PDA

View Full Version : NDI experience at large university



jtm57
11-13-2017, 12:53 PM
I wanted to briefly convey my recent experience trying to deploy NDI at a large university (rhymes with Stanford).

The sports video department is very enthusiastic about NDI conceptually, though they had no prior awareness of the capability. They instinctively embrace the notion that fewer wires is very desirable. However, NDI doesn't work on their internal network and the video group doesn't know why. Lacking any tools to diagnose the network problem, they went with their traditional setup and workflow for the day's athletic event. I noted that Apple Airplay worked fine on the same network.

spaulsen
11-13-2017, 03:46 PM
Hi jtm57,

Generally I've found that NDI is easily implemented on standard 1GB Ethernet networks, it just works. But, without knowing their setup and workflow its hard to say why they experienced an issue and what the possible resolution may be. Here's an example of a recent university implementing NDI within their production.

https://www.newtek.com/blog/2017/10/13/harvard-athletics-centralizes-control-rooms-with-ndi-and-existing-network/

Regards,
Steve

kanep
11-13-2017, 04:04 PM
There is a technical document that gives you information on the NDI, give this to your IT dept so they can make sure the networking is blocking traffic.
https://233b1d13b450eb6b33b4-ac2a33202ef9b63045cbb3afca178df8.ssl.cf1.rackcdn.c om//pdf/newtek-ndi-technical-brief.pdf

When you say it didn't work there is a lot of room for interpretation. Did NDI channels appear for you to try to connect to? Did it try to connect, but got nothing? Or was the video having performance issues?

As Steve mentions above, a lot more about your network is needed.

jtm57
11-13-2017, 11:25 PM
Hi jtm57,

Generally I've found that NDI is easily implemented on standard 1GB Ethernet networks, it just works. But, without knowing their setup and workflow its hard to say why they experienced an issue and what the possible resolution may be. Here's an example of a recent university implementing NDI within their production.

https://www.newtek.com/blog/2017/10/13/harvard-athletics-centralizes-control-rooms-with-ndi-and-existing-network/

Regards,
Steve

Yes, I've chatted with Imry. In Stanford's case, bandwidth isn't an issue -- the NDI stream we're working with is very low bit rate. NDI is somehow getting filtered, perhaps at the end point or in the network.

jtm57
11-13-2017, 11:31 PM
There is a technical document that gives you information on the NDI, give this to your IT dept so they can make sure the networking is blocking traffic.
https://233b1d13b450eb6b33b4-ac2a33202ef9b63045cbb3afca178df8.ssl.cf1.rackcdn.c om//pdf/newtek-ndi-technical-brief.pdf

When you say it didn't work there is a lot of room for interpretation. Did NDI channels appear for you to try to connect to? Did it try to connect, but got nothing? Or was the video having performance issues?

As Steve mentions above, a lot more about your network is needed.

The NDI channels didn't appear. Can't say what the issue is and perhaps Stanford IT will figure it out. It's a challenge, though. The video group has their levers and expertise which, in this case, doesn't include network diagnostics and configuration.

- - - Updated - - -


There is a technical document that gives you information on the NDI, give this to your IT dept so they can make sure the networking is blocking traffic.
https://233b1d13b450eb6b33b4-ac2a33202ef9b63045cbb3afca178df8.ssl.cf1.rackcdn.c om//pdf/newtek-ndi-technical-brief.pdf

When you say it didn't work there is a lot of room for interpretation. Did NDI channels appear for you to try to connect to? Did it try to connect, but got nothing? Or was the video having performance issues?

As Steve mentions above, a lot more about your network is needed.

Forgot: thanks much for the document. I'll pass that along.

Zane Condren
11-14-2017, 09:56 AM
Do you know if all of the devices are on the same subnet? If they are on separate subnets most networks block mDNS broadcasts between switches. Using NDI access manager you can manually enter the IP address of the sending device to the receiving device and it will connect without mDNS.

jtm57
11-15-2017, 11:10 PM
Do you know if all of the devices are on the same subnet? If they are on separate subnets most networks block mDNS broadcasts between switches. Using NDI access manager you can manually enter the IP address of the sending device to the receiving device and it will connect without mDNS.

Yes, IT says same subnet.

imryh
11-16-2017, 09:26 AM
Have you tried using access manager? Sometimes, even within the same subnet, there's some discovery issues. I have found NDI Access Manager to take care of those issues.

jtm57
11-17-2017, 12:53 PM
No, haven’t tried that. The opportunity has passed. I noticed that Airplay found Apple TVs on this network. I wondered why NDI discovery wasn’t as robust as it appears to use the same sort of protocol as Airplay.

SBowie
11-17-2017, 01:17 PM
Your IT guys probably opened the ports that AirPlay requires, while limiting others they thought were not needed.

jtm57
01-11-2018, 09:57 PM
Another NDI fail tonight, this time on a high school Wifi network. Airplay worked fine, NDI didn't. Suggest that a design goal for the NDI protocol is to be as robust as the Airplay protocol as they share very similar data and discovery functionality. Either that or better tools for diagnosing discovery and transport issues.

spaulsen
01-12-2018, 01:20 PM
NDI is designed for standard Ethernet networks and not wifi. NDI will work over a wireless network but depending on the bandwidth available and video being transported. NDI|HX is optimized for use on wifi however and products like the Connect Spark work very well on transporting signal over wifi.

livepad
01-12-2018, 02:40 PM
Another NDI fail tonight, this time on a high school Wifi network. Airplay worked fine, NDI didn't. Suggest that a design goal for the NDI protocol is to be as robust as the Airplay protocol as they share very similar data and discovery functionality. Either that or better tools for diagnosing discovery and transport issues.

The consistent failure at this site across different network tends to point more towards a systemic problem with overly exercised network restrictions.

NDI generally works great, right out of the box. You generally have to do quite a bit of work to stop it working, and I suspect that is exactly what is going on.

Most likely the overly zealous IT folks would need to back off a little and undo some of the network restrictions.

More than likely they have done that for AirPlay but not for NDI - yielding the situation you describe. its probably not a fault with NDI.

Using NDI Access will effectively eliminate a dependance on Bonjour (mDNS) and may be your solution, but requires explicit setup and it doesn't currently work (in both directions) on Mac and Linux.

jtm57
01-13-2018, 12:21 AM
NDI is designed for standard Ethernet networks and not wifi. NDI will work over a wireless network but depending on the bandwidth available and video being transported. NDI|HX is optimized for use on wifi however and products like the Connect Spark work very well on transporting signal over wifi.

Yes, I've heard that before. In this particular case, bandwidth isn't an issue -- it's the discovery protocol that fails. All of the NDI senders are low bit rate.

jtm57
01-13-2018, 12:45 AM
The consistent failure at this site across different network tends to point more towards a systemic problem with overly exercised network restrictions.

NDI generally works great, right out of the box. You generally have to do quite a bit of work to stop it working, and I suspect that is exactly what is going on.

Most likely the overly zealous IT folks would need to back off a little and undo some of the network restrictions.

More than likely they have done that for AirPlay but not for NDI - yielding the situation you describe. its probably not a fault with NDI.

Using NDI Access will effectively eliminate a dependance on Bonjour (mDNS) and may be your solution, but requires explicit setup and it doesn't currently work (in both directions) on Mac and Linux.

Overzealous is a judgement that I can't make without more data. In our four installations we've had four discovery failures so what might be viewed as network administration run amok might just be par for the course. The networking folks at this high school site will take a deep dive into why the NDI discovery is failing and I'm looking forward to that investigation.

Our experience is not that NDI works out of the box though I understand that others have had a higher success rate. Better diagnostic tools would be helpful.

livepad
01-13-2018, 06:43 AM
Overzealous is a judgement that I can't make without more data. In our four installations we've had four discovery failures so what might be viewed as network administration run amok might just be par for the course. The networking folks at this high school site will take a deep dive into why the NDI discovery is failing and I'm looking forward to that investigation.

Our experience is not that NDI works out of the box though I understand that others have had a higher success rate. Better diagnostic tools would be helpful.

One useful tool is Bonjour Browser. It lets you view Bonjour advertisements outside of an NDI-specific environment. it might let you see where Bonjour sources are and are not available and draw some conclusions from that.

Mac: Bonjour Browser (http://www.tildesoft.com)

Windows: Bonjour Browser (https://hobbyistsoftware.com/bonjourbrowser)

kanep
01-13-2018, 08:08 AM
I'd add that while is could be mDNS/Bonjour being blocked, it could also be ports 5960/TCP and up.

First, port 5960 is used as the directory of NDI sources available. If this port is blocked, even if mDNS gets through, the NDI application will not get a list of any sources available for use.

After that, ports 5961/TCP (and up) are used for the transmission of each NDI source. If you get the list of sources, but when you choose them no video appears, the blocking of these ports could be the problem.

livepad
01-14-2018, 11:17 AM
I'd add that while is could be mDNS/Bonjour being blocked, it could also be ports 5960/TCP and up.

First, port 5960 is used as the directory of NDI sources available. If this port is blocked, even if mDNS gets through, the NDI application will not get a list of any sources available for use.

After that, ports 5961/TCP (and up) are used for the transmission of each NDI source. If you get the list of sources, but when you choose them no video appears, the blocking of these ports could be the problem.

Just to clarify, I believe 5960 is specifically required for the NDI Access mechanism. I don't think its required when Bonjour mDNS is working properly.
However, as Kane says, 5961 onwards is where your NDI sources are going to exist for the actual video flow.

Given that the description appeared to be 'no sources appearing', and that NDI Access was not mentioned, on balance, it still seems likely that mDNS blocking is the issue.

jtm57
01-15-2018, 12:09 AM
I'd add that while is could be mDNS/Bonjour being blocked, it could also be ports 5960/TCP and up.

First, port 5960 is used as the directory of NDI sources available. If this port is blocked, even if mDNS gets through, the NDI application will not get a list of any sources available for use.

After that, ports 5961/TCP (and up) are used for the transmission of each NDI source. If you get the list of sources, but when you choose them no video appears, the blocking of these ports could be the problem.

Very good suggestions, thanks, I'll pass that on to the networking folks.

The organizational implications for in-house NDI deployment are challenging. The media group doesn't understand networking details (and typically doesn't control the levers even if they did). The networking folks are generally risk averse, as they should be, and even more so in education. "You want us to do...what? I'm not sure we can do that. Try the network as it is, call me in the morning." Separate groups, different language, painfully disconnected dialogue, if any. Slow progress, learning on both sides, fun and exciting to watch if not entirely at the desired pace.

jtm57
02-11-2018, 05:57 PM
Very good suggestions, thanks, I'll pass that on to the networking folks.

The organizational implications for in-house NDI deployment are challenging. The media group doesn't understand networking details (and typically doesn't control the levers even if they did). The networking folks are generally risk averse, as they should be, and even more so in education. "You want us to do...what? I'm not sure we can do that. Try the network as it is, call me in the morning." Separate groups, different language, painfully disconnected dialogue, if any. Slow progress, learning on both sides, fun and exciting to watch if not entirely at the desired pace.

Update: in real world NDI deployments in four public high schools and one medium sized, technically savvy and academically prestigious university, we are zero for five in finding an NDI-compatible and available network. In two cases, we've directly conveyed the NDI ports requirement to the networking group and they were unresponsive. Surprisingly, the university in-house video production group either wasn't interested in or capable of convincing the networking group to make the requisite port-level changes.

This is a serious impediment to using NDI-based workflow and products at least in the five schools we've visited. Perhaps there is a technical solution with less friction than "open these ports." Targeting relevant networking professionals with marketing advocacy/outreach -- starting with Newtek customers -- would be helpful, too.

Zane Condren
02-12-2018, 09:13 AM
If you can get your IT staff to agree to join a conference call I can schedule a call with our professional services staff to help them understand it.

jtm57
02-13-2018, 07:55 PM
Thank you, Zane. I appreciate the outreach and offer.