SQ5, AR2412, AR128 and networking.

SQ SQ General Discussions
1

Hello,
There are a few posts in the forum that say the networking that the Audio Rack devices are simply a Layer2 protocol, and can work with switches…
So I’ve been doing some “experiments” at home… results, (and questions) below.

First…
Obviously plugging the devices from the SQ Slink port out to either box directly just works.
Desk (slink) → (slink) AR2412, works (24 extra inputs available)
Desk (slink) → (slink) AR128 works (12 extra inputs available)

And plugging the devices in “by the book”, (attaching the AR128 to the expansion port of the AR2412) also (obviously) works.
Desk (slink) → (slink) AR2412 (expansion) → (slink) AR128 (32 extra inputs available.)

(hopefully that’s all obvious, but explains how I’m listing the connections.)

now trying to put an Ethernet switch in the middle between the desk and the audio rack box.
Desk (slink) → (eth0/1) switch (eth0/2) → (slink) AR2412 → works…
or appears to, extra channels are available, and audio is passed, but I don’t have the capacity to test all the channels at once, the link/err light shows red instead of orange, but it is not clear why.

I get the same result for:
Desk (slink) → (eth0/1) switch (eth0/2) → (slink) AR128
Desk (slink) → (eth0/1) switch (eth0/2) → (slink) AR2412 (expansion) → (slink) AR128
and… Desk (slink) → (slink) AR2412 (expansion) → (eth0/1) switch (eth0/2) → slink AR128 works, channels show up, passes audio, but red lights show…
(basically a red light for whatever device plugs into the switch, but I see channels hear audio in limited testing.)

So seems pretty good so far…
So the next tests are… Can I plug the desk into the switch, and the audio racks both into the switch. (all in default VLAN / using cheap unmanaged switch.) - the answer is a definite no this doesn’t work.

Desk (slink) → (eth1) switch
Switch (eth2) → (slink) AR2412
Switch (eth3) → (slink) AR128
again, red links on the link/err lights on the unit, but also, the first device you plug in, is likely to show up, and might pass audio for a bit, but eventually it seems that there is some conflict in the devices. eventually I only have desk inputs, all slink ports are greyed out.

that’s the last tests that can be done with a cheap switch, so the next tests (if anyone wanted to copy this) must be done on a managed switch. (config posted is for Cisco devices…)

Desk (slink) → (eth0/1 [vlan2]) switch
Switch (eth0/2 [vlan2]) → (slink) AR2412 (expansion) → (eth0/3 [vlan3]) → switch
Switch (eth0/4 [vlan3]) → (slink) AR128

(switch configuration)
interface FastEthernet0/1
description from desk
switchport access vlan 2
switchport mode access
!
interface FastEthernet0/2
description to AR2412 slink
switchport access vlan 2
switchport mode access
!
interface FastEthernet0/3
description from AR2412 expansion
switchport access vlan 3
switchport mode access
!
interface FastEthernet0/4
description to AR128 slink
switchport access vlan 3
switchport mode access

For those without the IT background, using VLans (virtual LANs) is a way of “splitting” the switch so that there are different broadcast domains, (so you can use 1 switch where otherwise there might have needed to be 2.) (so this is like putting 1 switch in between the desk and the AR2412, and a different switch between the AR2412 expansion port and the AR128.

Anyway… this also appears to work! I see all the channels on the desk,
BUT all the link/err lights show red (not yellow).

Again, I’ve tested sending a few channels of audio, - audio reaches the desk, but at home I don’t have the option of sending a “whole show” to the desk…

so… long, long, long introduction aside, three simple questions.

1, Has anyone else done this, did they get the same result?
2, What is the importance of the red link light? - does this specify error? will audio have jitters/cuts/stutters etc?
3, switch speed - I’ve tested with an old 10/100 switch, would using a Gb switch make a difference?

2

Hi Danny,

I´m not sure, I´ve ever seen an AR128. I know AR2412 and AR84. The only one with 12 is a DX012. Did I miss something?

Cheers.

3

there should be no testing required to find out how it works…

the old AB racks require Fast ethernet, that means 100MBit
if you plug them to a GBit switch they won’t work because the link doesn’t work
RED LIGHT! means not working at all

GigaACE and SLink are GBit
dSnake and ME is 100MBit only

https://www.allen-heath.com/media/DX-gigaACE-white-paper-1.pdf
https://www.allen-heath.com/media/SLinkConnections_V1_5_0.pdf

4

Andre… sorry, my (idiot) mistake, I put the boxes away before making the post, so didn’t have them right in front of me to read the model numbers.

Devices are AR2412 and AR84. (older GLD branded ones.)
(That should also clarify of course the ports on the boxes are dsnake. -not slink)

Steffen,
I think the DX white paper is exactly what I need, ports are in 100mb mode, but negotiated there - the paper indicates this may cause issues, I’ll see if configuring the port speed resolves the red light.

5

After looking at the network-packages etc. pp I will write down everything I found out so far. Perhaps it will help someone out there:

1, Has anyone else done this, did they get the same result?
yes. This is more or less normal, if you are using more than 1 Switch. When using more than one switch and using Broadcast or Multicast (what dsnake is doing) the switch "normally" will do a check, what devices are there in the network. Also known as IGMP Membership Report. (also this will happen every few minutes from each Switch that will handle the multicast) Every time the AR-Systems will receive an Broadcast/Multicast-package which is not the dsnake-protocoll a red light will flash and stay online for a few seconds. so this explains your observed behaviour:
(basically a red light for whatever device plugs into the switch, but I see channels hear au-dio in limited testing.)
Yes. Each time you plug something in the switch will do the Membership Report. More sophisticated protocols, Spanning-Tree, whatever else is using Broadcasts - so every time the AR-Systems will receive this package, they will go to error. It looks like the IGMP is small enough for the AR to ignore it - Though I have to test it with more than a few channels. Also ARP-Requests seems to be ignored - that's nice :D (only found out, since I mirrored the traffic and my PC was doing ARP-Requests for the DNS-Server :D)

Sometimes you can’t even switch off this behaviour. For example I got a problem that the D’link Dis-covery Protocol of one of my switches was send to the network - this actually got the AR to get a hickup and fail - and i was not able to disable this - so having to change the switch.

2, What is the importance of the red link light? – does this specify error? will audio have jitters/cuts/stutters etc?
The red light only tells you "something is wrong" - ideally it should not be shown. Thus, many of us switched to a media-converter and a single-line connection.
3, switch speed – I’ve tested with an old 10/100 switch, would using a Gb switch make a difference?
This should already be answered. At least for me the AR normally get a 100 Full-Duplex on the gigabit-Port. When you connect your SQ to a Gigabit-Switch, it will change the protocol to gigaACE - thus it won't be able to communicate with the AR - you have to manually setup the speed of the port to 100Mbps. Then the SQ will use dSnake.