VOIP: What, me worry? Technological limitations fast becoming a non-issue for Internet telephony [Info on HP/ASND SS7]
americasnetwork.com
By David Kopf, July 15, 1998
Voice over Internet protocol (VOIP) naysayers, you've got about a year
before you'll have to find another technology to knock. Internet telephony is
fast becoming a solution worthy of the public network; moreover, customers
seem to want it and, increasingly, so do carriers.
The VOIP market is maturing as subscribers-rom residential users to telecom
managers at large enterprises-realize the cost benefits of Internet telephony as
well as the range in applications. What's more, IP is what customers want. In a
Gartner Group Inc. (Stamford, Conn.) study on protocol distribution in wide
area networks (Figure 1), IP is skyrocketing and set to dominate other
protocols by the turn of the millennium. Consumer Internet telephony users will
give providers of residential VOIP services with $1 billion by 2002, according
to Forrester Research Inc. (Cambridge, Mass.). Also, voice and fax over the
Internet and corporate IP networks will draw 4% of standard telco revenues
away from the public switched telephone network (PSTN), and will save
business users $1 billion, Forrester says.
Where many facilities-based carriers once viewed VOIP with suspicion, they
now are studying how Internet telephony may benefit their voice business.
The big sticking point for VOIP has been the technology. Despite heavy
market interest, VOIP is still quite a new technology and until late hasn't been
ready for prime time. At its baby-steps stage, VOIP was limited to PC-to-PC
transmissions facilitated by client software but quickly grew to real service with
the advent of gateway-based VOIP. Instead of calling PCs, users now can dial
to a gateway connected to the Internet. That gateway, via an interactive voice
response (IVR) interface, prompts users to enter their billing information and
the number they want to reach. That first gateway connects across the 'Net to
the gateway closest to the dialed number, and establishes a VOIP connection
via H.323 protocol (the de facto VOIP standard). The second gateway
outdials to the recipient's number and the call is established.
Gateway-based VOIP sounds nifty but, upon closer inspection, raises many
questions: Should Internet telephony service providers (ITSPs) rely on a public,
shared, packet network like the Internet? Is a private backbone better? Will
users stand for multistage dialing? If so, for how long? What about interworking
the PSTN-especially intelligent network (IN) applications such as local
number portability (LNP)? How do services like centrex take advantage of
VOIP? The list grows longer as the technology progresses.
However, that checklist is quickly being answered as VOIP technology
accelerates at a pace matched only by service provider interest. Now the main
problem for ITSPs is quickly changing from "Where's the technology?" to
"Which approach should I take?"
SERVICE OPPORTUNITIES FOR ALL
Internet telephony is not the "carrier killer" that industry watchers initially
pegged it to be. Although the service provides an alternative to standard PSTN
voice telephony, there's no reason traditional telcos can't offer it, and they are.
Without doubt, VOIP is not limited to the simple tariff arbitrage application that
dominates most of the services offered by ITSPs. Instead of just a cheap call
from Los Angeles to Hong Kong, or New York to London, Internet telephony
represents to established carriers a whole range of services that can span a
carrier's entire business. Shawn Wiora, program manager for enhanced IP
services at GTE Corp. (Stamford, Conn.) says his company is placing "a
particular emphasis on IP telephony," especially when it comes to bundling
VOIP with GTE's current services. For GTE, VOIP would represent a
companywide effort.
Besides the obvious opportunities for VOIP at GTE's ISP arm, GTE
Internetworking (Cambridge, Mass.), GTE could find some VOIP services for
its online directory service, GTE Superpages, which is produced by GTE New
Media Services Inc. (Dallas/Fort Worth). The wireless angle for some sort of
mobile, IP-based device could find a home at GTE Wireless (Atlanta), and IP
telephony applications up in the wild blue yonder in regard to GTE Airfone
(Oakbrook, Ill.), which provides in-flight communications, Wiora says.
Obviously, GTE Long Distance, with 2 million customers, could find many
ways to offer up VOIP services to its users. "Voice over IP presents a
tremendous opportunity to these folks," Wiora says.
For GTE, bundling VOIP into other services may be the name of the game.
Wiora says the provider is studying four key bundling approaches:
Standard voice services. GTE's emphasis is in this arena, particularly in
long distance. "For GTE, we see a long-term play," he says.
Fax. Fax over IP (FOIP) does not pose the technological challenges that
real-time VOIP does, broadcasting faxes over the 'Net could be an
appealing GTE service to business users, particularly the small
office/home office (SOHO) market.
Messaging. While trying to maintain a live voice conversation over a
packet network might be touchy, store-and-forward communications
such as IP voice messaging could provide a more flexible voice mail
service for GTE. Moreover, GTE could offer bells and whistles like
unified messaging, which lets customers manage their voice, e-mail and
fax messages via a PC-based interface.
New access devices. This could appeal to GTE Wireless customers.
"You could have an IP phone that supports voice, but also e-mail,"
Wiora says. "You could respond by voice to an e-mail with a single
push of a button. You don't need a clunky keyboard."
Will all these opportunities, there are still some VOIP issues that are shaking
out and there are questions carriers need to answer in planning their VOIP
networks and services.
PSTN COMPATIBILITY
One of the biggest questions surrounding VOIP services has been interworking
and interoperability with the PSTN. Gateway-based VOIP is one things, but to
attract the numbers that would make residential Internet telephony service
possible, ITSPs need to to seamlessly with the SS7 network, and they need to
be able to work with tricky IN applications and services.
One thing that has pushed interworking between the PSTN and the Internet has
been increased data traffic on voice switches ("The post-switch, SS7 solution,"
July 1). Bellcore (Morristown, N.J.) and other vendors have developed
methods to offload dial-up Internet traffic out of the voice matrix to decongest
the PSTN using SS7 and IN capabilities; but in so doing, they also have
provided inspiration to vendors and other technology developers seeking to
route voice to the data network.
An important step in that direction was Hewlett Packard Co.'s (Palo Alto,
Calif.) June announcement that its OpenCall network platform, a mainstay
voice networking tool, would now provide SS7/ISUP as well as IP signaling
(see "Technology puzzles no more"). One of the first vendors to integrate
this capability into one of its systems was Ascend Communications Inc.
(Alameda, Calif.), which debuted its Ascend Signaling Gateway (ASG) system,
which provides a platform for not just offloading 'Net congestion from the
PSTN, but geared for provisioning straight forward VOIP services (Figure 2),
as well as providing more complex, IN-based apps such as alternate call
routing to specific networks.
"In the typical telephone network the SS7 does a bearer channel setup through
the level four, level five switches and connects a call from point A to point B,"
says Ted Butch, director of access product marketing for Ascend. With the
ASG, "The SS7 communicates with the Ascend Signaling Gateway and is able
to set up a bearer channel through the data network. So now you're able to set
up a bearer channel through the PSTN or through the data network."
At the data connection side, the ASG provides voice over data profiles so that
a VOIP transmission could be tunneled through a VPN into a private IP
backbone or other network. As Ascend boils more IN functionality into the
ASG (Q1-Q2 1999), the system will be able to offer call routing applications
that will let carriers apply service rules to route traffic to specific networks
(Figure 3).
However, PSTN interworking isn't the end-all, be-all solution to VOIP woes.
Internet telephony will most likely advance from both directions: developing
better interoperability between VOIP and the PSTN, but also moving more of
PSTN's functionality to a packet data environment, says Al Bender, vice
president and general manager of Nortel's (Brampton, Ontario) VOIP
solutions for service providers.
Nortel announced in late June its IPConnect portfolio of VOIP products, which
is geared to give service providers a carrier-class Internet telephony platform
using preexisting Nortel DMS, MMCS and CVX 1800 switches.
"The technologies we've been using have been trying to push data down the
voice network," Bender says. "Now that data has exceeded voice traffic on the
PSTN, the question is now, `How can we push voice down the data
network?'"
So, Internet telephony's deployment issues aren't limited to VOIP-SS7
interworking, but include challenges such as developing a complete set of
IP-based call services. Bender says the goal is to export to IP networks even
the lowliest of voice services, such as "This number is no longer in service"
announcements, all the way to linking LNP and other advanced IN (AIN)
functions to an IP environment.
PSTN interconnection is really a question of perspective, according to Bender.
It all depends on which side of the network you're starting on. Facilities mean a
lot to carriers that have built them, but new players may simply want the
applications that SS7 and IN/AIN provide without much care about which
protocols/technologies are really delivering them.
"The ILECs, etc. will still want to use their facilities, but ITSPs won't have a
mindset of pre-existing equipment," he says. "They don't want to buy AIN;
they want 800 services or caller ID. If you had a clean sheet of paper and
asked would we do it differently, the answer probably would be yes. As those
two collide, it will be interesting to watch."
And that's really what users want; they don't care about what technology their
voice services are based on, they just want the services, Bender says. That
requirement can scale from caller ID to 911 all the way up to centrex, he adds.
Also, VOIP needs to be as easy as standard PSTN voice services-or it
should make those services easier. Where IPConnect is concerned, it can
provide fundamental voice services, such as letting users reach 911 without
having to dial other numbers, and can provide potentially international centrex
services that extend far beyond the physical, geographic limits of PSTN-based
centrex.
QUALITY IS THE KEY
Another key component to Internet telephony success is quality. VOIP quality
has grown by leaps and bounds, especially if you consider that the ham
radio-like quality of early PC-to-PC Internet telephony marked the
technology's consumer birth only two or three years ago. But widespread,
business and residential, phone-to-phone VOIP is a different matter. The
quality has to be there.
For GTE this has meant heavy investment into research and development,
partnering with the right companies and building a backbone that can provide
PSTN/near-PSTN voice quality for Internet telephony. Quality of service
(QoS), in terms of network classes of service (like those associated with
asynchronous transfer mode) and in terms of the user's subjective experience,
has to be there for VOIP to succeed, Wiora says.
"We need to make sure that connection meets customers' expectations from
end to end," he adds.
To manage those expectations, carriers must manage their network latency,
because delays in voice conversations just won't work. A jitter here, a pause
there and users will hang up their IP phones. The whole network-from the
caller to the recipient-needs to be taken under consideration. What carriers
can't control-such as the public Internet, or a bad end-user device-will need
some over-compensation on the service provider's part.
"You need to build a budget for latency for each component in the connection,"
Wiora says. "Then work within that budget to deliver service."
Moreover, that budget has to scale. Of all the gateway-based Internet
telephony network services being offered, the idea of scaling to millions of
users may not scale to such an architecture. "Our approach is to go to market
with a network that understands what it takes to provide quality," Wiora says.
"You've got to understand how the 10 millionth customer will impact the
network."
That means management. The gateway systems that were developed were
mostly developed for the corporate market. To handle the hundreds of millions
of users that carrier-class VOIP would mean, ITSPs have to be able to
manage to that scale and ensure that they are meeting the quality levels they
offer. To do that Delta Three developed its own tools in-house, says Elie
Wurtman, president and CEO of ITSP Delta Three Inc. (New York).
That management grows more complex as ITSPs interconnect networks. The
range in VOIP network approaches (from compression to service tiers and so
on) affect Internet telephony interconnection. This again provides ITSPs with a
tough management challenge, Wurtman says.
CHANGING LANDSCAPE
As ITSPs learn to deal with scaling to meet a mushrooming market, one thing is
certain for Internet telephony; the business of providing it won't stay the same.
The current VOIP landscape as a means of international tariff arbitrage can't
last forever. While cheap long distance is attractive, VOIP will be a true
success once it reaches widescale deployment with a range of services to rival
that of the PSTN. Will that happen? "I really do believe IP telephones will be
ubiquitous," Bender says.
Ubiquity has its price, though. Widescale VOIP services means that the
regulatory climate will most likely change. While this won't be a big change for
service providers like GTE, which already deal the FCC and state public utility
commissions (PUCs) on a regular basis, smaller alternative providers, such as
ITSPs will have to dance to a new tune. Currently, in the United States, the
FCC and PUCs pretty much leave ITSPs alone.
Internet telephony providers don't pay large access fees to connect with other
networks fees like standard telcos do, and their cost to provide service is
significantly lower. (Bender estimates a call without access fees costs about one
cent to provide.) But if Internet telephony service usage grows large enough,
such growth might warrant regulatory bodies to reconsider hands-off practices.
Moreover, if ITSPs eventually must behave like regular telcos, the whole
question of access agreements must be addressed, Wiora says. To operate in
the telecom space, ITSPs will have to build out their customer care systems
and network management and operations support systems (OSS) so that they
interconnect and interoperate with other carrier-traditional telcos or
otherwise-so that they can share network information, report faults and
exchange customers in a reasonable fashion.
Does this mean that ITSPs will have to incorporate electronic bonding-the
complex and costly methodology by which the FCC and the 1996 Telecom
Act have mandated that wireline carriers exchange network and customer
information? That question, as well as the issue of access fees, will most likely
go unanswered, as regulators have yet to assess the potential market
implications of Internet telephony. Eventually, VOIP regulation will be handed
down, Bender says.
"What is uncertain is where the decision-making is taking place," Wiora says.
"Who has the final say-so."
July 15, 1998 table of contents
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