这里简单介绍一个我们已经实现的基于X.25网的电子邮件设计。电子邮件系统的设计原理是在局域网服务器上建立邮局,并开设用户信箱。用户分为局域网用户和远程用户,局域网用户通过局域网访问信箱;远程用户通过X.25或电话拨号的方式访问信箱。 (1)X.25网的通信原理。相对于传统的电话通信,X.25网通信可靠性高、速度快、误码率低、安全保密性好,远距离条件下使用费低。X.25网有同步专线(即X.25专线)、异步拨号 Here is a brief introduction to what we have achieved based on the X.25 network-based e-mail design. The design principle of the e-mail system is to establish a post office on the LAN server and set up a user mailbox. Users are divided into LAN users and remote users, LAN users through the LAN access mailbox; remote users through X.25 or telephone dial-up access mailbox. (1) X.25 network communication principle. Compared with traditional telephone communication, X.25 network communication has high reliability, high speed, low bit error rate, good security and privacy, and low usage fee under long-distance conditions. X.25 network has a dedicated green (ie X.25 green), asynchronous dialing