Need help debugging intermittent problem with DIR-825

[mgpaulus]

Hi all,

I had a DLink DI-524 that was working just great for me, but I wanted to add N support to my wireless for some Multimedia streaming over wireless that I wanted. I've played with several options (A Trendnet N extender, a Linksys WRT-610N, and the DIR-825). I had problems with the WRT-610, and the Trendnet didn't seem to want to connect at N rates. My best luck so far has been with the DIR-825, but I seem to have this one small problem:

Sometimes, the router seems to "clog" the network.

I have a linux box downstairs with a DVB-C card. Using dvbstream and azap, I am able to tune into a multiplex, and then stream a rtsp stream to my windows box upstairs. Upstairs I use TSReader to receive the rtsp stream and decode out the different streams. I can also double click a preview window and it will fire up VLC with the stream, for previewing/watching. Normally, this works fine. However, there are occasions when the network seems to get clogged and the stream data doesn't seem to transmit/receive correctly.

I have gigabit switches upstairs and downstairs. The machines in question all have gigabit cards, so bandwidth isn't a problem.

When this problem/issue is going on, I can unplug the router from my main switch, and the problem will go away (things become unclogged). Then I plug the router back in, and things become clogged again.

I have sent an email to dlink tech support, but no response.

My issue is that I'm not sure how to figure out what's going on. When I use iptraf on the linux box, I don't seem to see any traffic differences with the router plugged/unplugged. So, I'm not sure what to do to try to debug/diagnose the problem.

Oh yeah, a router reboot also clears the problem up.

Any pointers would be appreciated.

Thanks.

 

[mgpaulus]

Well, a bit more info. I installed ObjectPlanet's Network Probe 2.7. When streaming Video and the router disconnected, I see about 40 Megabits/second throughput. As soon as I connect the router to my switch, my throughput drops down to 5-10 Megabits/second. So, somehow the Router is definitely doing some throttling. But, I have no idea why.

 

[spidey07]

Make sure the NICs and router/switch ports are set to autonegotiate speed/duplex. A common problem is setting the NIC to a particular speed/full duplex thinking the switch will autonegotiate to full duplex.

That doesn't happen because by setting the duplex on the nic it doesn't send any autonegotiation information and the switchport will operate at half duplex. This is a duplex mismatch and absolutely kills performance.

Also homemade cables are a likely culprit, just because it works on one but not the other the cable could still be the problem. Some chipsets are better at dealing with it.

-edit-
Is this router gigabit or not? Many soho switches will use flow control to slow everything down when a 100 Base-T device is attached.