General Troubleshooting Tips - Cisco 7902G Administration Manual

Chapter 7 Troubleshooting the Cisco Unified IP Phone
Step 5
Step 6

General Troubleshooting Tips

Table 7-1 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
Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.0 (SCCP), Cisco Unified IP Phones
OL-8151-01
From Cisco Unified CallManager, select Device > Phone and verify that you have
assigned the correct MAC address to this Cisco Unified IP Phone.
To determine the MAC address of a phone, see the
Address of a Cisco Unified IP Phone" section on page
Power cycle the phone.
Table 7-1 provides general troubleshooting information for the
Cisco Unified IP Phones.
Explanation
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.
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 (lasting several minutes) on the
voice VLAN cause the IP phones to re-register with another
Cisco Unified CallManager server.
General Troubleshooting Tips
"Determining the MAC
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