ADSI Analog Display Services Interface -- Network Protocols and Standards developed by the Bell Regional Operating Companies and Bellcore for providing Data and Voice on the Analog POTS Infrastructure. AST Advanced Screen Telephony CAS CPE Alerting Signal -- Dualtone signal issued from network switches to alert the CPE of a pending data session. CIDCW Caller-ID on Call Waiting -- Network service which provides for transmission of Caller-ID information in conjunction with Call Waiting service delivery. Off-hook type service. CLASS Suite of network services which include, Call Waiting, Caller-ID (CID), Calling Name Delivery (CNAM), Calling Number Delivery, Caller-ID on Call Waiting (CIDCW), and Visual Message Waiting Indicator (VMWI). CPE Customer Premises Equipment POTS Plain Old Telephone Service -- Standard Analog Telephone Service TIA Telecommunications Industry Association -- Standards body for the telecommunications industry.