Computer-supported telecommunications applications (CSTA) is one of the more important standards for computer-telecommunications interfaces, addressing service and protocol definitions used to provide a link between computers and telecommunications systems. The services provided on a CSTA link between a telecommunications and computer network work much like the services that telecommunication network provides to a user at an access point. At the point of attachment to a telecommunications network, the "phone numbers" are sufficient to describe the desired object for involvement with a service. If a new object were created for the purposes of CSTA (e.g., a monitoring group), an identifier which would work like a phone number in that network would be assigned to that object. Additional handle-identifiers are created and provided after a service is initiated to differentiate between instances of the service being provided. To show this relationship, a functional model was created.