Chapter 2. Foundation of Networking Protocols

Users and networks are connected together by certain rules called network communication protocols . The Internet Protocol (IP), for example, is responsible for using prevailing rules to establish paths for packets. Communication protocols are the intelligence behind the driving force of packets and are tools by which a network designer can easily expand the capability of networks. One growth aspect of computer networking is clearly attributed to the ability to conveniently add new features to networks. New features can be added by connecting more hardware devices, thereby expanding networks. New features can also be added on top of existing hardware, allowing the network features to expand. The second method of network expansion requires modifications to communication protocols. This chapter focuses on the following:

• Five-layer TCP/IP model

• Seven-layer OSI protocol model

• Internet protocols and addressing

• Equal- size packet protocol model

The five-layer TCP/IP model is a widely accepted Internet backbone protocol structure. In this chapter, we give an overview of these five layers and leave any further details to be discussed in the remaining chapters. Among these five layers , the basics of network layer is designated a separate section in this chapter under Internet protocols. We make this arrangement since basic definitions related to this layer are required in the following few chapters.

As there are numerous protocols formed together to be used for the movement of packets, the explanation of all other protocols will be spread over almost all upcoming chapters. In the meanwhile, the reader is cautiously reminded that getting a good grasp of the fundamental materials discussed in this chapter is essential for following the future details or extensions described in the remaining of the book. At the end of this chapter, the equal-size packet protocol model will also be introduced.