With NDI 3.8
We are encountering on several projects an issue that can't be solved without Newtek's insight.
We work on multimedia installations that include many feeds : Dante audio, DMX, sensors... and are used to defining one VLAN per type of feed in order to manage our broadcast domains properly.
The following drawing shows a typical configuration that we use (note that we have most of the time 1x 10Gb adapter dedicated to NDI)
We do want to contain NDI in its own VLAN. This is for a reason : We do not want NDI automatic load-balance to take 100% of the Audio or ArtNET link, leaving nothing behind...
The general question is : how can we control NDI so that it will only use the adapters that we specify (as Dante does) ?What we already tried :
- We already asked NewTek's support about this and they indicated that access manager could help... but it looks like this tool is not meant for that.
- We tried to understand how the network adapter is elected by playing with the metrics and other type of parameter... no way to understand clearly and that only solves partially the problem.
- We wrote ACL in our switches :
- first version was pretty drastic and was to deny NDI feeds (UDP 5960-5970) on any VLAN other than NDI. It turned to NDI receivers not receiving the feeds anymore : the teaming algorithm seems not resilient enough to consider using an alternate network interface if the connection fails on the selected interface. With these ACL enabled : only the machines that (for an unknown reason) slected the NDI NIC by "default" could receive the feeds.
- we also worked on the discovery itself by denying mDNS on all VLANs except NDI. In this situation, a tool like NDI Analysis tool now clearly lists only IPs in the NDI subnet. But when we do connect the feeds, the "magic" behind NDI makes the feed going again through any of the other VLAN that the sender and receiver have in common... Moreover, no way for us to disable mDNS as a long term solution...
We would like to know :
- For a sender/receiver, is there a secret menu/config-file/network-adapter-naming-convention to tell NDI SDK not to use one or several Network Adapters ?
- If not, is there an official recipe for ACL that we could apply to our network so that NDI is contained in one single VLAN without creating side-effects?
- Could someone share detail about how a complete NDI handshake works (ex : sequence diagram) ? We could maybe have a better understanding of where the sender and receiver agrees on a specific network link to transport a feed ?