Voice Technology Basics
Welcome to the Voice Technology Basics lesson. Combined voice
and data networks are definitely a hot topic these days. In this module, we’ll
start by discussing the convergence of voice and data. We’ll present a bit
of history as well so that you understand how this all came about.
We’ll then move into discussing actual voice technology. There’s a
lot to cover here and a lot of vocabulary you’ll need to be familiar with.
We’ll start with understanding the traditional telephony equipment. We’ll
also discuss voice quality issues as well as enabling technologies such as compression
that are making voice/data networks possible.
After we cover the technology, we’ll discuss Voice over IP, Voice over Frame
Relay, and Voice over ATM. We’ll then cover some of the new applications
that are possible on combined voice/data networks.
Finally, we’ll look at how a company might migrate from traditional telephony
to an integrated voice/data network.
of Voice and Data
of Voice Technology Basics
in a Computer Telephony System and Voice Routing
over Data Networks
in Voice Technology
over Data Transports
over IP Components
- H.323 Interoperability
over Frame Relay
over Asynchronous Transfer Mode (ATM)
of Integrated Voice and Data Networks
- Capable Route
PBX Networking to New Voice Networking
Convergence of Voice and Data
Today, voice and data typically exist in two different networks.
Data networks use packet-switching technology, which sends packets across a network.
All packets share the available network bandwidth. At the same time, voice networks
use circuit switching, which seizes a trunk or line for dedicated use. But this
is all changing...
There is a lot of talk today about merging voice and data networks.
You may hear this referred to as multiservice networking or data/voice/video integration
or just voice/data integration. They all refer to the same thing. Merging multiple
infrastructures into one that carries all data, regardless of type.
In this new world order, voice is just plain data. The trends driving this integration
are cost initially--saving money. Significant amounts of money can be saved by
doing away with parallel infrastructures. In the long run, though, new business
applications are what will drive the integration of data and voice. Applications
- Integrated messaging
- Voice-enabled desktop applications
- Internet telephony
- Desktop video (Intel ProShare, Microsoft NetMeeting, etc.)
So, how does a combined network save money?
Data, Voice, and Video Integration Benefits
The place where you can realize the greatest savings is in
the wide-area network (WAN), where the bandwidth and services are very expensive.
The concept here is that at some point, you want voice data “to ride for
free.” If you look at the overall bandwidth requirements of voice compared
to the rest of the network, it is miniscule. If you had to charge per-packet or
per-kilobit, voice is basically “free.”
Companies should experience several kinds of cost savings. Traditionally, the
overall telecom budget includes three basic sections: capital equipment, support
overhead such as wages and salaries, and facilities. The majority of costs are
incurred in the facilities. Facilities charges are recurring, such as leased-line
charges which occur every month, as opposed to capital equipment, which can be
amortized over a couple of years.
Because facilities are the largest expense, this can also be the place where the
most money can be saved. The largest part of the facilities charge is the telecom
budget. If the telecom budget can be reduced, money can be leveraged out of that
to pay for network expansion.
People tell Cisco, “We have to leverage our budget to converge data, voice,
and video. We have exponential applications that demand growth and we don’t
know how to finance that.” Cisco advises customers to look at their established
budgets and see if there is any way to squeeze money out of them by putting in
a more efficient infrastructure with features such as compression, and move all
traffic over a single transport mechanism. On average, users can expect a 30 to
50 percent reduction in their IT budgets with convergence.
New applications that include voice are becoming increasingly important as they
drive competitive advantage.
Before we get into the nuts and bolts of voice technology, let’s take a
look at just a couple of these applications that multiservice networks enable.