The Open Systems Interconnection (OSI) Reference Model is the basis for much of modern networking. It is a layered model under which all networking protocols and services are defined. Many attempts at explaining OSI become too abstract and require a very high level of network design knowledge and experience to even begin to understand. This Pocket Guide presents a more practical, user friendly examination of the topic.

The author, Howard C. Berkowitz, CCSI, is an accomplished network designer and instructor who has written two books on network architecture. He effectively utilizes real-life experiences, analogies, and humor to clear up some of the most common confusions and misconceptions associated with the OSI Reference.

Sample questions (with correct answers and complete explantions),similar to those found on Cisco's certification exams are included in this reference. They'll help you test your OSI knowledge level before attempting the actual test.

Table-of-Contents
OSI Reference Model Pocket Guide

I. Introduction
II. Standards Bodies and Networking
III. What's A Layer
IV. So Why Layer?
V. The OSI Layers
VI. Practical Layering
VII. Representative Protocols at Various Layers
  A. Application
  B. Presentation
  C. Session
  D. Transport
  E. Network
    1) Hierarchical Addressing
    2) Hierarchical Routing in the Telephone Network
    3) Routers
  F. Data Link
  G. Physical
VIII. Congestion and Flow Control
  A. Buffering
  B. Source Quench
  C. Windowing
IX. Conclusions
X. Questions
XI. Answers & Explanations