# multicast connection testing tool



## bbzz (Oct 18, 2011)

I'm looking for a good open source tool to measure multicast delay, jitter, packet loss, etc for clients on local network. I guess something like Multicast Beacon, but for local LAN. I have pretty much no idea what to look for so any suggestion is welcome.


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## ecazamir (Oct 18, 2011)

If you encounter packet loss for unicast traffic, you'll encounter for multicast too. I assume that the above statement can be reversed: You'll have packet loss for unicast traffic if you encounter packet loss for multicast traffic.

A very useful tool to measure delay/jitter/packet loss is benchmarks/iperf. For windows is available a wrapper with a graphical frontend, called "jperf".


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## bbzz (Oct 18, 2011)

Yeah I remembered about iperf soon after I posted, good stuff. Is there anything else I could try? 
Thanks

BTW, 





> If you encounter packet loss for unicast traffic, you'll encounter for multicast too. I assume that the above statement can be reversed: You'll have packet loss for unicast traffic if you encounter packet loss for multicast traffic.



That may not be necessarily true.


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## ecazamir (Oct 18, 2011)

Of course, packet loss may occur on a single direction, if this is this case then unicast packet loss will definitely occur for a TCP connection. For UDP, it may be possible that the upstream (or downstream) packet flow to have no loss.
Please, let me know of other scenarios where multicast packet loss may occur AND a unicast TCP stream on the same network segment won't encounter loss.


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## bbzz (Oct 18, 2011)

How about a different QoS policy for two types of traffic.


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