Help, Torrents crash my modem.

Scosglen

I've had this problem for a while, but I'm just getting so sick of constantly running downstairs to unplug the modem and tweaking µTorrent settings to no avail that I'm asking for help.

I have an RCA DCM235 cable modem running through a WRT45G V8 wireless router. The setup is rock solid for all normal uses, but when I try to torrent things (particularly large files which take a while to complete), my download and upload speeds will begin to plummet to 0 and the internet connection for the whole network tanks. It can happen in five minutes or it can run a couple hours with no problem. The connectivity on a desktop in the basement which is wired into the router directly also goes out when this happens. Power cycling the router does nothing, and the internet always returns after power cycling the modem, so am fairly certain the crux of this problem is the modem.

The most commonly suggested problem here on the interwebs seems to be that my modem is being overwhelmed with too many connections. I've taken steps to counter this by carefully following some optimization guides but It has had no discernible effect. A test at dslreports rates my connection at 2500kbs/ 768kbs, and so I'm currently using the "xxx/768k" preset under the speedguide menu for µTorrent, which puts my settings to

Upload limit: 76kB/s
Upload slots: 5
Max Connections: 100 (Global 450, but I only ever run one torrent at a time)
Download capped arbitrarily by me at 500kB/s

I also have tried switching DHT off to no apparent result.


I'm running out of things to try. Any suggestions are very welcome, or feel free to inquire more specifically about my setup if I've forgotten something.

Barrakketh

I'm assuming you mean WRT54G for the router model, and you're having problems because it is a terrible router.

Later revisions of the router (v.5 and later) have half the RAM of the previous versions, and if my memory serves me correctly the firmware on the router tracks connections for something like five days. For a protocol like BitTorrent that creates many connections the router is going to choke.

The normal solution for most people who own Linksys routers and wish to use continue using torrents it to install 3rd party firmware on your router. In fact, the uTorrent FAQ says to install third party firmware.

Unless another forum member knows any tricks to modify the startup scripts on a stock router or a fork of the Linksys firmware released to fix this specific issue, you're probably out of luck.

EDIT: The table I was looking at may be outdated. The last part of my post and the sentence I removed can probably be ignored ;-)

rufo

What ISP are you on?

EDIT: That might be helpful, but it could also be the firmware problem that Barrakketh mentions. You can install DD-WRT on it, see http://www.dd-wrt.com/wiki/index.php/Linksys_WRT54G/GL/GS/GX#v8. Once you get it installed, you need to turn down the length of time it tracks connections and crank way up the maximum number of connections.

Personally I always go for the WRT54GLs, as they're rock solid out of the box and you can install the 3rd-party firmwares easily.

Scosglen

I'm on Comcast cable, unfortunately.

I'm temporarily living at home and so the network equipment in question actually belongs to my parents. My father is a network engineer and so he probably would not be very receptive to my installing hacked firmware on his router so that I can torrent things. If that's the only solution then I guess I may be SOL.

So was it a misunderstanding on my part that cycling the modem fixed it, and so I assumed the modem was the problem? We're sure the router is the problem?

edit: Now I'm a little confused. I researched that tracking problem you mentioned, and from the µTorrent FAQ I found

'The following note does NOT apply to WRT54G/GS v5 and up! Use the latest official firmware (1.00.9+) with those, they do not suffer from this specific problem (though they do suffer from different problems).' and then it goes on to discuss the tracking for up to 5 days thing.

Logging into the router says it's running Firmware Version: v8.00.2, the latest one available from the linksys website.

Barrakketh

Scosglen wrote: »

So was it a misunderstanding on my part that cycling the modem fixed it, and so I assumed the modem was the problem? We're sure the router is the problem?

I think it is most likely the router. Modems typically aren't the source of the problem unless they are very old or subject to overheating, but I'm not entirely sure what kind of work a cable modem has to do compared to an ADSL modem (which is what I've always had for HSI).

If you or your dad thinks it might be the modem, it would be best to find/borrow a different one to test with. I kept the ADSL modems from my former ISPs (which have only changed when I moved to an area with a different telco), and use them for troubleshooting purposes if someone is having trouble getting their router working.

Comcast isn't known for being torrent friendly, and if they don't have any competitors in your area they might be doing something more aggressive than just using Sandvine. I haven't heard of Comcast killing your connection until you reboot the modem, but I have read stories from people overseas who have had their ISPs do that do them.

Does your connection reliably drop after a specfic amount of time using uTorrent or after you download a certain amount of data with it?

edit: Now I'm a little confused. I researched that tracking problem you mentioned, and from the µTorrent FAQ I found

'The following note does NOT apply to WRT54G/GS v5 and up! Use the latest official firmware (1.00.9+) with those, they do not suffer from this specific problem (though they do suffer from different problems).' and then it goes on to discuss the tracking for up to 5 days thing.

I've seen the v.5 and v.6 choke up on torrents, so if it isn't the exact same problem it definitely exhibits similar behavior. It was a known problem for a couple of years with no fixes from Linksys, so I'm surprised that they got around to dealing with that bug.