So I basically switched from cable internet to DSL internet recently. Before, with cable, I had my ports forwarded without any problems. After the switch to DSL (AT&T), I can't properly forward ports for bittorrent and I'm getting really slow speeds. My guess is that it has something to do with the new modem we got... but I'm not sure. Or could it be the internet providers are blocking me?? Help please...

The modem brand is Westell. Model: 6100 series (I think)

The router brand is Rosewill. Model: RNX-EasyN4