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Good Ol’ Token Ring

Thursday, March 10th, 2016 by

trngLarge numbers of network administrators are confronting the fact that their tried-and-true technology may no longer meet their needs

Not long ago, Token-Ring technology was ferociously battling Ethernet for network domination. But now Token-Ring is fading into oblivion, done in by its high price and lack of a high-speed migration path. Because millions of Token-Ring connections are now in place, the change will be gradual, but more and more corporations are seeking ways to dump their Token-Ring networks. For companies moving into new offices or opening branch offices, the time may be right to make a complete switch.

For others, the technology represents such a large investment that the transition will take years. But studies show that few companies now consider Token-Ring strategic and many believe it is just a matter of time before they swap it out.

Token-Ring’s bleak prospects illustrate that a technology can fail despite superior features. The networking technique still offers greater reliability and more efficient bandwidth use than Ethernet. Token-Ring networks also support source routing, which moves information from LAN to LAN by examining data packet headers. This feature, which is not available with Ethernet networks, lets users route information with inexpensive bridges.

Because of these advantages, IBM became a major Token-Ring backer and helped the technology gain acceptance in many large corporations. But over time, even these companies soured on the technology.

“Almost every large organization we deal with has begun to outline plans to move away from Token-Ring during the next 18 to 24 months,” said Bob Travis, strategic accounts manager for the IBM vertical market at Cabletron Systems Inc., in Rochester, N.H.

Automated Data Processing Inc., of Roseland, N.J., represents a typical case. The company’s 5,000 employees work with a variety of computers and rely on 400 IBM Token-Ring LANs to exchange information.

ADP has shared networks, where a group of users sends data over one 16M-bps Token-Ring network. Because bottlenecks were emerging at users’ desktops, the company last year examined moving to switched LANs, where each user would have his or her own dedicated LAN connection. Michael Del Secolo, ADP’s senior director of network engineering, found that Ethernet switching products were less expensive and more powerful than Token-Ring alternatives.

The price is wrong

Lower pricing is one reason Ethernet has become more popular than Token-Ring. During the past few years, the pricing gap between the two networking techniques has widened. “Many PC vendors now include an Ethernet adapter on the motherboard, so we get an Ethernet connection almost for free,” said Del Secolo.

Cabletron’s Travis noted that prices for Ethernet adapters range from free to $90 and port connections (a plug in a switch or a wiring hub) range from $200 to $400. In comparison, a Token-Ring adapter is priced at roughly $200 to $400 and a port connection on a Token-Ring switch runs from $800 to $1,000.

There are a couple of reasons for the pricing difference. Because Token-Ring networking offers more features than Ethernet, the chip sets used to support Token-Ring adapters are more complicated–and more expensive–than those used with Ethernet, according to Justin Smith, a senior industry analyst at International Data Corp., in Framingham, Mass.

Accordingly, companies have been purchasing more Ethernet connections than Token-Ring products. IDC data shows that vendors shipped 4 million Token-Ring cards worldwide in 1996 compared with 34 million Ethernet adapters. The higher volume lets Ethernet suppliers spread operating costs over a larger product base and cut the price to customers, IDC’s Smith said.

The pricing difference was too great for ADP to ignore. “We don’t [expect to] add any Token-Ring switches or wiring hubs to our network; from now on, our purchases will all be Ethernet,” said Del Secolo. However, because his company has so many Token-Ring connections, the transition to Ethernet will take years, he added.

Several companies plan quicker transitions. Cabletron’s Travis estimated that one out of every five of its Token-Ring customers is actively moving to other technologies.

Bellz Enterprises Inc., in Memphis, Tenn., is one such company. In 1993, Bellz installed Cabletron Token-Ring network wiring hubs to support 1,000 users.

“At that time, Token-Ring networks supported the fastest desktop speed,” said Ben DiAngelo, Bellz’s corporate director of IS.

Last fall, Bellz began encountering random network failures. Because the problem was sporadic, pinpointing its source was difficult. “We spent two months trying to figure out what was happening,” he said. “We even purchased a Token-Ring switch, but that did not solve the problem.”

Eventually, the problem was identified as faulty adapters for PCs running Windows 95. DiAngelo concluded that his company did not have the right type of diagnostic tools because vendors focused first on Ethernet technology and only later on the Token-Ring networks.

“The gap between when new features are available on Ethernet networks and on Token-Ring networks has widened during the past few years because vendors do not seem to be allocating many resources to their Token-Ring products,” said Tom Stenson, a principal at M5 Systems Inc., a Braintree, Mass., consultancy.

Frustrated by that gap, Bellz began to map out plans to move into a new corporate office and had to determine how to move the corporate network.

“We didn’t see Token-Ring technology as our long-term networking solution and decided to bite the bullet and deploy another networking technology in the new building,” DiAngelo said.

Bellz officials envisioned eventually installing high-bandwidth applications, such as desktop videoconferencing, so the company’s decision came down to either Fast Ethernet or ATM. Videoconferencing applications have special bandwidth needs that would seem to be better suited to ATM networks.

Ring in the Bellz

Despite its interest in desktop videoconferencing, Bellz Enterprises opted to install Cabletron Fast Ethernet switches in its new building. Price was one consideration; 25M-bps ATM connections are in the same price range as those for Token-Ring. ATM just did not offer enough bang for the buck to justify the price difference, DiAngelo said.

Ethernet offered a more attractive migration path for Bellz. Moving from a switched 10M-bps Ethernet connection to 100M-bps links only requires changing a port connection.

Because of the long-term migration path, Ethernet has a bright future. IDC predicts worldwide Ethernet adapter use will rise from 34 million units shipped in 1996 to 45 million in the year 2000. Conversely, IDC projects Token-Ring adapter card shipments to decline from 4.2 million to 3 million.

Even as Token-Ring technology fades into the background, ADP’s Del Secolo has no regrets about his company’s decision. “In 1985, IBM said it would support Token-Ring technology for at least 10 years, and that turned out to be true,” he explained. “But nothing lasts forever. Now it’s time to move to another networking technology.”

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