由于联网、联机操作、设备小型化以及多媒体效应的结果，计算机系统环境正经历着硬件和软件两方面的动态变化。今天，计算机系统不仅是提高工作效率的工具，而且还应充分具备适应企业对策变化的高度通用性和灵活性。在这种环境中，用户对通信网络的需求包括高速、低价以及便于与局域网（ＬＡＮ）和计算机互配。因此，对于帧中继传输的关注正在增加。 Due to the results of networking, on-line operations, device miniaturization, and multimedia effects, the computer system environment is experiencing dynamic changes in both hardware and software. Today, computer systems are not only a tool to increase productivity, but also be highly versatile and flexible enough to adapt to changing business practices. In this environment, the user’s need for a communications network includes high speed, low cost and ease of interworking with a local area network (LAN) and a computer. Therefore, the concern for frame relay transmission is increasing.