OSI protocols

X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts and finalized in a publication known as The Orange Book in 1976.

Intermediate System to Intermediate System (IS-IS, also written ISIS) is a link-state interior gateway protocol (IGP) used to exchange routing information within a network. Routers share network topology information so they can find the most efficient paths for data. IS-IS is typically deployed within a single autonomous system and is used in large enterprise and service provider networks.

X.400 is a suite of ITU-T recommendations that define the ITU-T Message Handling System (MHS).

OSI Network Layer datagram service

FTAM, ISO standard 8571, is the OSI application layer protocol for file transfer, access and management.

identifying label for network endpoints used in Open Systems Interconnection networking

computer network management protocol

computer networking standard for accessing an X.500 directory service

information exchange standards