C H A P T E R 41 Configuring Voice Interfaces - Cisco Catalyst 4500 Series Configuration Manual

About Voice Interfaces
The Cisco 7960 IP Phone contains an integrated three-port 10/100 switch. The ports are dedicated
connections as described below:
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•
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Figure 41-1
Figure 41-1
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:
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•
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Note In all configurations, the voice traffic carries a Layer 3 IP precedence value (the default is 5 for voice
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:
•
•
Untagged traffic from the device attached to the Cisco IP phone passes using the phone unchanged,
Note
regardless of the trust state of the access port on the phone.
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
41-2
Port 1 connects to the Catalyst 4500 series switch or other device that supports voice-over-IP.
Port 2 is an internal 10/100 interface that carries the phone traffic.
Port 3 connects to a PC or other device.
shows one way to configure a Cisco 7960 IP Phone.
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.
IP Phone
IP
Chapter 41 Configuring Voice Interfaces
PC
Figure 41-1. You can configure Layer 2
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