Internet while downloading.

Can mean 2 things:
- Downloading at full speed, fills your whole upsteam channel, resulting in slow other things you can do on the internet
- Downloading at full speed, overloads your old router, which can't handle the downstream at the speed, while -also- allowing other connection to come through.

I limited my download speed to 500kb/s and it seems to have solved the inability to use the internet. Although you can still notice some sort of lag.