The multiparty applications pattern of network is going to definitely play an important role on the Internet. However, the traditional research of network architecture almost exclusively uses the “one to one” direct interaction model to describe various kinds of network interactions. The INSA (Interactive Network Services Architecture) reference model and network description language INSADL developed by the Laboratory of Computer Network and Information Integration (Southeast University) have introduced the component-based thought and interactive viewpoint to the research of network architecture. Moreover, INSADL has provided support for the modeling of network multiparty applications to some extent.

Nevertheless the modeling requirements of the multiparty applications are much more complicated than those of traditional network applications. The description of complex network interactions involving a non-fixed number of participating entities needs to be supported. It also raised the problem of how to represent the composite entity components, and sometimes the dynamic joining and leaving of entities from interactions should be dealt with. Therefore, INSADL still has some limitations. So we established a new network architecture formal description method on the basis of INSADL's component-based thought to support the depiction of multiparty application.

We discussed the detailed modeling schemas for different modeling elements. For entity components, we defined the inheritance relations between component classes by using the “extends” field and set rules for the overriding of grammar units in derived classes. We also introduced the “symbol transformation method” of CSP to simplify the definition of similar processes. Furthermore, the definition production of functions which describe the data processing of entities is given. For the modeling of the interaction connector, we improved the description used by INSADL. We adjusted the production of nonterminal ‹INSA_Role›, and add a new nonterminal ‹Multiplicity_Expression›. Thus an uncertain number of roles in an interaction connector can be explicitly denoted. Concerning the connection configuration, we took a similar measure as interaction connector to alternate the definition of nonterminals related with the instances of entity component classes, using multiplicity expressions within the brackets to specify the number of instances.

This paper establishes a foundation for further research of the multiparty application network system's properties using the formal method.