To safeguard the client's existing investment on communication systems, Avis's Asterisk Engineers can connect Asterisk to the legacy PBX, so that the client can use the rich feature set of Asterisk, and utilize previous investment on legacy PBXs. Whether there is a requirement of an IVR, a fax gateway, or simply increasing the capacity of the legacy PBX, Avis's engineers can innovate methods to use Asterisk along-with the legacy PBX, thus minimizing total cost of ownership.