The Gsm module supports every cell phone that complies the ETSI TS 127 007 standard.
Most of the cell phone manufacturer are supporting this standard. In the actual version, smartphones and pocket pc's are not supported.
The interface covers all functions of a cell phone. When a call is received the music player is placed in pause mode and a popup screen is showing the number, the name and if exists a photo from caller. You can accept the call by clicking the relevant button.
With the same simple way you can make calls too.