General Troubleshooting Tips - Cisco 7906G - Unified IP Phone VoIP Administration Manual

General Troubleshooting Tips

General Troubleshooting Tips
Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.1
9-16
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
Daisy-chaining IP phones.
Poor quality when calling
digital cell phones using the
G.729 protocol.
Prolonged broadcast storms
cause IP phones to re-register.
Chapter 9 Troubleshooting and Maintenance
Explanation
Cisco does not support connecting an IP phone
to another IP phone through the PC port. Each
IP phone should directly connect to a switch
port. If phones are connected together in a line
(daisy chaining by using the PC port), the
phones will not work.
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 (lasting several
minutes) on the voice VLAN cause the IP
phones to re-register with another
Cisco Unified Communications Manager
server.
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