RFC 1086 ISO-TP0 bridge between TCP and X.25 December 1988 connections using the TP0 protocol. This procedure is particularly useful in the following cases: 1. A host on an IP based internet can communicate with hosts on X.25 based networks providing the hosts are running ISO protocols. This also assumes a friendly gateway willing to run the actual TP0 bridge and make available to the IP host part of its X.25 address space. 2. A site having sparse connections to an X.25 network and using a TCP/IP based local area network for local communications. In this case all hosts on the LAN can have access to hosts on the X.25 network running ISO TP0. Pictorially, this memo describes interoperation in the following environment: +---------------------------------+ | | | +-----------------------------------+ | +----+ | +----+ | +----+ | | | | | | | | | | | | | +-----------|-----+ +--------------+ | | | | | TP0 | | | | TP0 | | | | +----+ | +----+ | +----+ | | TCP Host | Bridge Host| X.25 Host | | | | | | | | | | | | | +-------------------|-------------+ | TCP/IP Network | | | | +-----------------------------------+ X.25 Network 2. Definitions and Philosophy Some modest terminology and philosophy is introduced to aid readability and stir interest. The ISO Transport Service (TS) provides a reliable, packet-stream to its users [ISO8072]. The ISO Transport Protocol (TP) implements this service [ISO8073]. There are five classes of this protocol. The class is selected on the basis of the services offered by the underlying network service. Transport class 0 (TP0) is used when the network service offered is connection-oriented and error-detecting. Onions & Rose