Bit Torrent Stops HTTP Traffic

[Crisis_Averted]

Hello Neowin,

I am running Windows 7 on a linksys 802.11g router.

I have three computers connected to it via WIFI.

When I run utorrent to download files it kills my web browsing ability.

The torrent continues to run at full speed but HTTP traffic on any of the computers on the network simply dies.

I have comcast internet with 50Mbit down and 15 Mbit up.

I am an experience BT user and have never had this problem in the past.

I have tried patching my windows for max connections, but as i said this computer with this install worked fine in the past.

I have capped the upload and download speeds to 10KB in each direction and it still tanks the Web Browsing.

Also it does this not matter which computer I try to run utorrent on. Even if I run it on my mac book it still kills the web on all other computers.

I have tried lowering the global max connections, the max upload slots, and the partial allowed connections to no avail, but these setting all worked fine previously.

The only thing that has changed is I went from Comcast in Baltimore County MD to Harford County MD and they use different types of cable modems. It is a docsys 3 modem though.

Any help would be greatly appreciated as my wife goes nuts when she cant get Facebook while I am downloading a Linux Distro or I am sharing my Bands latest concert footage and music.

[Xilo]

Bittorrent kills any other traffic on your network. This has always been a problem

Turn on QoS in your router so http traffic has priority.

[agreenbhm]

Strange that limiting the connection to 10kb in both directions yields the same results. I agree with what was posted above; try QOS.

[Crisis_Averted]

Strange that limiting the connection to 10kb in both directions yields the same results. I agree with what was posted above; try QOS.

QOS is on on the router. But it seems to be a bianry thing. Either on or off but no other options once it is enabled.

[ilev]

Never happens to me. You can set max download/upload speed in uTorrent under : Preferences, Bandwidth - Max Download Rate, Max Upload Rate

[Crisis_Averted]

Bittorrent kills any other traffic on your network. This has always been a problem

Turn on QoS in your router so http traffic has priority.

The weird thing is that it never has in the past I can me be upping a torrent and at full megabyte per second and downloading at over three and it would keep my internet running smoothly. So this problem seems to have started recently.

[SyntaxError]

Windows 7 does not require patching for the half-open connection limit as it's now a registry setting. Your client needs to be set for the same limit you set in Windows, which most people don't seem to realize. Links at the bottom.

Using bittorrents only kills your network if your router simply can't handle the packet volume, or you haven't set up your client properly. Never let your torrent client use all your bandwidth. Set it to use maybe 75% each of your up and down speeds and see if anything changes. Adjust accordingly.

I've been using torrents for 8 years now from behind routers, both wired and wireless, and never had a problem. And I don't use QoS.

http://torrentfreak.com/speed-up-bitcomet-and-%C2%B5torrent/

http://forum.utorrent.com/viewtopic.php?id=6762

http://www.mydigitallife.info/2009/06/07/half-open-outbound-tcp-connections-limit-removed-in-windows-7-and-vista-sp2-no-patch-required/

It's also possible your Linksys is dying.

[Crisis_Averted]

Windows 7 does not require patching for the half-open connection limit as it's now a registry setting. Your client needs to be set for the same limit you set in Windows, which most people don't seem to realize. Links at the bottom.

Using bittorrents only kills your network if your router simply can't handle the packet volume, or you haven't set up your client properly. Never let your torrent client use all your bandwidth. Set it to use maybe 75% each of your up and down speeds and see if anything changes. Adjust accordingly.

I've been using torrents for 8 years now from behind routers, both wired and wireless, and never had a problem. And I don't use QoS.

http://torrentfreak.com/speed-up-bitcomet-and-%C2%B5torrent/

http://forum.utorrent.com/viewtopic.php?id=6762

http://www.mydigitallife.info/2009/06/07/half-open-outbound-tcp-connections-limit-removed-in-windows-7-and-vista-sp2-no-patch-required/

It's also possible your Linksys is dying.

The linksys is brand new.

My only problem with your above post, which I will try as soon as I get home, is why would it effect web traffic on other PC's on the network? I could understand if I maxxed out the 1/2 open connections and it disables the web access on just that box but not bring the entire networks web traffic down.

[SyntaxError]

It affects your entire network because there's only so much bandwidth available for your connection, and all the traffic goes through the same router.

BTW, not all routers are torrent-friendly. Many Linksys routers are not. New or not, you could have gotten a lemon, it happens.

Is your router crashing when torrents are going full speed? If not, then your router can handle it, which means the problem is your client simply isn't set up properly.

And trying to patch an OS that doesn't require a patch probably didn't help matters either.

[Crisis_Averted]

It affects your entire network because there's only so much bandwidth available for your connection, and all the traffic goes through the same router.

BTW, not all routers are torrent-friendly. Many Linksys routers are not. New or not, you could have gotten a lemon, it happens.

Is your router crashing when torrents are going full speed? If not, then your router can handle it, which means the problem is your client simply isn't set up properly.

Do you have a suggestions of a torrent friendly router?

Also I am not any where near maxing out a 50mbit/16mbit connection when the uploads and download speeds are capped at 10KB in each direction but it still kills the connection. But if you think that fixing the a 1/2 open connections will solve the problem I am willing to try anything.

[Southern Patriot]

Many Linksys routers (even new ones) have issues with BitTorrent due to the way they handle connections. This is well documented all over the web. The usual fix is to install DD-WRT firmware and adjust some setting for the max number of open connections.

[ilev]

Which port is open for utorrent ? did you by mistake configured utorrent on port 80 ?

[Crisis_Averted]

Which port is open for utorrent ? did you by mistake configured utorrent on port 80 ?

No I had utorrent choose a random port and then I forwarded it to the pc

Many Linksys routers (even new ones) have issues with BitTorrent due to the way they handle connections. This is well documented all over the web. The usual fix is to install DD-WRT firmware and adjust some setting for the max number of open connections.

I will try that at home tonight too and report back thanks.

[SyntaxError]

I couldn't suggest any new models. Best bet is to do some research before buying. The only wired router I've owned is 2 Linksys BEFSR41 models. One died after many years of heavy use, the other is only a year old put away as a backup in case my current router dies. It's a TP-Link TL-WR642G wireless G.

The Linksys WRT54G is also torrent friendly, even without DD-WRT. Don't know about the newer G2 model, reports seem hit and miss on that one.

As for your connection being maxed out when you have uTorrent set to 10kb both directions, sounds like you did something wrong, because uTorrent obeys it's settings just fine.

I'm on 10mbit down/1mbit up with Charter and I sometimes get as much as 1 megabyte/sec down with uTorrent and it doesn't affect my browsing speeds or network activity on any machine.

I have uTorrent set to the following under Bandwidth:

Global upload rating limit: 125kb/sec

Alternate upload rate: not checked

Global download rating limit: 0 (unlimited)

Global max connections: 600

Max connected peers per torrent: 100

Upload slots per torrent: 6

Use additional upload slots if upload speed <90%: checked

[boogerjones]

Which port is open for utorrent ? did you by mistake configured utorrent on port 80 ?

That wouldn't affect outbound HTTP traffic, which never uses port 80.

What do you mean that "HTTP traffic dies?" That doesn't make sense to me. What is the specific error you encounter? What shows up in the Windows Event Log?

The problem here is not bandwidth; limiting your upload/download speed won't change a thing. The problem is probably what a couple of people have said: some home routers can't handle lots of simultaneous connections. Especially when the router is negotiating encrypted traffic to wireless clients. Try an open-source firmware on your router.

It's also possible that your new cable modem just plain sucks. There's only one way to fix that.

Windows 7 does not limit half-open TCP connections; MS quickly realized that it was a pointless limit and removed it.

[Crisis_Averted]

That wouldn't affect outbound HTTP traffic, which never uses port 80.

What do you mean that "HTTP traffic dies?" That doesn't make sense to me. What is the specific error you encounter? What shows up in the Windows Event Log?

The problem here is not bandwidth; limiting your upload/download speed won't change a thing. The problem is probably what a couple of people have said: some home routers can't handle lots of simultaneous connections. Especially when the router is negotiating encrypted traffic to wireless clients. Try an open-source firmware on your router.

It's also possible that your new cable modem just plain sucks. There's only one way to fix that.

Windows 7 does not limit half-open TCP connections; MS quickly realized that it was a pointless limit and removed it.

By HTTP traffic I mean that if I open a web browser IE or Firefox it displays the message that it would if I had my network cable unplugged/wireless adapter unplugged.

[Southern Patriot]

The Linksys WRT54G is also torrent friendly, even without DD-WRT.

Uhh, no. That is actually one of the ones that is known to have problems that are only solved by DD-WRT! I know, I used to have one (well, still have it but just using it as a repeater now since the WAN port on it died).

[SyntaxError]

Uhh, no. That is actually one of the ones that is known to have problems that are only solved by DD-WRT! I know, I used to have one (well, still have it but just using it as a repeater now since the WAN port on it died).

Must be hit or miss for that model as well, cause I've used one with torrents without any problems. No DD-WRT either.

[Lewism]

The problem for many Linksys router is that the number of allowed connections is 512 and if a connection die, it is left open for 3600 seconds (1 hour). BitTorrent can fill up these connections very quickly and slow your network to a crawl because you can't start a new connection to visit a website.

DD-WRT or any third party firmware boost the number of connections to 4096 and kills them after 1 or 5 minutes instead of an hour.

[Drimacus]

Newest uTorrent build has a "bandwidth management" feature, it's enabled by default and might very well be your problem.

[pjw]

The linksys is brand new.

My only problem with your above post, which I will try as soon as I get home, is why would it effect web traffic on other PC's on the network? I could understand if I maxxed out the 1/2 open connections and it disables the web access on just that box but not bring the entire networks web traffic down.

Wait, if the linksys is brand new, did the problem start before or after the new router?

[Crisis_Averted]

Thank you all so much for the out pouring of help. I am going to try the custom firmware so I can increase the cap. Hopefully, that will do the trick.

Thanks.

[+BudMan MVC]

"have comcast internet with 50Mbit down and 15 Mbit up."

I have to ask what the point is if all your clients are wireless G? There is no possible way you can get anywhere close to 50Mbit down with wireless G.

For starters wireless is SHARED bandwidth - so your three clients are SHARING say at max about 23Mbps.. That 50Mbit wasted for sure.

Another thing -- since its shared bandwidth doing p2p over it is a killer for any other clients on the network. Does not matter if your going full bore download or just sending questions if they have a piece or not.. Only 1 client can be talking at any one time over wireless.. So doing p2p over wireless is going to be a clusterF it up for everyone. Put your p2p box on the wire (plug it in to the router) And then correctly limit is upload to not eat up all of your upload bandwidth.

Also I would highly suggest if your going to be running p2p over the linksys to put dd-wrt on it so you can adjust these setting - hopefully you purchased the wrt54GL model so you will have no issues with 3rd party.. And plain jane wrt54G have very limited memory compared to what they use to.

--

IP Filter Settings (adjust these for P2P)

If you have any peer-to-peer (P2P) applications running on your network please increase the maximum ports and lower the TCP/UDP timeouts. This is necessary to maintain router stability because peer-to-peer applications open many connections and don't close them properly. Consider using these:

* Maximum Ports: 4096

* TCP Timeout: 120 sec

* UDP Timeout: 120 sec

--

Wireless and p2p not a good mix -- especially if you want to have other clients using the wireless at the same time. Also it not really the download pipe that is the problem, its the upload pipe -- if your upload is full then you can not query dns, you can not ask the webserver for any pages to send you, etc. Depending on the wireless clients connection, its transmit speed can be very low -- so again since its shared bandwidth - one client transmitting, no other wireless clients can transmit.. So if you go one box sending p2p at a very low transmit rate -- the other wireless clients are just hostage to that.. Does not matter if you had 10G up and down from your ISP.. Your bottleneck is shared bandwidth of wireless and trying to run share files with 100's if not 1000's of peers.. Also even after you stop downloading/seeding a file -- there can be peers sending you traffic for days.. If the ports forwarded -- thats traffic on your wireless network, keeping other wireless clients from talking even if your p2p client wasn't even running.

edit: Take one of your wireless clients and run say speedtest.net on it -- its just plain impossible for you to see 50Mbit down over wireless G - just plain impossible, and I don't think you going to be anywhere close to 15mbit up either. Post the results.

For example here was my last test (im on comast as well - but this a wired connection and paying the lowest)

So lets see what speeds your actually seeing using your wireless router vs what your paying the ISP to get. You then need to set your p2p clients upload limit to under what your seeing.. And do it with a device wired to the router so you not eating up your shared wireless bandwidth.. Then your other wireless clients will be fine.

Edited March 9, 2010 by BudMan

[Crisis_Averted]

"have comcast internet with 50Mbit down and 15 Mbit up."

I have to ask what the point is if all your clients are wireless G? There is no possible way you can get anywhere close to 50Mbit down with wireless G.

For starters wireless is SHARED bandwidth - so your three clients are SHARING say at max about 23Mbps.. That 50Mbit wasted for sure.

Another thing -- since its shared bandwidth doing p2p over it is a killer for any other clients on the network. Does not matter if your going full bore download or just sending questions if they have a piece or not.. Only 1 client can be talking at any one time over wireless.. So doing p2p over wireless is going to be a clusterF it up for everyone. Put your p2p box on the wire (plug it in to the router) And then correctly limit is upload to not eat up all of your upload bandwidth.

Also I would highly suggest if your going to be running p2p over the linksys to put dd-wrt on it so you can adjust these setting - hopefully you purchased the wrt54GL model so you will have no issues with 3rd party.. And plain jane wrt54G have very limited memory compared to what they use to.

--

IP Filter Settings (adjust these for P2P)

If you have any peer-to-peer (P2P) applications running on your network please increase the maximum ports and lower the TCP/UDP timeouts. This is necessary to maintain router stability because peer-to-peer applications open many connections and don't close them properly. Consider using these:

* Maximum Ports: 4096

* TCP Timeout: 120 sec

* UDP Timeout: 120 sec

--

Wireless and p2p not a good mix -- especially if you want to have other clients using the wireless at the same time. Also it not really the download pipe that is the problem, its the upload pipe -- if your upload is full then you can not query dns, you can not ask the webserver for any pages to send you, etc. Depending on the wireless clients connection, its transmit speed can be very low -- so again since its shared bandwidth - one client transmitting, no other wireless clients can transmit.. So if you go one box sending p2p at a very low transmit rate -- the other wireless clients are just hostage to that.. Does not matter if you had 10G up and down from your ISP.. Your bottle next is shared bandwidth of wireless and trying to run share files with 100's if not 1000's of peers.. Also even after you stop downloading/seeding a file -- there can be peers sending you traffic for days.. If the ports forwarded -- thats traffic on your wireless network, keeping other wireless clients from talking even if your p2p client wasn't even running.

That makes a lot of sense. In my old apartment I always had the BT computer plugged directly into the router, now at my new house I use a low powered HTPC to do my downloading to save running my 800 watt power supply 24/7. I am probably saturating the wireless bandwidth the router can provide, thus kicking the other 2 wireless devices offline. I cant believe I didnt think of that sooner. Thanks!

[Crisis_Averted]

Well problem solved. I plugged my router directly into my HTPC that does the BTing and behold every thing works. I am downloading a file right now at a full 3.3MB/s and uploading at 1.1MB/s. I can browse the web on all computers while I am doing this as well.

Thanks to everyone for all your suggestions, especially to BUDMAN who hit the nail on the head.