Transition Networks to debut Gigabit Ethernet copper to fiber media converters

By: John Spofford
Managing Editor, Premises Networks Online

As the thirst for network bandwidth increases, the move to Gigabit Ethernet will be considered by most network managers. The overwhelming prevalence of Ethernet topologies and installed base of Category 5 or better grades of copper cable in LANs creates a good argument for copper-based Gigabit Ethernet. Further the cost competitiveness of copper Gigabit Ethernet products—which have debuted at a third less than comparable fiber products—accelerates the demand for Gigabit Ethernet.

Still Gigabit over copper is not the panacea vendors suggest: 1,000 Mbps over copper cabling clearly is abusing the cable's capability. And with Category 6 cable quite rare, even Cat 5E quickly runs into both distance and reliability limitations. What is needed when existing copper based LANs migrate to Gigabit Ethernet is a inexpensive way to mix in fiber links.

Promising to solve this problem, Transition Networks (Minneapolis, MN) is expected next month to announced a new line of Gigabit Ethernet copper to fiber media converters. The media conversion vendor's Gigabit copper to fiber converters allows network managers to reach users who reside beyond the copper distances without having to upgrade to a more costly fiber switch or router module.

The Gigabit Ethernet converters will convert 1000BaseT to 1000Base SX or LX. Transition Networks reports the new products are fully compliant with 1000BaseT IEEE 802.3ab and 1000BaseSX/LX IEEE 802.3 1998 standards.

With Transition's new Gigabit Copper to Fiber Media Converters, network managers have less worries about the cabling infrastructure already installed. Utilizing the new 1000BaseT to 1000Base SX/LX converters in conjunction with lower cost 1000Base-T switches gives network managers the opportunity to upgrade networks to Gigabit speeds in an economical manner, says Bill Shultz, product manager at Transition Networks.

"One of the big arguments for gigabit over copper is that the hardware is less expensive. You could get a 12-port gigabit copper blade cheaper than you can get a 12-port fiber blade," he says.

"If we use Cisco as an example, you put the gigabit copper blade in your Catalyst 5000 and you run whatever you can out of the copper ports. Then where you need additional distance you use media converters on those particular ports to get the longer distance across the fiber [links]. So you basically are able to use gigabit less expensively."

Potential market
Transition Networks expects strong demand for its new media converters. The high-tech market research firm Cahners In-Stat Group (Scottsdale, AZ) projects the Gigabit Ethernet market to grow more than 200% this year to almost $4 billion. Although the first significant volumes of Gigabit Ethernet over copper products only began shipping in the second quarter of 2000, by the end of the year copper Gigabit Ethernet is expected to be shipping more ports per quarter than fiber-based Gigabit Ethernet.

"Some of the applications we are going to see are going to be in [network] backbones, with a lot of heavy file transfer—engineering files, multimedia, application switching, transfers between server farms and more," Shultz says. "Gigabit copper to fiber also allows people to consolidate a lot of offices. Schools for example can consolidate data centers throughout a school district, using fiber they can transfer information to one location."

In addition, the converters can extend bandwidth to those outside the reach of the 1000 Base-T standard. "For those with longer distance applications, we will put in higher-powered optics that can reach out 25 km and up to 65 km. The distance will really depend on the fiber they are using," Shultz says.

Product features
Auto Negotiation—The new Gigabit Ethernet converter supports 1000BaseT half- or full-duplex Auto Negotiation. Because 100BaseSX/LX does not allow for Auto Negotiation between half- and full-duplex modes, the ability to select this manually is needed to ensure that the remote 1000BaseT links interoperate.

Link Pass Through—The converter automatically detects and reports loss of link on a connection using Link Pass Though. This feature allows the equipment at the remote end of a link failure to "see" this failure and respond with corrective actions, such as Spanning Tree fail-over links, proprietary trunking links, or failure reports through SNMP or remote monitoring procedures, such as RMON, built into the switch, router or hub.

Pause—The converter includes a user-selectable Pause option. Because auto negotiation is not supported over fiber, the converter will communicate to the attached network device that Pause is available. If Pause is not supported on one of the network devices, the Pause feature on the converter can be manually disabled.

The Gigabit Copper to Fiber Media Converter is available in a standalone form factor or will be made available as a chassis card for the company's Point System Conversion Center. The chassis card version used in conjunction with the Point System Conversion Center and the Transition Networks' Focal Point management software will allow the user to manage the product features through a graphical interface.

The full line of 1000BaseT to 1000Base SX/LX converters is expected to be announced on December 11, 2000.

Transition Networks designs and markets conversion technologies across a broad spectrum of networking protocols including Ethernet, Fast Ethernet, FDDI, ATM, Gigabit and Token Ring.

Transition Networks, Inc.
6475 City West Parkway
Minneapolis, Minnesota 55344
United States
Phone: 952-941-7600
Fax: 612-941-2322