Speeds Sometimes "Oscillate"

[JLMiller]

I've observed this behavior on two completely different systems (one in NH, one in FL). Most of the time, I can get respectable speeds for well-seeded torrents (90 KB up, 500+ KB down), but sometimes, I see "oscillating" in the speeds (usually download, but occasionally upload), approaching a maximum, then dropping quite low (but never going near zero). The periodicity is around 1/2 - 1 second.

Frequently when this happens, I can adjust the maximum limit down to just below the peak value, after which the rate stabilizes at the new maximum. Sometimes, however, that just slows things down further.

I've set everything up according to the recommended settings. Glasnost says I'm not being throttled by either ISP (fairpoint.net in NH; att.net in FL), and my port forwarding works.

Anyone have an idea what's happening?

Thanks.

- John

[rafi]

Other posters reported that effect, to no avail . The devs did not yet respond. Stay tuned... maybe they will...

[deanjones84]

my speed was constantly up and down, peaking around 180kbps and troughing at even parallels around 100kbps. and yeah i did the same: I just adjusted the maximum limit at 150 and it just stayed at 150. thats around the rate it should be for my internet speed give or take.

I also notice that when the upload spikes it affects the download rate, causing it to crash at the same time.. why is that?

[autoclave]

I've solved this problem by limiting global dl and ul speed to about 90-95% of the true speed. Say your true dl speed is 10000 kbit/s, limit it to 9500 kbit/s. I suspect the oscillating in the speed is due to excessive overhead which in second turn limit download speeds, but I've got no real evidence this is the reason.

I've always had this problem during the 10 years I've used bittorent, no matter pc, torrent client or broadband connection, and doing this does seem to stabilize the speed.

[JLMiller]

Yes, autoclave, that sometimes resolves the issue, but I'm more interested in the instances when limiting the speed allows the oscillation to continue, just at overall reduced speed. And, of course, I'd like to know the root cause, so I could resolve it for good.