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| There has been much hype surrounding the development of voice
over IP. Most information published is either at a conceptual level or has a clear
commercial bias. Voip-calculator.com aims to provide practical information for those
engineers and network managers who plan to use the technology. However, a brief
discussion of the motives in deploying the technology may be appropriate, and this white
paper aims to promote that debate. We make no apologies for the sceptical nature of this
document. This document only represents the authors' opinions. |
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| Network convergence is nothing new. Previously known by many names,
including Voice and Data Integration, it describes the process of transporting
more than one type of information across a single transmission medium. The scope of
the carried applications has broadened in the last few years, because the number of
applications available throughout an enterprise has increased. It is argued by
proponents of network convergence that bringing multiple applications together across a
single network introduces economies of scale. Whilst the pure bandwidth savings are
questionable, there may be other savings including network management costs, training and
real estate, although these can be difficult to quantify. It is for individual
network managers to assess these savings for themselves.
Nevertheless, purely in terms of bandwidth, it can still be more efficient to carry
voice and data separately within an enterprise network. It is suggested that readers
do not lose sight of this possibility. |
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| Having decided that network convergence is appropriate, a decision must
be made concerning whether the convergence should take place towards an existing voice
network, an existing data network or whether a new network technology should be developed. The
development of a new technology takes many years, and users tend to be impatient for
solutions. Therefore, the question of which network is used is usually answered by
studying the volumes of voice and data calls. At the beginning of the last decade,
the vast majority of traffic through a wide area network was voice traffic.
Integrated solutions usually involved providing the minimal data traffic with a free
ride over a network (albeit a digital network) which was designed for the
transmission of voice.
As data applications have developed, we find ourselves starting this decade with
greater volumes of data traffic than voice traffic across the wide area network.
Therefore, existing data networks are usually considered the logical choice for the
transport of converged traffic. |
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| Developed in the 1960s, TCP/IP is a suite of protocols supported by
practically every networked device in the world. It enables communications between
those devices across local and wide area networks. It can be used in enterprise
network, and is obviously one of the enabling technologies of the Internet. IP would
seem the logical choice for the inclusion of voice. Nevertheless, IP is a
connectionless protocol which delivers information on a best efforts basis.
The protocol was not developed with real time information such as voice or video in mind.
The basic protocol is completely unsuited to voice transmission: its delay
characteristics cannot be easily predicted and no guarantees are made by the protocol that
its data will be delivered in the correct order, or that it will be delivered at all.
There is much research in progress to improve the Internet protocols to support voice
and video with the aim of meeting the extremely high quality of service expectations of
voice applications users. |
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| As discussed, network convergence across a private network can be difficult to
justify. Arguably, the most exciting development is the passing of voice traffic
through the public Internet allowing the passing of calls between two voice switches
without having a direct connection between those switches. Similarly, calls to public
telephone numbers can be forwarded through the Internet to Internet Telephony Service
Providers for termination to the Public Telephone Network. Such carriers exist now,
and are offering customers large savings in long distance dialling. The technology
is in place to transport such calls across the Internet without a noticeble degredation in
voice quality.
Of course, the pricing model for Internet connectivity may change to reflect these
demands. |
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| This document has provided a very brief introduction into the motives for
developing voice over IP. There are many other considerations and drivers. For
example, an organisation may be able to improve its levels of customer service by
installing a Web enabled call centre allowing customer to speak and see customer service
representatives. There seems little doubt that Voice over IP will continue to be
developed and installed. Whether the technology is used within enterprise networks,
carrier network, or whether its greatest appeal is to consumer customers remains to be
seen.
Why not try our Voice
over IP Forum? It is an interactive newsgroup which you can use to exchange ideas
about network convergence.
Return
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| This document
should not be viewed as a consultative document. It is the readers' responsibility to
ensure that the most appropriate telecommunications strategy is applied to his or her
business. No liability is accepted by the authors for omission or error. |
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