Ptcl Wifi Modem

Previously I was using Dsl Modem AN1020-16T a non wifi ADSL2+ modem. Today I exchanged my modem with a new Wifi Modem KW5815U. On my previous modem I was able to connect with my friends DSL username but now in this new modem I am not able to connect with my friends username. I can only use mine. Does anyone know why is this so and how I can overcome this Problem?

Thanks.