11计算机网络的发展过程 标准化网络: Application Reduces complexity(one big Presentation problem to seven smaller ones Session Standardizes interfaces Transport Facilitates modular engIneering Network Assures interoperable Data link technology Physical Accelerates evolution Simplifies teaching and learning 数据通信与计算机网络——计算机网络概论数据通信与计算机网络——计算机网络概论 7 1.1 计算机网络的发展过程 标准化网络 ： 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical • Reduces complexity (one big problem to seven smaller ones) • Standardizes interfaces • Facilitates modular engineering • Assures interoperable technology • Accelerates evolution • Simplifies teaching and learning