Integrating your voice and data together using an IP network could
bring considerable benefits, as long as you implement it in phases,
says Danny Bradbury
When public relations people and IT executives in the UK get
telephone calls from this journalist (who is based in western
Canada), they often ask whether it isn't expensive to be making
calls so regularly from halfway across the world. Little do they
know that these calls are free, because I'm talking to them via an
Internet telephony service accessible from a browser.
With services such as Go2Call becoming increasingly prevalent,
conventional telephony carriers are getting worried. Connecting via
a PC headset over a cable modem link, I cut and paste telephone
numbers from Web sites, e-mail messages or my contact database
directly into the browser-based service, click on the dial button
and I'm conducting an interview without even having picked up the
phone.
There is a little bit of a time lag as speech travels from one
point to another over the Internet when using this service, as
there is with others such as Net2Phone (which unlike Go2Call
imposes charges). However, such inconveniences are justified when
call charges are so much cheaper, or even non-existent. When you
move into virtual private network (VPN)-based calling services,
where the quality of the transmission is easier to manage, such
problems become minimal.
Generally, in a corporate environment where offices are spread
over a wide area, voice-over-Internet-protocol (VoIP) services are
implemented using a gateway product that connects to a standard
exchange in the office. The gateways between the offices are linked
using a high-speed leased line or managed VPN.
When employee A at the London office decides to call employee B
at the California office, the call hits the local switchboard,
which then passes the call to the gateway. The gateway then
connects to the Californian gateway over the leased line using an
IP session, and the Californian gateway patches the call through to
the local exchange, giving the London caller a US dial tone. This
enables them to either dial someone within their own organisation,
or dial an external number from that exchange, dramatically cutting
the cost of a call across the Atlantic.
The most significant benefits of a VoIP system are cost-based.
If you analyse the total number of minutes that your staff spend
speaking to people within a remote office, (say, a branch office or
another region's headquarters), then offset that against the
proposed cost of a VoIP implementation, you can quickly produce a
cost benefit analysis.
Neil Wilkins, solutions marketing manager of VoIP equipment
supplier Enterasys, argues that telecommunications companies will
also reduce their costs to try and keep customers if the market
threat becomes large enough, and certainly some incumbent telephone
operators are starting to offer IP-based services to combat
competition from young upstarts in the telephony market.
There are technical and political obstacles to implementing a
VoIP service effectively. Nigel Williams, marketing director of
VoIP services specialist Voyager Networks, explains that
interdepartmental co-operation can be an issue during the planning
stage. "You have to think about the fact that you're bringing
together two departments in one organisation," he warns. "You need
buy-in at the highest level."
In many companies, the telephony system and the IT
infrastructure - including the data network - have been run by
different people in different departments. Forcing them to work
together takes careful team management.
Similarly, skills are an issue. Data networking experts are
relatively easy to find, and telephony experts can be sourced, but
hybrid experts that have sufficient technical skills in both areas
are in short supply. It's vital that whoever is handling the job
understands how to connect the two different infrastructures
together, and this becomes increasingly important as you integrate
applications into the VoIP network.
Ian Teswell, who was the in-house expert responsible for rolling
out a VoIP network at the Liverpool Housing Trust, argues that the
technical difficulties of implementing such solutions, and the
shortage of skilled staff, should not be overlooked. He found all
sorts of problems including the Cisco routers dropping voice calls
after 10 minutes. However, Williams says the housing trust was an
early adopter of this solution from Voyager and many of these
problems have been ironed out.
Another issue to consider when implementing a VoIP network is
the state of your existing infrastructure. Wilkins says, "It has to
be good and robust and predictable. You can get away with a lot of
things when sending data." He points out that service lapses, high
latency and other network problems are more noticeable in a voice
session. Consequently, you may need to review your current
infrastructure, ensuring that your switches are located properly
and offer a high-enough level of performance.
Generally, users start by implementing VoIP on the backbone. In
doing so, they will also conduct an analysis of your existing call
patterns, to ascertain the necessary capacity. Wilkins stipulates 6
kilobits per second for a voice circuit in an IP telephony link. He
adds that the average company can get away with one virtual voice
circuit for every 10 users on either side of the link. In heavy-use
environments, however, companies should increase the provision to
one voice circuit for every four users.
In many cases, network managers may want to think about varying
the network provision to cope with particular business conditions -
for example, decreasing the number of people per virtual voice
circuit between the legal and financial departments during a
corporate acquisition. This dynamic allocation will be easier if
the interface between your gateway and exchange is a digital one,
but might require more attention if you are connecting your gateway
into an analogue port.
You will also need to think about service differentiation, to
give your voice sessions priority over data communications. Wilkins
prioritises traffic on the local area network (Lan) on a
port-by-port basis on the switch, channelling voice traffic into
certain ports that are then given a higher priority than other
ports. If the traffic has to be passed over a wide area network,
which would involve passing through switches, then he utilises the
801.p and 801.q traffic management standards.
Perhaps one of the biggest issues that is often overlooked by
companies implementing VoIP services is billing. Many finance
departments will want to keep tabs on which departments are making
which calls, for internal accounting purposes. Changing not only
the way that calls are made but the very nature of the calls
themselves makes any existing call-tracking methods difficult to
maintain.
Wilkins proposes gathering call data and then using the
Lightweight Directory Access Protocol, which enables packets to be
fed into a directory network service, such as the Novell Directory
Service or Netscape Directory Server. Putting billing information
into these services rather than a relational database enables him
to use the network directory service for everything - including
policy-based networking, which is so important in a VoIP
environment. Policy-based networking enables administrators to set
the rules that manage the service differentiation in the network,
including call and data prioritisation.
Having upgraded your backbone to use VoIP services, you may
think about implementing it within the Lan. Williams says companies
may want to replace their branch exchange altogether with a VoIP
switch. "Then the port that comes out of the wall becomes both a
data and a voice port, and you plug in an IP telephone that goes
into the same socket as your data point," he explains.
This may be a more adventurous approach than some companies
would like. With firms still worried about the robustness of, say,
Windows NT-based software, they may be loath to replace their
tried-and-tested branch exchange equipment with newer equipment
such as this.
On the other hand, it would help with the skills problem,
because the technical staff implementing the system would at least
be working with modern, open standards and not interfacing to an
old, proprietary telephone exchange. Another option is to connect a
computer telephony integration (CTI) switch to the exchange, in the
same way that you connect the VoIP gateway for calls going out of
the building. The switch would then function as an interface
between the exchange and the IT infrastructure, enabling
applications to be integrated with the Lan-based data/telephony
infrastructure.
At this point, you can begin exploring other, more sophisticated
options. Heidi Bersin, senior vice-president of corporate marketing
at VoIP equipment supplier Clarent, explains that corporate
voicemail is one such application. "The problem with corporate
voice messaging at present is that companies require a box in each
office," she says. "Using the Internet, you can give every
corporation virtual local access to messages."
Other applications include unified messaging, which enables
companies to channel voice, e-mail and fax messages into a single,
easily-accessible mailbox. Accessing your messages from your PC
using a graphical user interface would make things much more
efficient because you could see which people had called you, thanks
to caller line identification techniques, for example.
Clearly, VoIP has a lot to offer, but you'll want to do a lot of
planning and the implementation should be iterative. Upgrade your
backbone first, and enjoy the resultant cost savings, but take a
look at the potential for other enhancements in the area of CTI,
too - just don't try to do it all at once.
Outsourcing your VoIP infrastructure
Another option for companies that don't feel as though they have
the expertise to set up a VoIP infrastructure in-house is to
outsource the service to another company. Many companies are now
offering third-party IP-based calling services, including
DeltaThree, Inter-tel and Dialpad.
There is also a growing market for call-me buttons, which can be
added to your Web site, enabling customers to initiate voice calls
with your representatives while surfing the site. One company
offering such services is Hearme, which offers its HearMe
VoiceNetwork. The service, available for a free 30-day trial, can
also be used for IP-based business conferencing. The service
handles voice signals from multiple users at a time, delivering
them to your desktop so that you can participate in a conference
call.
The company claims that you can be up and running with the
service in 15 minutes. Of course, it helps if end-users are surfing
in from a high-speed corporate leased line or a home-based DSL
service and not using a slower dial-up modem connection. Lynk, a
division of VoIP company BOS, offers a similar service that, like
HearMe's is available as a product instead of a service, if you
require.
Where to find VoIP service providers