ELECTRONIC MAII, SYSTEM

Abstract

The thesis presents an approach for design and development of an Electronic Mail System which is likely to be the future communic ati on media. Main features of an e~dsting electronic mail system known as 'Telemail° in the United States of America, are reviewed. Basic components inherent in electronic mail system are described and three main considerations in the design of the system are discussed. The system is based on packet-switching principle. Selection of an efficienti packet-switching network configuration is affected and a design algorithm for the network is presented. The store-andiforward packet switching network demands for an effi-cient routing technique to control flow of packets and handle failure conditions dynamically. The adaptive routing seems to be the proper answer for it. Queueing of packets is required at nodes of the network. Some problems arise in a packet switching network and two main problems i.e. ' t7meout problem' and 'out-of--sequence problem', are dis-cussed. Possibility of interconnecting several such systems is explored. The unit, through which the interconnection of two packet switching networks is accomplished, is called 'Gateway'.. It may be connected at two different levels in the network. The system requires interactive software in addition to network software. The interactive software enables users to communicate with the system. Some commands, such as LOGIN, SCAN, READ, FORWARD, ANSWER, COMPOSE, LADAT etc., for. providing interactive 'facilities to, the users are developed and flow charts of these commands are included. A number of commands. have been tested on DEC 2050. Finally some suggestions for further improvement in this work are given.