4500 series switch to a Cisco 7960 IP Phone can carry a mix of voice and data
traffic.
The three configurations for a port connected to a Cisco 7960 IP Phone are as follows:
•
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
46-2
Cisco 7960 IP Phone Connected to a Catalyst 4500 Series Switch
In the voice VLAN tagged with a Layer 2 CoS priority value
In the access VLAN tagged with a Layer 2 CoS priority value
In the access VLAN, untagged (no Layer 2 CoS priority value)
In trusted mode, all traffic received using the access port on the Cisco IP phone passes using the
phone unchanged.
In untrusted mode, all traffic in IEEE 802.1Q or IEEE 802.1p frames received using the access port
on the Cisco IP phone receive a configured Layer 2 CoS value. The default Layer 2 CoS value is 0.
Untrusted mode is the default.
All traffic is transmitted according to the default CoS priority of the port. it is the default.
IP Phone
IP
Chapter 46 Configuring Voice Interfaces
PC
Figure 46-1. You can configure Layer 2