Public packet switching networks are at various stages of development around the world, notably in the U.S., Canada, France, the United Kingdom and Japan. The success of these networks is highly dependent on the use of an agreed-upon standard device-independent interface between the packet networks and the user devices operating in the packet-mode. This interface consists of far more than the data link control procedure (i.e., HDLC), which administers the physical transmission medium between the data terminal equipment (DTE) and the network. The specification of the packet-mode interface defines a set of conventions governing the manner in which DTEs establish, maintain and clear calls, format control information and data into packets and manage the flow of data for many calls over a single circuit to and from the packet network.
This paper describes the International Packet-Mode Interface, developed jointly by Telenet Communications Corp., the Trans-Canada Telephone System (TCTS), the United Kingdom Post Office and the French PTT. This interface has been designed to enable DTEs such as computers, programmable terminal controllers and intelligent terminals to gain access to public packet networks throughout the world. The present status of international standardization of this interface within the CCITT is also covered.
Standardization of the International Packet-Mode Interface is to the advantage of teleprocessing users, manufacturers of data processing and terminal equipment and common carriers.