9-8
Cisco Unified IP Phone 7975G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP and SIP)
OL-15790-01
Chapter 9 Troubleshooting and Maintenance
Cisco Unified IP Phone Resets Unexpectedly
Verifying that the Phones Have Not Been Intentionally Reset
If you are not the only administrator with access to Cisco Unified Communications Manager, you should
verify that no one else has intentionally reset the phones.
You can check whether a Cisco Unified IP Phone received a command from
Cisco Unified Communications Manager to reset by pressing the
Settings
button on the phone and
choosing
Status > Network Statistics
. If the phone was recently reset one of these messages appears:
•
Reset-Reset—Phone closed due to receiving a Reset/Reset from Cisco Unified Communications
Manager Administration.
•
Reset-Restart—Phone closed due to receiving a Reset/Restart from Cisco Unified Communications
Manager Administration.
Eliminating DNS or Other Connectivity Errors
If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:
Procedure
Step 1
Use the
Erase
softkey to reset phone settings to their default values. See the
“Resetting or Restoring the
Cisco Unified IP Phone” section on page 9-14
for details.
Step 2
Modify DHCP and IP settings:
a.
Disable DHCP. See the
“Network Configuration Menu” section on page 4-5
for instructions.
b.
Assign static IP values to the phone. See the
“Network Configuration Menu” section on page 4-5
for instructions. Use the same default router setting used for other functioning Cisco Unified IP
Phones.
c.
Assign TFTP server. See the
“Network Configuration Menu” section on page 4-5
for instructions.
Use the same TFTP server used for other functioning Cisco Unified IP Phones.
Step 3
On the Cisco Unified Communications Manager server, verify that the local host files have the correct
Cisco Unified Communications Manager server name mapped to the correct IP address.
Step 4
From Cisco Unified Communications Manager, choose
System > Server
and verify that the server is
referred to by its IP address and not by its DNS name.
Step 5
From Cisco Unified Communications Manager, choose
Device > Phone
and verify that you have
assigned the correct MAC address to this Cisco Unified IP Phone. For information about determining a
MAC address, see the
“Determining the MAC Address of a Cisco Unified IP Phone” section on
page 2-13
.
Step 6
Power cycle the phone.
Checking Power Connection
In most cases, a phone will restart if it powers up by using external power but loses that connection and
switches to PoE. Similarly, a phone may restart if it powers up by using PoE and then gets connected to
an external power supply.