Research On Protocols Of Computer Network In UMS

The work presented in the dissertation is grounded on the development of a proprietary UMS (Unified Messaging System) called ZHX-UMS. The work involved in the dissertation is broken down into the following parts:general design of the structure of ZHX-UMS,analysis of ZHX-UMS service control,techniques and practices for protocol specification as well as implementation issuesand improvements for specified protocols applied in the system.By comparing ZHX-UMS with the structures of unified messaging systems worldwide,the author and her colleagues proposed a conceptual mode of a 3-layer ring for representing ZHX-UMS as well as developing a layered implementation structure. Further partition of each layer as well as control flow of the system is presented afterwards.Considered one of the most important parts of the dissertation,specification and implementation of two application-oriented protocols,called the NRDP (Network Related Dialogue Request Protocol) and NAKP (Network Related Protocol between layer A and K) were discussed in detail. The physical interface,communication procedure and working model used by NRDP were also introduced. With respect to the NAKP,the data unit,state-changing procedure,the service classification as well as the implementation for NAKP were offered.As the early parts of the dissertation mainly discuss the design and implementation of special application protocols for the experimental ZHX-UMS,leading to a feasible and functioning prototype,there is still much to do to develop the experimental system to actually become applicable. The improvement of the design of the protocols has been discussed later.