Ever heard of BitTorrent messing up networking?

[Felecha]

Yesterday I started having a problem with my internet, quite a number of sites gave me the error (in Opera, my browser):

You tried to access the address http://*****, which is currently unavailable. Please make sure that the Web address (URL) is correctly spelled and punctuated, then try reloading the page.

etc

It started first thing in the morning, and I presumed it was an ISP issue. I was getting it for probably half of my attempts at getting a page. Yahoo, Google, all over. At first it seemed to be specific to sites - some sites regularly failed, some didnt. I wondered about a big internet-wide crash or denial attacks or something. But then I saw a not-really-small number of sites that would sometimes work and sometimes not. I tried my wife's machine (small home network), no problems. So it's just me. Then it dawned on me - Saturday night I found a website that had an obscure song from 20 years ago that I loved and has never been on CD. It was part of a big BitTorrent file. I've only fiddled with BitTorrent once before, a couple years ago, I just dont do that stuff. So I tried to get it started, it seemed to not be working. I looked and BitTorrent didnt even seem to be installed, so I figured it got wiped out when I clean-installed XP a couple years ago. Anyway I went and got the latest BT Saturday night and installed and no problems, and started to get the file - 250mb of which I only wanted 1mb. It was crawling-slow so I went to bed. In the morning only like 2% had come in so I gave up.

That's when I found the surfing problem and it wasnt till later that I wondered if BT had screwed something up.

I found the same things in IE7, and my Outlook Express spent LONG times unable to connect.

I uninstalled BT, and rebooted, and the problem stayed the same. Darn! Then over the rest of the day (I didnt surf all day, just went online a number of times) the problem actually dropped off almost completely. Now this evening it has returned, but still at a lower rate of occurrence.

Like I said, I just have no idea. And I know a little about networking generally but nothing about this.

Ever hear of such a thing?

 

[KenAF2]

Are you using a router? Every router supports a maximum number of simultaneous connections, as defined in firmware. Routers with faster processors and more memory tend to support more simultaneous connections than routers with slower processors and less memory.

Whenever you use up all your simultaneous connections, as is often the case with p2p, you no longer have connections available to use for web browsing. Some of the new / better routers include built-in QoS to prioritize web connections over p2p connections.

Furthermore, whenever you use bittorrent or utorrent, seeds and peers cache your address and port(s) for hours, even days. They'll periodically try to reconnect to you, but obviously won't establish a connection since you don't have the torrent program running. Denial of all this traffic creates additional load on the router's cpu. Simply put, if you do a lot of p2p, it is advantageous to have a router with a faster processor that supports a high number of simultaneous connections and functional QoS.

I had the same problem you are reporting with my old Linksys router. I replaced it with the D-Link DGL-4300, which supports 180+ simultaneous connections and QoS to prioritize web traffic, and that completely eliminated the problem. D-Link has since released an improved version of that router, the DIR-655.

http://www.smallnetbuilder.com/component/option,com_chart/Itemid,189/chart,124/

Note D-Link increased the maximum simultaneous connections on the DIR-655 with the new 1.3 firmware released last week. AFAIK, it now does 180+ too.

The DGL-4300 sells for about $70 from Frys.com. If you want the newer DIR-655, that costs $100.

 

[p0lar]

Alternately, torrents (or anything for that matter) can completely saturate outbound bandwidth such that your TCP acknowledgments do not make timely exits from your network (or are altogether lost). The solution is to limit the amount of outbound bandwidth in the application and/or prioritize TCP acks, which should probably be implemented on higher-speed links anyway.

 

[Felecha]

KenAF2 - It's a LinkSys BEFSR41 router. Had it for ... 8 years? ... with no problem, this all happened at once. The max connections thing sorta makes sense, too, them trying to get back to me. i remember a screen telling me that there were 4 machines out there. Another time there were 2, another time 0. I dont want to try again, of course. If they know me, would uninstalling do anything to change that? Would it likely just "fade" over time, would the other ends "lose interest in me"?

And polar, you lost me, sorry.

 

[Battleangel3222]

Heh, seems im in the same boat with a thread below yours - let me know if you find a fix =(

 

[BoberFett]

Originally posted by: Felecha
KenAF2 - It's a LinkSys BEFSR41 router. Had it for ... 8 years? ... with no problem, this all happened at once. The max connections thing sorta makes sense, too, them trying to get back to me. i remember a screen telling me that there were 4 machines out there. Another time there were 2, another time 0. I dont want to try again, of course. If they know me, would uninstalling do anything to change that? Would it likely just "fade" over time, would the other ends "lose interest in me"?

And polar, you lost me, sorry.

I had a problem with the BEFSR41 and Bittorrent as well, only worse. A couple minutes after starting uTorrent, even with a low number of max connections, it would simply lock up. All traffic would halt, and I'd have to wait for a couple minutes for the router to... do something. Clear up it's tables, reboot itself, whatever it was doing. It's just a bad router for torrenting.

I'm now using an Actiontec GT701 (Qwest DSL modem/router) and it's better. Not perfect, things do seem to bog down after about a week straight of torrenting, but a quick reset and it's fine again.

 

[Felecha]

Now there's an idea - a reset would help, yes? The overall effect is very low now but still sometimes if fails, often just seems to drag its feet

Thanks all