 The CSTA standard specifies a call model (that is, how parties participate in a call and the steps a call goes through as it proceeds) and a set of messages that can be exchanged between a telephone system and a computer system.When both telephone systems and computer systems implement the CSTA standard, a customer can choose freely among competing products with confidence that they will interoperate.As described more fully below, the CT Connect development team participated in the definition of CSTA.