networkmodel

Network model is an abstract representation of a computer or communications network that specifies its structure, components, and behavior. It is used to analyze, design, simulate, and implement networked systems by encapsulating complexity and exposing essential interfaces and properties. A network model typically defines layers, modules, data flows, and the assumptions underlying performance measures such as delay, throughput, loss, and reliability.

Two widely known families are reference models and architectural models. Reference models organize functionality into layers with defined interactions; architectural models specify concrete protocols and interfaces used to implement a network. The OSI reference model (seven layers) and the TCP/IP model (four layers) are common examples. Other models include graph-based representations for topology, queuing theoretic models for performance, and stochastic models for traffic patterns.

Network models serve multiple purposes: guiding system design and protocol development, providing a basis for simulation and experimentation, and enabling quantitative analysis of capacity, scalability, and fault tolerance. They support planning, optimization, and standardization efforts across vendors and organizations.

While useful, models are simplifications and may omit rare events or complex interactions. Their usefulness depends on the validity of assumptions, granularity of the abstraction, and the accuracy of input data. In practice, researchers and engineers choose a model that balances realism and tractability for a given task, sometimes combining multiple models to cover different aspects of a network.