Messaging and Directory Server software used around the world in the Government, Military, Aviation and Commercial sectors.
The Isode M-Vault and M-Switch X.400 and X.500 protocols are usually over TCP/IP, using the RFC 2126 mapping of the OSI Transport Service onto TCP (RFC 2126 is the updated version of the more commonly referenced RFC 1006). This combination is known as ITOT (ISO Transport over TCP).
If there is a requirement to operate over a full OSI Stack, Isode can supply and support operation of its X.400 and X.500 products over a full OSI Stack, with various transport and network protocol combinations on all of the Isode platforms. The transport and network layers are provided by a third party. Isode recommends four providers with Transport and Network Protocols that are conformant to the OSI base standards and to the standard ISO profiles. Three of these products are also conformant to the ICAO (International Civil Aviation Organization) SARPS (Standard and Recommended Practices) profiles, required by the aviation industry. The ICAO SARPS profile is based on TP4/CLNP (Transport Protocol Class 4/Connectinless Network Protocol). The four products are:
- Sun Solstice OSI on Solaris (provides TP4/CLNP and TP0/X.25).
- The Boldon James Impart OSI Transport on Linux (ICAO SARPs conformant).
- The AirTel ATN Transport Server on Linux (ICAO SARPs conformant).
- The ProATN package from Sofreavia (ICAO SARPs conformant).
Each of these products can be integrated with the Isode products to provide a full OSI solution.
An alternate approach to operating the Isode products over a full OSI Stack is to operate them over TCP/IP (using RFC 2126) and then use a Transport Gateway to provide access through ISO Transport and Network protocols. Transport gateway talks RFC 2126 on one side and OSI Transport and Network protocols on the other. Externally this solution behaves as a full OSI implementation. Use of a transport gateway has two strong advantages:
- Applications can use RFC 2126 when
communicating internally, and can use full SARPS conformant stack when
communicating externally. - The OSI stack needs to be provided only on the transport gateway machine, and not on every machine running an application.
Two ICAO SARPS conformant transport gateways are available.
- The Impart Transport Gateway, is available from Boldon James for Windows and Unix.
- The BCI Transport Gateway is available from BCI.
An alternate approach is available to provide TP0 (Transport Protocol Class 0) over X.25, which is only available directly using Sun Solstice OSI. This approach is to use a TCP/X.25 gateway with support for ITOT (RFC 1006) framing. This is possible because ITOT uses TP0, and this can be used end to end. One suitable TCP/X.25 Gateway is available:
- Farsite FarLinx TCP-X25 Gateway is available from FarSite.
