Modeling and simulation for network transmission time reliability

As the high redundancy of network equipments and paths, connection reliability is no longer the most important parameter for networks. According to network function, this paper advances transmission time reliability as a common parameter to describe network congestion. It is defined to be the probability that networks will transmit material, energy or information timely when used under specified operating conditions. To evaluate this parameter, this paper presents four models, including structure model, routing model, service mechanism model and application model. Structure model is built to describe network topology; routing model and service mechanism model are used to express network operation mechanism; and application model is set up to generate network traffic. This paper also provides simulation flow and reliability evaluation method. Finally, the backbone of CERNET (china education and research network) is studied as a case, and the result shows that this modeling & simulation method is quite effectively. The contributions of this paper are: (1) A common network parameter, transmission time reliability, is advanced to describe network congestion, and it was only used for transportation systems before. (2) A modeling and simulation technology is expressed to evaluate the network transmission time reliability. Network operation mechanism which is covered in this method is not considered before.