Thrashing my upstream reduces packet loss. Why?

Hey all, this is my first post here. I hope you can help me.

So I have the Virgin Media 50Mb/s cable broadband and I've had many a problem with it. The first 6 months were plagued with packet loss due to over utilisation in my area.

It took them so long to fix it, along with many refunds to me. But once it finally worked, it worked great.

Anyway in my frustration I persevered with using the connection and found that my connection would stablise and the packet loss would reduce if I seeded a loads of data through torrents (Legal data. Linux distributions to be exact).

The problem has now started again and I am waiting for information from their tech support team before I go ahead and cancel my service (12 months are over thank God.)

So I'm currently back to blasting my upstream with data to stablise my connection and I just wondered how the hell does that work? Note that if I seed too much and saturate the connection I get much higher pings but 0 packet loss. if I seed just enough it gives me a near perfect connection.

The phenomenon is observable to the extent that I can do a couple of ping tests and get 4-10% average packet loss. Open torrent software and seed about 400Kb/s and the packet loss will drop to 0-1%. When I stop seeding data the packet loss goes up.

When my connection gets crappier later on tonight, I'll post some images to show you lot. Until then - any ideas why seeding loads of information stablises my connection?

Cheers,

Dan

Edited by deleted (Mon 26-Sep-11 15:33:39)

It could have something to do with the latency increasing, but sounds more like a problem on the VM side of things, does this packet loss affect throughput ?

I know it's a problem on VM side of things as they have confirmed, for my previous problem and this one, that it's an upstream utilisation issue.

IIRC throughput is rate of data transfer i.e. download/upload speed? If so, yes. My download speed takes a HUGE hit when I get packet loss. From 50Mb/s down to below 10Mb/s and even below 1MB/s on very bad nights. Strangely my upload stream remains largely unaffected.

In reply to a post by dillinger88:

I know it's a problem on VM side of things as they have confirmed, for my previous problem and this one, that it's an upstream utilisation issue.

IIRC throughput is rate of data transfer i.e. download/upload speed? If so, yes. My download speed takes a HUGE hit when I get packet loss. From 50Mb/s down to below 10Mb/s and even below 1MB/s on very bad nights. Strangely my upload stream remains largely unaffected.

I used to have a very similar problem, to your, my service was adsl,llu not cable, but i observed the same issues even the upstream appearing to chase away most of the packet loss, but this for me was caused by an outside source located near to my home so would only happen during it's hours of business,(EMI) coupled with my previous isp's kit and or my router's ability (several tried)to deal with this EMI

The the same source is still able to have an impact on my line, but not to same extent as it did before, i believe some of it my be down to brands of chipset used by both isp and end user, but although not impossible it's less likely that a cable connection could be seeing effect of EMI ect

Edited by tommy45 (Mon 26-Sep-11 16:12:50)

Thank you for your response, but I'm not sure what you're saying.

The phenomenon that I was referring to can bee seen in the image below.

[IMG]http://i52.tinypic.com/14k89j6.png[/IMG]

The packet loss reduces (in this case, disappears) when I start seeding data and I was wondering why it would do that.

See the red underline in each image to see the current upload throughput.