Layered Protocols

• A layered protocol architecture provides a conceptual framework for dividing the complex task of exchanging information between remote hosts into simpler tasks.
• Each protocol layer has a narrowly defined responsibility.
• A protocol layer provides a standard interface to the next higher protocol layer.
• Consequently, it hides the details of the underlying physical network infrastructure.
• Benefit: The same user-level (application) program can be used over very diverse communication networks.
• Example: The same WWW browser can be used when you are connected to the internet via a LAN or a dial-up line.

  

Figure 2.40: Protocol Layers