Chapter2 Preparing to Install the Cisco Unified IP Phone o n Your Network
Providing Power to the Phone
2-4
Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones
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•Data traffic present on the data/native VLAN may reduce the quality of
Voice-over-IP traffic.
•Network security may indicate a need to isolate the VLAN voice traffic from
the VLAN data traffic.
You can resolve these issues by isolating the voice traffic onto a separate VLAN.
The switch port that the phone is connected to would be configured to have
separate VLANs for carrying:
•Voice traffic to and from the IP phone (auxiliary VLAN, on the
Cisco Catalyst 6000 series, for example)
•Data traffic to and from the PC connected to the switch through the access
port of the IP phone (native VLAN)
Isolating the phones on a separate, auxiliary VLAN improves 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 each phone.
For more information, refer to the documentation included with a Cisco switch.
You can also access related documentation at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/index.htm
Related Topics
•Understanding the Phone Startup Process, page2-9
•Network Configuration Menu, page 4-7
Providing Power to the Phone
The Cisco Unified IP Phones 7970G/7971G-GE models can be powered in with
external power or with inline power. External power is provided through a
separate power supply. Inline power is provided by a switch through the Ethernet
cable attached to a phone.
The following sections provide more information about powering a phone:
•Power Guidelines, page2-5
•Phone Power Consumption and Display Brightness, page2-5
•Power Outage, page2-7
•Obtaining Additional Information about Power, page2-7