Network Overload? IPTV

  • Hello,

    I have managed to configure the firewall to allow BT TV through as per the thread here…

    I thought I would start a new thread as it a new issue.

    It would seem that the network is now overloaded when I am watching a IPTV channel on BT TV.

    The 'Find Out What's On BT TV' channel is SD and runs at about 2M Bits bandwidth and I can just use the internet and communicate with other machines on my network.

    If I change to a HD channel at about 9 - 10 M Bits bandwidth, no joy, timeouts. I have left a simple ping from one internal linux ip to another running and the response times jump from 1.5ms to > 8000ms. So this indicates that something is causing massive latency.

    My thoughts are the network (LAN) is getting flooded with multicast messages?

    Can anyone help with any suggestions as to how to fix it?

  • Don't just guess, make some educated guesses. Measure it. Take a traffic dump and look it over to see what the traffic looks like, then we can limit the possibilities from infinite to finite.

    System Activity info could help to, increase it's a performance issue.

  • I've seen this with older WLAN equipment, brought the whole net down with just one 300Kb/s Multicast stream.

  • You didn't say bit I guess you have a WLAN? Wireless LAN is vulnerable to being flooded by multicast traffic until saturated.

    Multicast traffic is implemented by broadcasts within an ethernet broadcast domain. Every node will receive all frames and has to ignore what he is not interested in.

    You can limit the Multicast traffic by using IGMP-aware switches. These devices interpret the IGMP (which is used for communicating which node is actively reading which multicast traffic). That allows these switches to limit the multicast traffic to those ports on which nodes are connected which want to receive the traffic. The feature is named "IGMP snooping" in switches.

    Whether or not this can help you however depends completely on you network structure. If you have connected your IP set via WLAN this will not help for example.

  • Could it be cheap network cards doing it?

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