The cable industry is facing a leap into the unknown in its
efforts to choose an intelligent-networking foundation for its emerging packet-telephony
Soaring demand for IN capabilities that will allow
providers of packet-voice services to match circuit-switched providers in delivering
feature-rich services is driving a legion of vendors to develop Internet protocol-based
solutions. Still, it's very early in the development curve to be making choices.
IN is the name given to a hierarchy of software that runs
on digital switches that support such services as 800- and 900-series numbers; call
waiting and forwarding and caller ID; and the underlying signaling system (SS7) that
performs everything from the initial call setup to delivery of many of the features from
the switch to the end-user.
The cable industry wants to set the parameters on its IN
approach as early as possible in the platform-development effort, but it can't move
too far ahead of the curve without risking making choices that are dead ends.
Not only are there no standards defining the interfaces
between the IN and IP domains, but very few of the emerging options are far enough along
in development to be tested by operators and other carriers seeking to define their
"The cable industry wants and needs the capabilities
that IN brings into the IP-voice environment, just like everyone else," said Scott
Wharton, senior marketing manager for service providers at VocalTec Communications Ltd.
VocalTec is a supplier that has been working closely with
the Packet Cable initiative at Cable Television Laboratories Inc.
"Operators are willing to do field trials without
final solutions in this area, but they won't deploy services commercially until they
have the IN component," Wharton said.
"The trick is to define what we want in terms of
functionality so that vendors know what to shoot for, but to wait on choices until we have
a better sense of where the standards are going," said a source close to the Packet
Cable group, which met with vendors in Denver last week.
"The potential 'gotcha' in that is that the
wrangling over standards could drag out longer then we're prepared to wait," the
Fortunately, the most crucial standards issue to resolve
isn't so much what IN-over-IP will look like in the all-IP domain, but what the
interface will be that allows IN functions to ride on top of IP. Several standards bodies
are looking at this issue, with myriad solutions to choose from, Wharton noted.
"SS7 exists as a standard today, which gives us a good
base to work from in addressing immediate needs," he added, noting that VocalTec has
tapped PSTN (public switched telephone network) supplier ECI Telecom Ltd. of Israel to
provide the expertise that it needs to begin adding SS7 features to its gatekeeper-server
"This is why the key standards issue to resolve right
now is the one that we and many other entities are working on with regard to the interface
between the gatekeeper and IN," Wharton said.
The gatekeeper is the control point within the
Internet-telephony model supported by the H.323 standard, version two of which is just
It must not only talk to IN in the legacy PSTN, so that
those features are provided over the circuit-connected side of a phone call; the
gatekeeper must also support an IN-over-IP capability that runs independent of the PSTN,
so that cable and other new entrants don't have to rely on access to incumbent
carrier's switches to make use of IN within the IP "cloud."
"Early on, you won't see people enabling access
to their switches for unfriendly applets," said Paul Tempest-Mitchell, manager of
systems engineering for Sun Microsystems Inc., in a reference to Sun's Java software
components that might be used to tap legacy IN resources.
Sun's solution is to offer a new IP-over-IN
development tool -- Java Advanced IN (JAIN) -- to use in equipping
IP-telecommunications-gateway servers and gatekeepers with software overlays that can
populate a carrier's IP domain with IN capabilities.
"What we came to realize, and what our customers
realize, is that because their services are IP-based, we could migrate away from the
switch-based SCP [service-control-point] model and run the service on Web devices, whether
it's the Web server, a PBX [private branch exchange], or handsets,"
Tempest-Mitchell said. "This opens development up to virtually anyone with a PC
Sun's approach and many other IP-centric approaches
don't represent a complete departure from traditional IN, insofar as they retain the
object-based software components known as "SIBBs" (service-independent building
blocks), which are the fundamental units of feature development.
"Java is an object-based language, so JAIN makes an
excellent tool for working within the IN architecture," Tempest-Mitchell added.
But Sun's approach relies on support from a Java
developer base that is still in the formative stages when it comes to creating telephony
applications, which could be a downside early on, suggested Bob Bryson, vice president of
product marketing for I-Link Inc.
"Java-based provisioning might be part of the
long-range solution, but we need as broad a support base as possible within the developer
community," Bryson said.
I-Link is a Salt Lake City-based next-generation
IP-communications company that has built much of its networking intelligence on
technologies supplied by its wholly owned subsidiaries -- MiBridge Inc. and ViaNet
Technologies Ltd. -- which are also supplying technology to third-party vendors.
"We're getting the SS7 core code from other
vendors, but we're implementing IN using our own technology inside our
gateways," Bryson said.
I-Link -- which is now serving some 35,000 customers in 25
markets after little more than one year in operation -- anticipates growing to 250,000
customers by the end of 1999 as it adds ever more features and functionality to its
service portfolio, Bryson said.
"The industry is evolving in the direction that
we're going, but we can't wait for vendors to mature products under the
standards process," he said.
With the H.323 standard still a work in progress, I- Link
takes the view that H.323 is a "subset" of its system, Bryson said.
"We're moving beyond the classic gateway
mentality," he noted.
I-Link, unlike many start-up carriers in the IP-voice
domain, has built from the beginning on the premise that the winning hand for packet
telephony is the advantage that IP offers over the legacy IN system as a universal
The firm's current feature set -- including integrated
voice and fax service, call "find-me," conferencing, enhanced e-mail and a
variety of custom calling options -- depends on IP-based functionalities built into the
I-Link backbone, offering customers lower-cost alternatives than are typically available
from incumbent carriers via IN-equipped circuit switches, Bryson said.
Starting in the second half of next year, I-Link will
extend the network-provisioning functionality to the customer premises via what Bryson
calls "C-4" -- a customer-communications-control-center device being developed
by ViaNet for deployment in conjunction with use of high-speed access lines.
"C-4 is an extension of the network to the premises,
where we'll be able to provision anywhere from four to 16 lines, as well as Internet
access over ISDN [integrated services digital network] or ADSL [asymmetrical digital
subscriber line], depending on what [access options are] available in the market,"
The C-4 box -- with 10baseT connections to computers, as
well as links to standard phones -- puts the IP gateway in the home or office, breaking
away from the H.323 gateway model, much as cable wants to do in packetizing calls at the
Developments like these may bode well for cable's
effort to find IN solutions. But, like I-Link, cable operators might find that
they're better off moving forward with proprietary solutions than waiting for a final
standardized solution under the H.323 process.
"One of the great advantages of developing features
for IP networks is that unlike the PSTN, you don't have to spend months on a project,
implement it on your switches and then start offering it commercially before you're
able to determine whether there's a market for it," Wharton said.
VocalTec is regularly adding to the features that its
gatekeeper can manage, he added, noting that the company's system now offers support
for such enhancements as call waiting and "follow-me," where users input
call-routing instructions through their Web browsers.
While VocalTec is already implementing features that it
expects to be part of version 3 of H.323, it will take a while for issues to be worked out
before the current version 2 -- which is only now going into commercial release -- is
superseded at the standards level, Wharton said.
Consequently, VocalTec and every other vendor seeking to
respond to early carrier demand for IN solutions will be pushing the envelope with
proprietary solutions that may or may not end up being standardized.