Cisco 7911G - IP Phone VoIP User Manual

Chapter 9 Troubleshooting and Maintenance
General Troubleshooting Tips
9-16
Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.0
OL11954-01
General Troubleshooting Tips
This section provides troubleshooting information for some common issues that
might occur on the Cisco Unified IP Phone.
Table 9-2 provides general troubleshooting information for the Cisco Unified IP
Phone.
Table 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 Communications
Manager, 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 Communications
Manager server.

Cisco 7911G - IP Phone VoIP Specifications

General

Brand	Cisco
Model	7911G - IP Phone VoIP
Category	IP Phone
Language	English