Thousands of Blue Screen events on remote IP cameras

[jonathancnewcomb]

Hello, I am a network engineer, I had a similar problem and I found that TCP retransmissions were the root cause of the problem. You can validate this by installing tcpdump and tcptrace on your linux box (look for them in your package manager) then use the following filter:

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$ tcpdump -i [interface] -w dump.out port 80

Let this run until you catch a loss of signal, then evaluate using tcptrace:
Use CTRL+C to break

Note: You should see "X packets received by filter" where X is > 0

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$ tcptrace dump.out

Now then, you will see a list of TCP streams that were captured, there will be a number associated. Find the number next to the stream for your camera and replace the "#" below with that number:

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$ tcptrace -r -l -o# dump.out

You will see values in the output such as RTT and max # retrans, ensure that your RTT is below 150ms and the number of retransmissions are close to 0 (this will vary depending on capture time). Also, you will see throughput used by the stream, ensure your switch is capable of handling the load. All switches have maximum throughput and you may have to take that into account too.

[mmike]

Similar issue here - I resolved it by removing any settings in "Maximum FPS" for each camera. HTH

Same problem, this fixed the issue. I also removed the Alarm Maximum FPS also to see what happens.

[Vladyck]

I had same problem. decreasing FPS & quality on camera appropriate to monitor`s settings / network bandwidth has resolved this