ISP throttling?

[andy200]

Hi there,

I've been using Shareaza happily for about 5 years or so and have never had any problems with downloads. About a month or so ago, the download speed suddenly plummeted to about 1 or 2 KB/s max, no matter how many sources were available. I followed all the troubleshooting tips I could find, with no change.
I hadn't changed anything when this started happening so I began to think that perhaps my ISP had started throttling P2P traffic. I was originally on Bulldog Broadband, who were subsequently taken over by Pipex/Tiscali a couple of years ago. I now pay my bills to Pipex and apparently have a Pipex Homecall up to 8Mb package - my line syncs at 3776kb/s. Normal internet use is fine - HTTP downloads can still max out the connection. Port forwarding is setup on the router and passes the Shareaza connection test. Searching the internet didn't reveal any recent issues with Pipex.

In an effort to get to the bottom of the problem I tried a few things :-

1. The Glasnost test for Gnutella doesn't reveal any evidence of throttling.
2. I downloaded Limewire and it can download at full speed (up to about 350 KB/s)
3. I changed my router - I did have a Solwise SAR-110 with a WRT-54G for wireless. I replaced them with a DG834G (£8 from ebay - bargain!).

I carried out one final test which makes me sure that the ISP is throttling Shareaza traffic :-

I setup a laptop with a clean install of XP SP3 (with the EVID4226 patch setting the half open connections to 50) and loaded Shareaza 2.5.3.0. I then tried downloading a file with about 300 sources via my Pipex connection - same result as before, downloading at about 1KB/s despite Shareaza reporting that it was downloading from about 20 peers. Most of the peers didn't have a speed against them and the ones that did were around 200 B/s. While Shareaza was still running, I disconnected the Pipex connection and plugged in a 3G card. As soon as the card had connected, the download speed in Shareaza shot up to about 200 KB/s. Unplugging the card and reconnecting the Pipex connection dropped the speed down to the 1 KB/s or so.

This seems fairly damning evidence that Pipex are throttling the traffic, but what I don't understand is why Limewire works OK - many of the peers that Shareaza is connecting to show as being Limewire clients, so unless Pipex can identify traffic as coming from Shareaza, I'm stumped!

If anyone has come across this before or has any suggestions then I'd be extremely grateful for any pointers. The last resort is to change ISPs, but that's a bit of a performance, so I'll only do that if it's the only solution.

Regards,
Andy.

[old_death]

Have you tried whether you pass the Shareaza connection test?

[andy200]

Hi,

Yes, the Shareaza connection test passes.

Regards,
Andy.

[old_death]

That's strange... However you might want to try changing the port Shareaza uses to something different than 6346 (and something not listed here), because there are service providers that limit the traffic on certain ports only...

[andy200]

I've tried a variety of different ports with the same result. It's as if the ISP is only interfering with Shareaza traffic - if I try the same ports with Limewire then everything works OK.

[siavoshkc]

Why not asking ISP if they filter or not? If they lie and say no and you prove it you are the winner. If they assert you know for sure.

[edit]
I don't think they filter only Shareaza. To do so they need to read every packet to detect Shareaza in handshakes.

[andy200]

I did as you suggested - they basically didn't tell me very much, other that P2P is against 'company policy' and I shouldn't be using it! There's nothing in their Terms and Conditions about not using P2P and their fair usage policy doesn't kick in until you reach over 100Gb per month, which I come nowehere near. The guy I spoke to was very pleasant, but didn't want to get drawn into a discussion as to what customers can and can't use their connection for, simply repeating the 'company policy'. That's enough proof for me - they clearly don't want customers who use P2P and are likely doing some sort of throttling or blocking, so I'll be taking my business elsewhere.

I still can't understand why it's only Shareaza that's affected - Limewire is fine but, as I like Shareaza, I'm happy to change ISPs to continue using it.

Many thanks for all the suggestions.

[zigozag]