SACS is a software-based PBX. No need to buy or rent expensive equipment.

SACS just needs a PC with an ISDN-card to receive or to make calls. On the other PCs in the local network you install SACSclient and your new PBX is ready to use. Voice over IP is the base of the internal communication.

SACS has all the nice features of a PBX, including Call Transfer, Extension Management, Music On Hold. And some more:
 è    personal /free phonebooks
 è    Import contacts from Outlook
 è    Answering machines
 è    unlimited recording space
 è    Menus
 è    Designer for automated call handling (IVR)
 è    Detailed reporting
 è    User management
 

SACS is licensed only for the calls you need simultanously. You can easily integrate more licenses as you need them.