Gigabit Ethernet to the Internet

Were used to thinking of gigabit Ethernet as the technology of choice for linking together Fast Ethernet switches, locking together storage area networks and binding servers into clusters. It can be more. Much more.

Companies like Extreme Networks and Foundry Networks are taking Gigabit Ethernet from the back office to the wide area network (WAN). Thats because Gigabit Ethernet is cheaper to run and implement than asynchronous transfer mode (ATM) or dense wavelength division multiplexing (DWDM). Analysts from The Yankee Group estimate that Ethernet-based Internet can be delivered at one-fifth the cost of other broadband Internet services.

There are other advantages. For example, with Gigabit Ethernet, you can use fiber to deliver variable Internet bandwidth to your customers. The Extreme Networks Alpine “i” series switches can, for instance, deliver 500Kbps to 1Gbps traffic without any physical provisioning. Pretty impressive stuff.

In the future, you also can expect to see first-mile Gigabit Ethernet delivered over copper. The copper Gigabit Ethernet technology, IEEE 802.3ab standard (a.k.a 1000Base-T), has found a home in back offices, but its practical range is only 100 meters over ordinary Category (Cat) 5 cabling.

Extreme is pushing that range. The company now claims it can deliver Ethernet over T-1 and DS-3 circuits or even with very high-bit-rate DSL (VDSL) over Cat 5 at distances of up to several miles.

For now, though, optical fiber, usually in the form of a synchronous optical network (Sonet), will be the physical medium for most Internet deployments.

There are two broad ways to handle Gigabit Ethernet on Sonet. The first, Extremes approach, is simply to use Sonets fiber purely as a physical media and run Gigabit Ethernet over it, just as if it were a fiber-optic cable. Foundry, however, wraps Gigabit Ethernet frames within Sonet frames with its Global Ethernet approach.

You always end up paying one way or the other. In the case of Gigabit Ethernet, the cost is in quality of service and bandwidth control. Even the gigabit supporters admit that they lag behind ATM in these areas. But, the Gigabit Ethernet players are moving forward quickly on an Internet Engineering Task Force (IETF) standard called Common Open Policy Service protocol for Provisioning (COPS-PR), which will address those shortcomings.

But price talks, and many commercial customers just want inexpensive, high-speed bandwidth. Business bandwidth providers like Yipes already are delivering these services to paying customers. Extreme, which is in the midst of buying Optranet, a broadband IP services firm, is betting its company that Ethernet really will go everywhere.