Cisco Systems 8961 manual 12-13

Chapter 12 Troubleshooting and Maintenance

General Troubleshooting Tips

Table 12-2	Cisco Unified IP Phone Troubleshooting (continued)
Summary		Explanation
Blocky or distorted video		Blocky or distorted video is generally a symptom of a degraded network. It is
		also caused by endpoints that do not closely adhere to video transmission
		standards.
		If the network is degraded, navigate to AdminSettings > Status > CallStatistics
		> Video > Video statistics, and check the following:
		•	Rcvr Lost Packets
		•	Rcvr Discarded
		•	Avg Jitter
		•	Max Jitter
No Video or black video screen		The video is black and no picture appears on the screen.
		• Verify that video is enabled in the Cisco Unified CM.
		• Cisco Unified IP Phone 8961, 9951, and 9971 phones do not display videos
			with a resolution higher than VGA (640x480). If the other endpoint
			transmits at a resolution greater than VGA, it will result in a black screen.
			Check the resolution of the transmitting endpoint.
		• There might not be any packets received for video display. Check the Rcvr
			Packets (would be zero in this case) in the AdminSettings > Status >
			CallStatistics > Video > Video statistics.
		• Ensure that the transmitting phone has the camera shutter completely open.
Frozen video		When the phone stops receiving video packets, the video displayed will pause,
		displaying the last decoded video frame.
		• Check if the received packets count is incrementing or not, by navigating to
			AdminSettings > Status > CallStatistics > Video > Video statistics >
			Rcvr Packets statistics.
		• Try to hold and then resume the call to clear the issue.
		• If the transmitting phone is also Cisco Unified IP Phone 8961 or 9951 or
			9971, check the LED on top of the camera. If there is no light illuminated
			(either green or red) then the remote camera might not be transmitting video.
Slow moving video or jittery video		The frame rate of the received video is low. Check the rate by navigating to
		AdminSettings > Status > CallStatistics > Video > Video statistics > Rcvr
		Frame Rate. Frame rates less than 15 fps will result in slow-moving video.
Audio/Video synchronization is poor		• Check if RTCP is enabled in the Cisco Unified Communications Manager.
		• Audio/video synronization is generally caused a by degraded network
			connection. Check by navigating to navigating to AdminSettings > Status
			> CallStatistics > Video > Video statistics > Avg Jitter and
			AdminSettings > Status > CallStatistics > Video > Video statistics > Max
			Jitter values.
		• Try to hold and then resume the call to restore the audio/video
			synchronization.

	Cisco Unified IP Phone 8961, 9951, and 9971 Administration Guide for Cisco Unified Communications Manager 8.5 (SIP)
OL-20861-01		12-13