8/10/98 Telephony (Pg. Unavail. Online) (See Bold)
1998 WL 6611556
Telephony
Copyright 1998 by PRIMEDIA Intertec, a PRIMEDIA Company. All rights reserved.
Monday, August 10, 1998
Switching & Transmission
Collective effort: DSL vendors see interoperability as key to mass deployment
Wayne Carter
A multitude of digital subscriber line vendors have cropped up over
the last few years, most with an approach at least slightly different
from the others'. There's ADSL, IDSL, VDSL, SDSL and, in the ADSL world,
CAP and DMT modulation schemes. Every vendor has its own equipment, and
it's difficult for carriers to identify whose is best.
But the vendors are finally ready to tighten up the industry. Central
office equipment manufacturers are trying to achieve interoperability
with as many customer premises brands as possible, and vice versa. Such
connections allow carriers to select CO equipment with the knowledge
that they can allow end users to choose their connection equipment from
a pool of possible vendors.
Westell developed an interoperability lab about a year ago and is now
beginning to receive other vendors' equipment for testing.
"All the companies developing equipment realize the market potential
is larger than any one company can serve," said Paul Harrington,
managing engineer for Westell's lab. "We'd rather have a small
percentage of a large market than a large percentage of a small
market."
Customer premises equipment vendor Efficient Networks has been busy
working with CO vendors. Efficient already had a lab, primarily for
asynchronous transfer mode testing, and started to add DSL test
capability about 18 months ago. Its initial tests began about nine
months ago, and in that time Efficient has completed testing with at
least eight companies, including Diamond Lane Communications, DSC
Communications, Ericsson and Redback Networks. And more companies'
equipment is currently in the test phase, which begins with testing at
the physical interface layer, then progresses up the protocol stack (see
figure).
Developments on the CO side have enabled the quick leap to
interoperability testing, said Greg Langdon, Efficient's marketing vice
president.
Even vendors that have end-to-end solutions, DSLAMs and CPE are
eagerly pursuing interoperability.
John Reister, product marketing director for Copper Mountain Networks,
said his company builds customer premises devices just to ensure that
customers can get a satisfactory solution. Copper Mountain now has a lab
and invites CPE vendors to test there with Copper Mountain DSLAMs.
Running the labs isn't as easy as setting up and inviting other
vendors. Some may be fearful that information about their equipment and
test results may be shared with other vendors testing at the same lab.
Westell had worked with third-party laboratories including
university-owned labs before it established its facility, Harrington
said. The company will continue to pursue third-party lab relationships
as well as run its own.
The move toward interoperability testing is seen as key for the market
by the equipment vendors, but Fred McClimans, CEO of Current Analysis,
said it won't push DSL into the mainstream.
"Interoperability is not necessary to offer DSL service, but most
carriers will want multiple vendors," McClimans said.
Still, the vendors believe interoperability is vital to the long-term
health of the market-and of their individual companies. Reister said any
company that tries to sell end-to-end proprietary solutions has no
long-term prospects in the market, and that's what's driving Copper
Mountain to align with multiple CPE vendors.
Texas Instruments and Alcatel are among the large DSL vendors that are
recognizing the importance of interoperability. The companies announced
in late July that they have achieved interoperability between their CO
and CPE equipment lines.
"Ninety percent of the work was done in public, in standards," said
Terry Riley, business development director for TI's broadband access
unit. "By the time we got together one-on-one, the work we had left to
do was far less than anyone had feared."
The interoperability and standards push reinforces the belief that DSL
won't prosper without flexible CPE options, said Rick Galatioto,
Alcatel's product manager for local networks.
"We believe the CPE market should be open," he said. "No one company
can develop all the types of CPE required."
In addition to its efforts with TI, Alcatel is in interoperability
discussions with companies, including Lucent Technologies, Pairgain and
Advanced Micro Devices.
Although testing is progressing among DSL vendors, Riley said the
process could be further expedited.
"What's really needed is a neutral lab," he said, adding that an
initiative is underway through the ADSL Forum to establish such a
facility. He said the goal is to avoid the troubles that plagued 56K
modem technology, which was deployed without a standard in place.
The testing between Alcatel and TI validates the standard at Layer 1
and Layer 2, but the cloak-and-dagger environment that surrounds
intercompany testing today must give way to fully standardized testing
eventually, Galatioto said.
"We expect an independent lab, such as Bellcore or the University of
New Hampshire, will take over the testing," he said.
Briefly
FULL SERVICE AHEAD U S West plans to deploy the NLevel3 digital loop
carrier and fiber-to-the-curb systems from Next Level Communications.
The DLC system will deliver integrated video, data and telephone service
in POTS line-sized applications, and the FTTC will provide the same
services iZn new developments and other selected areas. U S West is
using NLevel3 systems in Phoenix.
GEARING UP FOR IP Softcom Microsystems' GigaBlade network accelerator
converts and forwards 64-byte packets at full OC-12 rates. Based on a
broadband access processor, the GigaBlade aggregates bursty IP traffic
onto Sonet-ready payloads, which can be fed into the broadband
backbone.
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