通信协议的实体行为描述语言CPEBSDL

Communication Protocol Entity Behavioral Specification and Description Language

提出了一种通信协议的实体描述语言CPEBSDL.CPEBSDL语言是一种描述能力很强的语言,它可以对协议实体的状态、行为及协议实体对资源的控制和访问进行形式化的描述,同以往的描述语言不同,CPEBSDL语言把协议实体之间复杂的交互行为看做是实体对协议中共同使用到的资源的控制和访问,从而简化了交互行为描述的复杂性,便于对协议进行分析和测试.给出CPEBSDL语言规则对应的上下文无关文法G(CPEBSDL),并给出了G(CPEBSDL)的乔姆斯基范式,在此基础上给出了一个判定协议行为的CPEBSDL语言描述是否合法的判定算法——CYK协议行为序列的合法性验证算法.作为一个实例,用CPEBSDL语言对ISDN数据链路层协议LAPD的链接过程进行了完整的描述,并给出了一个判定协议行为序列是否合法的例子.

A language named CPEBSDL （communication protocol entity behavioral specification and description language） is presented. The CPEBSDL language has a powerful ability on protocol description, it can describe protocol entity＇s states, behaviors and controlling and accessing to resources. The CPEBSDL regards the interaction between protocol entities as entities＇ control of the same resource. So the interactions between protocol entities can be denoted by the resources that entities mutually control. When a complicated protocol is required to describe by CPEBSDL, every single protocol entity＇s description can be established respectively, and then the whole description of protocols can be obtained by integrating every single protocol entity＇s description. In this point, the CPEBSDL make protocol analysis and testing easier. The CPEBSDL＇ regulation is proved to be equal to a context-free grammar G （CPEBSDL） and the G （CPEBSDL）is transformed to its Chomsky normal form. Based on those foundation, an algorithm that can validate whether a given protocol behavior sequence accords with CPEBSDL＇ regulation is proposed. Compared with traditional and classical protocol description languages, the CPEBSDL can decompose complicated protocol＇s behaviors to every single protocol entity＇s behaviors. Furthermore, the CPEBSDL can be easily translated into Petri nets, in which protocol＇s Petri nets can be modeled automatically if the protocol is described by the CPEBSDL. For example, the whole procedures of describing LAPD protocol using CPEBSDL are given and an example of validating the protocol behavior sequence is given too.