Cisco 7941G Administration Guide - Page 244

General Troubleshooting Tips Chapter 9 Troubleshooting and Maintenance Table 9-2 Cisco Unified IP Phone Troubleshooting (continued) Summary Explanation 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 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. Loopback condition. A loopback condition can occur when the following conditions are met: • The SW Port Configuration option in the Network Configuration menu on the phone is set to 10 Half (10-BaseT / half duplex) • The phone receives power from an external power supply • The phone is powered down (the power supply is disconnected) In this case, the switch port on the phone can become disabled and the following message will appear in the switch console log: HALF_DUX_COLLISION_EXCEED_THRESHOLD To resolve this problem, re-enable the port from the switch. 9-16 Cisco Unified IP Phone 7961G/7961G-GE and 7941G/7941G-GE for Cisco Unified Communications Manager 6.1 OL-14620-01