Re: "Next Generation," DSLAM- CSCO, LU, NT, PAIR, PDYN, ALA?
Thread- A follow-up article to the one Ray just referenced. One reason I like this article is that good old legacy word again- ATM. I still think ATM is going to be a lot more important than most technology experts have forecast. And I like the number of times it's repeated in the piece below.<g>
Now the second part that interests me is what is stated at the very bottom of the article. I have no idea what the writer is talking about when she states Alcatel is not in this, "next generation," space. I'm lost on that one. Maybe it's a matter of semantics. It's so hard to label what used to be such unique pieces of equipment, as the new world of convergence comes into play. I would have to think ALA(the actual world leader in the DSL space) has a product in what the writer calls, "next-generation DSLAM." I took it to mean a DSLAM dropped in a RT. Or NGDLC. But apparently(judging from Ray's upstream link) they are not the same thing? Can anyone shed some light on this? -MikeM(From Florida)
******************************
New DSLAMs Set To Rock Access World
By Carol Wilson, Inter@ctive Week
February 9, 2000-- The integrated access market is about to be swamped by Digital Subscriber Line equipment that is combining voice and data in newly efficient ways. Using a new generation of DSL Access Multiplexers, competitive carriers will be able to offer even small businesses affordable voice and high-speed data services now available only to companies that can justify the expense of a T1 (1.5-megabit-per-second) access line.
Equipment vendors that are building and shipping next-generation DSL Access Multiplexers (DSLAMs) or other integrated access gear include Accelerated Networks; Cisco Systems; Lucent Technologies; Nortel Networks, through its recent acquisition of Promatory Communications; PairGain Technologies; and Paradyne. Meanwhile, service providers as diverse as Digital Broadband Communications, a Massachusetts carrier serving 70 central offices (COs) in the Boston area, and MCI WorldCom have begun putting the new equipment to work.
The arrival of next-generation DSLAMs will cement the role that Asynchronous Transfer Mode (ATM) will play at the access edge of the public network.
"We will leverage our ATM backbone network and use voice-over-DSL as the access piece," says Barry Zipp, director of product marketing for voice-over-DSL at MCI WorldCom, which demon strated voice over various classes of ATM at ComNet 2000 in late January.
Voice Vote
By combining voice and data onto a single copper line using ATM transport over DSL, competitive carriers can deliver voice services — which generate 10 times more revenue than data — and significantly improve their bottom line.
"What people have realized is that voice services are still generating the revenue," says Parag Sheth, vice president of marketing at Siemens Information and Communications Networks, which announced Surpass, a platform that includes integrated access over DSL, at ComNet. "What carriers want us to do is help them provide voice over their packet networks, and at the same time lower the cost of operations."
Although there is DSL equipment based primarily or exclusively on Internet Protocol (IP), the consensus among vendors and carriers is that ATM will be much more commonly used for integrating voice, data, video and multimedia services in public access networks.
"DSL really anchors ATM in the access network," says Frank Wiener, vice president of broadband access products at Paradyne, which makes the GrandSlam DSLAM. "It has the flexibility required for network operators that want to do both wholesale and retail services. If you are doing wholesale only — selling to other carriers — then an IP solution can work. But as soon as you want to do retail, you really need ATM."
ATM is likely to be in the access network for some time to come, says Kevin Walsh, vice president of marketing at Accelerated, which is providing its integrated access devices to MCI WorldCom for its Smart Bandwidth service.
"ATM is the right tool for the job in many ways," Walsh says. "It is flexible enough to offer the variety of services required in access networks, and it has quality-of-service characteristics that aren't yet available in IP."
Integrating voice and data services over one access network is a no-brainer. Not only does it offer carriers the chance to reap revenue from a variety of sources; it lowers costs by letting them operate one network, rather than separate networks for their voice and data services.
There are a few ways to integrate voice and data, however. One is to use integrated access devices to connect customers to a variety of networks, including basic T1 dedicated links or ATM, frame relay or packet networks.
The new DSLAMs enable an ATM-based service that can operate over existing telephone lines and work with voice-over-DSL gear from companies such as Jetstream Communications, CopperCom and TollBridge Technologies. By using copper lines already in place and adding multiple voice lines and high-speed data service, competitive carriers can make the most of their capital.
For new local competitors in particular, integrated access via DSL represents the best chance to lock in a wider range of customers by offering a full suite of services at reasonable cost.
"Why offer the same thing the incumbent does, at a discount, when you can offer much more and charge a premium?" asks consultant Tom Nolle, president of CIMI and a strong advocate of using ATM to provide a wide range of voice services, including high-market enhanced voice offerings.
Venturing into voice means providing a more reliable and higher-quality network, says Timothy Waters, vice president of marketing at Promatory (www.promatory.com), which was ac-quired last month by Nortel (www.nortelnetworks.com). "Reliability is what drives the need for a next generation of DSLAMs," says Waters, who once headed Ameritech's DSL deployment. "As soon as you get into voice services, you have to be able to guarantee a quality of service."
The Need for Intelligence
Those guarantees aren't possible with most of the earlier DSLAMs , says Kevin Woods, director of marketing at PairGain, which unveiled its next-gen DSLAM, Avidia, more than a year ago and has sold its system to 30 carriers.
"DSLAMs today are service-dumb — they are low-cost but single mode," Woods says. "Next-generation DSLAMs run a wider variety of services, including multiple versions of DSL, and have the intelligence to do other services such as virtual private networks [VPNs], as well as voice."
There is no one set definition of a next-gen DSLAM. But to provide reliable voice and enhanced data services such as VPNs, a DSLAM must support Switched Virtual Circuits (SVCs), or what some vendors are now calling "soft" Permanent Virtual Circuits. These connections are software-defined and more flexible than PVCs. Voice service is offered using ATM Adaptation Layer 1, AAL2 and AAL5.
"We think that SVCs are actually the critical piece here," Walsh says. "If you start putting hundreds of voice and data calls onto the network, you need the flexibility of SVCs. We think AAL2 is the most efficient way of handling voice because you can assign the bandwidth dynamically, do silence suppression and voice compression to get the actual bandwidth consumed by voice down very low."
In addition to the voice transport, how ever, the new DSLAMs need to solve other DSL deployment problems, argues Subash Mediratta, director of product technical marketing for multi-DSL products at Lucent (www.lucent.com), which announced its Stinger next-gen DSLAM last fall.
"One of the big problems in DSL deployment is that a carrier can't sell a service if you aren't sure you are going to be able to offer it," Mediratta says.
Since not every business or consumer is either close enough to a CO to get DSL or served by a copper line that comes directly from the CO, carriers can't sell a DSL service until the line is qualified to carry it. Lucent has built line qualification into its Stinger, so carriers can prequalify lines, create a database and know whether service is available when customers first try to order, Mediratta says.
Next-gen DSLAMs also need to offer options on how carriers can provide voice services. In addition to supporting developing protocols such as the Media Gateway Control Protocol and the Session Initiation Protocol, DSLAMs need the flexibility to support older protocols including the H.323 standard, says Tim McShane, senior director of DSL/ Integrated Access Device marketing at Cisco (www.cisco.com).
"What you want to offer is maximum flexibility to support multiple protocols," McShane says.
One company conspicuously absent from the next-gen DSLAM party is the current leader in providing DSLAMs to carriers, both in the U.S. and globally is Alcatel.
Through software upgrades, Alcatel is offering such features as SVCs in its current generation of DSLAMs, according to Jay Fausch, senior director for marketing and business development at Alcatel USA's DSL business unit. |
