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Using Linux To Make a Slow, Awful WAN Connection

Julie188 writes "This is a brilliant little Linux trick from Windows fanboy Tyson Kopczynski. He wanted to test a new Windows 7 feature called Branch Cache, which caches remote data on the local machine to reduce traffic on a stressed out WAN connection. But how to fake a crappy WAN? Linux. 'The command that I executed (tc) made use of Linux Traffic Control (a kernel thing) which allows me to easily interject 100ms latency on eth1. Boff, Bonk, Pow, Plop, Kapow, swa-a-p, whamm, zzzzzwap, bam ... instant WAN crappiness,' he writes."

10 of 110 comments (clear)

  1. so.... by Anonymous Coward · · Score: 5, Funny

    Linux has to be forced to degrade network performance. Windows does it automatically.

    Did MS ever fix that 10 TCP/IP connection limit?

    1. Re:so.... by Anonymous Coward · · Score: 5, Funny

      Did MS ever fix that 10 TCP/IP connection limit?

      What? So if I open a tenth browser tab I won't be abl

    2. Re:so.... by BattleApple · · Score: 5, Funny

      well at least it hit the submit button for you before crashing

  2. Re:Lol. by ushering05401 · · Score: 5, Funny

    Linux, 'cause even Windows techs need real tools sometimes.

  3. Seems like a lot of work by seebs · · Score: 4, Funny

    Why not just use a Vista box and play an MP3?

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    1. Re:Seems like a lot of work by Tubal-Cain · · Score: 4, Funny

      my Windows NT 4.0 workstation box running on a Pentium 166Mhz machine would never skip playing an MP3 no matter what I threw at it.

      Try throwing bricks.

  4. Re:Goal? by umeboshi · · Score: 4, Informative

    This seems to be valuable in situations where you are developing an application that will be accessing a database behind a dsl firewall. It would be nice to be able to profile the performance on your local network, instead of having it run too slowly to be used in the field. This happened to me once, and I fixed the problem by using a subselect, instead of multiple sql commands, but this wasn't readily obvious as the library was hiding the details of the process, and the speed of the local network compensated for the ineffiency(sp) of the code.

  5. Excellent tool for testing by hwyhobo · · Score: 4, Insightful

    Such capability is very useful to network folks to predict application behavior and best management approaches in various environments. We used FreeBSD for that purpose, but the effect was the same. We injected 350ms latency in each direction, and presto - satellite communication. That is enough to cripple TCP connectivity through a sizable pipe (latency will preclude the flow from taking entire pipe). By testing various acceleration methodologies, you can see first hand which one will allow you to fully utilize the bandwidth you are paying for, all in the comfort of your lab.

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  6. Re:Shit wifi performace is a standard Linux 'featu by KillerBob · · Score: 4, Interesting

    *raises hand*

    Intel 8945J integrated wireless on my laptop. Dual boot, Zenwalk Linux and XP MCE 2005. Until the most recent driver from Intel, the wireless card was *significantly* stabler under Linux. It's now just as stable under Windows (though I replaced by router with a new D-Link 802.11n router recently too), but the throughput at long range is still better in Linux.

    As an example of the latter under Windows the useable range on my wlan caps out at about 25m. that's enough to cover my house, and much of the front lawn. Under Linux, I was able to connect to my network from the picnic table at the park across the street, about 100m. I was only getting 1mbit of throughput, probably less, but it was definitely getting better error correction and a more useable connection at that range than under Windows.

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  7. Re:Lol. by im_thatoneguy · · Score: 4, Funny

    Dear lord if you're going to troll... at least get the grammar right:

    Linux, 'cause even Windows techs can be real tools sometimes