Chapter 2 - Networking Standards and the OSI Model

The text begins with network standards organizations and the necessity of maintaining minimum industry standards. The chapter gives a brief description of each following along with the role they play:

• ANSI – American National Standards Institute
• EIA – Electronic Industries Alliance
• IEEE – Institute of Electrical and Electronics Engineers
• ISO – International Organization for Standardization
• ITU – International Telecommunications Union
• ISOC – Internet Society

The OSI model began in the early 1980’s and set universal specifications that made it possible for computer platforms across the world to communicate. The OSI (Open Systems Interconnection) model represents seven layers in network communications. See chart below.

In this model the layers communicate with the same layer from one computer to another. A way to help remember these different layers is to create a sentence using words that begin with the first letter of each layer. For example “Programmers Dare Not Throw Salty Pretzels Away”.

It is important to understand that data issued from a software application are not in the same form as the data that your NIC (network interface card) sends to the network. At each layer of the OSI model, some information is added to the original data. The data requests that transfer between layers is done in the form of protocol data units (PDU). Finally, your request in the form of many frames hits the NIC at the physical layer. The physical layer does not interpret the frames or information it simply transmits them over the broadband.

I found this chapter to have a wealth of information as well as many diagrams and charts. I thought it had a systematic and logical approach in its presentation. It was good foundation material.      

Chapter 1 – Introduction to Networking

This chapter was a good starting point it discussed and provided suggestions for finding a job in networking field. A few ideas discussed were to search the Web, visit a career center, and network with like-minded professionals. These were only a few of the many suggestions covered. It went on to talk about pursuing a certification and the benefits from doing so, such as better salary, greater opportunities, access to better support, and professional respect. 

The lesson began with covering networks. It touched on how networks are used and the various services i.e. file and print, access, communications, internet, and management. Each one plays a different role in “network services”. The two fundamental network models are client/server and peer to peer. The following are the advantages and disadvantages of a peer to peer network.

•  Simple to configure.
•  Often less expensive to start up and maintain.

Disadvantage:

• Not very flexible.
• Not necessarily secure
• Not particle for connecting more than a handful of computers.

The other type of network is the client/server which has a central computer known as a server, to facilitate communications and resource sharing between other computers on the network. Some of the common elements of a client/server network are:

• Workstation
• Server
• Client
• Nic (network interface card
• Node
• Host
• Nos (network operating system)
• Packet
• Address
• Backbone
• Topology

The book explains these components. It goes to review how networks are classified by size. Very simply they are LAN (local area network), MAN (metropolitan area network), and Wan (wide area network). 

I found this chapter to be a good foundation in understanding network principles. It provided many diagrams with good descriptions.