I'm sure I can do better, but how?

[kanenas]

Hi all.
I got my aDSL upgraded to 3000/512 and no matter what I try I'm at about half the capacity.
System is Win2K SP3, PIII-600, 650M RAM, Speedtouch USB.
I have to go through a proxy and a firewall so the TCP Analyzer test can't see my machine. My MTU is at 1500 in any case.
I've tried a number of Lobo's suggestions and at the moment I'm using the parameters from mnosteele52 from his Tips link.
On the average my tests (say at DSLreports) clock between 1300K and 1500K for downloads, and 200K to 250K for uploads.
Clearing the cache and repeating the test right away, I get many times weird results like the download cut in half and the upload jumping to 800K (I wish).
Where might the problem be for this variety and how can I improve the results?
The right TCPWindowSize seems to be around the figure in the Tips (227760 works a bit better for me) but still the results are way too low.
PCPitstop clocks the downloads at around 2M (its upload test doesn't get past the firewall) and Speedtest at around 550K (with an occasional 1100K when I use the 227760 windowsize with a minimal set of the rest of the parameters).
Any ideas?
Thanks in advance.

[mnosteele52]

The proxy is going to slow you down and so is the USB modem, with that said try the following in Cablenut:

DefaultReceiveWindow = 384000
DefaultSendWindow = 65536
DisableAddressSharing = 1
InitialLargeBufferCount = 100
InitialMediumBufferCount = 240
InitialSmallBufferCount = 320
LargeBufferSize = 81920
MaxFastTransmit = 64000
MediumBufferSize = 15040
PriorityBoost = 0
SmallBufferSize = 1280
TransmitWorker = 32
FastSendDatagramThreshold = 4096
EnableFastRouteLookup = 1
EnablePMTUDiscovery = 1
IgnorePushBitsOnReceive = 0
GlobalMaxTcpWindowSize = 52560 or 64240 or 96360 or 128480
MaxFreeTcbs = 8000
MaxHashTableSize = 16384
MaxNormLookupMemory = 5000000
SackOpts = 1
SynAttackProtect = 1
Tcp1323Opts = 0 (set to 1 if TcpReceiveWindow is 65535 or higher)
TcpLogLevel = 1
TcpMaxDupAcks = 2
TcpMaxHalfOpen = 100
TcpMaxHalfRetried = 80
TcpRecvSegmentSize = 1460
TcpSendSegmentSize = 1460
TcpTimedWaitDelay = 30
TcpUseRFC1122UrgentPointer = 0
TcpWindowSize = 52560 or 64240 or 96360 or 128480
MaxConnectionsPer1_0Server = 40
MaxConnectionsPerServer = 20
DefaultTTL = 64
DisableUserTOSSetting = 0
TcpMaxDataRetransmissions = 6
DefaultTOSValue = 92

:D ;)

[mnosteele52]

Also you might check out the DSL Wiring (http://dslnuts.com/DSLwiring.shtml) article by Dannjr.;)

[kanenas]

Thanks for the response.
I tried these settings (they were 99% the same as in your tips page) and it didn't get any better.
The download speed varied a bit (up by around 100K at dslreport, down by 100K at PCpitstop and down by 300K at Speedtest). The upload speed averaged about the same but varied a lot.
Clearing the cache always and backing up to the test page, I did a sequence of tests at dslreports using the LA server.
Some strange results there:
test 1: down=1231K up=-3999K (negative 4M!!)
test 2: down=1459K up=465K
test 3: down=1563K up=232K
I disabled the trojan and virus monitors now.
test 4: down=1472K up=98K (!!)
test 5: down=1580K up=182K
It looks like the download is around 1500K and the upload 200K or so. Still way below the caps.
On with the tweaking...
Take care.

[mnosteele52]

Personally I think it's the USB modem, is there any way you can try a modem with an ethernet connection?:)

[Mohan-san]

Originally posted by mnosteele52
Personally I think it's the USB modem, is there any way you can try a modem with an ethernet connection?:)

Hey hey hey, stop mouthing off the USB modems. :p ;) :)

But it might explain why I only get 90%+ of my caps. :rolleyes:

[UOD]

Unplug any other USB devices on your system that are competing for available bandwidth...remember...USB is a shared bandwidth allocation.

In any case...mnosteele52 is correct. Get off that USB connection and get on the fast lane with ethernet! (if you can;) )

[kanenas]

Thank you all for the responses.
I tried to replace the USB modem (supplied by the company) since it wouldn't work with my dual processor system (I run in single processor mode now).
Unfortunately there are no Ethernet DSL modems available locally (there are NO DSL modems at all actually on the local market since the service is not available outside our company).
I managed to find a company in the States that accepted credit cards and shipped internationally but they only had a firewall/router I was looking for and not any DSL modems.
So now I have a firewall in its carton collecting dust until I locate the modem.
As an aside, what's the difference between a Cable modem and a DSL one, if any. Everybody seems to sell Cable modems. If they are compatible I could maybe get one of those.
As for the USB bus, I use an external USB hub that has on it the modem as well as an X-Rite colorimeter. I doubt the inactive colorimeter would affect the speed.
The other possibility might be low-quality telephone wiring. That's also installed by our company and they are known to keep the impedances way below normal, but there's nothing I can do about it.
Thanks again for the help.