Cisco Unified Ip Phone Power; Power Guidelines - Cisco 7975G Software Manual

Cisco Unified IP Phones and Telephony Networks
• The current VLANs might be configured on an IP subnet basis. However, an additional IP address might
• Data traffic present on the data/native VLAN may reduce the quality of VoIP traffic.
• Network security may indicate a need to isolate the VLAN voice traffic from the VLAN data traffic.
Resolve these issues by isolating the voice traffic onto a separate VLAN. The switch port to which the phone
connects 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 that connects to the switch through the access port of the IP phone (native
Isolation of 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 not enough IP addresses exist for each
phone.
For more information, see the documentation included with a Cisco switch. You can also access related
documentation at this URL:
http://cisco.com/en/US/products/hw/switches/index.html
Related Topics
Phone Startup Process, on page 36
Network Configuration Menu, on page 66

Cisco Unified IP Phone Power

Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G can be powered with external power
or with Power over Ethernet (PoE). A separate power supply provides external power. A switch through the
Ethernet cable that is attached to a phone provides PoE.
When you install a phone powered with external power, connect the power supply to the phone and to a
Caution
power outlet before you connect the Ethernet cable to the phone. When you remove a phone that is powered
with external power, disconnect the Ethernet cable from the phone before you disconnect the power supply.
The following sections provide more information about phone power:

Power Guidelines

The following table provides guidelines that apply to external power and to PoE power for Cisco Unified IP
Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G.
not be available to assign the phone to the same subnet as other devices connect to the same port.
VLAN)
Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G Administration Guide for Cisco Unified
Cisco Unified IP Phone Power
Communications Manager 9.0 (SCCP and SIP)
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