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Upload Rate Bouncy Bouncy


forbiddenera

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Hi there.

I've had an issue with utorrent for a very long time now, and I'm not sure if it's utorrent or my connection or configuration.

It only happens sometimes, but when downloading a torrent, my upload rate will not be stable, it'll hit the limit and start slowing down until about 5-10% of the limit, then it will shoot up 10 or 15% above the limit in a short burst, which continues to slow down until it repeats. This happens consistently and manages to flood my upload causing download issues even with my Linux router traffic shaping upstream (or not) in the middle.

I have 25mbps downstream and 1mbps upstream. It does not matter even if I set my upload limit to say 30kB/sec.

Number of connections doesn't seem to be a contributing factor. I do not know if this happens with any other torrent applications, and I'm not inclined to try as utorrent rocks.

This usually happens worse:

bouncy.jpg

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Err... that's a vertical grid up to 4.5Mbit right... your traffic look fine. However your variance is every 10 seconds... Connections per second when they churn create overhead and upload. I'm guessing you've got that upload set ~ 35 in the picture and scale @ 1 sec. which isn't a very good average for sustained speeds. Scale it back to 5 or 30 seconds.. you'll see the lines generally at a variance within 10% of the upload limit.

What are you concurrent connections, max halfopen settings, and connect speed? A constant churn of connections is about 1KiBps per 10, and sustained traffic for HAVEs/GOTs is ~ 1KiBps per 100 peers. Truthfully DHT uses more traffic, but that's spread out more, usually only announcing every 15 minutes.

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I don't use DHT as it's not allowed on most of my trackers.

As I said, concurrent connections doesn't seem to affect things and that picture is hardly a good example, honestly it seems like a long-standing bug in utorrent.

When it's working properly the upload does not vary in the slightest and my downloads are great.

I usually run 750 concurrent per torrent, unlimited global, 750 half open and 750 connect speed, but as I said, lowering these to 100 even doesn't solve the problem WHEN its occurs, which is only sometimes.

Also, couldn't there be separate limits in utorrent to limit overhead and shared upload?

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And no, there can't be separate limits to data transfer rates and overhead rates, because µTorrent can't calculate the overhead.

I disagree, overhead is not hard to estimate or provision for, it also can't be difficult to limit the rate of outgoing packets.

How can utorrent NOT calculate the overhead? It's not hard to figure out what part of a packet is data and what is not.

I don't think it would be difficult to setup an HTB system where outgoing torrent traffic and connections have their own classes and provisions.

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... overhead is overhead. I re-state my observation of your post. 1 second intervals are irrelevant for statistical significance AND the sliding average uT uses for display. Show me something scaled to 5 or 30 second intervals (I bet you wonder how I know you set that to 1 second, with only 2 minutes of display data) which consistently goes over the upload limit set and we can talk.

Regarding DHT k point taken. As I said previously an abundantly high halfopen and max connections CAN cause lots of extra bandwidth when churning peers.

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1, 5 and 30 second intervals, problem 10x more apparent now with no settings change since last screenshot.

bouncy2.jpg

Essentially, my point is, no matter what, utorrent under no condition should not allow the upstream output exceed the limit, which it is, admitted by it's own graph.

The torrents downloading clearly slow down on the upload rate and then have a huge burst, sometimes with multiple torrents it's only one that has a burst of upload.

Initially my thought was a flood of connections due to it adapting to number of upload slots vs upload rate, however I have it limited to 1 upload slot and adding additional is disabled.

I'm also a software developer, so I do actually have a clue what I'm talking about.

I should also note that on the days it works, the upload rate has an apparent variance of less than 1%.

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Thanks for the multiple pictures. The rhythmic timing coinciding with decrease in download suggests peer disconnect or some other throttling coming into effect. I wasn't aiming to be disrespectful, and I have no doubt you know what you're talking about--you're the one staring at the graph after all :P. Unfortunately overhead is still overhead. I would like you to also observe the variance only starts after you increase the upload above .25Mbit. Perhaps you don't have that kind of connection, or your ISP does not allow you to use that much bandwidth during the time you tested. uT will try to use up to and as much upload bandwidth as you set the limit at. Are you SURE your ISP doesn't use shaping profiles to "remedy" filesharers using up their bandwidth?

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Hi,

I've set the upload bandwidth higher and lower to no avail, the times when it's stable I'm able to have an upload rate of about 90kB/s with little variance in the graph. The latter graphs were with an upload limit of about 0.5 Mbit which is about half my upload.

There are no time based limits with my ISP, though it is cable so neighborhood influenced bandwidth could be a factor however I've had this issue off and on for at least a year, at multiple houses.

My ISP uses ellecoya switches limiting torrential bandwidth however they only affect unencrypted torrents. Beyond that my ISP has no shaping and theres no reason my torrents shouldn't achieve a download rate near 25Mbit, though to be honest, I've hardly got over 10Mbit since I've upgraded to 25Mbit and will probably switch back to 10Mbit until such a time the advertised speeds are stable enough to be worth the cost.

Regardless, this happened on my 10Mbit and 5Mbit lines at previous houses.

Again, the only thing deceiving me from agreeing that it's my ISP or similar is that as I said, utorrent should never send out packets above the upload rate, weather or not previous packets have filled a buffer (or something) somewhere, which it clearly is, consistently.

Also, I've noticed, that most times when simply seeding and not leeching that the upload rate is sustained and consistent.

And blast this forum and it's stupid 'no multiple posts' function!

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... If you can't send out @ ~90 or above you don't have a 1Mbit up line. If you can send out @ 90 or above for HTTP, then your ISP is shaping torrent traffic. If you can't download @ your advertised 10 or 25 Mbit rates, again your ISP is shaping torrent traffic. AFAIK both the openoffice and slackware test torrents max out 100 Mbit synchronous lines.

It is common sense that seeding only will create a more stable upload since you don't have to worry about receiving ACKs for packets and send out HAVEs for pieces from peers.

uT does its best to keep your traffic at the limits you set, but it WILL be in a variance of up to 10% ( on low-bandwidth lines ) depending upon overhead. Overhead is not counted in peer traffic and is not included in the limits calculations. Overhead can therefore be defined as the bandwidth used by additional features. Included in these figures are DHT, which iirc uses something like 90 MiB a day and peer communication amounts to 180MiB per 100 active connections a day.

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Except on the OpenOffice (and similar) test torrents, don't expect to get more than 5 times the download speed than you're uploading back. And with really big torrents (over 1 GB in size), that can get even worse -- even download falling below upload often.

Having said that, my guess is your settings are sabotaging uTorrent and causing bursty upload speeds as a result.

"I usually run 750 concurrent per torrent, unlimited global, 750 half open and 750 connect speed, but as I said, lowering these to 100 even doesn't solve the problem WHEN its occurs, which is only sometimes."

Reset those numbers to defaults, then run Speed Guide (CTRL+G) and test the xx/1mbit setting. Try to keep the average upload speed PER upload slot within 2-10 KiloBYTES/sec if you do tweak the values.

Half open shouldn't need to be over 20 with a connection as slow as yours, unless uTorrent is firewalled...and even then 40 would be complete overkill -- including causing possible router/modem overloads.

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