Datapac X.25 service characteristics
Antony Rybczynski, D. F. Weir · 1977
Datapac is a nation-wide public packet switching data communications network operated by the Trans-Canada Telephone System. Datapac, as other networks being developed around the world, allows terminals to access its services by using a standard interface: CCITT Recommendation X.25. Recommendation X.25 defines a set of conventions governing the manner in which packet terminals format control information and data into packets, establish, maintain and clear calls, and manage the transmission and flow of data to and from a packet network. Recommendation X.25 defines a user/network interface; it does not define the end-to-end service provided by the network though clearly there is a close functional correspondence between signalling provided across the interface and across the network.