Seeding speed too low

[FooBarWidget]

I have a server, which I call JoeDalton. These are the specifications:

- Windows XP SP2 with latest updates.

- Both the seeder (utorrent) and the tracker (BNTN) run on that server.

- I'm sure that, at the moment, I'm the only user of the bandwidth.

- The server also hosts an FTP.

If I download a large file (1.2 GB) on my own computer from JoeDalton's FTP, then the download speed is around 120 KB/sec. I just setup a torrent for that same file, but no matter what I do, my download speed (and thus JoeDalton's upload speed) is only around 25 KB.

- The server is behind a personal firewall (Windows XP's builtin firewall), but BNTN and uTorrent are both on the allow list. I used telnet to check whether the ports are reachable, and they are.

- The server is not behind NAT, or any hardware firewalls.

- I read uTorrent's speed guide, and Azureus's speed guide. Both didn't help. The speed guide also says that the port is reachable.

- My server's IP address is owned by Sago Networks, and according to the guides Sago Networks is not known to be a provider which throttles Bittorrent speed.

- No virus scanner installed, no other firewall products installed, no other internet security products installed.

- 100 MBit connection to the Internet. According to the speed test my speed is 10147/5017 Kbps.

- I don't know what modem my server has. I don't have physical access to the server. I'm not sure whether the server's behind a router.

- There is no other network activity at the moment I was testing seeding speed. No browser activity, no FTP activity, no uTorrent downloads, nothing.

- I have read the entire uTorrent FAQ.

- peer.lazy_bitfield was already set to true. Setting it to false didn't have any effect on the speed.

- JoeDalton's upload speed limit is set to unlimited.

I noticed something strange: the icon on the right of the DHT status displays an exclamation. It says "no incoming connections" (JoeDalton is uploading at the moment). But when I use the speed guide to test whether the uTorrent port is open, it says that the port *is* open.

Does anyone know how to solve this?

[kurahashi]

Did you try to limit upload speed? Actually unlimited upload can behave a little tricky.

Other thing - while the ISP the server is can be ok, there is still possibility that higher tiers (internet interoperators, which are selling their bandwidth to the ISPs) can somehow proritize the flow in their network, making such differences.

[Switeck]

"According to the speed test my speed is 10147/5017 Kbps."

Speed Guide (CTRL+G) would place your connection somewhere between the xx/2mbit and xx/10mbit setting. You can do some simple math to figure out what the average of those 2 settings would be...which should roughly match your connection.

[FooBarWidget]

Did you try to limit upload speed?

Yes. I tried limiting the upload speed to the speed as reported by the speed test. It didn't have any effect.