VoIP, Voice over Internet Protocol and Internet telephony
Is it good enough for business?
For a business call the technology would work well but would the
overall reliability and voice quality be good enough? We have got
used to very high reliability and good quality of service (QOS) in
the PSTN and traditional telephone systems - what level of non-availability
or dropped calls would you accept in you business calls to customers
or key suppliers, or between your own managers and staff? 99.9% availability
sounds good but that could be one hour every 42 days or one day every
three years without a phone service. And what about audio quality
- jittery, broken, delayed speech perhaps at times of congestion?
If you are using ADSL broadband then you could be sharing a 512kbps
connection with 50 residential users or 20 other businesses all with
say 10 users - it only takes one user to be downloading streamed audio
or video or some other intensive application to slow everything down
for everyone.
Vendors can demonstrate high quality VoIP systems in operation so
what is the problem. Well first of all we have to differentiate between
VoIP on a local or wide area ‘managed’ network and Internet
telephony over the largely unmanaged (in a prioritised traffic sense)
public Internet.
IP, Internet Protocol allows computers and similar devices with different
operating systems to communicate with each other using an 'open' common
protocol - a language and way of doing things - rather than their
own 'closed' proprietary protocols. It is the basis of the Internet
where Windows PCs, Macs, Unix, Linux, PDAs, mobile phones and various
other machines and systems can communicate transparently. It has become
the networking protocol of choice for local area and wide area networks,
becoming intranets and extranets and using Internet developed applications.
Internet Protocol allows for some data packets to be prioritised
over others so routers can be configured to recognise certain types
of packet, real-time voice or video packets, for example, and give
them priority over more 'bursty' data traffic. It doesn't matter if
a data transfer is a bit jittery as long as the file eventually arrives
within a reasonable time. With recorded streamed audio and video the
packets can be buffered and local presentation started when seamless
delivery is predicted. But with real-time voice and video telephony
buffering would not be appropriate and jittery delivery would mean
poor or even unusable quality.
So, on a local or wide area network owned by one company, or several
networks run on an agreed commercial basis, standard configuration
of routers and prioritisation of voice packets is feasible, but that
degree of cooperation on the thousands, if not hundreds of thousands,
of networks which makes up the public Internet is some time away -
that is even if the traditional telecoms operators who own much of
the infrastructure which carries the Internet want to allow it to
cannibalise their traditional PSTN business.
Voice and data convergence
Now all the above may put you off Internet telephony as your full-time,
single-solution telephony service, but the applications that are enabled
by a converged voice and data network over IP are many and varied,
and the savings you may be able to make particularly if you are having
new network cabling and hardware installed should make you look at
VoIP and a converged voice and data LAN to see what the wider benefits
might be. IP handsets can plug directly into a computer or enabled
verions through the LAN sockets, and a VoIP gateway from your LAN
to the PSTN allows you to utilise the best of both technologies as
appropriate.
