CertiGuide to Network+  9  Chapter 0100:  Network Protocols       9  II  Protocol Suite Overview

Protocols for Conversations 1 III  Protocol Suite Characteristics

Remember that we mentioned in the overview of the OSI model, that there are different protocols to perform the functions at each layer of the OSI model?

A group of related protocols that perform all (or most – sometimes all aren’t needed) of these functions is referred to as a protocol suite, protocol stack or protocol family. Each of the protocols in the suite knows how to work in conjunction with other protocols in the suite, allowing data to be passed up from lower level (more physically-oriented) protocols to higher (more logical conversation-oriented), and higher level protocols to lower, in an organized fashion.

There are two basic types of protocol suites: vendor-defined, and industry standard-defined. Vendor-defined protocol suites (sometimes called proprietary protocols) were generally created by operating system suppliers, and designed to work optimally with that vendor’s operating system. The down-side to these is that with different operating systems requiring different protocols, in order for computers running different vendors’ operating systems to communicate with each other, you need to use a gateway to translate from one protocol to another, or a third party version of one vendor’s protocol suite, or “stack”, that runs on another type of system. These gateways and third-party protocol suites are an extra expense item, and require additional resources to maintain.

Vendor-defined protocol suites we’ll look at in this chapter include:

1. IPX/SPX … by Novell
   
   
2. NetBEUI … by Microsoft
   
   
3. AppleTalk … by Apple

In contrast to these vendor-specific protocol suites, some protocol suites were created by industry standards groups, with the intention that the protocol suites would be implemented on a wide variety of operating systems and platforms. The emphasis here is on flexibility and openness rather than performance or operating system convenience. The most popular of these standards-defined protocol suites is TCP/IP, the protocol suite used by the Internet. This chapter contains an overview of the basic characteristics of TCP/IP, which is described in more detail in a later chapter. In general, you’re more likely to find interoperability among multiple vendors’ systems, where industry standard protocols are used.

Protocols for Conversations 1 III  Protocol Suite Characteristics