Computer network in the recent time has continued to evolve and has gone beyond just a collection of interconnected devices. Networking is a process of connecting computers, printers, routers etc. over a medium for the purpose of sharing information/resources. It is a very viable tool in the day-to-day running of an organisation. Research in data communication and networking has resulted in new technologies in which the goal is to be able to exchange data such as text, audio, video etc. Recently, no good establishment can effectively and efficiently work without a good computer network or internet. In Nigeria, virtually every establishment has got one but how these networks are managed, the quality of service and the general performances of these networks are questionable. In this paper, we present; plan, design and simulation of computer network, a case study of Federal University of Technology Owerri (FUTO). The result of the work clearly showed that the simulated network has an edge over the existing real time network in reliability. Approximately 96% of data sent were received successfully on the simulated network and only about 4% were lost. In the existing real time network about 67% packets were received successfully while about 33% got lost on transit. This paper when implemented will solve problems we have identified with the university network.