What could cause tremendous slow down in a DSL connection?

[Syringer]

These people in my apt building have a DSL connection split among a router between four people..and one of them recently was affected by the worm blaster virus. I cleaned it out, set them up with a firewall, but download speeds would still only be around 2-3 kb/s..

I also checked the log file of the router, and there seemed to be a great amount of activity going on. I'm not a networking guru, so I have no idea what a log file is supposed to look like, but there seemed to be dozens of things listed for each minute, even when no one was accessing the internet.

Anyone have a diagnosis? We have cable in our place so I can't say how good the Verizon service is around here..

 

[ITJunkie]

It would help if you can post a sample from the log files.

 

[JackMDS]

Did you optimized the TCP/IP Stack for DSL?

 

[StraightPipe]

is that your speeds in file xfer apps (like kazaa)? you should go somewhere reliable to test your speeds like BandwidthPlace or testmyspeed.com


jack, how do you "optimize the TCP/IP Stack for DSL"

are you talkig about changing MTU?

 

[Syringer]

Everything on the connection is slow..browsing pages take forever, and pretty much any attempt of accessing something on the internet takes forever..

And I'm not at the computer right now, but I might be able to post a sample later..

 

[Syringer]

And I was also told that the DSL was fast at one point, right when it was installed..but now the speeds are barely comparable to even dial-up connections..

 

[StraightPipe]

my dsl is really fast, do a speed test, that will give you a clue as to how "fast" yours is.

you could also be plagued with bad things llike viruses, that could easily explain the slow down.

Usually an active connection when your not doing anything indicates that you have bugs on there like "dialers" or "data miners"


you can get a program like Adaware 6 for free thats really good at scanning your system for these little buggers.

:music: check out www.lavasoft.de , to download it for free :music:

 

[JackMDS]

Download DrTCP: <a target=new class=ftalternatingbarlinklarge href="http://www.dslre
ports.com/front/DRTCP021.exe">http://www.dslreports.com/front/DRTCP021.exe</a>

Run the program, it will show the current settings of TCP/IP parameters. Write them down.

You can change any variable that you want, click Apply, and reboot the computer, if no good; you can always change to your original values.

Start with:

MaxMTU - for DSL =1492 Cable=1500 DialUp=576

Tcp Receive - 255552

Window Scaling - Yes

Time Stamping - No

Selective Acks - Yes

Path MTU Discovery - Yes.

Black Hole - NO

Max Duplicate - 2

TTL - 64

Notice it said above Start with

These settings are not written in "stone" there is variability depending on the computer other setting. So try few setting and measure your Download for each setting.

In addition, in case a person has a Router the Router's MTU if set differently can affect the general MTU.

Link: Measuring the "Speed" of Internet Connection.