IGMP / Multicast Video Issue


Just installed a MyNet N900 wireless router.  For the most part, everything works great - PC’s, Laptops, Webcam, Kindle Fire, Kindle DX, Android Phones, etc.

I also have a WD LiveHub running the Skitter App for IPTV - Multicast Video.  The LiveHub is running over Cat5 wiring through a WD Live Wire Ethernet over Power device.  So far, so good.

Where I run into trouble is using a WD Live box connected wirelessly.  The device connects, the Skitter App loads, logs in, pulls the guide data, but won’t stream the multicast video.  I’m assuming that it is an issue with IGMP snooping/querying over the wireless link.

I’ve had similar issues with other manufacturer’s routers, with the lone exception of the Innoband 4000-R2.  The only problem with that router was throughput  - I was getting a maximum of 20MB over a 50mb pipe. Allowing multicast over the wireless link was simple - a checkbox that allowed/disallowed IGMP.

The WD MyNet is doing everything (plus getting throughputs of up to 58.8MB) EXCEPT allow multicast video over the wireless portion of the router.

My usual test is to use the VideoLAN VLC player  on my laptop and open the stream directly with the UDP address.  I’m getting similar results there.  If I connect the laptop with a cat5 cable, the VLC player runs the streams fine, if I connect wirelessly, the streams are choppy at best with distorted audio and pixelated video.

Any ideas?



I think you’ve already diagnosed the issue.

Multicast support over WiFi is dodgy at best … for ANY vendor, especially expecting IGMP to work on the WiFi side.

To find out what’s really going on, you’re going to need a Wireless PC running Wireshark.

If the failure to stream is due to multicast FLOODING (due to lack of IGMP), you’ll see that on the PC.

If you’re NOT seeing packet flooding, then there’s something else going on.

Keep in mind that IGMP snooping will generally only affect the “link” between the Wireless Radio and the router.

If you have a multicast stream heading to the AP, the AP itself must replicate EVERY packet to EVERY device that’s associated to the AP.

So if you have three devices associated to the WiFi AP, every multicast packet has to be “copied” three times, re-encrypted, and changed to the outbound datarate for each individual client.

So before you do ANY WiFi test, you may need to make sure there are NO other clients associated.

That’s why WiFi multicast is SO DIFFICULT.