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TCP Optimizer - Windows 2000 Server - How to increase upload

Posted: Wed Aug 19, 2015 12:31 pm
by sebek
Hi,
I'm from Italy (new in this forum), first of all excuse my bad english.
I use TCP Optimizer 3.0.8 on a Windows 2000 Server (Unfortunately :( ), virtualized machine on VMware ESX.
In our company we recently have an Internet connection via radio link of 10Mbps in download and 10Mbps in upload.
Via TCP Optimizer we solved the problem of the download (thanks!), but uploading comes up to 2Mbps.
Technicians have told me that seems to be a problem with the TCP / IP stack of Windows 2000, you confirm?
Or you can avoid this problem in any way?

This is our actual configuration:

TcpWindowSize=142500
GlobalMaxTcpWindowSize=142500
DefaultReceiveWindow=-2
EnablePMTUDiscovery=1
EnablePMTUBHDetect=0
SackOpts=1
DefaultTTL=64
TcpMaxDupAcks=2
Tcp1323Opts=1
MaxConnectionsPerServer=8
MaxConnectionsPer1_0Server=8
InternetMTU=-1
{D6277990-4C6A-11CF-8D87-00AA0060F5BF}=-2
NegativeCacheTime=0
MaxNegativeCacheTtl=-1
NonBestEffortLimit=0
DisableUserTOSSetting=-1
DefaultTOSValue=-1
LocalPriority=5
HostsPriority=6
DnsPriority=7
NetbtPriority=8
SizReqBuf=16384
ProtocolMTU=-2
TCPNoDelay=-1
MaxUserPort=65534
TcpTimedWaitDelay=30
[]
MTU=1500
TcpWindowSize=-1
NonBestEffortLimit=100
TcpAckFrequency=-1
TcpDelAckTicks=-1
[]
MTU=1500
TcpWindowSize=-1
NonBestEffortLimit=100
TcpAckFrequency=-1
TcpDelAckTicks=-1
[]
MTU=1500
TcpWindowSize=-1
NonBestEffortLimit=100
TcpAckFrequency=-1
TcpDelAckTicks=-1
[]
MTU=-1
TcpWindowSize=-1
NonBestEffortLimit=100
TcpAckFrequency=-1
TcpDelAckTicks=-1

Thank you very much!
Riccardo

Posted: Wed Aug 19, 2015 1:35 pm
by Philip
You can try setting the duplex on your NIC manually, and turning off any TCP offloads that may be present in the network adapter settings (Large Send Offload, etc.)

Other than that, if you've already tried the TCP Optimizer you've done all the basic tweaks.

How are you testing, how far is the testing server from your physical location ?

Posted: Wed Aug 19, 2015 2:33 pm
by sebek
Thank you for your reply.
I try to set duplex in all different mode, but nothing...
I don't found "Large Send Offload"...I've try all other setting in "adapter settings", but nothing...

I re-try "Optimal" in TCP Optimezer and reboot the server, but the result it's the same...download OK (about 9-10Mbps) but upload still 0,5-1,5Mbps

I try test with different test server in different location (distant from a few to several hundred kilometers, but the result does not change much).

Also you know this limit in windows 2000 server or is there anything else I can do?

Thank you again!

Posted: Wed Aug 19, 2015 6:19 pm
by Philip
You may want to try with a different computer (different OS) in the same location to rule out the very likely possibility that it is your Internet provider.

Do traceroutes look normal (i.e. not very high latency spikes close to you on the first few hops) ?

I am not aware of a Windows 2k Server limitation that would cap it out at those speeds (unless it is a very distant server on a different continent, where TCP Send Window buffers start to play a major role).

Posted: Fri Aug 21, 2015 12:05 pm
by RaisinCain
BS Phillip. I tried to "optimize" my connection. It doesn't work. Face up to it. I had to roll back and my speeds were better.

Posted: Fri Aug 21, 2015 2:15 pm
by Philip
RaisinCain, you are free to do whatever you want, just don't troll my posts without anything to contribute. I know your (incorrect) opinion about tweaking that you are trying to imply should be universal already. The original poster did solve their download issues with the Optimizer btw.