Articles & News About Jobs & Employment

How Does a Token Ring Work

Token Ring is a type of a local area network (LAN) technology first thought out by an IBM developer, Olof S?derblom, in the 1960s. Its US patents were first credited in 1981 and was later promoted by IBM throughout the early 1980s. Then, it was popularized by IBM when its Token Ring architecture was founded on active multi-station access units (MSAUs or MAUs) and the IBM Structured Cabling System. The Institute of Electrical and Electronics Engineers also standardized the Token Ring as IEEE 802.5. Although very successful in its early days, with the introduction of 10-BASE-T (Ethernet) and the EIA/TIA 5638 cabling standard, its popularity and name fell by the early 1990s. IBM tried to revive it through an intense marketing campaign as it tried to outdo Ethernet in terms of performance and reliability, but was unable to match its adequately priced competition. Today, IBM no longer supports, promotes, or uses the Token Ring.

Brief History When it was tested in 1985 by IBM, the Token Ring transmitted data at 4 Mbit/s and eventually reached the 16 Mbit/s benchmark in 1989 with the 802.5 standard being extended to support it. Apollo Computer outdid IBM in 1981 when they introduced their Apollo Token Ring (ATR), by transmitting at a 12 Mbit/s speed and along with Proteon who introduced their ProNet-10 Token Ring in 1984 which reached 10 Mbit/s. Ironically though, IBMs was not compatible with neither of the twos Token Rings.

Inside the Technology As anyone might be able to guess, as the name suggest, the Token Ring LAN is when stations are ordered in a ring topology. In this ring, stations will transmit data from one ring station to another with a control token in the middle circulating. To pictorially put, a Token Ring network is like a star, with loops going in and out from the middle of the station to the hubs at the outside. It is cabled with the IBM Type-1 shielded twisted pair. However, these hermaphroditic connectors were not the most ideal cables, as they were quite huge, requiring a 3 x 3 cm space, and made up of complex and fragile plastic pieces.

A Token Ring is basically a local area network protocol within the data link layer (DLL) of the OSI model. As its name suggests, it uses what is called a token, a three-byte frame, which revolves around a ring in a loop. Since each station repeats this procedure of using the token and the ring, and to its downstream neighbor, this is how access is established among the stations. A station would acquire the necessary token and then transmit it.

Later, 4 Mbit/s and 16 Mbit/s speeds were standardized by the IEEE 802.5 working group. As technology developed, 100 Mbit/s was standardized and eventually, 1000 Mbit/s speed too in 2001, although none were bought in the market.

Although the Token Ring LAN was deemed superior to the Ethernet at the beginning, tests showed otherwise. With the introduction of switched and faster versions of the Ethernet, the Token Ring began to show lags and eventually fell behind in performance and reliability too.

Inserting the Token Ring There is a five phrase ring insertion process before a station can be a part of the ring network. If one of the steps are not done properly, there could be an error. l Lobe Check (Phrase 0): The station that is to be placed in the network will first perform a lobe media check. It is wrapped at the MSAU and then send and receive 2000 test frames to see that there is no error during these transmissions. l Physical Insertion (Phrase 1): A 5 volt signal will be sent by the station to the MSAU. This opens up the relay. l Address Verification (Phrase 2): Then, the station will transmit MAC frames to the destination address field of the Token Ring frame using its own MAC address. If everything is normal (frame is returned with the address is copied), the station is to participate every seven seconds in a ring poll process. This process is the time when the station fully identifies itself as a portion of the MAC management functions. l Participating in ring poll (Phase 3): Now, the station will learn its Nearest Active Upstream Neighbor (NAUN). Then, its other downstream neighbors will know of its address, which also completes the creation of a new ring map. l Requesting Initialization (Phrase 4): Last but not least, the station will send out a request to the parameter server to be correctly configured for the ring. This is done through a special address known as the Token Ring bridge.

James Smith writes on topics such as Token Ring , Asynchronous Transfer Mode and Lan Switches for The Tech FAQ.

Other Article Sites

findabook.com  moneycd.info  a-mortgage.info   about-lemon-laws.info  aboutstudentloans.info
all-about-publishing.info  auctions-articles.info  bestcollege-university.com  bestispconnection.com
biblefolder.com  blogger-website.com  books-used.info  brokers-guide.info  buywindows.info  cable-dsl.info
career-miner.com  carpel-tunnel.info  cashinaflash.info  cashloanreviews.info  casinobell.com  chat-house.info
clearmycredit.info  collegeloantips.info  crones.info  depression-articles.info   dirnic.net  dishguides.info
divers-below.com  expodog.info   financewizz.com  fire-insurance.info  getgood.info  handleit.net   it-idea.info
health-supplies.info  hosting-right.com  insidealert.com  insurance-facts.info  jobs-employment.info
justgood.info  lookgold.net   lowcost-travel.info  money-source.info  myhostzone.info  numisblog.com
peoplesearchfinder.info  pr-articles.info  realeas.com   refinancing-guides.info  spyware-remove.info
telelot.info  the-law.info   toppaid.info  travel-deals.info  travelcorrect.com  wedding-guide-site.com
your-blog.info  your-credit.info

Job Work From Home On My Computer
In my long quest for a job, work from home on my computer seemed to be the best available option Especially, since I needed to work around the many schedules of my family

On Campus Interviews - A Chance For Your "First Job" As Well As Career Employment
During the course of training or secondary educations some organizations - companies, firms as well as major non-profit organizations of great status and reputation will offer campus interviews to graduating students in such fields as engineering, electronics, business management, law accounting, computer information systems and marketing

Legitimate Work From Home Jobs - 4 Important Things to Consider Before Starting This Career Path
When you are selecting legitimate work from home jobs career, money is important, but there are some other factors that should be considered before making the final decision Before beginning even legitimate work from home jobs career, you should think about some of the factors that will help to make your venture succeed or fail

Work at Home Jobs Vs Self Employment
Work at Home Jobs vs Owning a Home Based BusinessNot everyone is interested in owning their own home business, but a lot of people are interested in dropping out of the rat race a little bit. More and more jobs are available where you can work from home.

7 Benefits of Owning a Computer Work at Home Job
Computer work at home jobs are growing in numbers Some cost very little to start-up and others are completely free to start

Work at Home Data Entry Jobs, Work at Home, Data Entry Jobs
37 Work at Home Data Entry Jobs - The New Age Career Move

Work at Home Agent - Job Ideas For a Work at Home Agent
Are you interested in jobs that require you to spend hours on the phone talking to customers If you like personal relations work and have good interpersonal skills, then do consider the opportunity of being a work at home agent

Legitimate Work At Home Jobs - Become Wealthy Working From Home
It all started when I was franticly going from company to company passing out my resume, needing a job so bad it hurt I had a college degree but could not get hired no matter what for the life of me

Home Computer Work - 3 Ideas For Home Computer Work Jobs
Surely, many people out there have told you about the wonders of working from home and being your own boss Well, not only are you able to save on transportation costs and have more time to spend with your family, you are also able to do whatever you like, whenever you feel like it

Work at Home Businesses Versus Work at Home Jobs
Is a work at home business better than a work at home job? You bet. Hands down. But each option has pros and cons. It may be that for right now you're just not ready to start a work at home business. Its a big committment. That's OK. But if you're dedicated, smart and willing to work harder than most, settling for a work at home job could be selling yourself short.

Work at Home Data Entry Jobs Career Are Available Now
Work at home data entry jobs career allow you the freedom to spend more time with your family It is perfect employment for someone who is looking for a job they can control themselves

Work From Home Jobs For Moms - Jobs You Can Do at Home
A Legitimate Work from home job is a desire that many moms have, and being able to generate a great income while working from home is very possible I created this work from home jobs for moms lens to give you information about legitimate work from home jobs for moms, and for anyone looking to make part time to full time income

Work From Home - How To Prepare For A Work From Home Job
Surely, you must have already heard about the perks of working from home Not only do you get the opportunity of being with your loved ones, but also the chance of earning good money doing what you like

At Home Work - Find Your Next Work At Home Job
At home work is easy to find these days thanks to the internet Work from home jobs are a form of self employment, which is hitting today's society in huge numbers