Proliferation of Access Modes Demands Integration at the Edge

Amid the explosion in access network options aimed at overcoming the legendary "last-mile" bottleneck a new point of concern has surfaced for local Service Providers. The problem arises, as customers demand a wide variety of high-speed data services - including G.Lite, ADSL, IDSL, HDSL2 and SDSL - in addition to traditional services such as POTS, ISDN, Special Services, T1 and E1 circuits. To meet this demand efficiently, service providers must find an access vehicle that combines narrowband service functionality with multi-service broadband support. Platforms, which deliver only a portion of the aforementioned service set and mandate multiple platform deployment, will not provide the necessary capital and operational model for profitable service delivery.

Making matters worse, the deployment environments for these access platforms varies widely within a service provider network - from the central office switch, to a collocation cage within a central office, to an outside plant site, to a customer premise - requiring a variety of interfaces and high degree of scalability. Nothing better illustrates the challenge service providers face than their efforts to achieve Digital Subscriber Line (DSL) coverage, which, today, typically can be used to reach only 50-60 percent of their customers. SBC Communications, for example, which has been contracted to supply DSL access to America Online, plans to have 539 central offices and 9.8 million lines equipped for DSL by year's end. "SBC won't be in a position to offer anything approaching ubiquitous coverage until it finds ways to serve customers connected to the Central Office via Digital Loop Carriers and to fill in other gaps where lines are too long or too noisy to carry the high-speed DSL signal," says SBC spokesman Michael Coe.

Customer Response Strong

Further complicating things within the DSL category, service providers specializing in supplying DSL facilities to ISPs and other carriers are preparing to add new flavors as they move beyond their existing base in the business market to accommodate residential demand as well. "Customer response has been incredibly strong," says John Stormer, vice president of marketing at NorthPoint Communications, a national provider of high-speed, local data network services, which is now operating in over a dozen major urban markets. "We're at the point of inflection that should allow us to expand our market base very rapidly."

"We anticipate 95 percent of the customers will be former dial-up users as we move into the mainstream," Stormer says, noting that, with facilities reaching 80 to 90 percent of the small business market in the 13 cities it now serves, NorthPoint can easily reach 20 percent of the residential market as well.

How is the industry going to cope with the "edge bottleneck" that all these and many other access strategies threaten to exacerbate to the point of crisis? Steve Edwards, vice president, Data Access Networks for Nortel Networks, points to a recent move by Bell Atlantic as a bellwether to how the industry might proceed in the search for solutions.

Bell Atlantic, seeking to make itself more effective in meeting the multiple access requirements of customers served by Digital Loop Carriers (DLC), recently became the first carrier to choose Nortel Networks' next-generation solution for the "edge bottleneck," the Universal Edge 9000. "Bell Atlantic signed a $600-million contract for the first release of the Universal Edge; this allows them to transfer to a Unified Network and gain efficient delivery of traditional DLC narrowband services as well as broadband data via various DSL Service modules," according to Edwards.

Last Mile/First Mile

The convergence of disparate networks will create greater value for service providers by delivering integrated network solutions spanning data and telephony while integrating both carrier and enterprise networks into an easy-to-manage, end-to-end network solution. "Delivering a next generation, IP-optimized, packet-based solution for voice, data, and video traffic is what Nortel Networks' Unified Network is all about and it starts with the "last mile/first mile" of the network," Edwards says. "As bandwidth intelligence moves to the edge, meeting the growing demand of applications, access platforms must evolve from narrow band TDM focus networks into a packetized broadband network delivering these new enhanced services.

Edwards calls the Universal Edge 9000 the showcase of Nortel Networks' next generation access solutions. "The key for the future is service versatility combined with platform flexibility, giving service providers the ability to meet any end-users' need while eliminating the potential for stranding a substantial capital investment," Edwards says. "The Universal Edge supports DSLAM, Broadband DLC, DMS, and Voice over Packet evolution combined with a wide variety of xDSL applications."

Delivering high bandwidth across the entire network, "megabits for the masses", as Nortel Networks calls it, is a major driver in today's access market. In the residential market space, providers require easily deployable data solutions that leverage the existing copper plant and allow for affordable pricing. Solutions like Nortel Networks' 1 Meg-Modem and industry standard G.Lite is targeted at this residential space. By integrating voice and data functionality to deliver high speed access as well as voice service, Nortel Networks minimizes capital and operational expenditures required by service providers. Designed to minimize the need for filters at phone extensions and allow plug and play modem installation, Nortel Networks has delivered the first truly consumer-installable service with their 1-Meg Modem.

As the leader in splitterless and filterless DSL deployments worldwide, Nortel Networks will leverage the experience they gained in the design and deployment of their 1-Meg Modem to enhance the delivery of G.Lite technology, providing the same consumer advantages delivered today by the 1-Meg Modem.

New access platforms must also provide additional features that facilitate application delivery across these high bandwidth pipes. Support for features such as Quality of Service provide additional means of revenue generation through enhanced services, such as Voice over DSL, coupled with Virtual Private Networks (VPN) and managed router services, allowing service providers to differentiate their offerings. To address this emerging market Nortel Networks most recently acquired Shasta Networks, Inc, which has developed a new class of service-enabling gateways and subscriber policy management systems for use at the edge of public IP networks.

"The Shasta Subscriber Service System (SSS) allows Service Providers to offer a wide range of hosted applications, such as e-commerce, sales automation, virtual private networks and managed security, for small-and medium-sized businesses and specialized communities of interest," according to Edwards. In combination with Nortel Networks' broadband access systems, the Shasta technology permits service providers to aggregate thousands of subscribers, centrally provisioning highly customized IP services at affordable costs. "Before this, Service Providers could only sell managed router services from the edge, neutralizing cost advantages over enterprise solutions; now they will be sold from a focused, centralized position- with costs shared across a larger user base," Edwards notes.

Migrating To A Pure Packet Network

The evolution of access beyond 2000 will be dependent on the progression of voice traffic carried over the first mile. At present, voice is TDM based, with data predominantly carried as an overlay or hybrid solution. In the future, voice will exclusively become an IP service carried on the high-speed packetized access networks. Businesses making purchase decisions today are challenged with migrating their current network to a pure packet network, while retaining existing investments.

"Nortel Networks recognizes this need, and designed the Universal Edge 9000 portfolio to provide the access gateway of tomorrow, utilizing Voice over DSL via our ATM/IP packet-based Succession solution." says Edwards. "Our SUCCESSION Network is the first global next-generation solution that meets the explosive growth requirements for data and multimedia-based services immediately, while opening the door to tomorrow's IP-based services.