|
The
public telephone network and the equipment that makes it possible
are taken for granted in most parts of the world. Availability
of a telephone and access to a low-cost, high-quality worldwide
network is considered to be essential in modern society (telephones
are even expected to work when the power is off). Anything
that would jeopardize this is usually treated with suspicion.
There is, however, a paradigm shift beginning to occur since
more and more communications is in digital form and transported
via packet networks such as IP, ATM cells, and Frame Relay
frames. Since data traffic is growing much faster than telephone
traffic, there has been considerable interest in transporting
voice over data networks (as opposed to the more traditional
data over voice networks).
Support
for voice communications using the Internet Protocol (IP),
which is usually, just called "Voice over IP" or
VoIP, has become especially attractive given the low-cost,
flat rate pricing of the public Internet. In fact, toll quality
telephony over IP has now become one of the key steps leading
to the convergence of the voice, video, and data communications
industries. The feasibility of carrying voice and call signaling
messages over the Internet has already been demonstrated but
delivering high-quality commercial products, establishing
public services, and convincing users to buy into the vision
are just beginning.
|
VoIP
can be defined as the ability to make telephone calls (i.e.,
to do everything we can do today with the PSTN) and to send
facsimiles over IP-based data networks with a suitable quality
of service (QoS) and a much superior cost/benefit. Equipment
producers see VoIP as a new opportunity to innovate and compete.
The challenge for them is turning this vision into reality
by quickly developing new VoIP-enabled equipment. For Internet
service providers, the possibility of introducing usage-based
pricing and increasing their traffic volumes is very attractive.
Users are seeking new types of integrated voice/data applications
as well as cost benefits.
Successfully
delivering voice over packet networks presents a tremendous
opportunity; however, implementing the products is not as
straightforward a task as it may first appear. This Technology
Guide examines the technologies, infrastructures, software,
and systems that will be necessary to realize VoIP on a large
scale. Product development challenges such as ensuring interoperability,
scalability, and cost/effectiveness will be discussed. The
types of applications that will both drive the market and
benefit the most from the convergence of voice and data networks
will be identified.
|
