Phone Resets Due To Intentional Reset; Phone Resets Due To Dns Or Other Connectivity Issues; Phone Does Not Power Up - Cisco 7821 Administration Manual

Cisco IP Phone Reset Problems
Solution
Isolating the phones on a separate auxiliary VLAN increases the quality of the voice traffic.

Phone Resets Due to Intentional Reset

Problem
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.
Solution
You can check if a Cisco IP Phone received a command from Cisco Unified Communications Manager to
reset by pressing Applications on the phone and choosing Admin Settings > Status > Network Statistics.
• If the Restart Cause field displays Reset-Reset, the phone receives a Reset/Reset from Cisco Unified
Communications Manager Administration.
• If the Restart Cause field displays Reset-Restart, the phone closed because it received a Reset/Restart
from Cisco Unified Communications Manager Administration.

Phone Resets Due to DNS or Other Connectivity Issues

Problem
The phone reset continues and you suspect DNS or other connectivity issues.
Solution
If the phone continues to reset, eliminate DNS or other connectivity errors by following the procedure in
Determine DNS or Connectivity Issues, on page

Phone Does Not Power Up

Problem
The phone does not appear to be powered up.
Solution
In most cases, a phone restarts 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 connects to an external power
supply.
Cisco IP Phone 7821, 7841, and 7861 Administration Guide for Cisco Unified Communications Manager 10.0
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