CSSOC03In a society in which information is one of the highest-valued commodities, information networks are the economic backbone. Therefore, network vulnerability is a major hazard. Analysis of communications system traffic suggests that there are a variety of similar dynamical characteristics in widely varying systems. There are some universal features of communication networks that may determine the main dynamics of communications. These are: 1) hardware limitations, 2) forcing from the increasing use, and 3) high degree of system complexity. These common features drive the system dynamics and determine its main vulnerabilities. The nontrivial character of network dynamics has been found in traffic analysis of local area networks that display self-similarities and long-range correlations. This suggests a complex dynamics in the traffic of packets over the network. In this work simple distribution network models with different levels of complexity are examined and compared to each other and to real Internet data.