Cisco 8831 Administration Guide

Voice VLAN setup errors
Problem
If the conference phone appears to reset during heavy network usage (for example, following extensive web
surfing on a computer connected to the same switch as conference phone), it is likely that you do not have a
voice VLAN configured.
Solution
Isolating the conference phones on a separate auxiliary VLAN increases the quality of the voice traffic. See
the “Cisco Unified IP Communications product interactions” section for details.
DNS or other connectivity errors
Problem
The phone reset continues and you suspect DNS or other connectivity issues.
Solution
If the conference phone continues to reset, follow the procedure in Determine DNS or connectivity issues.
Power connection problems
Problem
The conference station does not appear to be powered up.
Solution
In most cases, a conference phone will restart if it powers up using external power but loses that connection
and switches to Power over Ethernet (PoE). Similarly, a conference phone may restart if it powers up using
PoE and then gets connected to an external power supply.
Audio and display problems
The following sections describe how to resolve audio and display problems.
Display is wavy
Problem
The display appears to have rolling lines of a wavy pattern.
Cisco Unified IP Conference Phone 8831 Administration Guide for Cisco Unified Communications Manager
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Troubleshooting and maintenance
Power connection problems

Cisco 8831 Specifications

General

Brand	Cisco
Model	8831
Category	IP Phone
Language	English