Another Bittorrent Question

October 9, 2007 11:32 AM

I've seen this and this,and this. When I'm running Transmission (I used to use Azareus, with the same problems, but I switched because a lot of the trackers I used banned it. I will switch if anyone can suggest a better client) on OSX it kills all of my web browsing. Even when I turn on Speed Limiter there is no web browsing. I'm only downloading one file, with one peer at the moment, for what that's worth. But when I cap upload at 5k, web browsing works again (by the way, I browse with Firefox). That doesn't seem right to me. I have Time Warner Road Runner cable internet and a Netgear WGR614v7 - 54 Mbps Wireless Router. Is there anything I'm overlooking to be able to browse the web while downloading torrents?
posted by apetpsychic to computers & internet (14 comments total)

I use Azureus on OS X with pretty much the exact same setup (except my ISP is Eircom in Ireland), without any problems. Maybe your ISP is doing something funky with BT traffic.
posted by ReiToei at 11:38 AM on October 9, 2007

That's correct behaviour. Put simply, packets have to be acknowledged, and if you're soaking up all your up-bandwidth with file transfers you won't have any left over to respond to the web server. Keep at least 2k/sec free (which is what you're doing by capping at 5k) and you'll be fine.

(You could try playing with the QoS settings on your network hardware, but to be honest limiting is easier and works better).
posted by Leon at 11:41 AM on October 9, 2007

I guess I didn't realize, but 10k upload is something that would normally interfere with other internet usage?
posted by apetpsychic at 11:45 AM on October 9, 2007

Get Carrafix and read the webpage and doc to understand how it works.

Your web browsing is most likely jacked up, not because you are maxing out your download pipe, but because you are maxing out your upload pipe.

In order to receive a web page, your computer has to send a bunch of tiny packets that basically acknowledge that it received the last webpage data packet and is ready for the next one. These are called ACK packets because they ACKnowledge that the data was received.

If your upload is maxed out, which file sharing apps often do without really even telling you that it's happening, the ACK packets can't get through and the webserver whose page you're trying to browse doesn't send the rest of the page. Now all you have to do is throttle your upload usage from 100% of its capacity to 99% - the ACK packets are tiny and they'll be able to get through just fine in that remaining 1% of free upload pipe.

Incidentally, Carrafix is just a pretty graphical UI to some IP control utilities which are already installed on your Mac. I think they're called ifconfig and ipfw and maybe one other, but I can't recall off the top of my head.
posted by ikkyu2 at 11:46 AM on October 9, 2007

Torrents are not downloads. They are peer-to-peer. This question is covered in every single FAQ about BT. Cap your upload or your network goes to crap. Find out what your pipe's max upload speed is, and make sure you have some to spare. Limiting your client to 5K is probably overkill.
posted by mzurer at 11:47 AM on October 9, 2007

My max upload speed is 180k. Thanks for the lesson, though I've been reading bittorrent tutorials for months.

Had you read what I said, I too feel like 5k is overkill. But when I set it to 10k, the web browsing stops working. That is my question.
posted by apetpsychic at 11:49 AM on October 9, 2007

Sorry, I didn't put what Speed Limiter on Transmission sets your upload speed to, which is 10k.
posted by apetpsychic at 11:52 AM on October 9, 2007

And I didn't mean to sound as bitchy as I just did. Thanks for the tip ikkyu2.
posted by apetpsychic at 11:53 AM on October 9, 2007

My max upload speed is 180k.

Bits or bytes?

But when I cap upload at 5k, web browsing works again

Bits or bytes?
posted by neustile at 11:55 AM on October 9, 2007

KB/ s sorry
posted by apetpsychic at 11:56 AM on October 9, 2007

Have you tried actually verifying your sustained download/upload caps during peak traffic? Cable ISPs are notorious for advertising unsustainable upload and download rates then capping 'troublesome' users.

My suggestion would be to run your torrents in two modes, a 'full' mode when you're not using your network, and 'reduced' mode when you're web-browsing.

Feel free to take my suggestions with a grain of salt, I don't actually have to deal with commercial ISPs.
posted by onalark at 12:31 PM on October 9, 2007

You should check forums to see if your provider is in the habit of locking down bit torrent traffic. If they are, you may need to do things like encrypt all your torrent traffic or try other tricks like that in order to stay under their radar. It's possible that your ISP watches to make sure you aren't uploading too much data via BitTorrent, which incidentally usually means fewer peers will send you data. Rogers here in Canada is notorious for throttling BitTorrent traffic.
posted by chunking express at 6:39 AM on October 10, 2007

Sorry to hear about your torrent troubles. :(

Just so you know, Time Warner Road Runner uses packet shaping so your Internet Service Provider may be partially to blame:
TW Officially Announces Packet Shaping for All RR Users (DSL Reports)

Also, it seems your Netgear WGR614 Wireless Router is on Azureus' list of "bad routers" as well:
Bad Routers (Azureus)

While this doesn't help you very much, hopefully it will help people shopping for service providers and routers to avoid these companies/products.

Again, sorry to hear about your problem. I hope you find a solution.
posted by stringbean at 11:48 AM on October 10, 2007

Limiting your max global connections might help if the source of the slowdown is your router, as per stringbean's link. I've had good luck with SpeedScheduler when I used azureus, it has very finely-grained scheduling options.
posted by Skorgu at 1:26 PM on October 11, 2007