The Internet telephony industry is being bombarded with new entrants and new products
on a daily basis. Telcos are merging with ISPs, hardware vendors are striking deals with
service providers, and computer-telephony integration (CTI) developers are rapidly
designing new Internet telephony products so they are not left behind. PBX vendors are exploring ways to integrate Internet telephony directly to the switch,
thus eliminating external gateways. Last, but certainly not least, most every networking
company has announced Internet telephony products and mapped out a voice and data
integration strategy revolving around Internet Protocol (IP) telephony for the future.
Never before in the history of computer technology have so
many disparate industry vendors converged and aligned their strategic directions in the
exact same direction so quickly. Telcos, ISPs, PBX vendors, WAN vendors, CTI vendors,
resellers, distributors, developers, and entrepreneurs are all scrambling to get a piece
of a market that promises tremendous returns on investment.
Anyone who is interested in getting involved in this market must have an understanding
of the tremendous variety of available products designed to facilitate Internet telephony.
The proliferation of choices available to Internet telephony implementers can act as
more of a hindrance than a facilitator if it is not clear for which application each
disparate product is best suited. I will investigate some of the different ways in which
you can implement Internet telephony hardware and the strengths and weaknesses of each
approach. It's really fascinating to see how many different alternatives exist, enabling
anyone to use IP to transmit voice, fax, and video traffic. For those of you who did not
read the Publisher's Outlook in the premiere issue of INTERNET TELEPHONY, please take a moment to read the sidebar entitled A Brief History Of Internet Telephony before continuing further.
PC-BASED GATEWAYS: OLD FAITHFUL
There are three different hardware solutions available for implementing multichannel
Internet telephony. The oldest and most established solution is the PC-based gateway. In
this example, a PC is configured with Digital Signal Processing (DSP) resource boards,
which can be obtained from companies such as Dialogic, Natural Microsystems, Brooktrout,
Linkon, Analogic, Voxware, Xantel, and Commetrex. (As both Dialogic and Linkon sell
products on Solaris platforms as well, let's use the term PC-based gateway to include
Solaris gateways as well.) See the box entitled Contact
Information to obtain more information from these
vendors. With this many vendors pushing developers to use their products, we might actually see
over 100 Internet telephony gateway vendors offering solutions based on PCs in the not too
distant future. Venture capitalists are practically throwing money at these companies
without batting an eyelash. The various gateway companies I speak with tell me that their
business plan enables them to be successful if they receive but a fraction of one percent
of the total market share of Internet telephony products sold. I expect this market to
expand for some time to come.
THE ROUTER AS THE CHALLENGER
The second hardware solution for Internet telephony users is that of a router with an
onboard voice module. As router vendors saw an incredible proliferation of equipment on the network used to
facilitate the conversion of voice to IP packets that ultimately were transported by their
routers, they saw a huge opportunity. This opportunity, of course, was to eliminate the
need for standalone gateways altogether and have voice converted to IP packets in the
router itself. Cisco made a huge splash last year with voice modules integrated into their
3600 series routers.
THIS IS DEFINITELY NOT YOUR FATHER'S PBX
The third hardware solution is that of the IP module added on to the PBX.
Just as the router vendors see a tremendous opportunity behind their products, the PBX
vendors see a tremendous opportunity ahead of their switches. Lucent is the first major PBX company I am aware of that has committed itself to
developing a product, which will allow native IP telephony trunk support in the PBX.
It's almost as if these developments have happened overnight. It is almost not
plausible that these dissimilar companies would be considered competitors.
I believe that the commitment made to this market by every vendor in the above market
spaces underscores the fact that Internet telephony will eventually become the de facto
standard for all telephony. Of course, this prediction will not be borne out overnight. I
imagine it will take place over the next few decades. Never before have so many vendors
decided at the same time that a tremendous paradigm shift must take place in
telecommunications. The word revolution is horribly overused, but if ever there was a context within which
I feel comfortable using it, it certainly fits as far as Internet telephony
Now that we are all comfortable with the variety of hardware products that can make
Internet telephony possible, we must decide the pros and cons of each method.
Since the PC-based Internet telephony gateway started things off, it is a great
starting point for us as well. (My thanks to Jack Chase of Natural MicroSystems for
assisting me with this section of the Outlook.) Most initial IP telephony gateways have
been deployed because gateway components have been available for some time. There is an
abundance of vendors with PC-based gateway solutions. These PC-based servers have the advantage of being based on an open platform with
readily available telephony interfaces such as T1 and E1, as well as various analog and
BRI interfaces. These interfaces have been available for years and are bulletproof.
Furthermore, a variety of vendors compete to supply these interfaces, so there is a
built-in safeguard against overpricing.
Secondly, the PBX or switch integration issues have already been worked out with a
PC-based gateway solution. There are dozens of PBXs on the market and voice board vendors have already developed
tools that allow developers to synchronize their gateway with whichever switch they like.
This integration applies not only to customer premise equipment (CPE) but SS7 and the
Advanced Intelligent Network (AIN) interfaces also readily available for PC-based
The open architecture of a PC-based gateway means that value added services can be
easily added to the gateway. Industry standard TDM buses such as SCbus, MVIP, and H.100 allow users to plug in many
board types to allow extra services like speech recognition, text to speech, protocol
coprocessors, fax boards, and the like. Some multi-function boards can allow you to take
advantage of IVR, fax, and Internet telephony on the same board drastically
reducing the cost of the gateway.
There is also the issue of scalability. Servers can be easily scaled from a few to hundreds of ports. Routers, which were
initially limited to a handful of ports, have received T1 interfaces bringing the port
number to 24. Server board density for computer telephony should reach 120 ports per board
in the next few months and 240 ports within a year. Expect voice port densities to
increase rapidly for PC servers and routers alike.
A single Internet telephony board that can be acquired from companies such as Nortel
(through their Micom division) can plug into a 386 or better machine and have you up in
running for under $2,000 (not including the PC). So, the entry cost to using a PC-based gateway is low.
Internet telephony board vendors supply their products with rich APIs that allow
developers to truly make user-friendly applications. In turn, it may be possible for
resellers and even end users to customize PC-based gateways with little programming
experience. This opens up a world of flexibility for companies such as Internet telephony
long-distance service providers that would like to offer enhanced services to their
customers. Once customers are connected to a gateway, they can have their account balance
read to them through a text-to-speech interface.They can also take advantage of dial-by-name functions and any other enhanced service
that the service provider may provide.
In many cases, when using an Internet telephony gateway, some type of billing needs to
take place. A corporate solution may bill each department. A service provider may need to keep track of various account numbers, which are
accessed through calling cards. The complex billing process is best suited to a PC; having
the gateway on the same PC simplifies the processing of tracking call times, and other
details about the calls.
Traditional CTI application generator vendors have hinted to me that they will soon
enter the Internet telephony space.It may soon be possible to use these products to graphically develop Internet telephony
Another strong argument for PC-based Internet telephony gateway deployment will be the
ease in development time that these products will see when Microsoft releases TAPI 3.0
later this year. Microsoft's Telephony Application Programming Interface (TAPI) 3.0 is a
set of telephony APIs conforming to the COM model and integrating seamlessly between
regular telephony and Internet telephony. TAPI 3.0 applications can be written in any
language, such as Java, C/C++, and the Microsoft Visual Basic programming system. COM is a
component technology that provides a common object model for both local and network
software integration and delivers a single, widely implemented standard allowing
applications from multiple vendors to integrate seamlessly over the Internet and corporate
The only drawback to using a PC-based gateway is the PC itself. PCs have not yet
reached the reliability level of the central office (CO) or even a PBX. Similar to a PBX,
a router has a closed architecture and an absence of moving parts. It is safe to say that
a router is definitely more reliable than a PC at the moment. Since Internet telephony
traffic will ultimately pass through the router anyway, the addition of a PC-based gateway
preceding the router adds an additional failure point in the network.
If you are routing mission-critical Internet telephony traffic through a PC that is not
from an industrial computer manufacturer, you should have your telecommunications license
revoked.Many industrial computer vendors specialize in telephony. It is imperative that you do
not use a clone vendor or even a name-brand vendor. Issues of redundancy are usually not
addressed by mainstream PC vendors, since it is tolerable to have your desktop PC fail
from time to time. It is simply not permissible for your Internet telephony gateway to
crash at all.
Additionally, CompactPCI boards are now becoming available for computer telephony
applications. This rugged industrial computer backplane, coupled with future hot swap
capability, should allow these industrial computers to become as robust as the central
office equipment used by Internet Service Providers (ISPs) as well as the telco's own CO.
We will soon receive all the reliability of an embedded system with the flexibility of a
THE ROUTER-BASED APPROACH
The IP telephony enabled router has some interesting pros and cons of its own. The
router offers an embedded solution with bulletproof operation.Little, if any, maintenance (such as disk defragmentation and virus checking) is
required. These systems are relatively easy to configure and get running as well.
Router vendors bring along with them a vast sales force and name recognition.
PC-based gateway vendors may have a head start, but networking vendors are huge PR and
marketing machines and they may end up dominating the scene if and when they decide to do
an all-out media blitz. An important point to note is that the networking vendors will
further legitimize Internet telephony as they promote their products. This, in turn, helps
expand the whole market to the benefit of everyone.
If networking vendors feel that they need external resellers to help them dis tribute
more products to their customers, they have a tremendous head start over PC-based gateway
vendors that have little experience in this area. A few exceptions to this would be the PC gateway vendors Inter-Tel, Siemens, and
The proprietary nature of router configuration languages means that you need a
networking manager who is familiar with the type of router language you are using. Each
router has its own language that must be understood in order to change router
configurations. Cisco uses a fairly simple language called IOS, which uses an interface consisting of a
command followed by a parameter or number of parameters. An example of this would be: say you were interested in setting the bandwidth value for
an interface, you would simply specify "band-width x," where x is the value in
kilobits per second .Communication with the router takes place through a serial port using a dumb terminal
interface, a GUI, or more recently, a Web interface.
THE FUTURE -THE PBX-BASED APPROACH
PBX vendors are in the most competitive environment they have ever seen. With the
potential to lose business to PC PBX vendors as well as router vendors, they are
scrambling to stay on the leading edge. There has been a tremendous amount of
announcements made recently by PBX vendors who know that the market is changing, so it's
safe to say they are taking the competitive threats very seriously.
Lucent Technologies already has a strong presence in the PC-based Internet telephony
market. They have recently announced that they will provide IP telephony trunk interfaces
directly to their Definity Enterprise Communications Server as well.
By introducing IP telephony trunk interfaces directly to the switch/server, the need
for an independent gateway is eliminated. Some of the most useful features of a PBX are
least cost routing and class of service differentiation.
These various features can now be used for calls made over packet networks as well. The
PBX can be configured to route calls through the Internet when traffic is usually light
and can conversely route calls through an intranet when traffic on the Internet is usually
The variety of call accounting products on the market should now be able to keep track
of your Internet telephony calls as if they were traveling over the PSTN. So, the
advantage here is rock-solid PBX reliability and minimal training (assuming you have a
switch that supports Internet telephony trunks).
A recent conversation in my office revolved around the fact that someone suggested that
PBX vendors might yet get the last laugh over networking vendors by connecting router
boards directly to the PBX. This is feasible and actually pretty logical. The PBX already
has a well-deserved reputation for reliability, and the vendors already have an
established distribution channel. The only missing link is training the thousands of PBX resellers (Interconnects) to
understand data networking. Many interconnects are currently busy learning the networking market or are merging
with network VARs so that they are positioned correctly to sell Internet telephony and CTI
products. In fact, we are seeing the emergence of more and more of these hybrid (data +
telephony) resellers with each passing day.
As with most things in life, no two Internet telephony hardware buyers are alike. It is
for this reason that the proliferation of new ways to harness IP telephony should emerge
quickly. As a service provider, the PC-based gateway makes a great deal of sense, since the
ability to enhance the core functionality of the gateway by adding IVR capability to allow
debit accounts, etc., is crucial. Billing systems can also be implemented easily on a
The corporate or remote office hardware solution gets a bit more involved. Do you have
competent networking people that you can rely on? If so, the router is a great way to go
for a couple of lines. Conversely, if your telecom reseller or department is well versed
in new technology, it may be wiser to side with the PBX approach. Is scalability an issue?
Will you need other services such as fax? Gateways look pretty attractive in these cases.
When applied to corporate long-distance bills, Internet telephony hardware has the
potential to pay for itself in well under a year depending on call volume and traffic
patterns. As a service provider or reseller, the financial opportunities are immense:
There are just so many ways to get involved in Internet telephony. There are unlimited
opportunities worldwide for this technology. When trying to choose between the three different types of hardware platforms discussed
here, the question to ask is not which to choose, as much as why didn't I implement or
resell Internet telephony products sooner.