Cisco Ip Phone Connections; Cisco Ip Phone Voice Traffic - Cisco 7604 Configuration Manual

Understanding Cisco IP Phone Support

Cisco IP Phone Connections

The Cisco IP phone contains an integrated 3-port 10/100 switch. The ports are dedicated connections to
these devices:
•
•
•
Figure 16-1
Figure 16-1 Cisco IP Phone Connected to a Switch
10/100 module
Catalyst switch or

Cisco IP Phone Voice Traffic

The Cisco IP phone transmits voice traffic with Layer 3 IP precedence and Layer 2 CoS values, which
are both set to 5 by default. The sound quality of a Cisco IP phone call can deteriorate if the voice traffic
is transmitted unevenly. To provide more predictable voice traffic flow, you can configure QoS to trust the
Layer 3 IP precedence or Layer 2 CoS value in the voice traffic (refer to
PFC
You can configure the ports on WS-X6548-RJ-45 and WS-X6548-RJ-21 switching modules to trust
Note
received Layer 2 CoS values (QoS port architecture 1p1q0t/1p3q1t). The WS-X6548-RJ-45 and
WS-X6548-RJ-21 switching modules cannot supply power to Cisco IP phones. Configure QoS policies
that use the Layer 3 IP precedence value on other switching modules.
You can configure a Layer 2 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 Cisco IP phone.
You can configure Layer 2 access ports on the router to send Cisco Discovery Protocol (CDP) packets
that instruct an attached Cisco IP phone to transmit voice traffic to the router in any of the following
ways:
•
•
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
16-2
Port 1 connects to the router.
Port 2 is an internal 10/100 interface that carries the Cisco IP phone traffic.
Port 3 connects to a PC or other device.
shows a Cisco IP phone connected between a router and a PC.
Cisco Router
QoS").
In the voice VLAN, tagged with a Layer 2 CoS priority value
In the access VLAN, tagged with a Layer 2 CoS priority value
Cisco IP Phone 7960
Phone
ASIC
P2
3-port
P1
P3
switch
Access
port
Chapter 16 Configuring Cisco IP Phone Support
Workstation/PC
Chapter 41, "Configuring
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