logo

Live Production Software Forums


Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Options
Go to last post Go to first unread
Andrew  
#1 Posted : Tuesday, March 2, 2021 6:54:31 AM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
I doubt this is actually a vMix problem, more a NDI / network configuration / multicast issue.

I'm experiencing significant NDI freezes when roughly 15 or more devices are receiving a NDI feed from vmix.

Device often needs to look at another NDI feed and back to the main one to make it work again. I think that just immediately cuts off another device, although not had opportunity to check that for sure.

Available bandwidth is not a problem.

vMix > 10GBe > Managed switch, 2 x 10GB ports, 8 x 1GB ports (GS110EMX) > 1GBe > 4 x 8 port 1GB switches (GS308) > devices... (laptops)

If I instead share out the 4 vMix NDI outputs amongst all the devices, so each NDI feed is only received by a handful of devices, it's all fine.

My networking knowledge is limited, but as far as I know with multicast vMix wouldn't even know if 1 or 100 things were watching it's NDI feed anyway.

So what could be causing this?

Have followed Newtek's switch config guidelines as close as I can given the limited feature set in the 10GB switch, and the 1GB switches are unmanaged.

Jumbo frames off.
QoS off.
IGMP on.

Network has other NDI traffic, each of the 20 laptops are screensharing back to vMix, various production monitors, vmix calls etc. These all function properly.
Network also serves internet to devices that need it.
No firewalls.

I don't typically have 20 devices on hand to test this, but I have an opportunity next week so any suggestions anyone has would be most welcome!

Cheers


xaver  
#2 Posted : Tuesday, March 2, 2021 7:37:40 AM(UTC)
xaver

Rank: Advanced Member

Groups: Registered
Joined: 11/11/2016(UTC)
Posts: 378
Man
Location: Europe

Thanks: 23 times
Was thanked: 38 time(s) in 32 post(s)
AFAIK vMix NDI isn't multicast
so it needs one connection per client
Andrew  
#3 Posted : Tuesday, March 2, 2021 9:06:05 AM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
Ah, interesting, then I might be saturating the 1GB links between the switches.

Thank you, I'll look into that.
Andrew  
#4 Posted : Tuesday, March 2, 2021 9:40:49 AM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
Ahh no it can't be bandwidth, because it works when I spread the load between 4 vmix outputs.

Perhaps vmix simply has a limit to the number of NDI clients per output.
mavik  
#5 Posted : Tuesday, March 2, 2021 9:51:33 AM(UTC)
mavik

Rank: Advanced Member

Groups: Registered
Joined: 4/23/2017(UTC)
Posts: 1,126
Man
Location: Germany

Thanks: 3 times
Was thanked: 164 time(s) in 146 post(s)
The bandwidth can very quickly be a problem.


To get a multicast you may need to go via HDMI into an NDI encoder that supports multicast. Make sure your network is multicast enabled. That isn#t switched on by default in most cases.
Andrew  
#6 Posted : Tuesday, March 2, 2021 11:17:17 AM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
Just done a quick test with a few devices. Multicast appears to be working properly. Same bandwidth on the vmix PC with 1 or 5 clients.

I should mention that NDI access manager has multicast enabled of course.
AudioGreg  
#7 Posted : Tuesday, March 2, 2021 12:40:07 PM(UTC)
AudioGreg

Rank: Advanced Member

Groups: Registered
Joined: 7/1/2020(UTC)
Posts: 78
United States
Location: Earth

Was thanked: 15 time(s) in 13 post(s)
Try turning IGMP off, does this make any difference? IGMP trims where multicast packets go...if turning it off improves your issue then perhaps the IGMP rules need adjusting. I've also found that IGMP functionality isn't always enforced equally between different brands of switches.
Andrew  
#8 Posted : Tuesday, March 2, 2021 7:53:57 PM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
My suspicion is that would be quite detrimental on the network, as the vMix PC has many NDI feeds available it could saturate the whole network with unnecessary data without IGMP snooping on.

Could be a good testing exercise though (if I turn off all the other NDI outputs) to see if it solves the 15+ limit, will give it a go next week, thanks.
3xscreen  
#9 Posted : Thursday, March 4, 2021 7:39:21 PM(UTC)
3xscreen

Rank: Member

Groups: Registered
Joined: 7/9/2020(UTC)
Posts: 11
United Kingdom
Location: London

Was thanked: 1 time(s) in 1 post(s)
We had a very similar issue yesterday when doing a vMix production where we were taking two speakers and their slide feeds from MS Teams using it's NDI broadcast feature, mixing in vMix with PiPs, branded backgrounds, namestraps, VTs, etc - and then broadcasting the mixed production on BlueJeans and to a backup microsite. We had primary and backup machines on the MS Teams call. At then time of the production we had vMix sessions open on 3 or 4 other machines and a couple of other machines turned on that put NDI on to the network.

What I didn't realise was:
- if NDI output is selected on a vMix machine, it gets output on to the network even when External isn't selected
- it seems it is the number of available NDI sources rather than the number of selected NDI sources that is significant for vMix machines. We were seeing jerkiness on the 3 NDI sources we were using and we fixed it by turning off the vMix machines we weren't using - that's what it seemed anyways

What we are going to do is migrate all our vMix machines to 10GB Ethernet and create a NDI production VLAN

regards, Scott
Andrew  
#10 Posted : Saturday, March 6, 2021 9:59:41 PM(UTC)
Andrew

Rank: Advanced Member

Groups: Registered
Joined: 6/26/2011(UTC)
Posts: 30
Location: London

Was thanked: 8 time(s) in 4 post(s)
Yeah External output is unrelated to NDI.

Your observation of the number of NDI sources available on the network affecting the stability is not something I've seen, we often have well over 100.

Were the other vMix machines also pulling the same NDI feeds you were using on your main broadcast machine?
3xscreen  
#11 Posted : Saturday, March 6, 2021 11:02:27 PM(UTC)
3xscreen

Rank: Member

Groups: Registered
Joined: 7/9/2020(UTC)
Posts: 11
United Kingdom
Location: London

Was thanked: 1 time(s) in 1 post(s)
Cheers Andrew for the reply. I think I wasn't seeing the forest for the trees - the issue was more likely that we had too much NDI traffic on a Gigabit Ethernet network and we should migrate to 10 Gb - ie. nothing to do with the vMix machine itself
dperaltajr  
#12 Posted : Sunday, March 7, 2021 4:08:34 AM(UTC)
dperaltajr

Rank: Member

Groups: Registered
Joined: 3/24/2020(UTC)
Posts: 27
United States
Location: Burlingame, CA

Was thanked: 5 time(s) in 3 post(s)
Have you tried enabling multicast for your device? You can set this up using NDI Access Manager then restart vmix.
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.