简单数据链路协议的同步性能

Frame alignment of simple data link protocol

简单数据链路协议 (SDL)是一种新的且具有实现简单和低开销特点的数据链路协议 ,其同步方式采用了帧头循环冗余码 (CRC)校验实现。互联网工作组 (IETF)建议给出了适用于互联网协议 (IP)数据包传输的多捕捉器的 SDL帧同步方案。采用状态转移方程的方法 ,对其同步平均持续时间、失步平均持续时间等主要性能进行了研究 ,并给出了数据分析结果。针对该方案失步平均持续时间过长的缺点 ,提出了一种改进的帧同步方案。理论分析和计算结果表明 ,此方案可以有效降低 SDL 帧同步的失步平均持续时间 ,改善了 SDL 帧同步系统的性能。

Simple data link (SDL) is a new data link protocol with simple processing and low overhead cost. The frame alignment of SDL with multi frame catchers provided by recommendation of internet engineering task force (ITEF) that is suitable for internet protocol (IP) data packets trasmission is implemented with a header cyclic redundant code (CRC). This paper analyzes the algorithm performance including mean time to frame and mean time to frame loss using transition functions. The results show that the mean time of frame loss is too long. To overcome this shortage, an improved algorithm is put forward in this paper. The theoretic analysis and computation results show it greatly decrease the mean time of frame loss and amend the performances of SDL frame synchronizer.