Fibre DR Link Trunk

[millstParticipant]

I’ve opened a support request on this as well but I thought I’d ask the community as well. If I can get this issue solved I’ll do a write up and maybe even a tutorial video on how to set it up as I think it could be very useful for a lot of companies who are trying to implement multi network fibre solutions (Dante, NDI, Lighting etc all down a single fibre from FOH).

We are setting up a fibre based system so we can pump everything down a single fibre pair from stage to FOH.

We chose the Microtik CRS328 as it has 24 ports with PoE on each and 4 x SFP+ ports for 10Gbit fibre trunks which is really nice.
This allows PoE dante devices, IP8 controllers and NDI decoders to plug straight into the core switch without any injectors. We were hoping it was going to be the holy grail of easy gig setups 🙂

We have seperate VLANs for everything, a general laptop VLAN with internet etc, a VLAN for Dante, a VLAN for NDI video and a VLAN for Lighting control. These all work great and we have no issues with Dante glitches or dropping NDI packets.
Then we have 4 ports setup on each switch for use as gigAce or DR link extension, ports. For example port 24 is in its own VLAN and the only other ports on it is port 24 in the other switch (Auto neg is off and ports set to 100Mbps FD for DR and 1000Mbps for gigAce).

This is where we have run into fun 🙂

We are finding the DR link in particular is having issues, the whole solution works perfectly so long as there are no other devices on the switch and no other traffic going down the trunk, but as soon as we plug in a Dante source etc on another VLAN then the dLive loses clock sync with the expander and we start hearing audio glitches. Dante continues working perfectly when this is happening.

We have turned off all Layer 3 prototols on the VLANs for the DR Link switch pairs and there is no other traffic getting into the VLANs that could be causing this.

Our conclusion is that it must be a QoS issue on the trunk and for some reason the Dante packets are being prioritised over the DR Link ones. Even though there is 10Gbit of bandwith available and the DR link VLAN is only using 100Mbps.

I’ve had a look at the DR Link documentation but I can’t see anything about QoS settings.

Do you have any recommended QoS settings for DR Link VLANs?

Do you have any working configurations that you could share for Microtik Switches (The CRS 328 switches really could be the perfect compliment to a large dLive setup if we can get it working. I’m happy to share my working config and do a full write up on this setup after we get it going).

I’ve opened a similar request on the Microtik forums to see if we can solve it from that end, but I thought I’d drop you a line on this to see if you have any experience in these sorts of issues or if you have a working Microtik config you could share.

Regards

Toby Mills
noise productions ltd
http://www.np.co.nz

[SwellParticipant]

Toby,

I’m commenting because I too am interested in this and hopefully the solution. I can’t say for sure why it’s not working. I was going to mention forcing the Vlan to layer 2 100mbs but it seems like you already did that.

Anyone else had success with this yet?

Side note, those Dante DT168 stage boxes are looking more attractive for this type of use in the future.

[millstParticipant]

I’m still battling this. I’ve resorted to fibre media converters over another pair in the fibre.

I have it all working but the CPU in the switches is running at 100% and dropping packets.

It appears the expander traffic is leaking into the cpu and overloading it so I just have to figure out how to stop this happening.

I won’t give up till I get it working.

[Author]

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