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View Full Version : devolo dlan SB3 problem



martintyler
2006-04-10, 14:41
Hi,

I recently got a devolo high speed dlan thing to use instead of wireless since i moved my server and the wireless wasnt as convenient.

Very easy setup and thought it was all great, tested some music and all seemed fine. But when i later listened to music for a bit longer the problems started.

My setup is slimserver box connected to my router using the dlan connection, and the SB3 is a wired connection to the router.

The devolo 'informer' util shows 80+ Mbps most of the time, but after a few minutes of playing flac's (which need about 1Mbps) informer says the bandwidth has dropped to 1Mbps (i dont think it displays less than this), and shortly after the SB3 buffer is empty and the music cuts in and out.

If i stop this, after a while informer says its ok again, and i can play music again.. for a few minutes before it happens again.

What is odd though is that i can copy files fine and the NetTest plugin for SB3 can run at 1Mbps (or more) for as long as i want to test for. If I play music, wait for the problem to occur then start the NetTest plugin at 1Mbps it will show about 50% - but I cannot get the problem to occur any other way than SB3 playing flacs (mp3's are fine, but use less bandwidth of course)

What could slimserver/SB3 be doing that affects the dlan bandwidth? dlan support response was a set of standard questions about noisy mains, other equipment, using wall sockets not extentions etc - none of which address the fact that NetTest (or anything else i tried) works fine.

Any ideas?

dennisd
2006-04-12, 10:31
Martin,
I have 4 of these wonderful devices and they work great in the UK for streaming 192kps mp3 to a mix of SB2s & SB3s for the last few months. (I missed delivery of 3 more today.) I will shut down my wireless system as being too flacky to survive in real world conditions when these show up. Several friends have 2-3 of these without problems. None of us are near your bandwidth though and we don't use FLAC.

As a workaround, try to bandwidth limit your network using the Player Setting BITRATE LIMITING. Your music should play fine while you debug the situation. That will take the pressure off, because it sounds really good. You can use the bitrate to determine where the network breaks down too.

I'd recommend temporarily moving the SB3/Devolo system to the next plug over from the one connected to the Router's Devolo. If it won't work there using FLAC, then re-check your calculations on FLAC bandwidth. If it works fine there, try other plugs and see what your sensitivity is to the uncontrolled house wiring situation. (If you are in the US, moving it close eliminates a L1-L2 problem.) If it does not work there, at least you are close to the computer and can debug everything without getting up!

If you are on Windows, you can check the Networking bandwith on the task manager and see if it matches your calculations. Likewise you can look at how it loads your SB3. One sharp peak is good. If it trails out for many, many seconds, it is struggling to keep up. That tab will also tell you about your bandwidth card. You need a 100BaseT to keep up with the Devolo. 10BaseT "might" work, but is the limiting factor. For reference, my six units load up at about 2.7% of a 1Gbs for about 6 seconds across a combination of wired, wireless and Devolo units. The Wireless units stretch this out to another 30 seconds at 0.3%.

You could turn on the buffer full option display on the SB3 for more information. (I think it is a plugin and a screensaver option.) All that will do is prove the SB3 is starving for data I expect. While interesting, it served only to confirm that the problem I was having was wireless data starvation.

You also do not say what processor you are running. Look at the CPU load and if it is more than a few % to Slim.exe steady state, you may have a different problem. If that occurs, download the latest 6.2.2 beta and see if that helps. That is what I run.

Anyway all the best and enjoy the journey!
Dennis

martintyler
2006-04-12, 15:53
Thanks for the pointers.

Its not too convenient to move where it's plugged in, but i will try and give it a go soon.

I am in London, UK btw.

I am running windows and used the network monitor to help diagnose the problem. It supports what i described.. there is an initial spike at the start of each track, then a constant rate of about 1Mpbs (keeping the SB buffer full), if it makes it to the end of a song the bandwidth drops off (emptying the SB buffer) until the spike for the start of the next track. When the problem occurs it shows the bandwidth dropping to about 500kbps - but more spikey than the fairly flat line before the problem starts.

I dont remember noticing a cpu problem, but dont think i was thinking along those lines, i will have to check it again.