Manager; Insufficient Bandwidth For Video Calls; Video Changes Resolution - Cisco Unified IP Phone 8941 Administration Manual

Audio and Video Problems
Cause
There may be a mismatch in the jitter configuration.
Solution
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.
Poor Audio Quality with Calls that Route Outside Cisco Unified Communications Manager
Problem
Poor quality occurs with tandem audio encoding. Tandem encoding can occur when calls are made between
an IP Phone and a digital cellular phone, when a conference bridge is used, or in situations where IP-to-IP
calls are partially routed across the PSTN.
Cause
In these cases, use of voice codecs such as G.729 and iLBC may result in poor voice quality.
Solution
Use the G.729 and iLBC codecs only when absolutely necessary.

Insufficient Bandwidth for Video Calls

Problem
Users report that calls with video suddenly drop the video component of the call. The video part of a call
cannot be established.
Cause
The network has run out of resources for the video call.
Solution
Changes need to be made on the Cisco Unified Communications Manager. For more information, see Cisco
Unified Communications Manager Systems Guide.

Video Changes Resolution

Problem
Users report that calls with video change the video resolution (become more grainy) during the call.
Cause
The network is experiencing network resource limitations and the phone is attempting to compensate by
changing the video resolution.
Cisco Unified IP Phone 8941 and 8945 Administration Guide for Cisco Unified Communications Manager 10.0
(SCCP and SIP)
178