We mainly replace old telephony equipment. If, for instance, there is an old Alcatel telephone system (digital or analog), and the customer asks us for a new option for IP telephony, then we offer both the Cisco- and Asterisk-based systems. We know the billing, we know the pricing of the items and what we can offer with both solutions. There are multiple factors involved when selecting a vendor * stability * support * features. If the product is stable, the product has good support, and it has enough features which we can offer to our clients, then the product is under our consideration.