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Several proprietary, splitterless technologies have been released over the past six months with varying degrees of success. Paradyne Corp.'s MVL (Multiple Virtual Lines), Cisco's EZ-DSL and Northern Telecom's Etherloop technologies all trade off on standards in favor of inexpensive equipment implementations and relaxed deployment requirements. Etherloop features lower power requirements, more resistance to disturbance in the same wire bundle and greater speeds. It's not a DSL technology, but neither does it suffer from many of DSL's drawbacks.

Paradyne's MVL, another non-DSL technology that runs over the same copper loops, has been stretched as far as 24,000 feet from the CO, with multiple 768-Kbps streams running on a single telephone wire. Cisco's EZ-DSL, which uses the CiDSL chipset from GlobeSpan Semiconductor, is the only DSL technology of the three. It's RADSL and splitterless, but requires that filters be placed on any telephone sets used while the data line is in use.

Both Nortel and Paradyne are aggressively pursuing standards bodies with their technologies, but it's still too early to say whether they will make any serious inroads against the forthcoming G.lite standard.

End Note DSL companies are consolidating rapidly, and it's likely that only a handful of major players will be left by the middle of 1999, when the consumer market is expected to really take hold. That market should drive DSL equipment prices down and, if enough competition exists between CLECs and ILECs, connection prices should also drop precipitously. For Covad rival Northpoint, regulatory issues that could impede competition are a major concern. The 1996 Telecommunications Act states that ILECs must provide collocation space if they have space available. In COs where little space is available, there may be few, if any, opportunities for CLECs to compete.

Whether you perceive DSL as a pain, a potential gold mine or a "quick and dirty hack," as Andrew Tanenbaum called it in his widely used reference work Computer Networks, it's valuable to IT departments as a big, inexpensive pipeline to the corporate LAN and the Internet, and it will drive a new class of high-bandwidth applications for consumers. Noise or no noise, it's the best thing going for general-purpose, high-bandwidth connectivity.

Send your comments on this article to Jason Levitt at jlevitt@cmp.com.