Cisco 7931G Administration Guide - Page 220

General Troubleshooting Tips Chapter 9 Troubleshooting and Maintenance Table 9-2 Cisco Unified IP Phone Troubleshooting (continued) Summary Explanation Display issues If the display appears to have rolling lines or a wavy pattern, it might be interacting with certain types of older fluorescent lights in the building. Moving the phone away from the lights, or replacing the lights, should resolve the problem. Dual-Tone Multi-Frequency (DTMF) When you are on a call that requires keypad input, if you press delay the keys too quickly, some of them might not be recognized. Codec mismatch between the phone and another device The RxType and the TxType statistics show the codec that is being used for a conversation between this Cisco Unified IP Phone and the other device. The values of these statistics should match. If they do not, verify that the other device can handle the codec conversation or that a transcoder is in place to handle the service. See the "Call Statistics Screen" section on page 7-16 for information about displaying these statistics. Sound sample mismatch between the phone and another device The RxSize and the TxSize statistics show the size of the voice packets that are being used in a conversation between this Cisco Unified IP Phone and the other device. The values of these statistics should match. See the "Call Statistics Screen" section on page 7-16 for information about displaying these statistics. Gaps in voice calls Check the AvgJtr and the MaxJtr statistics. A large variance between these statistics might indicate a problem with jitter on the network or periodic high rates of network activity. See the "Call Statistics Screen" section on page 7-16 for information about displaying these statistics. 9-16 Cisco Unified IP Phone 7931G Administration Guide for Cisco Unified Communications Manager 6.0 OL-12457-01