Cisco 7906G Administration Guide

9-15
Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager 5.1
OL-11515-01
Chapter 9 Troubleshooting and Maintenance
General Troubleshooting Tips
General Troubleshooting Tips
Table 9-2 provides general troubleshooting information for the
Cisco Unified IP Phone.
Ta b l e 9-2 Cisco Unified IP Phone Troubleshooting
Summary Explanation
Daisy-chaining IP phones. Do not connect an IP phone to another IP
phone through the access port. Each IP
phone should directly connect to a switch
port. If you connect IP phones together in
a line (daisy-chaining), a problem with
one phone can affect all subsequent
phones in the line. Also, all phones on the
line share bandwidth.
Poor quality when calling digital cell
phones using the G.729 protocol.
In Cisco Unified CallManager, you can
configure the network to use the G.729
protocol (the default is G.711). When
using G.729, calls between an IP phone
and a digital cellular phone will have poor
voice quality. Use G.729 only when
absolutely necessary.
Prolonged broadcast storms cause IP
phones to re-register.
Prolonged broadcast storms (lasting
several minutes) on the voice VLAN
cause the IP phones to re-register with
another Cisco
Unified CallManager
server.

Cisco 7906G Specifications

General

Brand	Cisco
Model	7906G
Category	IP Phone
Language	English