Technical IBM Token Ring

¶ … IBM Token Ring. The writer explores the history of the token ring, its functions and its future. The writer also discusses some of the trouble shooting methods that are used to correct any problems. TOKEN RING SYSTEM BY IBM International Business Machines (IBM) has been on the leading edge of technology since the explosi0on began. The technological explosion that has occurred in the last four decades has taken mankind to heights it never knew was possible. IBM has been a leader in the industry since the industry was born.

IBM began its journey into success in the early 1900's and has been re-inventing the wheel since then. One of the most advanced inventions in IBM's history was the invention of the token ring. The token ring created a level in the world of technology that has served as a building block for many other technological advances. Before one can fully understand the impact of the token ring one must first have a grasp of its history and importance in the history of technology.

The token ring was first introduced to the world in the year 1970. IBM brought its product to the market after many tests and reports as to its use and viability for the market place. It was such an important advancement in the world of technology that it is still IBM's primary local area network (LAN) today. The IEEE 802.5 shares a complete compatible with the IBM token ring which also makes the token ring a highly marketable product.

Some of the aspects that are important to understand about the IBM token ring include: Data rates (4.16) Stations segments (290/72) ology (Star) Media (Twisted Pair) Signaling (Baseband) Access Method (Token Passing) Encoding (Differential Manchester) The token ring operates as a token passing network by moving a small frame that is called a token around the network. When one possesses the token one obtains the right to transmit around the network using the system.

Receiving nodes are designed to pass the information further around the network if when it receives the information it has no information. The token is passes around to different stations and each token can hold the information for a stored predetermined amount of time before it must pass it on to the next station in the network. If one wanted to compare the token to an understandable no technical term it could be best compared to a building block with additions.

When the token is passed from station to station an exact process takes place to process it around the network, The token is sent to the first station and the station will hold it for the predetermined amount of time. If the station has any information to contribute to the network need that information is added to the token by changing one of the bits in the token. When this occurs at the first station it is referred to as the beginning of a start-of-frame sequence.

Once this occurs the information has been appended and the token is then sent to the next station for the same process. If the next station does not have an additional information to add to the token is quickly passed to the next station and the process continues until all the information has been placed on the token and utilized for the purpose it was intended. The system is designed in such a manner that a collision of information on the network system is a virtual impossibility.

This is because as information is being processed and added to the token as it makes its way around the network no other addition to a token can be done. This means that if others want to add information to the network as it moves around each station the others have to wait. This is an important aspect of the token ring system because the inability to collide means the prevention of potential problems within the network system. The system is also designed for an early token release ability.

This means if a station receives a token and the station does not have any new information to apply to the token the station is able and authorized to perform an early release of that token. When an early token release occurs the system can enter another token to the system as soon as the early release occurs. The token ring is sent through the network system until it reaches its destination. It gathers data at each station that is holding data for that particular token in the system sequence.

If the station has no data the token ring is passed on to the next station and when all the information is obtained it is received and utilized for further purpose and additions of information. When the token ring that has been sent around the system gathering information has completed its journey it ends its trip at the original sending station and it is removed and used for its function. Token ring networks use a sophisticated priority system.

What this means to the token ring system is that there are predetermined high priority uses and users. These are given the ability to use the system ahead of others and more often than others. The token ring system has two fields called the priority field and the reservation field. Again, if one was to compare the system to a non-technical term it could be likened to a poker game.

In some poker games one must have a certain level of points within their hand before they are allowed to open the bets. The token ring system works in a similar fashion. Tokens are "marked" so that a station must have a certain level of priority coding or higher to be able to seize that particular token and begin sending it around the network system gathering information. The token ring network is designed with ability to self detect a wide range of network faults.

This ability cuts down on the crashes and stop ups that would otherwise occur and it allows for the smooth and continual use of a pass around system of information gathering. One of the stopgap measures that are in place deals with using a station as a sort of look out scout. The station is designated as an active monitor.

Any station can be chosen as the monitor but its job is to coordinate and oversee the timing of the stations sending out the token ring and the release of the next tokens as the time is right to do so. Another ability of the network of token rings is the ability to remove defective and continuous frame tokens. These are tokens that for one reason or another become defective while being.