General Troubleshooting Tips - Cisco 7965G Administration Manual

Chapter 9 Troubleshooting and Maintenance
Table 9-1
Problem
Factory Reset Deleted 802.1X Shared Secret
Phone cannot obtain a DHCP-assigned
IP address
Phone does not register with
Cisco Unified Communications
Manager
Phone status display as "Configuring
IP" or "Registering"
Cannot access phone menus to verify
802.1X status

General Troubleshooting Tips

Table 9-2
Table 9-2
Summary
Daisy-chaining IP
phones
Poor quality when
calling digital cell
phones using the G.729
protocol
Prolonged broadcast
storms cause IP phones
to reset, or be unable to
make or answer a call
OL-12650-01
Cisco Unified IP Phone Security Troubleshooting (continued)
provides general troubleshooting information for the Cisco Unified IP Phone.
Cisco Unified IP Phone Troubleshooting
Explanation
Daisy chaining (connecting an IP phone to another
IP phone through the access port) is not supported.
Each IP phone should directly connect to a switch
port.
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.
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.
Cisco Unified IP Phone 7965G and 7945G Administration Guide for Cisco Unified Communications Manager 6.0
Possible Cause
These errors typically indicate that the
phone has completed a factory reset
(see the "Performing a Factory Reset"
section on page 9-16) while 802.1X
was enabled. A factory reset deletes
the shared secret, which is required for
802.1X authentication and network
access. To resolve this, you have two
options:
Temporarily disable 802.1X
•
authentication on the switch.
Temporarily move the phone to a
•
network environment that is not
using 802.1X authentication.
Once the phone starts up normally in
one of these conditions, you can access
the 802.1X configuration menus and
re-enter the shared secret (see the
"802.1X Authentication and Status"
section on page 4-36).
General Troubleshooting Tips
9-11