http://www.rfc-editor.org/rfc/rfc0874.txt
RFC 0874: Critique of X.25, M.A. Padlipsky1982-09-01T23:00:00-00:00This RFC is an analysis of X.25 pointing out some problems in the conceptual model, particularly the conflict between the interface aspects and the end-to-end aspects. The memo also touches on security, and implementation issues. Originally published as M82-50 by the MITRE Corporation, Bedford, Massachusetts.