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Network Dropping Out + Strange Behaviour

PostPosted: 08 Dec 2015, 23:54
by tobias
Hi all,

Recently set up 2x AL-88c via a switch and am getting frequent dropouts - MIDI notes stop/hang, AL-88c's disappear and/or flicker from CopperLan Manager application window.

Also, all connections I had made from AL-88c MIDI "ins" to computer's VM ports have disappeared and a few anomalous connections which I didn't make have mysteriously appeared in CopperLan Manager (for instance, output AL-88c port 1 routed itself to AL-88c input port 8 in between sessions for no apparent reason).

Set up:

Copperlan Hardware:
1x MacBook pro unibody 2012, 2.7GHz Quad-core Intel Core i7, OSX 10.8 Mountain Lion
1x Cisco SF100D-05 5 Port 10/100 Desktop Switch plugged directly into ethernet port on MacBook
2x AL-88c plugged into switch, nothing else on switch. (Internet etc. are all on wifi)

USB/FW MIDI devices (connected but not currently configured in Copperlan - definitely planning to once AL-88c's are working properly):
1x MOTU Express 128
1x Elektron TM-1
1x Evolution UC-33
1x M-Audio Trigger Finger
1x RME FF800

Software Installed:
Ableton 9
Logic Pro X
Pro Tools 10
Reason 8
Numerology 4
MidiQuest 11

So far, I've only tested this with Ableton sending MIDI but from troubleshooting and watching the dropouts happen in Copperlan Manager, I think the Cisco switch is causing the dropouts as neither AL-88c seem to have any problems when they're plugged in alone. The switch is brand new, I guess it could be defective but would like to know if there's some network config I can try to make this connection stable?

Also, is there a reason Copperlan Manager "forgot" half my routing between sessions and created its own connections? - I have 30+ MIDI devices so I don't want to be redoing my config every time!

Really great protocol/program btw, will be indispensable once I've got it all working properly!


Re: Network Dropping Out + Strange Behaviour

PostPosted: 09 Dec 2015, 09:46
by CopperPhil

Yes indeed, it looks like you have some connection issue between the AL-88 and the computer.

Dropouts can occur in case of heavy MIDI traffic from the computer to MIDI interfaces that are not fast enough to digest the incoming MIDI (if you send MIDI from a computer faster than the physical MIDI speed). But if the problem does not occur when you connect directly the AL-88 to the computer, then it should be due to something else. You can also have dropouts if the AL-88 CPU is overloaded. But it should not, we made tests in our lab sending and receiving MIDI at full MIDI speed on all the ports. Just to be sure, can you check if some of your MIDI gear connected to AL-88 MIDI IN are generating high rate messaging (such as clocks or something...).

So if you see the connections or the devices blinking in the CopperLan Manager, then it means that the network is not stable. You can launch the CopperLan Manager from a console adding "-developer" argument to the command line, then you'll see an additional panel on the right giving logs about what is happening on the network. You'll probably see "network changed" and "netwotk stable" coming regularly.

Unstable network could explain what you see, the wrong connections are strange but could be a border effect. So the first thing to do is checking all the cables, ensure that you are using good cables, that they are well clipped in the Ethernet ports. Then it would be interesting to test another Ethernet switch. We already got some issue feedback related to Cisco managed or Level3 optimized switches, but yours is a simple non-managed switch so it should be working. But if you can test using a simple DLink or something similar...

Re: Network Dropping Out + Strange Behaviour

PostPosted: 10 Dec 2015, 00:13
by tobias
Thanks for the prompt response Phil, I'll run some more tests, try different cables and see if I can get my hands on another switch over the next couple of days and get back to you.

Re: Network Dropping Out + Strange Behaviour

PostPosted: 19 Jan 2016, 01:09
by tobias
Apologies for not posting back sooner.

It appears my switch was the culprit for the dropouts, replaced with a TP-Link SF1005D and has been stable since.

Don't know if the Cisco was faulty or if it was just doesn't like the Alyseums or my computer or something else, I guess if anyone reads this researching how to set up multiple Al-88s, avoid using a Cisco switch based on my experience.

I did have an instance where CopperLan Manager forgot all my input routing again (the routing from AL-88c's inputs to my Mac's VM inputs), i can't pinpoint the time or circumstances as to when it happened though. Thankfully I had saved snapshots of my set-up so restoring was a breeze.

I have to say, CopperLan is excellent for MIDI routing, not only with the Alyseum products but also with any USB MIDI devices, being able to route anything anywhere, merging etc, is fantastic.

Re: Network Dropping Out + Strange Behaviour

PostPosted: 19 Jan 2016, 10:56
by CopperPhil
Thank you for your feedback, Tobias!

It is possible that the AL-88 disable connections that are not possible after 1 minute, so the AL-88 could drop the connections if the destinations are not present on the network for 1 minute (for example, you turn on the AL-88, and then the computer which take more than 1 minute go get up and running). It is an optional CopperLan feature and I don't remember if it is disabled or not in the AL-88 firmware. If it is the case, you just have to ensure that the AL-88 destinations are available when you turn it on.