DSL Gets 'Bazaar'

Posted 05/15/2000

DSL Gets 'Bazaar'
Amid the Noise of an Expanding Vendor Marketplace, Buyers Face Tough Technology Choices
By Peter Lambert

Just over a year ago, buyers of DSL technologies had little more than a strip mall's worth of vendors from which to find CO and customer premises equipment to get started launching DSL services. Suddenly this spring, buyers faced a bustling, noisy, colorful and confusing marketplace bazaar.

Such is the price of playing with a technology whose time has come--or rather, is experiencing a second, or even third coming.

The slogging first incarnation of residential DSL shifted into a higher gear last winter when SBC Communications Inc. (www.sbc.com) committed to a $6 billion, broadband, packet-based network rebuild that its executives describe as a "once-in-60-years" event. Other regional Bell companies promised to follow that lead. Simultaneously, CLEC DSL providers focusing on high-speed Internet access to businesses steadily found a national footprint. Players, including Covad Communications Co. (www.covad.com), NorthPoint Communications Inc. (www.northpoint.net) and Rhythms NetConnections Inc.  www.rhythms.net), began to count their DSL CO deployments in the many hundreds.

Now comes a third wave: bundled services DSL for businesses, multitenant unit (MTU) offices and residences. With that comes a menagerie of value-added IADs, service-level QoS controls, subscriber management systems, IP VPN management systems, network-hosted virtual routers and firewalls, media gateways, softswitches, enhanced telephony feature servers and flow-through provisioning systems, as well as broadband service portals, customer care software and more.

So too has come a third wave of DSL service providers, such as Allegiance Telecom Inc. (www.allegiancetele.com), McLeodUSA Inc. (www.mcleodusa.com), Mpower Communications Corp. (www.mpowercom.com), PaeTec Communications Inc. (www.paetec.com) and Picus Communications (www.picus.com). These carriers claim a telephony heritage unknown to earlier national DSL carriers, and they are opening COs with not only DSLAMs and fast data modems, but also with voice over DSL (VoDSL) gateways, Class 5 switches and even server-based telephony softswitches.

By moving beyond broadband Internet access, these carriers promise to set new benchmarks in DSL revenue potential. "We're offering voice and data over DSL and plain old telephone service in every central office we open," says Rolla Huff, president and CEO of Mpower, which, by three months after launch in January, reported that 7 percent to 10 percent of DSLs sold included VoDSL.

"Voice will continue to be an application all our customers want," Huff says. "We can supply both voice and data, as well as associated services like local call features and web hosting, so we'll be looking at $600 to $700 revenue per month, per DSL line, rather than the $60 to $70 a month of a pure Internet-access-only DSL play."

To fill in their own VoDSL portfolios, Covad, NorthPoint and Rhythms have gone outside, forming VoDSL partnerships with established national telephony carriers GST Telecommunications Inc. (www.gstcorp.com), Focal Communications Corp. (www.focal.com) and MCI WorldCom Corp. (www.wcom.com), respectively.

All these carriers are rushing to further expand DSL data service offerings, too. @Link Networks Inc. (www.atlinknetworks.com), for example, is focused on integrating platforms to manage VPNs and to host multimedia content, business applications, business-to-business extranets and business services web portals, as exemplified by Allegiance Telecom's partnership with web and application hosting specialist Go2Net Inc. (www.go2net.com) earlier this year.

@Link Networks will emphasize business data first. "We'll provide next-generation, multiservice access and functionality, including very robust point-to-point and point-to-multipoint VPNs with quality of service and class of service down to the desktop," @Link Networks Chairman and CEO Alex Good said on the heels of a $225 million purchase of Nortel Networks Corp. (www.nortelnetworks.com) DSLAM, switching, optical, IP service provisioning and gateway systems in March. "We're now in a position to provide private, secure communications for local network extension, voice applications and other business-critical applications at price points that small businesses can afford."

For such buyers, the sheer number and kinds of products to kick around at this year's June SUPERCOMM gathering will prove wearing on the toes.

Even more critically, buyers this year will face some forks in the road in choosing among fundamentally different underlying technologies.

Generation What?

CLECs intent on bringing bundled services to the small and medium-sized business markets now face a bewildering chorus of claims about what constitutes a "next-generation" DSL platform.

The tangle begins at the DSLAM, as well as the IAD (see "IADs Embrace Increasing Number of Interfaces, Functions and Pocketbooks," ). One camp of DSLAM vendors is making the next-gen claim based on use of ATM QoS and traffic engineering mechanisms to support toll-quality voice, real-time file transfers and other delay-sensitive applications--a task to which best-effort IP routing is ill suited. These ATM-centric vendors include Alcatel USA (www.usa.alcatel.com), Lucent Technologies Inc. (www.lucent.com), Nortel, Nokia High Speed Access Products (www.nokia.com), PairGain Technologies Inc. (www.pairgain.com) and Paradyne Networks Inc. (www.paradyne.com).

Another group of vendors argues that ATM adds unneeded complexity; that provisioning of ATM virtual circuits (VCs) at the "Link Layer" (Layer 2) cannot be automated at large scale, and that ATM fails to tackle demand for the "high-touch" routing functions needed to support advanced IP services. For vendors, including AccessLan Communications Inc. (www.accesslan.com) and Copper Mountain Networks Inc. (www.coppermountain.com), the emphasis is on building an IP services layer on top of Layer 3 routing over DSL access.

"If second-generation supports voice at Layer 2, then the third generation is Layer 3 packet classification, prioritization, QoS and switched path assignment," say AccessLan Marketing Vice President Kumar Shah.

"ATM-centric DSLAMs have no capability to examine and differentiate among multiple IP flows that may travel in any one VC," Shah says. In contrast, AccessLan's new intelligent DSLAM (i-SLAM) and Internet scaling architecture "are designed for packet-level processing, because the DSLAM has to become more IP-aware to differentiate and classify traffic if DSL providers are to take advantage of the revenue opportunities inherent in new IP services like application hosting, media content, e-commerce and differentiated Internet access," Shah adds.

The QoS debate remains hotly contested. Market-leading first-generation DSLAMs from Copper Mountain and others employ frame relay transport between the CPE and DSLAM. But the newer ATM vendors emphasize their use of ATM to create separate VCs for voice and data within the DSL pipe, and then shape bandwidth and optimize connections for each service type.

"It's no longer speeds and feeds," says Dennis Klein, director of the xDSL product line for Lucent. "The issue now is what makes for next generation, and that includes high-density, high- availability, compatibility with all CPE and DSL types, quality of service, ease of installation and maintenance, and flow-through provisioning end to end, from order entry to provisioning the local loop and core resources, just like the voice network."

ATM VC provisioning also is key to some early efforts by CLECs, including Chibardun Telephone Cooperative Inc. (www.chibardun.com), to bundle multichannel digital television services into the next-gen, 30mbps VDSL services as well. "We demultiplex satellite and other feeds, apply rate control and format to ATM cells," explains Lee Rainey, director of marketing for Tektronix Inc. subsidiary VideoTele.com Inc. (www.videotele.com), supplier of digital "headend" gear to Chibardun Telephone Cooperative.

Copper Mountain claims equal traffic-shaping virtues without benefit of ATM Layer 2 QoS help. "If next-generation CPE, edge and core products are going IP, why shouldn't access products do the same?" asks Keith Higgins, Copper Mountain's director of product marketing. "We've showed we can do toll-quality voice with separate [frame relay] VCs with the whole range of QoS controls."

Copper Mountain customer Mpower shares the confidence that it can support VoDSL performance without ATM. "From our point of view, ATM-based DSLAMs only route at the ATM layer, so we're discounting them as last generation, because the issue is managed versus unmanaged networks, and we manage the network without ATM," says John Boersma, senior vice president of technology development for Mpower. "We're focused instead on moving above Layer 3, and vendors like Copper Mountain and AccessLan interest us because of their higher level routing."

In contrast, @Link Networks' selection of Nortel's Promatory Communications Inc.'s (www.promatory.com) Intelligent Multiservice Access System (IMAS) DSLAM put that provider firmly in the ATM camp. "This is a system which we have 100 percent confidence will deliver QoS," says @Link Networks' Good. "In time, networks can mature to accomplish QoS end to end at the IP level, but for now, we know we can hit the market with technology that everyone agrees works: ATM."

The emerging implementation of ATM-switched virtual circuits (SVCs) solves the scaling challenge, says Kevin Walsh, vice president of marketing for Accelerated Networks Inc. (www.acceleratednetworks.com), a maker of ATM-based DSLAMs, gateways and IADs. "Yes, configuring ATM permanent virtual circuits for millions of end points is a nonstarter, but ATM enables the dialing of digits on your phone to automatically provision the SVC," he says.

"You need technologies like PNNI [private network-to-network interface] and MPLS to achieve scale, and our view is that the chip manufacturers and the software code maturity are further along in PNNI," says Kevin Woods, director of Avidia System marketing for PairGain, which is soon to be acquired by ADC Telecommunications Inc. (www.adc.com).

CLECs may become further interested in ATM-based DSL as new rules force regional Bells to share their lines with broadband providers--a possible boon to ATM-based ADSL equipment supplier Alcatel USA.

Voice Value

There is little debate about the potential for voice services to greatly multiply small-business broadband revenues. With more than a half dozen active customers now, VoDSL gateway maker Jetstream Communications Inc. (www.jetstream.com) estimates that DSLs bundling eight voice lines with high-speed data can typically garner 360 percent higher revenue than data-only DSL.

"At rates typically under $500 a month, DSL now gets you 384 kilobit per second symmetrical data access, a fixed number of long-distance telephone minutes, plus free local calling," says Peter Bourne, vice president and general manager of integrated access for CPE maker Efficient Networks Inc. (www.efficient.com). "That's a good deal for a small office or home office that lacks an army of accountants to scrub a telecommunications bill every month."

Consequently, Jetstream and its nearest competitors, CopperCom Inc. (www.coppercom.com) and TollBridge Technologies Inc. (www.tollbridgetech.com), continue to rack up customers and partnerships with DSLAM and CPE makers.

Gateway makers also are vying to accommodate an emerging generation of mediation switches and softswitches designed to replace mainframe Class 5 switches with low-cost, server-based hardware for carriage of voice over ATM, IP and other all-packet networks. Formal softswitch partners so far include, ipVerse Inc. (www.ipverse.com) and telecom technologies inc. (www.telecomtechnologies.com). In February, CopperCom went further than a partnership, acquiring class-independent switch maker DTI Networks Inc.

The softswitch architecture--with media gateways controlled by media gateways controllers and signaling gateways--promises to yield a number of key benefits. These benefits include new market entry at one-tenth to one-twentieth the cost of a Class 5 switch; call control that can span both packet and circuit networks; and open interfaces to a universe of World Wide Web-like application servers and development environments for rapid service and feature innovation.

Jetstream now argues that it can use its existing platform to bring a number of those benefits to market even before the still nascent softswitch architecture arrives. In addition to leveraging CLASS and local calling features like call forwarding from existing Class 5 switches, Jetstream plans to introduce stand-alone call control servers and application servers using the same Q.931 common message channel signaling protocol that it already runs between its gateway and IAD systems.

As session initiation protocol (SIP), media gateway control protocol (MGCP) and other softswitch interfaces mature, Jetstream intends to support them. In the meantime "we can use the existing Class 5, the VoDSL network, the IAD and call control servers to support next-generation services now, even before softswitches arrive," says Stephen Gleave, vice president of marketing for Jetstream.

Accelerated Networks enables similar call control gateway connections and user browser access in the interim. CopperCom argues that the softswitch architecture has already arrived in the form of DTI's mediation switch and extensible markup language (XML)-based call policy markup language (CPML). This system gives users web browser access to their service management pages and also integrates with CopperCom's gateway and IAD systems.

IP IQ

The desire to offer small businesses the kind of advanced private data and Internet services associated with big corporate data networks is now finding its way into every service provider's broadband request for proposals. In that arena, a new debate is arising over how many CO boxes it will take to do the job.

Currently, most DSL access services are split from voice traffic at ATM switches, then sent to subscriber management and aggregation platforms, a market led by Redback Networks Inc. (www.redback.com). In April, Redback Networks announced its newest platform, the SMS 10000, designed to aggregate hundreds of thousands of data sessions from dozens of DSLAMs at a MegaPoP.

In addition to aggregation, the SMS 10000 will conduct packet-level processing on each session to apply subscriber services ranging from private router addressing, VPN access and firewall security to traffic shaping--all based on policy automation that applies subscriber rules on a per-VC basis. Such a MegaPoP platform "is needed to accommodate the growing number of subscribers and the growing number of IP applications like media streaming and data mining," across a combination of DSL, private and dial-up data networks, says Mark Weiner, Redback Networks' director of corporate marketing.

Large IP carriers have adopted similar IP service switching platforms in recent months. PSINet Inc. (www.psi.net), for example, purchased IP service switches from Ennovate Networks Inc., (www.ennovatenetworks.com); and Qwest Communications International Inc. (www.qwest.com) purchased IP service switches from both CoSine Communications Inc. (www.cosinecom.com) and Nortel Shasta. Because the @Link-Nortel deal includes Shasta IP service switches, as well as ATM-based DSLAMs, packet-level processing also is reaching down into local DSL networks.

AccessLan hopes to accelerate that trend with its i-SLAM, which will integrate IP aggregation, packet prioritization, VPN management and other packet-level advanced IP service functions.

Whether a service provider targets private data, Internet access, entertainment content or quality telephony, it seems that DSL is singing a more inviting siren song with more than one hook. Service providers may find that any door in is a good door.

Source: Jetstream Communications Inc. (www.jetstream.com)