DEVELOPMENTAL STUDY ON ELECTRONIC MAIL SYSTEM WITH SWITCHING SERVER

提出了一种具有交换服务功能的电子邮件系统，并对系统的开发进行了基础性的研究。在这个系统里。在服务器和智能终端（例如个人计算机）之间分配功能。终端仅在需要数据传输时才接入服务器。因此减少了服务器上的业务负载，从而小的处理器可以服务于大量的终端。为了实现所提出的系统，已经对（1）终端和服务器之间的功能的最佳分配、（2）用于数据传输的透明和可靠的协议、以及（3）业务特性的性能评估进行了研究。在图坦卡蒙大学校园网上，以工程工作站（夏普1X5）为服务器，通过对服务器和终端（NEC PC9801）的编程，构建了原型系统并进行了测试。话务量分析表明，与传统的功能集中的系统相比，该系统可提供十倍以上的终端服务。

An electronic mail system with switching serve ris proposed and fundamental studies have been made for the system development. In this system. functions are dis- tributed between the server and intelligent terminals such as personal computers. The terminal accesses to the serve only when data transmission is required. and thus, the traffic load on the server is reduced, whereby a small processor can serve a large number of terminals. To realized the proposed system, studies have been made on (1) optimum distribution of functions between terminal and server, (2) transparent and reliable protocol for data transmission, and (3) performance evaluation of traffic characteristics. On the TUT campus computer network, and engineering workstation (sharp 1X5) is used as the server and the prototype system is constructed and tested by making programs for the serve and a terminal (NEC PC9801). The traffic analysis shows that the proposed system can serve as many as over ten times terminals compared with the conventional system of concentrated functions.