X.400 glossary

Term

Description

ADMD

Administrative management domain name. This is an X.400 address attribute.

DDA type

Domain-defined attribute type. This is an X.400 address attribute.

DDA value

Domain-defined attribute value. This is an X.400 address attribute.

EDIM

An EDI message (EDIM) is the message payload exchanged by trading partners. This is applicable to X.435 only and not X.420.

EDIN

An EDI notification (EDIN) is a receipt returned to the message originator by the message recipient. This is applicable to X.435 only and not X.420. An EDI notification can be positive, indicating the recipient accepted the message, or negative, indicating the recipient rejected the message.

external MTA

The X.400 subsystem within the trading engine has one running local MTA. The local MTA exchanges messages with external (remote) MTAs.

lower OSI layer

Lower protocol levels of the X.400 subsystem.

message transfer agent

See MTA in this table.

MHS

Message handling service. MHS is an electronic mail system that provides store-and-forward services for sending messages to users of the mail system.

MS

Message store. A mail box for storing messages. The message store P7 access client is used for accessing a remote message store mailbox

MS P7 client

Terms for the process in the X.400 subsystem that accesses an external message store to retrieve or deliver messages. This is using the standardized X.400 protocol called P7.

MTA

Message transfer agent. This is the message switch within an X.400 network. It accepts messages submitted by message originators' UAs for transmission to recipients' UAs. The transmission is normally done through other MTAs.

MTC process

Message transfer communication process. A process in the X.400 subsystem that handles the communication with external MTAs. The MTC process is a part of the local MTA.

MTS

Message transfer service. The functional component of MTS is MTA.

O/R address

Originator/recipient (O/R) addresses identify message senders and receivers. An O/R address consists of required and optional values organized hierarchically.

O/R descriptor

Originator/recipient descriptor is the standardized X.420 address. The O/R descriptor has some optional user friendly address attributes in addition to the O/R address.

OSI

Open system interconnection.

OSITP process

OSITP (open system interconnection transport) is the name of the process in the X.400 subsystem that handles the lower protocol levels in the OSI protocol stack (the transport and network layers).

P7 client

Message store P7 client.

PRMD

Private management domain name. This is an X.400 address attribute.

UA

The X.400 user agent. In Internet email this is the same as the mail user agent (MUA).

upper OSI layer

Upper protocol levels of the X.400 subsystem.

user agent

See UA in this table.

X.400

A suite of ITU-T recommendations defining standards for data communication networks for message handling systems. More commonly known as email.

X.400 subsystem

The X.400 trading engine that runs as a sub-system of Interchange.

X.420

Developed in 1984, X.420 preceded X.435 as an X.400 standard. Also known as IPM for interpersonal messaging, X.420 was intended as an electronic mail system for people and not applications. But as e-commerce exchanges grew, some companies adopted X.420 for business-to-business electronic data interchange. In 1990 the X.435 standard was introduced for EDI message exchanges (see X.435). However, X.420 remained the more commonly used standard.

X.420 local partner

A local X.420 user. Defines the X.400 addresses of the community.

X.420 remote partner

A partner with whom X.420 messages are exchanged. Defines the X.400 addresses of the partner.

X.420 UA

The X.420 user agent is the interface between the user (application) and the X.400 message transfer system. It helps the user to encode and decode inbound and outbound messages according the X.420 protocol.

X.420 UA process

The X.420 user agent process in the X.400 subsystem.

X.435

An X.400 standard for exchanging EDI messages between trading partners. X.435 supports use of receipts named EDINs that are signed by message recipients and sent to message originators. EDINs are proof for originators that messages were received by the intended recipients. X.435 supports the following EDI message types: X12, EDIFACT and TRADACOMS.

X.435 security

The security services in the X.435 protocol are comprised of digitally signed EDI transmissions and acknowledgments. The generation and verification of digital signatures are based on RSA, a public-key cryptography system. The local X.435 UA has an RSA key pair consisting of one private and one public key. The private key is stored encrypted locally. The public key must be made available to your partners before any communication involving digital signatures can take place.

X.435 UA

The X.435 user agent is the interface between the user (application) and the X.400 message transfer system. It helps the user to encode and decode inbound and outbound messages according the X.435 protocol.

X.435 UA process

The X.435 user agent process in the X.400 subsystem.

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