March 2004 Mfg.Trust

Mfg.Trust is a monthly feature of the
            NCMS InfraGard Manufacturing Industry Association
                        Infrastructure assurance for manufacturers
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This month – IP Telephony
This is not your father’s telephone system!

See the Resources Page for this Story 

Editor's Preface:

This month’s article on Internet Protocol (IP) Telephony is certainly not about MY father’s telephone system. When I was very young (remembered best for taking apart alarm clocks and plugging anything into the wall sockets) my father was a telephone repairman. One day he brought home this amazing mechanical marvel. It was a rotary stepping switch. Banks of these switches, cleverly wired, ran the telephone central offices. The switch had a stack of ten disks. Each disk had ten contacts. A hundred wires came out of it. The installed base was staggering. Cleaning contacts was a full time job. DSL service was a future dream.

Things have changed. The same company that built rotary stepping switches invented the transistor (a better switch, among other things). Others developed digital technologies. Circuit switched technology for voice calls seems silly nowadays (see Resources Page - How IP Telephony Works). Why waste a whole circuit on just one conversation? For that matter, shouldn’t phone numbers call people rather than houses or offices? And offices, shouldn’t they be a set of resources where people work, rather than one fixed location?

IP telephony is an important technology for realizing these changes in our lives. It is no longer an experiment. The technology behind it, Voice over IP (VoIP) has been around for ten years. It has been adopted by practically all the major telecom carriers and service providers. You may not even be aware of the change.

To examine the issue, read on. As always, our Resources Section at http://trust.ncms.org contains a rich set of links for further reading.

Editor

IP TELEPHONY

First Stage Growth – Transparent to the Customer

Today, the principal advantage of simple VoIP telephony is that it saves money,
especially on international calls. To most callers, the VoIP service today is largely
indistinguishable from traditional circuit switched telephone service. Yet, the
service provider gains a tremendous improvement in network capacity. Savings of 70%
to 90% for international calls are possible, while many companies can enjoy a 20% to
30% reduction in costs for domestic long distance.

Second Stage Growth – Business Acceptance

That call you made across the corporate or educational institution campus might have
been sent over the corporate LAN, with your voice “data” commingled with the emails
and database files moving on the same network. If you are building a new facility, it
does not always make sense to route two wires into each office, when one will do. IP
telephony is creating new value and new capabilities for buyers and users of
technology.

All the leading business telephone systems vendors realized that their future is in
IP-based communications. They all have developed families of IP-PBXs (Private Branch
Exchange) for business use. PBX is a legacy term. Perhaps these devices are more
accurately labeled “call processing managers” as in Cisco Systems terminology. They
all have migration strategies that allow adoption of new technology in a
non-disruptive way.

These PBXs are the link between the old and the new. They have traditional features
such as hold, transfer, and conferencing. However, they also permit a new set of
features that are not possible in the traditional circuit-switched world. These
systems begin to combine the functions of the phone and the personal computer.

Third Stage Growth – New Capabilities

It would be more accurate to say that it is not necessary to blur the functions of a
phone and a computer. A capable PDA replaces many functions of the computer, and the
phone can be built in. Such devices are called IP softphones. One device available
now docks a HP iPAQ into a cradle of an IP phone. Wherever you plug in becomes not
only your phone but your “office” as the network recognizes your preferences and
permissions.

It’s easy to imagine that the cradle is not essential. Given a wireless network in
the workplace and currently available devices, workers can be connected to the
enterprise communications system and have access to a full suite of services from
their PDA.

Further, the workplace is not essential for this purpose. These same sorts of
capabilities extend to telecommuting solutions that offer a secure, remote extension
by connecting IP telephones into a virtual private network from home or the road.

Used in a different way, the integrated communications that brings workers together
can also bring workers from different companies together with (appropriately secure)
collaboration tools.

PROS and CONS – a big win for the CONS

The dark side of IP telephony is that it is a boon to criminals and terrorists. IP
telephone calls can be difficult to trace. (See Resources page) This is a thorny
issue for law enforcement, government, and telecoms companies. Finding the right
balance may not be simple or fast, as there are important privacy issues for all of
us to consider.

Cisco Systems offers advice (see Resources page) about keeping the voice and data
networks logically segmented. This keeps data tools from being used on voice packets,
and defends against an eavesdropping attack with a tool called "voice over
misconfigured Internet telephones" (also known as vomit). That tool takes an IP phone
conversation trace and reassembles it into a wave file for easy listening.

It should be apparent that your network resiliency, robustness, and security become
yet more important when it also carries the phone system. IP telephony more directly
exposes the phone and voice mail systems to hackers. (Actually, phone systems are
exposed now, but now use less well-known technology. This keeps the amateurs and
“kiddies” out, but not the pros.)

Conclusion

Because of the changing dynamics of the enterprise, IP telephony is now poised to
become a strategic benefit to the overall business. Businesses must consider IP
telephony to remain competitive. The drivers include the increase in mobile workers,
a desire for productivity tools that leverage the communications infrastructure, and
a mandate to do more with less.

Technology marches along. IP telephony is already adopted by telecoms providers and
is working its way into our business and personal lives. The convergence of phones,
data, and video (that’s coming too) will certainly affect our lives as devices and
services become useful, powerful, mature, and affordable.

Will our grandchildren ask, “What’s a phone?”

LINKS

How IP-Telephony Works
http://computer.howstuffworks.com/ip-telephony.htm

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