Sudden Drop In Network Transfer Speeds

By Bumble ยท 19 replies
Jan 27, 2008
  1. So, the long and short of it is: my network transfer speeds have bottomed out, and I have no idea why.

    Here are the details:
    -My computer is running Windows XP
    -I am on a college campus network, and we are forced to connect to the internet via Cisco Clean Access Agent
    -I have 2 Seagate Barracuda 3.0 Gb/s SATA drives, 1 300GB and 1 500GB
    -My cabling is run through a hub in my room and then from the hub's uplink to the wall (but my computer is the only one plugged into the hub). I've tried it direct to the wall, as well, and it doesn't seem to have a huge impact
    -I added a value to my registry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters called TcpWindowSize with Decimal value 2920 which--I think this was the cause, anyways--took transfer time for a 700MB file down to about 10 minutes from 30-40 [but last year, I was averaging about 2 minutes for a file this size]
    -Download Speed: 396 kbps (49.5 KB/sec transfer rate)
    Upload Speed: 214 kbps (26.8 KB/sec transfer rate)
    -I have tried Right click > Repair on the LAN network in Network Connections, but it didn't seem to do anything

    I think that about covers my situation. Please inquire if you want/need any more (or more specific) information. I'd really like to get my computer back to where it was! Thanks for the help.

  2. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Welcome to TechSpot...

    Have you use the tool TCP Optimizer from
    Match your current rated download speed with this program. 0 to 20MB down.

    Are you using a switch or just a hub?
    How old are these hub or switch you're using?
  3. Bumble

    Bumble TS Rookie Topic Starter

    Thanks for the welcome!

    I'll check out TCP Optimizer.

    The hub (it is a hub) is rather old--several years, at least. It's a Unicom Micro-Net/5 5-port 10Base-T Hub.
  4. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Besides the repair tool you need to right click on the network device.
    Click on properties
    Click on TCP/IP
    Click on the Advanced button
    Scroll down to the metric and make sure your router IP address is listed there.
    If not? Then add it to that list.
    Now click on WINS Tab
    Scroll down to and make sure you see NetBIOS Over TCP/IP Enabled.
    Click okay and apply.
    Before we go...

    Click on start
    click on run
    type: cmd

    type: ipconfig /flushdns
    check and see if you get any sort of error?
    If so type: REG ADD HKLM\SYSTEM\CurrentControlSet\Services\Dnscache /V Start /T REG_DWORD /F /D 2
    Wait for the PC to say OKay
    Reboot the PC
    Got to line: 2

    If no error when you do ipconfig /flushdns
    continue here

    type: ipconfig /registerdns
    type: nbtstat -r
    type: netsh interface ip delete arpcache
    Reboot PC

    Line: 2
    type: ipconfig /flushdns
    type: ipconfig /registerdns
    type: nbtstat -r
    type: netsh interface ip delete arpcache

    Reboot PC
  5. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Wow 10base and how is the rest of your network 10/100 and you set them to 100Full or just 10 all the way?

    I would recommend getting a brand new 5 or 8-port switch (netgear) don't have to spend a lot. I don't know if FS105 (5-port) or FS108 (8-port) is available in your area?

    Switches/hub go after after so many hours of operation and don't perform as well as they did.
  6. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Well what I've posted above should give you the amo you need to fix your problem.

    The faster your download speed from your ISP the faster downloads will be..
    The switch better because all the ports will get 10/100 or 100 if the router is set correctly. Netgear has auto detect ports on all ports so uplink is auto and can be use in any port 5 or 8. Plus the switch is faster. Hubs were slower you had to wait per request operation. Switches give device full access and they don't have to wait.
  7. Bumble

    Bumble TS Rookie Topic Starter

    Honestly not sure what the first bit means, or how to set/change any of that. I'll look into a new switch/hub (it seems like a switch is a better idea, as long as I'm getting a new piece of hardware?). However, in lieu of that, would cutting it out and plugging directly into the wall do the trick?

    I'm waiting for a couple things to finish and then I'm gonna go about the first process you posted [not quite ready to reboot]. Thanks for the speedy replies, great help!

  8. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    No problem! I was just at the right time to help you out...
  9. Bumble

    Bumble TS Rookie Topic Starter

    So, it seems to be pretty much cured after I went through what you instructed and took the hub out of the equation. Thanks so much for the help! Still a bit wonky when I have Azureus open, but that's to be expected. Times are way down, just the same.

    Thanks again,
  10. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    google TCP Sackopts

    also set Full Duplex mode on the adapter
  11. Bumble

    Bumble TS Rookie Topic Starter

    What am I looking for on the TCP Sackopts search? A tutorial? A program?

    And how do I change the mode for the adapter?

  12. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    SackOpts is a tcp setting added to the registry to improve TCP performance.
    mode for the adapter

    View Network Connections->right click the Lan->properties
    pull down to TCP/IP and select it
    click properties

    ensure you have FULL Duplex
  13. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Jobeard that enabled by default when you use TCP Optimizer for larger connections..
  14. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    yes that's true, but you might have noticed that I am a minimalist -- change as little as
    possible to effect the result.

    I've found problems where things were set under the covers and I didn't have records
    of the specifics.

    SackOpts and Full Duplex are easy to set manually without impacting other settings.

    again, there's always multiple means to any end :)
  15. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Okay that makes sense.... In the router you can change the WAN from default auto to 10, 10/100 or 100Full Duplex. Some routers have 1000 Full Duplex for WAN setting. As most of us here have 30, 40 and 100 (fiber) downloads.

    I found out that:

    Motorola Cable Modem can only handle up to 30mbps downloads
    WebStar Cable Modem can only handle up to 43mbps downloads
  16. Bumble

    Bumble TS Rookie Topic Starter

    I don't actually have access to the router, since I'm on a college campus. But my speeds are back to about where they used to be. Thanks again!

    There's no chance these changes will affect my ping or ping stability in online games, is there?
  17. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    >changes will affect ...
    these are global to all TCP and only improve, not degrade performance.
    (hint: they ought to be the defaults :) )
  18. tipstir

    tipstir TS Ambassador Posts: 2,477   +126

    Never be the defaults MS will never do it... They should... Jobeard having the Router appear in My Network Places shouldn't be a problem as Vista has it there. XP never have the feature enabled. I like to know that the Router is seeing my wired and wireless desktops, laptops, servers... If it not working then UPnP or Discovery is screwed up again. I use a program called Network View which maps out the network discovery into a Network Diagram. Good to have it also functions as network montior the same like you're a Network Engineer would do. If a system is down it will alert you by sound or voice. If the device is up it will tell you by sound or voice. But like you say everyone has different ways...

    OP (orignal poster) is happy now.. That's what counts!
  19. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    we agree :)

    I added my router address to the host file and various network tools always seem to
    locate it anyway. I just don't like the exposure created by SSDP and UPnP.

  20. Bumble

    Bumble TS Rookie Topic Starter

    Thanks again for your consistently speedy, correct, and friendly help! I, and many others on my network, are much happier for it. I'll definitely be back if I run into any further issues with my computer that I can't fix myself--this is a great community and site. Maybe after I catch up on work, I'll even flip through the forums and get towards being a full-fledged member :D (at the very least, I'll be back with a case mod I've been working on over the past couple months).
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