What is X.400? The EDI transfer protocol

Various communication channels are used in the B2B environment for the secure exchange of electronic data. X.400 is one of the most popular AS2 transfer protocols, along with EDI. The X.400 standard was published by the French committee CCITT (Comité Consultatif International Télégraphique et Téléphonique) in 1984 and extended in 1988. One of the greatest advantages of X.400 is the security offered due to the closed (physical) network. In contrast to "simple" e-mails transferred via the internet, X.400 uses its own network. This "own" network can in this case be seen as an alternative for the old familiar internet. The official technical term for such networks is VAN (Value Added Networks). In addition, the X.400 network offers controlled access points, which make it possible to identify individual domain operators.

How are X.400 networks constructed?

The exchange of E-Mails in X.400 networks takes place via mailboxes. The difference to the familiar internet e-mail exchange is that in X.400 networks there are only known providers and unique (contractually secured) connection paths on which messages are sent through the network. An X.400 subscriber can therefore access his mailbox with his personal access data within the X.400 network and synchronise his messages. Access by third parties can thus be excluded.

X.400 in a modern EDI solution?

Electronic data exchange via X.400 usually involves EDI systems that do not communicate directly with each other. When two companies communicate via X.400, an X.400 provider is used, which serves as a communication network between the two players. In concrete terms, this means that EDI messages are stored in the mailbox for dispatch and then forwarded to a recipient mailbox. Such mail systems are also called store-and-forward networks.

Electronic data exchange using X.400 as the communication protocol is considered by many to be "outmoded". The focus is on the comparatively high costs that arise when using it. Nevertheless, X.400 is still frequently used as a communication channel for electronic data exchange. The advantage is mainly for trading groups that have to interact with a large number of suppliers on several EDI process levels. Message exchange of DESADV (delivery notification), INVOIC (invoice) and ORDERS (outgoing order) require a higher potential of requirements regarding data quality and scope.