Upload really fine, download 0kB/s and SLOWLY rising

[ishpileprekozile]

Hi.

I have BitComet 0.77,

ADSL download:256kbps upload:64kbps

when i start a torrent (and it has enough seeds) upload speed quickly reaches its normal speed (kB/s Up column shows like 6-7 total), but download is stuck at 0kB/s, and just sometimes reaches 1kB/s. When I leave it like that for 5-6 hours, download speed slowly increases and reaches 8-11kB/s which is pretty ok for me. When I close BitComet and open it again (or just stop and start torrent) the speed is again 0kB/s and I have to wait for hours again for even really bad values (like 3 or 4 kB/s).

I would be really thankful for any advice or any replies at all.

(So my U/D Ratio is well above 1.0 and they call dsl users leechers :D )

[The UnUsual Suspect]

You might have two problems here.

First, you need to go through our settings guide.

Be sure to disable dht (unless a torrent's tracker is offline, you don't need it, and its using bandwidth, which you don't have a lot of.

Also, your max upload needs to be calulated (info in settings guide).

Now, do you get "remote" peers? or are they all "local".

If they are all local, then you need to setup your router, and/or firewall.

Suspect

[ishpileprekozile]

Suspect,

thank you very much for that really quick response.

I went through that settings guide earlier and now I did it again, just in case.

....disabled dht... but it's not any better (at least as I can see...) :(

...determined upload speed and limited max upload at 80% of it. (6kB/s)

I get some local and some remote peers, does that mean firewall is not my problem?

and no, i don't use router.

I use some ASUS external USB modem.. Windows XP SP2...

Do you know something else could cause this problem?

anyway thank you again for your reply. I will try to solve this somehow, (or just wait few hours :lol:)

[ishpileprekozile]

ok i figured something out.....

the more I limit max upload speed, the better download speed I achieve.

for example, when i limit it to 3kBps, download speed immediately jumps to 10-11kBps. I really don't understand why is this like it because when i tested my upload speed as recommended 80% of it turned out to be much higher than 3kBps.

And, as I mentioned before, when I limit it to 6kBps, Dn column says 0kBps and Up column says 6kBps.

And btw, for testing purposes I also tried to limit upload speed to 1 and 2kBps, but it mysteriously returns to 3kBps. Is this a bug or anti-leecher feature ? :)

[kluelos]

TCP is a two-way protocol. This means that for everything you receive, you must send an acknowledgement. If you don't, then the sender assumes you didn't get it, and sends it again. If you DID already get it, then that was a waste of time.

So upstream bandwidth is important, because it carries not just what you're uploading, but the acks for what you're downloading too. If you overload your upstream bandwidth, some of the packets you send will time out and expire before they ever get a chance to make it to the head of the queue.

That's why limiting your upstream speed is so important, and why limiting it correctly can actually increase your download speed: you're no longer wasting time with duplicate packets that were never ack'ed.

[ishpileprekozile]

@kluelos: thanks for explanation! I really was wandering WHY? but just didn't want to bother too much. And your brief post made it all clear for me now.

Many thanks to both of you. You were really helpful! :D