Today companies are looking to differentiate themselves
based on the services they offer -- not necessarily on
their products. In some cases, traditional products --
like the transport of calls -- are becoming a commodity
business. This fact is true for PSTN providers as well
as for newer mobile operators. We all know it is not
uncommon to pay five cents a minute for landline
transport and pay $30 a month for 3,600 minutes from a
mobile operator. Since the race to get new subscribers
seems to have peaked, service providers are looking to
create value and reduce customer churn by offering
enhanced services that keep customers loyal.
One of the services that these vendors are looking at
in order to keep minutes in their network is
conferencing. It is still a fact that a simple call that
brings key players together -- without involving travel --
is still one of the fastest, most efficient ways to make
quick, high-quality decisions. For the service provider,
if they can drive down cost and drive up usage, the
business customer is likely to use more minutes and stay
with a specific carrier. That fact, coupled with the
ubiquity of the Internet, is causing service providers
as well as their business customers to evaluate the way
they handle audio conferencing.
As VoIP becomes more common in business
communications, everyone is looking at ways in which
both the services and the service delivery mechanism are
changing. Lots of questions are being asked: Is anyone
using VoIP today? If so, is it affecting the actual
conference? Will VoIP change the way we conduct
conference calls? Will it impact the way conference
calls are established? Will it impact quality?
Who Is Using VoIP?
The appeal of free long-distance calls or inexpensive
international calls is attractive to consumers. Even
though there may be some reduction in voice quality,
consumers will accept it if the savings are large
enough. Consumers may even use primitive "push-to-talk"
sequences that they would never tolerate on a normal
call in order to save money on lengthy international
VoIP has also become common in the business
environment. The primary appeals in the business
environment is the savings associated with managing a
single network and the bandwidth provided by the IP
connection to the desktop. Savings on long-distance
charges are a secondary benefit, since costs have
already declined to a few cents per minute. Systems such
as IP/PBX and IP/Centrex will provide business-quality
audio. However, it will be years before most businesses
have an entirely VoIP infrastructure because of
depreciation schedules on existing switching equipment,
the lack of five-nines reliability within the data
network, and the overall quality of voice calls that run
on an IP network. Thus, the challenge for carriers is to
provide a platform that can seamlessly bridge
traditional PSTN calls with VoIP calls as existing
businesses slowly migrate from the PSTN to the more
economical VoIP one.
The end user isn't interested in technology for
technology's sake or whether their call is being carried
over PSTN, IP, or the Internet. What they care about is:
- Ease of use -- participating in a conference call
must be as easy as picking up their phone and
entering an access number.
- Voice quality -- business users expect "toll
quality" voice. They won't accept long delays, echo,
or any other interruptions.
- Availability anytime/anywhere -- the advantage of
conference calls is that participants can join the
conference from wherever they are. They must be able
to join the call using any available device: a
landline phone, a cell phone, or a PC.
The Case For Mixed Conferences
The average conference call involves five to six
parties, is usually geographically dispersed, spans
corporate boundaries, and can involve customers,
suppliers. Frequently, parties on a conference call are
at a location other than their office and it is unlikely
that all parties will be on the same network
infrastructure. Even as VoIP becomes commonplace in
businesses, conference participants will continue to use
the PSTN. VoIP calls will originate from users at
smaller locations where the economics of single access
networks are easily proven or from a remote location
where the end-user has only a single access line for
both voice and data.
The challenge is to provide a conferencing solution
that seamlessly bridges calls from VoIP networks and the
PSTN. Bridging several PSTN calls in a single conference
is complex. All PSTN calls arrive as circuit switched
calls using network signaling protocols such as T1, E1,
or ISDN. Bridging VoIP calls together adds complexity.
Packet networks inherently have more delay than
circuit-switched networks. And industry standards are
still evolving with rivaling network protocols -- H.323,
SIP, MGCP, etc.
Bridging PSTN and VoIP calls on a single conference
requires terminating the end-user call, no matter what
network they originated on, then converting all of the
audio streams to a common format, and then providing
echo cancellation and mixing the audio streams to ensure
a high-quality audio experience.
Conferencing systems designed to bridge the VoIP and
PSTN worlds will have an internal gateway that performs
the proper protocol and voice compression conversions.
Legacy conferencing systems may use external gateways,
but overall performance will suffer, and system
administration will be more complex.
THE PROMISE OF VOIP
As the quality and availability of Internet voice
traffic increases, the question of how VoIP can be
exploited for business communication becomes
increasingly important. The promise of cost savings and
the creation of valuable new services including using IP
for voice are driving considerable interest among
providers and businesses alike. The interest stems from
the realization that IP costs less because it is more
efficient to transport voice as packets over an IP
network, versus transport on a switched circuit network.
The cost savings from using IP to transport voice
calls can be realized in three areas. The first is
through lower conference call termination (phone company
"800" number) charges. Conference attendees who can use
an IP capable end point (whether soft phone, IP phone
handset, or most importantly, traditional handsets tied
to a traditional PBX behind a gateway) can make voice
calls over IP directly to the service providers
By using a managed IP network to transport the voice
traffic from users to the conference service provider,
all circuit switched 800-number calls are avoided.
Conferencing Service Providers thus avoid the expensive
800-number charges which average about 25 percent of
total operating costs. These charges are paid to the
PSTN carrier, for every call, at the rate of
approximately two cents per minute: Two cents per minute
for every user in every conference. By eliminating these
toll charges, conference service providers can save a
large portion of their operating costs and gain a
significant competitive price advantage.
The IP network required is relatively simple. A
customer with a traditional PBX, provisions the
conferencing 800-number traffic (a PBX setting) to
divert to a router via a T1 line. Gateway cards in the
router compress and packetized the voice streams. The
router then sends the voice packets over the managed IP
network to the conference bridge's IP address. A managed
IP service (available from many national Internet
service providers) is needed in order to ensure a high
quality of service (QoS) for the voice traffic.
The second potential savings from voice traffic over
IP is realized by any conferencing service provider that
has a geographically dispersed operation. Once regional
conferencing equipment sites are linked via IP,
resources can be shared (or load leveled) at no
additional charge from the phone company. Peaks caused
by differences in time zones, or business usage can mean
the need to purchase and operate less equipment.
The third savings from VoIP is in the bandwidth
reduction with IP to support the same amount (ports) of
conferencing. The most common standard for VoIP
traffic is to use G.729.A encoding. G.729.A delivers
toll-quality voice, with an 8:1 compression. Meaning
that PSTN phone traffic, which required 64K, is sent via
IP using only 8K bandwidth. For a large customer of
conferencing, this can mean a reduction of T1 lines, and
associated monthly charges.
BUILDING NEW BRIDGES
Conferencing is an integral tool of business
communications. As VoIP is deployed in the corporate
environment, conferencing systems must be able to
seamlessly bridge VoIP calls with traditional PSTN
calls. A well-designed system will make this requirement
transparent to end-users and will provide the same
service to all users independent of the transport
network. These systems will make it easy for businesses
to migrate from an all PSTN infrastructure to a mixed
PSTN/VoIP environment as networking technologies
continue to evolve.
Conferencing has grown in importance because it is
the exception to have key people in the same place at
the same time -- not the rule. Conferencing solutions
are making it easy to get people together. VoIP is
bringing new options into the mix and enabling providers
to offer cost effective solutions to their business
customers without having these customers sacrifice
Ron Elwell is the CEO of Octave
Communications, Inc. Octave has helped set new
industry standards for ease of use, capabilities,
capacity, reliability, size, performance, and cost.
To The November 2001 Table Of Contents ]