asterCC package provides a call center solution and a billing solution for asterisk, the most important feature is, asterCC could work with all asterisk based solutions and no need do any modification to the original system,  as we have tested, including:

Trixbox
Elastix
Callweaver
Freepbx
Magiclink
Fonesoft
asterisk2billing (a2b)
pbx in a flash
…

so when you are using a asterisk based system and want [...]