Cisco 8961 Administration Manual page 313

Troubleshooting and Maintenance
Step 4
Step 5
Step 6
General Troubleshooting Information
The following table provides general troubleshooting information for the Cisco Unified IP Phone.
Table 57: Cisco Unified IP Phone troubleshooting
Summary
Connecting a Cisco Unified IP Phone
to another Cisco Unified IP Phone
Prolonged broadcast storms cause IP
phones to reset, or be unable to make
or answer a call
Moving a network connection from
the phone to a workstation
Changing the telephone
configuration
REVIEW DRAFT - CISCO CONFIDENTIAL
Command or Action
Select Save.
On the phone, perform the functions.
Return to the Cisco Unified
Communications Manager
Administration window selected in Step
1, and turn debugging off.
Cisco Unified IP Phone 8961, 9951, and 9971 Administration Guide for Cisco Unified Communications Manager 10.0
Purpose
• 7 - Debugging
Explanation
Cisco does not support connecting an IP phone to another IP Phone
through the PC port. Each IP Phone should connect directly to a switch
port. If phones are connected together in a line by using the PC port,
the phones do not work.
A prolonged Layer 2 broadcast storm (lasting several minutes) on the
voice VLAN may cause IP phones to reset, lose an active call, or be
unable to initiate or answer a call. Phones may not come up until a
broadcast storm ends.
If you power your phone through the network connection, you must
be careful if you decide to unplug the network connection of the phone
and plug the cable into a desktop computer.
Caution The network card in the computer cannot receive power
through the network connection; if power comes through
the connection, the network card can be destroyed. To
protect a network card, wait 10 seconds or longer after
unplugging the cable from the phone before plugging it
into a computer. This delay gives the switch enough time
to recognize that there is no longer a phone on the line and
to stop providing power to the cable.
By default, the network configuration options are locked to prevent
users from making changes that could impact their network
connectivity. You must unlock the network configuration options
before you can configure them. See
103 for details.
General Troubleshooting Information
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