X.25 AND RELATED RECOMMENDATIONS IN IBM PRODUCTS

IBM's use of Recommendation X. 25 and related recommendations of the International Telegraph and Telephone Consultative Committee is described. After reviewing the development history of X. 25 and some of the motivations for using it, the paper gives an overview of packet-switched data networks. A brief technical description is then given of Recommendation X. 25 and some other recommendations used in conjunction with X. 25. The architectural relationships between X. 25 and IBM's Systems Network Architecture (SNA) are described for packet-switched X. 25 connections between SNA nodes and for X. 25 connections between SNA and non-SNA nodes. Specific elements of Recommendation X. 25 used in SNA nodes are defined. After several IBM products that support X. 25 and some of the related recommendations are described, IBM's equipment for testing the X. 25 interface is discussed.