@Home Does Its Own Modem Certification


Another form of cable-modem-certification testing is on
vendors' to-do lists.

@Home Network is conducting its own interoperability tests,
saying that parameters other than those identified in Cable Television Laboratories Inc.'s
DOCSIS (Data Over Cable Service Interface Specification) effort need certification before
modems can run on its network.

Meanwhile, work continued last week to identify cable-modem
vendors with gear that passes DOCSIS. At press time, the sixth "certification
wave" was under way at CableLabs' headquarters in Louisville, Colo., but no vendors
were expected to pass until early next year.

In @Home's case, the DOCSIS specification is thorough, but
not far-reaching enough for its goal of a "managed network," where no remote
technical staff is needed to keep its backbone running smoothly.

"We call it a 'lights-out' management-systems
architecture," because it runs in the dark, without the need for human interaction,
said Ran Atkinson, manager of cable and networking technology for @Home.

"Because of that, it is critically important to us
that any product in the network -- whether a router or a bridger or a cable modem -- is
fully manageable out of band, so that the NOC [network-operations center] can manage
it," Atkinson added.

MSOs are counting on the "managed networks" of
@Home and Road Runner to make sure that their high-speed-data traffic -- whether for
Internet access, Internet-protocol phone calls or telecommuting -- safely gets from one
place to the next without bogging down in the larger, public Internet.

Because of that, @Home's MSO affiliates said they're in
favor of the additional certification.

"A managed network really does you no good if you have
unmanaged components on it," noted Susan Marshall, vice president of products and
technology for TCI.NET, the Internet-service provider arm of Tele-Communications Inc.

Atkinson said the @Home-certification tests started this
past summer, and they will continue through 1999. No vendors will be excluded from the
tests, he added, explaining, "@Home has an open-door policy."

Whether or not that door opens for a fee remains to be
seen. Atkinson wouldn't comment when asked if @Home plans to charge vendors certification
fees, even though two vendors said last week that they received notification from @Home
noting a forthcoming fee structure.

Vendors are also concerned that a third layer of
certification, on the other side of the United States, is in the mix: from Road Runner.
David Fellows, who stepped down as interim chief technical officer for Road Runner last
Wednesday, said the high-speed-data service is putting a test facility together near its
new headquarters in Fairfax, Va.

"The point of any independent testing is that there
are certain parameters that CableLabs doesn't test, like performance," Fellows said,
recounting an old telco tale about how one could connect a string to a block of wood and
pass early telephone-certification tests because they were so narrowly defined.

With modems, there are performance questions beyond product
interoperability, Fellows and others said, like whether or not the modem actually works,
what the actual data throughput is and how long it takes to boot up in cable's
"always-on" environment.

Buck Gee, vice president of marketing for Com21 Inc., said
the @Home tests are necessary.

"It has to be done, and it reinforces the reality that
interoperability is not easy," Gee said. "If @Home didn't do this, there would
be a lot of people who would be surprised when they went out and deployed their DOCSIS
modems in an actual managed network."

Com21 was the first vendor to stick its neck out for
independent, third-party tests that ascertain the actual performance its DOCSIS modems.
Earlier this month, it hired the Tolly Group, which ran a batch of preliminary tests at
the Western Show.

The early tests showed Com21's DOCSIS gear running at
"wire speed," meaning that the modem enabled the maximum number of 64-byte
packets to run. After ratcheting up to the largest-sized packets -- 1,500 bytes -- Com21's
modems still ran at the best-case rate of 10 megabits per second, Gee said. The 10-mbps
rate held steady even after IP filtering was activated, he added.