Specification and testing of the behaviour of network management agents using SDL-92
We develop a method for specifying the behavior of network management agents for the Internet framework using SDL-92 which is object-oriented. The starting point is the definition of a management information base (MIB) in ASN.1 with macros as well as the description of the simple network management protocol version 2 (SNMPv2 protocol). The behavior of an agent is defined in an SDL-92 process which dynamically creates processes for the rows of the tables of the MIB and in several procedures that process variable bindings in protocol data units (PDUs) and carry out specific operations on conceptual rows such as creation, retrieval, and bulk retrieval. Some reusable, MIB-independent process types and procedures are identified. For large MIBs, we first obtain a class diagram representation of the MIB. From the class diagram, the classes with behavior are mapped to process types representing conceptual rows of specific tabular objects. SNMPv2 protocol operations on these tabular objects can be easily specified with the help of MIB-independent procedures. Next, considered is the generation of test cases. MIB test cases can be generated from the SDL-92 specification using specification analysis and behavior inversion techniques. Many test cases for an example single-table MIB are designed and specified in tree and tabular combined notation (TTCN) based on the specification in SDL-92.