Why P2P might be slow

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dogwomble
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Why P2P might be slow

Post by dogwomble » Tue Oct 23, 2007 9:45 am

Hey peoples,

A common "complaint" of P2P users on ExeTel is slow transfer speeds, particularly on BitTorrent. Some people are very quick to blame it all on the NetEnforcer, but this is just one link in the chain. There are many possibilities that you need to consider - P2P is jsut a tad more complicated than standard HTTP/FTP traffic.

Here are some other things that you need to consider.

- Port Forwarding. Have you configured this in your router? And do you also use a software based firewall? Both of these will need to have the necessary ports forwarded/opened for BT. Remember - if you configure BT to allow a maximum of 10 transfers, you'll need to forward a range of 10 ports to allow this traffic through, and these ports must match the ones you've configured in your BT client.

- Seeds/Leechers ratio. If you have one seed providing a swarm for 10 users, of course your speeds are going to be worse than 10 seeds swarming 1 user. Picking a torrent with a large number of seeds and a small number of leechers will (generally) give you better results.

- Bandwidth/Congestion at remote site or at a point in between. It makes sense that your ADFSL2 syncing at 19 megabit means nothing if you're downloading from a dialup user, irrespective of where you're getting it from. In respect to BT, it could just be that the remote sites you're getting it from just don't have the bandwidth right now, or there is congestion at one point (and that's any point, not necessarily Exetel) that is slowing things down. If this is the case, you're outta luck, there's really nothing anybody can do.

- Maximum number of connections. As of Windows XP SP2, the number of concurrent limits on open TCP/IP connections was set at 64. This can interfere with P2P traffic, because it uses at least 1 connection for every host it connects to. This is particularly noticeable when you have multiple torrents running, and this could generate hundreds of connections. You'll need to fix this in the registry - however make sure you know what you're doing before you jump in there. Chances are, if you've got BT running and your web speeds goes down the crapper, this is your problem.

- Old computer. I don't think this much of an issue anymore with most computers in use being fairly recent, but if your computer is running sluggishly, or is an older model that should have been made a museum piece some time ago, then sorry, it's either time to fix the sluggishness or buy a new PC.

- Dodgy router. I know I had a problem with my old DLink where it could not handle beyond a certain number of connections. Too many connections and it would just freak out. Sometimes, a firmware upgrade will fix it - make sure you're running the latest firmware in your router. But make sure you know how to upgrade that, or else you could turn your expensive wireless router into a doorstop.

- Upstream settings in BT software. Set this incorrectly and your downstream also suffers.

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marrow
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Post by marrow » Thu Oct 25, 2007 9:15 pm

thanks for this post helpful and informative

wraithdragon
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Post by wraithdragon » Tue Nov 20, 2007 12:25 pm

Yo dogwomble!
This is a great post man. While I personally knew most of this stuff already, and don't really have speed issues, I do think that I could be downloading faster (providing the circumstances are right).

I didn't however know that if a max of 10 connections is set, that I needed to forward 10 ports. So if the torrent program I use only operates on one port, then how do I know what other ports to forward to the torrent program?

Um, if you can help me out, thanks! If not, still a great post =)
Well thats just like... your opinion, man.

DougFiasco
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Post by DougFiasco » Sun Nov 25, 2007 10:54 am

If using uTorrent, under preference->connection, down where it says "global bandwidth limitig"... Check the "Automatic" for max download speed. I found my download speed doubled...

I'm still a P2P noob, so sorry if this obvious...

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CoreyPlover
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Post by CoreyPlover » Sun Nov 25, 2007 12:27 pm

Another technique that can result in speed increases is to overload the trackers. Create a list of, say, the 10 most common trackers that you find in torrents and simply paste this list into each of your torrents. For example, in uTorrent you can right click a torrent and choose Properties to edit the trackers. There shouldn't be any great performance hit since trackers are only updated infrequently and any trackers without that torrent will just time out. By doing this, you can increase the number of peers and seed you can connect to, which will vastly help speeds on torrents with few seeders.

lovs2look
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P2P settings

Post by lovs2look » Fri Jan 11, 2008 3:41 pm

Great post, thanks!

Didn't know about the number of ports thingy either. I use Azureus and you can only set one port in it, so how would you set many ports?

BTW; The TCP/IP patch from here http://www.lvllord.de/ is highly recommended by me. I used it to open up 100 connections, but I think that may be not enough. I'll try 200 tonight, see how I go.

:wink:

sonicBlue
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Post by sonicBlue » Mon Mar 10, 2008 8:38 pm

Just thought I would mention another possible cause of speed slowing: too much RAM usage.

I found that with uTorrent 1.7.7 , my system RAM would keep getting consumed while downloading , and after a few hours there would be almost none left and everything would become slow.

If you keep an eye on how much free memory there is in the windows task manager , you should find that it stays relatively the same, and if it keeps dropping then there is a problem.

Apparently it is an issue with Windows pagefile caching (or something to that effect).

In the new uTorrent 1.8 beta there is a fix for it in the preferences under "disable windows disk caching".

hope that helps

lovs2look
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Post by lovs2look » Mon Mar 10, 2008 9:01 pm

Will keep an eye on it, thanks.
I hate betas now tho' *trembles*

sonicBlue
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Post by sonicBlue » Mon Mar 10, 2008 10:40 pm

lovs2look wrote: I hate betas now tho' *trembles*
Why have they stuffed up your PC or something?

I dont want to use beta if its going to risk killing my comp cos its new :(

skyrex
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Post by skyrex » Mon Mar 31, 2008 9:26 pm

apparently there is also encapsulation/encryption software available that will "hide" P2P packets from servers etc so it doesnt appear to be P2P traffic and instead of being throttled it is sent as per normal

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CoreyPlover
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Post by CoreyPlover » Tue Apr 01, 2008 12:20 am

skyrex wrote:apparently there is also encapsulation/encryption software available that will "hide" P2P packets from servers etc so it doesnt appear to be P2P traffic and instead of being throttled it is sent as per normal
There are 3 reasons why you should not set encryption for P2P via Exetel:
1. Encryption makes it impossible for inspecting software to determine the exact contents of a P2P packet, but the fact that it is still a P2P packet is still easily detectable and throttle-able if so desired.
2. Encrypting your packets will mean that you miss out on the speed benefits of P2P caching that Exetel have implemented because the hash of the encrypted packet will not match the hash of the cached packet
3. Exetel are not throttling much anymore. The P2P caching system generates enough additional P2P bandwidth to negate the need for Exetel to enforce throttling except at times of high usage and the intention is to eventually phase out throttling.

ccmmreid
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Re: Why P2P might be slow

Post by ccmmreid » Mon Jun 09, 2008 2:32 am

These images are from the Exetel Members Facilities page for Network Status:
p2pcachegraph.JPG
p2pcachegraph.JPG (143.64 KiB) Viewed 11342 times
adsl1optus150link.JPG
adsl1optus150link.JPG (147.79 KiB) Viewed 11342 times
adsl1optus150link2.JPG
adsl1optus150link2.JPG (118.08 KiB) Viewed 11335 times
As far as I know the blue line represents what users are downloading and the green is what we upload.

The p2p cache is always maxed out for the downloads while the adsl1 optus link has some bandwidth left.

When the cache link was started back in november it shows immediately a decrease in bandwidth use on the optus link.

So if when downloading P2P it always goes through the cache and not utilising available bandwidth on the optus link we will no doubt be unable to get our max speed for downloads due to the fact that there is no bandwidth left on the P2P cache link.

If this is the case, and please correct me if I'm wrong, then our only real solution is for Exetel to use both links for P2P (priority on the P2P link of course) to get the most out of available bandwidth or get a second P2P cache 1Gbps link.

Seeing as more and more people are churning or joining Exetel, mainly as I did for 48GB offpeak downloads for P2P, I would think that the extra revenue Exetel are making from their new customers would allow for such expansion, or else the more people join the slower it will be for the rest of us.

Thankyou.

Ditman1
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Re: Why P2P might be slow

Post by Ditman1 » Fri Mar 20, 2009 8:21 am

dogwomble wrote:Hey peoples,

- Port Forwarding. Have you configured this in your router? And do you also use a software based firewall? Both of these will need to have the necessary ports forwarded/opened for BT. Remember - if you configure BT to allow a maximum of 10 transfers, you'll need to forward a range of 10 ports to allow this traffic through, and these ports must match the ones you've configured in your BT client.
Excellent advice. I have checked port forwarding.com and it only shows how to forward 1 port in utorrent.

How can you forward multiple ports and have utorrent use them ?

Router side is no problem just utorrent side not sure about.

Thanks

ManUtdFans
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Re: Why P2P might be slow

Post by ManUtdFans » Fri Sep 04, 2009 11:32 am

I am using the random port for P2P, how do I know which 10 ports to be forwarded?

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CoreyPlover
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Re: Why P2P might be slow

Post by CoreyPlover » Sat Sep 05, 2009 12:54 pm

You don't need to forward 10 ports. Only the single port listed in your torrent client configuration.

Firewalls work like one way valves. Any incoming packets are blocked by default unless the "valve" for that port is open. But outgoing packets can get through the firewall no problem. In addition, the firewall is smart enough to accept any packets that are in direct response to an outgoing packet that your computer initiated.

So, the only port your computer needs to "listen" on is the torrect client port, so this needs to be explicitly opened. At any time however, there will be many transfers occurring, on random ports, but these don't need to be listed in your router because your computer initiated them and these ports are temporarily opened automatically by your router and then closed once the data has been transferred. Try running the Command Prompt command "NETSTAT-a" to see all the ports your computer is communicating on at any moment. There will be one for every peer you are connected to regardless of which ports you have explicitly opened on your router

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