downloads drop out, restart every few seconds

[frobb]

I'm using Transmission 1.50 on a MacBook running 10.4.11. I have ADSL internet coming through a D-Link DSL-502T router, then through a wireless router which my mac is picking up through its inbuilt wireless connection.

This doesn't always happen, usually only after I've been downloading for a while - suddenly my download rate will drop all the way to zero, stay there for about three seconds, go back up again (to 250 or so if it's a well seeded torrent) then after another five seconds or so back down again to zero in and endless cycle until I restart the program. Sometimes it goes back to normal when I restart, but tonight it isn't. If I'm running multiple torrents they all go back down to 0.0 at the same time, it's not like they're dropping out independently of each other. Can anyone help?

I've heard that something called port forwarding could fix this problem but I have no idea where to find the relevant info for my setup. Thanks for your help.

[guilherme]

Port forwarding instructions for your ADSL modem here. I believe you have to forward that port to you wireless router's internel IP adress (you should be able to check that on the 'DHCP' option), rather than to your internal IP address.
There's a chance it won't work right away - that would probably be because your wireless router does not support UPnP/NAT-PMP. In that case, you also need to search PortForward for your wireless router's instructions and forward the same port you just did on your modem, but this time to your MacBook's IP address (which you can check in your MB's Network Preference Panel, under Airport) =)

Transmission-related stuff can be found here

[TheBang]

I've seen this type of behavior that POSSIBLY could be related to disk i/o issues. Are you using an internal disk or external disk? Can you try downloading the data to a different drive than the one you've currently been using?