A critical analysis of the X.400 model of message handling systems

The CCITT X.400 model of store and forward Message Handling Systems (MHS) serves as a common basis for the definition of electronic mail services and protocols both within CCITT and ISO. This paper presents an analysis of this model and its related recommendations from two perspectives. First the concepts of service, protocol and interface are discussed together with their application to this model; second the positioning within ISO's reference model for Open Systems Interconnection (OSI) is commented on

A critial anaysis of the X.400 model of message handling systems

The CTIT X.400 model of store and forward Message Handling Systems (MHS) serves as a common basis for the definition of electronic mail services and protocols both within CTIT and ISO. This paper presents an analysis of this model and its related recommendations from two perspectives. First the concepts of service, protocol and interface are discussed together with their application to this model; second the positioning within ISO's reference model for Open Systems Interconnection (OSI) is commented on

Telecommunications Hardware and Software Systems made in CMEA Countries and Yugoslavia

The telecommunications hardware and software systems used in CMEA (Council of Mutual Economic Assistance) countries and Yugoslavia are a most complex field of investigation. For this reason in this study the following approach has been adopted: Rather than collecting and presenting all CMEA telecommunications hardware and software systems in a directory type of form, which would neither be complete nor fully up to date (even at the time of data collection), a general analysis is given, with sufficient detailed information to make it useful. During the analysis we will discuss in depth the different classes of telecommunications hardware and software systems, their past, present, and potential future. In order to do this, the analysis has to include all major levels of the International Standardization Organization's Open System Interconnection (ISO/OSI) Reference Model--and this is the way we handle the telecommunications hardware and software systems of the CMEA countries and of Yugoslavia