ISO/IEC ISP 10613-7:1994/Amd 2:1998Information technology — International Standardized Profile RA — Relaying the Connectionless-mode Network Service — Part 7: PSDN subnetwork-dependent, media-dependent requirements for virtual calls over a permanent accessAmendment 2: Reference Optional Security Requirements Specific to X.25 Subnetworks — Rann.11n1