Entire Network Limited to 10Mbps

January 16, 2009 at 16:59:21
Specs: Windows XP, Intel Pentium 4 2.6 GHz HT - 1GB
My entire network seems to be restricted to 10Mbps on file transfers.

I've got a home network set up as shown in the linked image. The 'main' router (Trendnet TEW-432 i think) has wireless enabled and is connected to a DSL modem, the second router (D-Link DI-604) has DHCP disabled, and an assigned IP to act as a switch with 2 computers connected to it.

http://i4.photobucket.com/albums/y1...

I have tried various disconnections and combinations of computers transferring files, including disconnecting the TrendNet router from the D-Link and testing the transfer between the two computers connected on the D-Link (though it occurs to me I did not test the computers connected to the other router in that state). In any case, I consistently get transfers limited to 10 Mbps (everything should be 100 Mbps capable)

I recently had a newer D-Link DI-624 die on me, and it was replaced by the older DI-604 I had sitting around; before that, as far as I remember, the transfer rates were fine, but even if the DI-604 is problematic, it should not be restricting transfer between 'Comp 3' and 'Comp 4' (see diagram) should it?

3 of the 4 computers are running XP Pro with SP3 installed, the other is running Vista. All have different adapters, but none have had recent driver changes.

What other approaches should I be taking to diagnose and fix the problem? I would love some suggestions as I am about at the point of banging my head against a brick wall.


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#1
January 16, 2009 at 17:12:11
If you try a transfer between 1 and 2 or between 3 and 4 is it still 10 meg ? If those routers are 100 meg then it should not be restricting unless some of your nics in your pcs were restricted to 10 meg half or full duplex for some reason . It really can only be 2 things either your routers are old and only support 10 meg or your nics are hardcoded to 10 meg for some reason.

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#2
January 16, 2009 at 17:31:17
"10 Mbps (everything should be 100 Mbps capable)"

Is the second router connected via its wan interface?

older router wan interfaces were only 10mb

and yes it could restrict lan transfers if the switch is configured for 10mb

"I consistently get transfers limited to 10 Mbps (everything should be 100 Mbps capable)"

How are you determining this?



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#3
January 16, 2009 at 19:57:53
Try hard setting both sides of the link to 100/full, sometimes a flaky nic can just have a hard time auto-negotiating.

There should be a setting on the switch to change the port to 100/full duplex, and/or you also need to set the computer link under the nic properties in device manager.


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Related Solutions

#4
January 16, 2009 at 22:42:32
1.If you try a transfer between 1 and 2 or between 3 and 4 is it still 10 meg ?

Yea I had tried both scenarios. I also tried between 1 and 2 just using the switch with the router disconnected, same difference. Both routers are supposed to be 10/100 (just doublechecked product specs again), and all the nics show up in network connections as 10/100. I have also checked to make sure 'auto' is selected for each.

2.Is the second router connected via its wan interface?

No, connected at both ends through LAN ports.

3."I consistently get transfers limited to 10 Mbps (everything should be 100 Mbps capable)"

How are you determining this?

I was doing it by beginning large file transfers (both of large single files, and folders containing a number of files to see if that made a difference); letting the transfer run for a few minutes to stabilize, then taking the filesize, converting to megabits and dividing by elapsed time + estimated time remaining.. calculation always gives me between 9 and 10 Mbps.

4.Try hard setting both sides of the link to 100/full

Will try this in the morn.

5.There should be a setting on the switch to change the port to 100/full duplex, and/or you also need to set the computer link under the nic properties in device manager

I haven't been able to find a way to manually set in the config pages of either router. I may also try flashing the firmware on the DI-604 (since I don't remember problems before it was hooked up; though I can't be sure when this really started)

Thanks for the suggestions so far..


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#5
January 17, 2009 at 06:40:53
Just so you know, every SOHO router I've ever looked at wasn't a "managed switch". If it's not managed, you can't adjust the speed on individual ports. By default, they're all "auto".

I'm thinking that your math may be faulty. I can see no reason for you to be getting only 10 Mbps transfer rates. I'm not sure exactly what's wrong with your calculations (it's too early in the morning for me to think that hard) but something about it is striking me as being off.


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#6
January 17, 2009 at 08:33:46
I'm thinking that your math may be faulty

1 GB = 8192 Mb

7 GB file x 8192 Mb = 57344 Mb
5 minutes transfer time before cancelling + 100 minutes estimated time remaining = 105 minutes = 6300 sec

57344 Mb / 6300 sec = 9.1 Mbps

Anything out of place?

Try hard setting both sides of the link to 100/full
Just did this on computers 1 and 2, still just under 10 Mbps. Task Manager shows the link speed as 100 Mbps, but network utilization tops at just over 10% averages ~5% (visually) when running a transfer.


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#7
January 17, 2009 at 08:47:20
"+ 100 minutes estimated time "

you can't estimate this. so you must be getting this from the file transfer ballon which is built on an algorithm I wouldn't ever trust [seen it say hours then its done in minutes]

always trust your gut Curt R :-)


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#8
January 17, 2009 at 08:55:41
@wanderer

Granted its a bad practice. That said, I've left the file for as long as 20 minutes and its not done, when if I were getting 100 Mbps it should be done in 10. Even getting 50 Mbps would finish in 20..

I suppose the obvious thing to do would be to let the whole thing run and measure the true elapsed time.


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#9
January 17, 2009 at 09:22:11
pick a smaller file and yes let it complete.

Realize your transfer rate really is determined on how fast the hard drives can deliver and recieve the data.


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#10
January 17, 2009 at 10:35:32
I've identified the problem, and it is infact the D-Link router somehow limiting the whole system (even between Comp 3 and 4 despite no reason to go through the second router).

I realized I had tested a transfer between Comp 1 and 2 just through the D-Link (e.g. no WAN, just LAN), but I didn't try between Comp 3 and 4 with the router out of the loop. I just unplugged the D-Link and connected Comp 1 to the Trendnet and a transfer between Comp 1 and Comp 3 finished 7.2 GB in an appropriate 14 minutes.

A reset to factory settings on the D-Link didn't fix the problem, and I can't find a firmware update, so I guess I'll have to do some shopping. Thanks for your suggestions.


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#11
January 18, 2009 at 06:24:56
Sorry, I didn't check back sooner (my wife had a long "to do" list for me yesterday....lol)

Yeah, that's what was bugging me....the 'estimated' time. We all know from long experience that windows sucks for estimating time to finish a download. If I had a dollar for every time the download showed "< 1 min" remaining and then sat there while it downloaded for another 10 minutes.

Regardless, you've found the issue. It's very odd that the switch/router would reduce itself to 10 Mbps but if that's what your troubleshooting has shown you, then at least you know what the problem is and what to do about it.


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#12
January 24, 2009 at 22:58:15
1st, for future reference for all, NetDoppler from WildPackets is a free thoughput testing utility that I've always found very handy.

http://www.wildpackets.com/support/...

Assume that I already did an Internet search.


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