• What is the switching architecture of the system 85 PBX? (text+figure)

• What Is The Internal Structure Of The Communication Switching Module? (text+figure)

• What Is The Internal Structure Of The Control Complex? (text+figure)

• What Is The Digital Communications Protocol (DCP)? (text+figure)

• How Are Data Devices Connected To System 85? (text+figure)

• How Does Modem Pooling Work? (text)

• What Is The Digital Service Interface (DS-1)? (text)

• What Is An Applications Processor? (text+figure)

• What applications are available on the APs? (text)

• What is the electronic tandem network (ETN)? (text+figure)

• What is the distributed communication system (DCS)? (text+figure)