CTS system - Basic Video quality troubleshooting

High level description

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1. Obtain an accurate problem description:
  • Display flickering, snowy
  • Pinkish,greenish,blueish
  • Black Display during loopback as well as during the call
  • Half image, zoom in
  • Other....

Obtain pictures or video when problem is happening

2. Problem details:
• New install, upgrade?
• Reproducible, random
• Start of the call, end of the call, after display is idle?
• Point to point calls?, Multi-point calls?
• Do we have a video or a picture when problem occurs.
• Problem only with one type of unit? Interop ?
• Problem appears after firmware upgrade? Any network changes? 
• Any message during the failure (i.e Network congestion etc.)
• Verify type of Display and generation (CTS 500 GEN2 37", CTS 1000 GEN2 65", etc)
• Obtain app code and boot code:
  - App code, boot code and firmware must be the same on all three displays

Isolating the problem

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• We can try first a loopback with encoder enabled, this will confirm codec itself is not dropping packets

From SSH CLI:
diag display loopback full enable

• If ICMP is enabled across the path we can use mtr to see which device may be introducing delay, packet loss, etc. 

 utils network mtr count 100 tos  160

Replace 160 for your current QoS marking:

http://mytelepresence.blogspot.com/2010/04/telepresence-system-mtr-utility.html

• Verify Packets sent/receive show proper QoS value and proper policy maps are matched

• Network devices:

Verify SRND guide to make sure we meet network requirements:

http://www.cisco.com/en/US/docs/solutions/Enterprise/Video/TP-Book.html

1) ‘show run’ output

In addition, I would suggest collecting the following information to further isolate network traffic:

1)  Interf type x/y <- WAN interface
2) ‘load-interval 30’
3) Reproduce problem and keep call up for perhaps 5 mins and then collect
the following information while the call is still up and while packet loss is being seen:

a) ‘show interf intftype x/y’
b) ‘show policy-map interf intftype x/y ’
c) ‘show queue intftype x/y’

The above should allow us to (a) determine what our guaranteed bandwidth really is (b) determine where we are seeing drops (ex: interface drops vs software queuing drops).