Asterisk has revolutionized TDM and VoIP telephony in the last decade. It is fair to say that we have no realistic count of the number of Asterisk based PBX, gateways and other VoIP applications running currently around the world. It is certain that this will be a mind boggling number. We are not totally aware of the number of call centers around the world which use Asterisk in some form or the other. Overall it is safe to assume that Asterisk telephony represents a significant percentage of the contact center technology platform as well.
Contact Center Software for Asterisk Telephony
Information for Asterisk based contact centers