[RndTbl] Shaw packet loss

Mike Pfaiffer high.res.mike at gmail.com
Tue Oct 19 11:16:01 CDT 2010

On 10-10-19 11:07 AM, Sean Walberg wrote:
> On Tue, Oct 19, 2010 at 10:57 AM, Mike Pfaiffer<high.res.mike at gmail.com>wrote:
>>         Give it a try. Grab a movie or something. Use a bittorrent client
>> capable of capping the up and down speed. Ktorrent can do this. See what
>> you can get for both up and down uncapped. Then try running say Firefox
>> and look at its performance. Stop the bittorrent transfer and look at
>> Firefox again in a few minutes. Set up a cap in bittorrent say 10K on
>> both the up and down (bear in mind this is supposed to be a
>> multi-megabit connection). Restart your bittorrent and see what happens
>> with Firefox. You'll notice the bittorrent will transfer to what ever
>> maximum you set while other programs will barely function on the
>> internet. Local transfers on the LAN are fine though.
> Like you, I haven't done any formal testing, but my wife has uT going non
> stop and I haven't had any problems with my download speed unless she
> forgets to cap her upstream. uT is running forced encryption, FWIW.

	Without encryption the problem IS worse.

> It's almost a certainty that Shaw has DPI policies dealing with torrent. I'm
> not disputing what you're seeing, but correlation does not equal causation.

	Quite correct. As you hint in the next paragraph it is worth looking 
at. Still, even with a large HTTP or ftp download the problems aren't there.

> As a start, try doing some Wireshark I/O graphs on the various streams with
> and without a torrent running. Do the bandwidth of the non torrent flows
> change? Is there a change in the TCP setup times? Are ACK packets being
> delayed? Are you seeing loss?

	I'll have to get back to you on that. That's not something I've done yet.

> Sean


More information about the Roundtable mailing list