The IP-telecommunications sector's push to develop
more scaleable and feature-rich approaches to the business is driving the development of
new integrated switching and gateway devices that could prove highly useful to the cable
Voice-over-IP (Internet protocol) service has been built on
the use of stand-alone gateway servers interacting with call-control centers, known as
gatekeepers, to allow bypass-voice-data networks to interface with public switched-circuit
But many entities are looking for more scaleable approaches
to network architectures that more tightly integrate various functionalities to meet
specific service and legacy infrastructure requirements.
Using the H.323 gatekeeper/gateway architecture in
isolation from other networking components to develop IP telecommunications as a
mainstream business "feels like a boiling-the-ocean kind of thing," said Alex
Mendez, vice president and general manager of Cisco Systems Inc.
"We have to figure out how to make it scale,"
Mendez added. "We have to build gateway functionalities and applications into the
network. Gateways alone aren't going to get the job done."
This is the view that cable has had since the inception of
its PacketCable agenda more than one year ago, noted Steve Craddock, vice president for
new-media development at Comcast Corp. "We need quality of service on the fly, and
H.323 was never designed to do that," he added.
"We're looking for [infrastructure] products that
will allow us to move quickly to commercial deployment, which means that we recognize that
we'll be making changes in components as we go along over time," Craddock said.
"We can't wait for the perfect product, or for standards to define the perfect
product, because the perfect product will never come along."
But Craddock -- who heads the PacketCable business
committee -- and his colleagues within the Cable Television Laboratories Inc.-spearheaded
effort can take comfort in the fact that much of the vendor community is swimming in
cable's direction when it comes to building IP-voice-enabled components that are
customized to specific network and service niche requirements.
Entering the product pipeline in the months ahead are a
wide range of hybrid solutions that defy traditional categorization, including: router
switches with gateways built in; pure IP-voice switches with built-in IP-based
intelligence, dispensing with gateways altogether; core and edge ATM
(asynchronous-transfer-mode) switches with integrated gateways; traditional Class 5
switches with gateway capabilities; and an endless array of hybrid end-user premises
"We're doing a lot of work to build signaling
plans that span market segments from private networks, to next-generation green-field
carrier networks, to large-scale local-access types of public networks," said
Alistair Woodman, product-line manager for packet-voice technologies at Cisco.
"There are many different strategies with customer
needs for voice end-points in multiple locations, often driven by the regulatory and
interconnection requirements of their individual market positions," he added.
Where integration of gateways and routers is concerned, for
example, Cisco, having already added IP-voice-gateway functionality to its 3600 and 2600
premises routers, can be expected to incorporate such functionality into larger-scale edge
devices, as well, Woodman said.
"It's the middle range between the small end-user
devices and the big core switches, at the edge of the wide area, where it seems to make
the most sense to integrate gateways into IP- and ATM-type devices," Woodman added.
What the operating community on all sides must focus on,
given the rising tide of integrated devices entering the market, is how to position
intelligence in the network, noted Joe Rinde, director of Internet architecture at MCI
"The IP central office is not the IP switches, or
routers, or IP-PSTN [public switched telephone network] gateways -- those are the
plumbing," he said. "The heart of the network -- the servers that provide
end-users with the functionality that adds value to the service -- may be geographically
separate from the [central office], and they might even belong to a third party."
In the broadband-access domain, one assumes that broadband
customers are connected via IP devices, as will be the case in cable's implementation
of IP telephony, noted Kent Elliott, president and CEO of Vienna Systems Corp., a supplier
of voice-over-IP hardware and software products that has been working with the PacketCable
Consequently, he said, providing features and the
integrated switch/router/servers that support such provisioning is as likely to occur at
the edge as it is at the core, if not more so.
"IP-voice switching is more than just routing;
it's call processing, call control and end-user device control, which doesn't
happen in a tunneling marketplace," Elliott said.
The reference to tunneling was a dig at network designs
based on straight router-to-router linkage, where intelligence is colocated or integrated
with the router.
While Vienna supports equipment in this vein, as well as
IP-voice integration directly into central-office switches, its primary thrust is in the
direction of distributed, intelligent IP-voice and multimedia switching.
"We're going to license intelligent technology to
end-points of other vendors," Elliott said. "I'll build call-processing
servers, but by licensing to other vendors, I'll be adding to the number of
end-points that interface with applications built on our platform."
Acting on this strategy, Vienna has teamed up with Advanced
Computer Communications, a supplier of multiservice remote-access concentrators, to
develop scaleable IP gateways that can be inserted as adjunct processor cards into
central-office switches or built directly into IP router/switches.
"The role for IP telephony is increasingly going to be
as a facilitator of communications in data applications of every possible type," he
noted. "It's not about duplicating voice service as we know it today."
This is where the call for hybrid devices is strongest,
said Ed Grainger, IP-network-service partner manager at Sun Microsystems Inc., which has
recently begun working with unnamed router vendors, as well as traditional switch
suppliers, to facilitate IP switch/gateway integration.
In one of its first steps in this direction, Sun has allied
with Natural MicroSystems Inc. (NMS) in a collaboration on IP-telephony OEM
(original-equipment manufacturer) solutions that bring together NMS' DSP-based
(digital signal processor) IP-telephony processing platform with Sun's
"UltraSPARC" UNIX and Solaris operating-system server environment.
The move puts NMS in a position to offer UNIX, as well as
the Windows NT server-based solutions that have long been part of the firm's
"This type of integration is what is required not only
to deliver differentiated services to customers, but to give customers the power to
self-administer their networks," Grainger said.
In the case of integrated IP-router switches and gateways,
Sun is "talking to clients that are looking at a level of convergence where
identifying where the router ends and the gateway begins to get pretty muddy," noted
Jeff Veis, group manager for telco-OEM products at Sun. "With IP, you can tie all of
those functionalities together."