Web Caching and Replication

Chapter 1. Network Layers and Protocols

Computer networks and network protocols are extremely complex. Network designers realized early that, to deal with this complexity, they needed to define some abstractions. Therefore, the concept of layering was introduced to provide increasingly complex functionality through standardized interfaces. With layering, network functionality is implemented as a stack of layers, where each layer uses a standard interface provided by the layer directly below in the stack and exposes a standard interface to the layer directly above. Layering hides the complexity of each layer from the next layer up the stack.