The Cisco Sip Ip Phone With A Catalyst Switch - Cisco 7960g Administrator's Manual

Chapter 1 Product Overview

The Cisco SIP IP Phone with a Catalyst Switch

To function in the IP telephony network, the Cisco SIP IP phone must be connected to a networking
device, such as a Catalyst switch, to obtain network connectivity.
The Cisco SIP IP phone has an internal Ethernet switch, which enables it to switch traffic coming from
the phone, access port, and the network port.
If a computer is connected to the access port, packets traveling to and from the computer and to and from
the phone share the same physical link to the switch and the same port on the switch.
This configuration has these implications for the VLAN configuration on the network:
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•
You can resolve these issues by isolating the voice traffic onto a separate VLAN on each of the ports
connected to a phone. The switch port configured for connecting a phone would have separate VLANs
configured for carrying:
•
•
Isolating the phones on a separate, auxiliary VLAN increases the quality of the voice traffic and allows
a large number of phones to be added to an existing network where there are not enough IP addresses.
For more information, refer to the documentation included with the Catalyst switch or available online
at the following URL:
http://www.cisco.com/univercd/home/index.htm
OL-2206-01
The current VLANs might be configured on an IP subnet basis, and additional IP addresses might
not be available to assign the phone to a port so that it belongs to the same subnet as other devices
(PC) connected to the same port.
Data traffic present on the VLAN supporting phones might reduce the quality of VoIP traffic.
Voice traffic to and from the Cisco SIP IP phone (auxiliary VLAN)
Data traffic to and from the PC connected to the switch through the access port of the Cisco SIP IP
phone (native VLAN)
The Cisco SIP IP Phone with a Catalyst Switch
Cisco SIP IP Phone Administrator Guide Version 3.0
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