BitTorrent experts - is this normal?? - Page 2

Phantom Power · 03-05-2007, 08:12 PM

I also have vonage, and the same thing occurs with me. However, the problem has nothing to do with bittorrent, or Vonage particularly, but rather the protocols used by each and your home router.

VOIP technologies use UDP protocol, where each packet is sent off on its merry way and left to fend for itself. Most other internet traffic is sent via TCP, which is a stateful connection protocol. Each packet has a sequence number and must be acknowledged by the receiving side. If a packet is not acknowledged within a reasonable amount of time it's resent until it is acknowledged. This is why when you send a file over the chaos of the internet, it all gets there in one piece and in the correct order.

Here's where the problem lies. Switches/Routers typically have multiple hosts on them. When packets come in to any port, their headers are analyzed and the device checks its lookup tables to determine which outgoing ports to send it out on. This takes time, even though the amount of time is miniscule. If packets are coming in on more than one port (say port A for your comp running bittorrent and port B for your phone), and they both have the same outgoing port (port I for the port that goes to your cable modem etc), and they're both running at close to maximum transfer rate then you get the problem.

Say you have a 100Mbps router. You have 90 Mbps coming on on Port A, and 90 Mbps coming in on Port B. You can only send out 100Mbps on port I, so what happens with the extra packets ? The router has an internal memory buffer, and the packets are queued up. For regular internet traffic, which tends to be quite "bursty" this is fine, since you get 2 ports spiking in bandwidth at the same time, they get queued and delt with. But when you have two applications that are sending an almost constant stream of data at full transfer rate, the queue fills up. What does the router do with packets when it's queue is full ? It tosses them.

The packets that are tossed are never received by the other end. For the TCP connection, this is not a big deal, since they never get acknowledged and get resent. The UDP packets are gone forever though. The other side never gets them, and that's why the other party that's listening to you hears you breaking up severly, but you can hear them fine.

Higher quality routers will have more internal memory to buffer the packets, but it's always a finite amount (sadly). You need to get your combined transfer rates for both VOIP and BitTorrent down to below the maximum transfer rate of the router.

Hope that helps.

eric · 03-05-2007, 09:57 PM

i'd switch over to utorrent as its what im running because i had the same problem

what it was doing is downloading and then corrupting (i tryed 2 files and said the hell with it)

after its done downloading it will normally seed thus it looks like its downloading agian

with utorrent you can normally just click stop after its done downloading and it will stop

also which site are you getting your torrents from? i use thepiratebay.org myself and ive got nothing but great results with that and utorrent

respiegel · 03-06-2007, 12:45 AM

uTorrrent is the best!

Jaan · 03-06-2007, 01:18 AM

Where are you getting the trackers? Sounds like there are a lot of fakes out there that you're trying to download. The evil corporations do that to popular torrents just to waste your time.

Of course, I'm sure you're only downloading Linux distros and the latest episode of Star Trek New Voyages...so that can't possibly be the case (c:

Mininova, Pirate Bay and Demonoid are all good places to get trackers. If you want an invite code to Demonoid let me know (anyone else too).

Clearush · 03-12-2007, 12:55 AM

I'll third utorrent as being a great torrent client - much better than Azureus which is what I was using previously.

I am on Sunrocket and Roadrunner cable and I have to shut down any upload or download traffic when the phone is in use even with the torrent throttled back. It even gets choppy with FTP.

p8ntguykenny · 03-17-2007, 07:08 PM

Maybe I can shed some much needed light on your situation.

When you download a packet through any bittorrent a few things happen. First a hash check is performed on the packet. For a multitude of reasons, when another person is downloading a packet, it can become corrupt. If they are using an odd client, it may not perform the required hash check. If this is the case, when they upload that packet, it will fail the hash check if you have a client that does perform it. If this is the only person uploading a particular packet to you, you can end up downloading it multiple times, each time it fails the hash so it's discarded and your client attempts to download it again.

The problem has nothing to do with your client per se. If for some reason your client is incorrectly performing hash checks and discarding otherwise correct packets, then it is the problem. But if you're using a mainstream client, this is the least likely of problems. The most likely is that a person is uploading a corrupt packet and is the only person uploading that particular packet(due to a low number of seeds/peers). For older files with few people UL/DLing it, this can be an unavoidable problem.

03-05-2007, 08:12 PM	#11 (permalink)
Phantom Power Pump Gun Dealer Join Date: Mar 2006 Location: Pender Island, BC	I also have vonage, and the same thing occurs with me. However, the problem has nothing to do with bittorrent, or Vonage particularly, but rather the protocols used by each and your home router. VOIP technologies use UDP protocol, where each packet is sent off on its merry way and left to fend for itself. Most other internet traffic is sent via TCP, which is a stateful connection protocol. Each packet has a sequence number and must be acknowledged by the receiving side. If a packet is not acknowledged within a reasonable amount of time it's resent until it is acknowledged. This is why when you send a file over the chaos of the internet, it all gets there in one piece and in the correct order. Here's where the problem lies. Switches/Routers typically have multiple hosts on them. When packets come in to any port, their headers are analyzed and the device checks its lookup tables to determine which outgoing ports to send it out on. This takes time, even though the amount of time is miniscule. If packets are coming in on more than one port (say port A for your comp running bittorrent and port B for your phone), and they both have the same outgoing port (port I for the port that goes to your cable modem etc), and they're both running at close to maximum transfer rate then you get the problem. Say you have a 100Mbps router. You have 90 Mbps coming on on Port A, and 90 Mbps coming in on Port B. You can only send out 100Mbps on port I, so what happens with the extra packets ? The router has an internal memory buffer, and the packets are queued up. For regular internet traffic, which tends to be quite "bursty" this is fine, since you get 2 ports spiking in bandwidth at the same time, they get queued and delt with. But when you have two applications that are sending an almost constant stream of data at full transfer rate, the queue fills up. What does the router do with packets when it's queue is full ? It tosses them. The packets that are tossed are never received by the other end. For the TCP connection, this is not a big deal, since they never get acknowledged and get resent. The UDP packets are gone forever though. The other side never gets them, and that's why the other party that's listening to you hears you breaking up severly, but you can hear them fine. Higher quality routers will have more internal memory to buffer the packets, but it's always a finite amount (sadly). You need to get your combined transfer rates for both VOIP and BitTorrent down to below the maximum transfer rate of the router. Hope that helps. __________________

03-06-2007, 12:45 AM	#13 (permalink)
respiegel MCB Member Join Date: Apr 2006 Location: Huntsville, AL	uTorrrent is the best! __________________ My PBN Feedback \|\| My AO Feedback \|\| My MCB Feedback

03-06-2007, 01:18 AM	#14 (permalink)
Jaan MCB Member Join Date: Aug 2006 Location: People's Republic of Massachusetts	Where are you getting the trackers? Sounds like there are a lot of fakes out there that you're trying to download. The evil corporations do that to popular torrents just to waste your time. Of course, I'm sure you're only downloading Linux distros and the latest episode of Star Trek New Voyages...so that can't possibly be the case (c: Mininova, Pirate Bay and Demonoid are all good places to get trackers. If you want an invite code to Demonoid let me know (anyone else too). __________________

03-12-2007, 12:55 AM	#15 (permalink)
Clearush MCB Member Join Date: Mar 2006 Location: HTown, TX	I'll third utorrent as being a great torrent client - much better than Azureus which is what I was using previously. I am on Sunrocket and Roadrunner cable and I have to shut down any upload or download traffic when the phone is in use even with the torrent throttled back. It even gets choppy with FTP. __________________ Carter's Commando Texas division Black Watch Scenario Paintball Team My SCP Feedback Ebay Feedback MCB Feedback

03-05-2007, 09:57 PM	#12 (permalink)
eric Seasoned Member Join Date: Apr 2006 Location: Port Colborne,ON	i'd switch over to utorrent as its what im running because i had the same problem what it was doing is downloading and then corrupting (i tryed 2 files and said the hell with it) after its done downloading it will normally seed thus it looks like its downloading agian with utorrent you can normally just click stop after its done downloading and it will stop also which site are you getting your torrents from? i use thepiratebay.org myself and ive got nothing but great results with that and utorrent

03-17-2007, 07:08 PM	#16 (permalink)
p8ntguykenny MCB Member Join Date: Sep 2006 Location: Los Angeles, CA	Maybe I can shed some much needed light on your situation. When you download a packet through any bittorrent a few things happen. First a hash check is performed on the packet. For a multitude of reasons, when another person is downloading a packet, it can become corrupt. If they are using an odd client, it may not perform the required hash check. If this is the case, when they upload that packet, it will fail the hash check if you have a client that does perform it. If this is the only person uploading a particular packet to you, you can end up downloading it multiple times, each time it fails the hash so it's discarded and your client attempts to download it again. The problem has nothing to do with your client per se. If for some reason your client is incorrectly performing hash checks and discarding otherwise correct packets, then it is the problem. But if you're using a mainstream client, this is the least likely of problems. The most likely is that a person is uploading a corrupt packet and is the only person uploading that particular packet(due to a low number of seeds/peers). For older files with few people UL/DLing it, this can be an unavoidable problem.