Networking Standards

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Standards. People seem to be talking about standards so much these days, what do they mean? Now that I have covered some basic concepts of Networks in the previous article, we can talk about communication. However, in order for communication to take place, there must be some rules, some standards with which to transfer and receive information.

For example, you cannot talk to a friend (communicate) without having some sort of protocols, like who talks first, when is it your turn to yak, what do pauses mean, are you required to interject with some "uh huh"s or "You don’t say" or "You gotta be kidding!" or some responses like that. A common ground must be laid out first, what kind of manner is acceptable. Basically, networking standards are rules by which communication takes place.

Thus grew protocols for the interaction and interrelation of the various components of network architecture. We shall look at two types of standards which emerged when the computer era exploded and began the network revolution that took the masses by storm that er… well, let’s just call it the Internet Boom. That was when people became interested in ‘interconnecting’ and ‘internetworking’ via networked computers.

Open Systems Architecture

People talk about open systems architecture, what in the boondocks are they? An open system architecture deals with diverse systems who can inter-operate with other systems of different sort. Closed system standards would obviously mean system protocols which are ‘proprietary’ to their architecture. These just means that other systems are not compatible to talk to it.

These are called de facto standards. Protocols which arose from widespread commercial and educational use.

In the days of yore, most corporations made their protocols proprietary, which meant non-compatibility with a competitor’s product. This was done in the mentality that it would garner more sales for their own stuff. However, as time went by, they came to see that such a selfish attitude only drove them towards certain ruin as people preferred more diversity in their choice of systems to purchase.

For example, several large corporations, including IBM® , Honeywell, and Digital Equipment Corporation (DEC®) each had their own standards for how their own computer would connect to each other. These standards described the mechanisms required to move data from one computer to another. They were not compatible because networks adhering to IBM’s Systems Network Architecture (SNA) could not directly communicate with DEC’s Digital Network Architecture (DNA). It’s just like a Chinese man talking to a Tutsi tribal warchief. Definitely no go.

After awhile, these same people saw the need to inter operate with other vendors, and thus was born the de jure standards. These were developed with the intent to enhance connectivity by making the protocols or specifications public so that independent manufacturers may build to it. It is non-proprietary, which means that no single company creates or owns the rights to them.

This is analogous to sign and body language used to communicate between the Chinese man and the Tutsi tribal warchief. A smile is a universal acceptance gesture, where one of frown and anger would denote rejection, or negative response. No one race owns the rights to sign and body language (of course we do not talk about the sign language used between mute people).

An example of a de jure set of standards would be the TCP/IP protocol used widely in the Internet today. The Internet is just basically a large large large WAN that spans the entire globe and interconnects everyone from everywhere.

Standards Organizations and the ISO

Who develops the de jure standards? Well, one of them is the International Standards Organization (ISO) whose name is derived from the Greek prefix iso, which means "the same". They develop and publish standards and coordinates the activities of all national standardization bodies.

Rules Governing the Communication Process

Information interchange is a very complex matter, and therefore, networks has to rely on many many rules in order to manage the transaction. Some of the rules that govern these processes are :

• Procedures used to initiate and end an interaction
  (Telephone example : "Hello"s and "Toodle loo" and "Bye Bye" and "Well Same to you too buster!" begin and end conversations)
• Signals used to represent data on the media
  (Telephone example : Voice, or sound waves that is transmitted through the handpiece)
• Methods used to direct a message to the intended destination
  (Telephone example : telephone exchange creates a circuit for the duration of the call, so all information is passed from sender to receiver as long as neither hangs up)
• Procedures used to control the rate of data flow
  (Telephone example : Use of "Hang on" or "Slow down a minute" or "Could you repeat that, sloooowly again?" if the conversation gets too fast)
• Methods used to enable different computer types to communicate
  (Telephone example : A professor from Australia would probably need to learn some cockney slang in order to communicate with a Londoner selling "Buncha Flawers ‘guv?")
• Ways to ensure that messages are received correctly
  (Telephone example : Use of echoing in order to make sure the receiver heard correctly that Brad Pitt is single again)

Transmitting and Receiving Data

When two computers transmit data over a network, one is the transmitting or sending computer and the other is the receiving computer. Like the speaker and the speakee in a telephone conversation, or a crowded room. On a network, however, data is passed in the forms of frames, which are messages broken into smaller chunks with transport header attached.

These are analogous to a message being shouted across a crowded room between two people, who interject their sentence with the name of the other party to make sure that the information is passed along to the right people.

The OSI Model

The OSI (Open Systems Interconnection) model was released by the ISO in 1984, and provides a useful structure for defining and describing the various processes underlying the open systems networking.

The ISO OSI model incorporates the following characteristics :

• It is designed to establish data-communication standards that promote multi-vendor interoperability
• It consists of seven layers, with a specific set of network functions allocated to each layer and guildelines for implementation of the interfaces between layers
• It specifies the set of protocols and interfaces to implement at each layer.

To help you remember the name of the seven layers, there are a few phrases below that will do the trick. (If you are going to sit for the Networking Essentials exam, you BETTER remember them)

• All People Seem To Need Data Processing (top down)
• Please Do Not Throw Sausage Pizza Away (bottom up)
• Paula Did Networking Till She Passed Away (bottom up)

We shall be discussing each layers and what they do in the next upcoming topic, but I will leave you with this :

Layer 1, the Physical Layer, deals with the protocols that control communication on the network media (like what pin connects to which color wire to fit which kind of socket).

Layer 7, the Application layer, interfaces the network services with the applications in use on the computer (like the programs that we use in order to run networking services, for example e-mail programs like Pegasus, or Eudora, or even Outlook Express, ftp clients, web browsers, and telnet clients).

The five layers in between – Data Link, Network, Transport, Session and Presentation – perform the intermediate communication tasks, in order words, the mundane boring job of managing communication process.

You will understand more in the next topic, when I expand on each layer and what they do for network communicatis.

If you have any comments, please feel free to email me at foogy@geocities.com
Copyrighted 1997 Lim Pei Mun J
Last updated : 4 May 1998

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