NDI Multicasting

Hello,
I am trying to use NDI multicasting but so far I wasn’t successful. Unicasting works as expected, but once I enable multicasting in NDI Access Manager on source computer, stream won’t start on destination computers (using NDI In TOP). I have enabled IGMP Snooping based on this document but it didn’t help. Firewall doesn’t seem to be an issue here as I tried disabling it. I guess I am missing something important here but I can’t figure out what is it :smiley: Should I also somehow configure destination computers via NDI Access Manager? Thanks.

I have tested this outside of Touchdesigner (using NDI Test Patterns and NDI Studio Monitor) but results were the same. I know this is not particularly Touchdesigner-related topic, but I am wondering whether did anyone managed to get multicast working with NDI? Thanks :slight_smile:

hi,

never tested but maybe have a look at Sienna NDI Access Manager where you can set multicast addresses

Thanks for reply. I will give it a try but I guess this is somehow related to IGMP queries and snooping. I am not very skilled at setting up networks so I am still trying to figure out where have I done logical errors in my IGMP setup.

well IGMP snooping is managed by routers so you need to activate it on your routers.

Then each sources / destinations can have a local address but the streams need to refer to dedicated multicast addresses like 239.x.x.x for the routers to treat them as multicast transport.

The source will push the data on a channel group on which the destinations need to register to read the stream

I am working only with L2 network so I don’t have any routers / L3 switches connected. Nevertheless I have my switches set to IGMP snooping while one switch also acts as a IGMP querier.

If I am not mistaken IGMP querier should send queries to all hosts asking them whether they want to join multicast stream. If they subscribe to this stream, querier then forwards stream to them (while switches in-between forward this traffic to proper ports based on “snooped” IGMP messages).

Even though I can see that there is some incoming network traffic present on clients (this traffic starts as soon as they subscribe to mukticast stream), NDI Monitor shows just black data.

Hello,
I have been fighting with this problem over last weeks but I haven’t figured it out yet. Please has anyone here got NDI multicasting to work? I believe I have my network configured correctly for multicasting as RTSP with multicasting works as expected. I have followed this video from Cisco and configured my switch for both IGMP querier and IGMP snooping. However, once I select NDI stream it is empty.

I am starting to feel like there is a problem with NDI when using multicasting. Feel free to also check out this thread where is the same problem described in detail. Only solution described there was to downgrade NDI version.

Ahh, I just tried to downgrade Touchdesigner to version 2020.20625 (with NDI 4.1 if I am not mistaken) and it works without any problem. The whole time I thought I have some problem with my network setup but it was just NDI SDK multicasting regression…