Part 2 of Unified Access Article from Phone + Magazine:
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To enable multiple voice and data services over T1 lines, Cisco is providing in its enterprise routers compression of voice over IP (VoIP) from 64kbps signals into 8kbps. That scheme can squeeze 24 voice lines and 512kb of data into a T1 with room to spare for additional applications, says Cisco's multiservice access marketing director Byron Henderson.
Complementary to, but not dependent on, Cisco's all-IP vision, CAC, Premisys and VINA incorporate both data and voice interfaces in their slim CPE access devices, along with IP, frame and ATM outputs to the WAN.
VINA's Business Office Exchange (BOX) T1 CPE box, for example, integrates voice (including Class 5 CO dialing intelligence), frame relay and virtual private network (VPN) encryption, tunneling and authorization access interfaces for secure remote access over the Internet.
"We're seeing [SBC Communi-cations Inc.'s] Pacific Bell going into a market trial," says VINA marketing director Tom Barsi. "This kind of integrated access is critical to incumbents defensively, because it reduces churn to less than 2 percent, and it also answers the incumbents' copper shortage."
The current problem, most agree, lies with the fact that the typical business must deploy one set of lines and equipment for voice access, seperate lines and equipment for private data, and yet other seperate lines and equipment for Internet access.
That logic also applies to CLECs such as Intermedia Communications Inc., Tampa, Fla., which is using VINA and CAC integrated access devices to deliver its "Single T" integrated T1 services. "Essentially, we're moving the shared part of the [wide area] network out to the customer premises," says Bob Rouse, executive vice president of engineering for Intermedia. "That way, the protocol adaptation and routing decisions occur at the CPE, optimizing the customer's network as well as our own."
Unlike Cisco, Premisys and a raft of other vendors including Accelerated Networks Inc., Moorpark, Calif., expect that, while non-real-time applications may be integrated over IP, real-time applications such as voice--which require guarantees of network delay and on-time performance--will require ATM switching, with its ability to provision controlled bandwidth VCs for any service.
"We see frame, voice and IP collapsing into service provider ATM networks, because there's no other technology that manages quality for multiple services and protocol types," says Premisys' Drake.
Counting itself the fourth-largest frame relay provider in the United States, Intermedia expects to cover all those access options, leveraging both frame and ATM in its backbone networks to accommodate "voice over X," including VoIP, over frame relay or over ATM, Rouse says. In up to 90 cities, as early as next year, Intermedia plans to introduce VoIP, which can be delivered from customer to Intermedia facilities via the Single T service, Rouse notes. "We can go to a 300-node frame relay customer and offer IP voice over our networks with off-net calls passing through gateways to the PSTN."
While ATM figures as a multiservice foundation for the backbone segments of carrier networks like Intermedia's, even IP-centric Cisco isn't discounting the extension of ATM all the way to the customer demarcation, at least for customers demanding greater than T1 capacity. Its year-old partnership with ADC utilizes inverse multiplexing over ATM (IMA) to bond together multiple T1 lines. IMA allows service providers to offer not only 1.5mbps T1 and 45mbps T3 services, but also 3mbps, 6mbps, 12mbps and 24mbps access options in between.
IMA hides ATM management complexities from customers, allowing them to retain their investments in voice PBXs, IP routers and frame relay equipment and know-how. At the same time, IMA's underlying ATM VC technology enables the provisioning--via software command--of on-demand "virtual" connections between a customer and multiple voice, Internet and private data WAN networks over a single pipe.
Consequently, IMA could answer pent-up demand for access greater than T1. Then, for many customers, greater access bandwidth more easily can accommodate multiple traffic types per connection.
Leading access and CO systems makers, including Sentient and Lucent Technologies Inc., Murray Hill, N.J., are leading efforts to demonstrate interoperability among their IMA products, giving ATM new life as a multiservice access network solution.
Virtualized Access Links
For those carriers who won't wait for a shakeout among multiservice technologies, some key technological trends promise to mitigate the risks of deploying new products quickly.
Specifically, virtually all flavors of the new multiservice access products claim to be built on distributed and modular computing models that yield low-cost, low-risk, pay-as-you-grow capital investment requirements, compared with the costs of current access infrastructure.
Many vendors describe this distributed model as the "unbundling" of large, multimillion-dollar mainframe-computer-like CO switches, service aggregation and multiplexing devices into modularized components. Those components can be distributed far and wide in carrier and customer networks in the form of distributed boxes that are priced individually in the thousands of dollars, and which together can operate as a single, centrally managed device.
In addition to enabling pay-as-you-grow deployments, the distributed-component approach allows vendors to combine different technologies into single "any-service-on-any-port" boxes that can, for example, allow a service provider to provision IP, frame relay, ATM or voice on any given port through a software command, without the need to move actual physical wires from one port to another.
This migration from equipment that requires physical network reconfiguration to any-service-on-any-port equipment translates to the ability to "virtualize" the links between the customer and the various destinations of the customer's traffic, whether those destinations be the PSTN, public Internet or private frame relay, ATM or IP networks.
"TDM is very rigid, requiring that you touch wires and ports and devices to turn up a new service," says Kevin Walsh, marketing vice president for Accelerated Networks. "You need something that virtualizes the network so you can plug into any service provider at the software level."
In other words, Walsh adds, "You should be able to instruct the network to dynamically connect to the service provider you want. The local carrier's role should be to provide a virtual connection from the customer to the services provider--to turn off a connection to one provider and create a new connection to another with a simple command."
For the service provider, this can alter the current environment in which 70 percent of provisioning costs are attributable to people "manually reconfiguring networks or rolling out in trucks to touch wires," he says. In theory, at least, such software-based service provisioning would create a more rapid, less labor-intensive process for turning up a new WAN access link at lower cost--a clear competitive advantage for any service provider.
To virtualize access links, Accelerated Networks plans to deliver both an IAD for the customer premises and a multiservice access platform (MSAP) for the CO. Fundamentally, the MSAP grooms and concentrates traffic, then uses gateways among unlike networks to virtualize multiservice connections.
Focused on unifying CO multiservice gear, two other startups, Vienna, Va.-based Advanced Switching Communications Inc. (ASC) and Westford, Mass.-based Castle Networks Inc., say their equipment can take in frame relay, ATM, IP and circuit voice traffic, then either statistically multiplex each traffic flow directly to WAN destinations via IP tunnels or ATM VCs.
On the customer side, ASC's RBOX supports inverse multiplexing over ATM (via IMA) or over frame relay (via multilink point-to-point protocol), as well as outputs to IP or TDM voice networks.
Both ASC and Castle claim radical cost reduction, as well as intelligent multiservice interworking. They offer their modularized CO gear as a low-cost alternative to deploying full-blown $3 million switches, a particular need for competitive carriers seeking open remote COs in smaller markets with unproven demand. Castle claims it can deliver more than 25 times as many multiservice ports per $10,000 to $20,000 rack. ASC claims it can cut $50,000 T1 "common equipment" costs to $10,000 to $15,000.
"The economics of establishing a service provider footprint in a 31st or 100th largest city require the unbundling of the central office switch or multiplexer, just as the 1980s mainframe computer has been unbundled into distributed servers and clients," says ASC chief operating officer and co-founder Ron Westernik. "Then you can grow the system elegantly as demand grows."
At bottom, such "componentized" technologies could prove critical in making the migration to integrated access equipment affordable.
"There's a need for a media-aware front-end to core networks in the wide area, to take all the traffic at the edge and put it into packets or cells," says Randy Brumfield, product marketing director for TransMedia Communications Inc., San Jose, Calif., another startup focused on providing integrated, multiservice, multinetwork gateways to service providers. "The opportunity here is to provide a media adapter that can deliver any media across any network at any speed."
In need of such equipment, national DSL services carrier NorthPoint Communications Inc., San Francisco, currently guarantees zero packet loss over its networks, "an ideal environment for multimedia," says chief technical officer Bill Euske. However, until customer equipment with both voice and data ports appears, the service remains data only. By the first quarter of 1999, NorthPoint and its local CLEC partners expect to begin beta trials of such DSL-compatible, multiservice equipment for the small to mid-size business customer sites targeted by the service. "Then in the local central office or regional node, we need corresponding multiservice gateways with a convincing path to scale to hundreds and thousands of ports," Euske says. "I'm only interested in products that support a modular, distributed model that can start small and scale to very high density for the gateway function."
Whatever the technological methods, it appears that economics and market demand are pushing service providers to collapse multiple access lines into single lines from customer to CO.
For those carriers who do this, the potential advantages over competitors include the ability to automate the linking of those lines to every kind of public and private WAN and the ability to instantly provision new voice, private data or Internet access service with no more than a software command.
According to Accelerated's Walsh, "The single-service provider, whether that's Internet access, dial tone or private networking, is a nonstarter."
Peter Lambert is features editor for PHONE+ Magazine. |
