Research On Real-time Property Of Networked Test System

With the development of the technology of computer and network, more and more test systems apply network technology for it merits. "Network is instrument" describes the tendency of networked test. Networked test system is essentially real-time, which is basic request. Surrounding real-time property of networked test system, this thesis studies systematically and deeply on the analysis of real-time test technology, real-time evaluating, synchronization and technology of enhancing real-time property based on the resource reservation protocol (RSVP).First, this thesis does some research in the real-time network based on TCP/IP, and majorly analyzes the real-time property of Internet. By analyzing the characteristics of real-time networked test system and network based on TCP/IP, we bring forward some ways to improve the real-time property of networked test system, such as bandwidth increasing, resource allocating and data compressing.Secondly, we study the testing methods for real-time indicators of network, and especially give detail description of testing methods for packets delay and packets loss rate. Aiming at evaluating the real-time property of networked testing system, by testing indications of it, this thesis designs a real-time networked test evaluating system, which uses the technology of Management Information System (MIS) to realize the automatic data organization and sharing.Then, this dissertation introduces some clock synchronization sources and the implementation of clock synchronization using the technology of hardware and software. The way of clock synchronization using ICMP is described which is simple and practical.Finally, the dissertation brings forth a solution for improving indications of real-time behavior which is based on RSVP. At the beginning, we analyze the principle and realization of RSVP, and then simulate the network that supports RSVP by the network simulation software NS2. The conclusion to be draw is that the RSVP is the preferred solution in these types of applications according to the result of the experiment.