DSL graduates to worldwide testing standards – Internet/Web/Online Service Information
New specifications for DSL interoperability aim to unlock the mass market by boosting service providers’ confidence.
The DSL Forum of Fremont, California, in answer to strong requests from service provider members, is developing specifications and standard procedures to test the interoperability of digital subscriber line equipment.
The procedures, which will be accessible from officially recognized, independent, but commercial, test centers in Europe and the United States, should enable more detailed interoperability testing, much of which is now carried out at the University of New Hampshire or in vendors’ and operators’ own laboratories (see box).
Interop cost and time burdens
Operators have said they do not want the cost and time burdens of doing interoperability testing themselves, and have pushed for standard procedures to relieve them of some testing requirements and increase their confidence in test results.
“There is a need to create confidence among operators for deploying [digital subscriber line services],” said Frank Van der Putten, director of standardization in Alcatel’s DSL access business unit, based in Belgium. “Operators have said that it is too expensive to test DSLAMs and CPEs in their own labs.”
Much progress has already been made with DSL interoperability. At the Supercomm trade show in Atlanta earlier this month, the DSL Forum demonstrated interoperability among add/drop multiplexers (DSLAMs) and customer premises equipment (CPE) from about 40 different vendors.
But operators still say network performance suffers when they implement equipment from different manufacturers, even though technically it can work together.
“There is still a bit of ‘proprietary-ness’ in the industry: you still get different performance when they work together,” said Nigel Billington, principal engineer at BT Exact Technologies, formerly known as BT Laboratories, based in Ipswich, England.
Operators want interoperability tests to include network performance criteria–currently their biggest concern in terms of network operations.
“From a service provider’s point of view we need the industry to be in a position to understand what real interoperability means,” said Billington. “Vendors may have their own test plans, but service providers are concerned with reach performance and the ability to carry certain types of traffic.”
Operators now require detailed testing to be confident in DSL deployments. “Detailed testing is a step beyond interoperability,” said Alcatel’s Van der Putten. “If CPEs, for example, are not adequately tested, then operators have to deal with more calls in their call centers. They want the confidence that the boxes will work, but they don’t want to test them themselves.”
Looking at the nuts and bolts
Getting into detailed testing means examining everything that can happen in the loop plant, according to Van der Putten, including the effect of short and long loops, as well as loops with radio interference or impulse noise.
Billington, at BT, said the Forum is discussing whether to keep nonattributable statistics to tack how the industry is achieving the new interoperability specifications. “The Forum is building on the DSL standards with performance specifications,” he added.
Meanwhile, the Forum’s independent test lab program will continue its goal of achieving a mass market for DSL. “Interoperability is one of the biggest keys to unlocking the mass market, and facilitating a mass market is what we’re trying to do,” said Mark Peden, chair of the Forum’s G8 working group, responsible for the independent test lab program, and vice president for technology marketing at Simpler Networks Inc., of Saint-Laurent, Quebec, Canada.
Sometimes university isn’t the best place to learn: commercial centers open
At its next meeting in Oslo this week [18 June], the DSL Forum will complete its interoperability test plans and the standard template for reporting test results. It will also begin reviewing the nominated test houses for formal “recognition”.
“Service providers are going to feel more comfortable with certain test houses and test results,” said Mark Peden, chair of the DSL Forum’s G8 working group.
Currently, most basic interoperability testing is carried out at the University of New Hampshire (UNH). The DSL Forum’s plan will create a standard, formalized procedure that can be accessed from many more test houses in several new markets.
Even though the DSL Forum will “recognize” certain test labs, they will still operate on a commercial basis. “One of the biggest problems of the labs will be getting the DSLAMs,” said Steve Kingdom, international DSL and telecoms sales and marketing manager at KTL, a telecoms test laboratory and wholly owned subsidiary of Kingston communications, based in Hull, England. “They will rely on a lot of equipment donations from vendors because DSLAMs are expensive. But the labs that will be the most successful will be the ones with the most DSLAMs,” he said.
Test houses that have nominated themselves to date include ATG NAIL (Santa Rosa, California), CETECOM CT Services (Saarbrucken, Germany), Henderson communications Laboratories (Moreno Valley, California), KTL (Hull, England), Laboratoire Europeen ADSL (LEA) (Rennes, France), Lucent Technologies (Murray Hill, New Jersey), Telia ProSoft AB (Haninge, Sweden) and TUV Rheinland of North America, Inc. (cologne).
“Interoperability testing is all done out of UNH, but they’re not very commercially aware,” said KTL’s Kingdom. “There are six-to-nine-month wait times, and you can only book in two-week slots. So, there are advantages in going through a commercial lab,” he claimed.
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