| With the communication network playing an increasingly important role in our production and life,Modern information society has a increased demand for qualified personnel in access system,switching system,transmission system,and other related fields.But due to lacking of communication networks training platform,it is always unable to fully carry out the process of practice session in traditional college communication education.The communication network training system is designed to precisely solve the problem above.It is been constructed with mainstream communication facilities and necessary management software system as a small communication network to simulate the actual communication network.The system contains several sub-systems like SDH,soft exchange,wireless communication etc.It can completely satisfy the need of teaching and experiment of various communication subjects,and help the university to build the first-class communication network laboratory,raise student's ability of applying theory to reality.This article mainly discussed the design and implementation of the communication network training system software based on RMI cache method, author's main research work is as follows:(1)The basic concept of the communication network training system is introduced and then we present the system's overall hardware composition structure and topologies design of its several sub-systems.(2)Refers to the RUP software development process,with the aid of the UML modeling tool,the system is design as a small C/S distributional architecture system on RMI technical,and the system's model is established.We first carry on the demand analysis,according to mainly use cases we design the classes,and then divide the system structure into three main parts:the view,the model,the controller. These modules are designed and realized then.(3)In practice too many repeated remote method invocations may affect the performance of application.The paper gives a method for RMI based on client side cache.A client first query in local cache whether there is the stub or result the client tries to invocate,and if they exist the client will directly use them without further remote method call through the network.The performance comparison shows that the method improves the performance of RMI by decreasing repeated invocation times and reducing network bandwidth occupied.(4)Summarizes,proposes and analyzes some problems of the system that need to be improved further.Carry on the forecast to the future work.The system has already been in use in the Qingdao Scientific and technical university and other several universities.It has obtained good feedback on the actual teaching and experiment. |
