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Is
Your Network Ready for IP Telephony? Here’s How to
Make the Assessment
A complete analysis of infrastructure readiness that
replicates IP telephony production network conditions
with live voice and data traffic is key to making a
smooth transition to convergence.
The
maxim “look before you leap” applies to anyone who
makes a major investment in a new venture.
Unfortunately, many companies make the jump to
convergence with infrastructures that aren’t ready to
carry time-sensitive traffic. Many networks simply
aren’t prepared to handle voice traffic at the time
they make the cut over to IP telephony.
When
companies transition to IP telephony with an
infrastructure that isn’t quite ready for prime time
the results can be at the very least disappointing and
at the worst downright disastrous. Degraded voice
quality and dropped calls are common consequences of a
network that can’t support the demands of real-time
traffic. A delay of milliseconds in the delivery of
voice packets can have a significantly negative impact
on call quality.
Companies
can avoid these unfortunate surprises by fully testing
their network’s readiness in advance of an IP
deployment. A trusted solution provider is a good source
of comprehensive network assessment services that use
active test traffic to gauge how the mix of voice and
data application traffic will impact the production
network and will perform under various conditions. Some
IP telephony equipment vendors also offer comprehensive
network assessment services to verify IP telephony
readiness. But companies need to choose carefully,
because all infrastructure assessment services aren’t
created equally.
What
businesses need is a solution provider or an IP
telephony equipment vendor that can analyze all areas of
the network infrastructure, including every WAN link and
LAN segment under varying conditions. A comprehensive
network assessment looks beyond basic capacity issues to
examine whether the underlying infrastructure and the
WAN equipment are compatible with IP telephony traffic.
The assessment also gauges whether the necessary
protocols and standards are supported to carry voice.
If
the infrastructure isn’t ready, a network assessment
provides the specific information the organization needs
to make corrections to bring the infrastructure up to
speed before the converged network goes live. Using
information collected during these assessments, network
testers should be able to make specific suggestions to
their clients about things like quality of service (QoS)
settings, queuing controls, and packet drop policies.
See
the Big Picture
To get an accurate view of a network’s readiness to
handle convergence, a network assessment gathers
statistics from both the LAN and from WAN links over
several days. Unlike a so-called “snapshot” analysis
which collects statistics from a data network during a
single point in time to test its readiness for a new
application, a network assessment that gathers
statistics over the course of several days can draw a
more complete picture of performance as conditions
change. Because voice demands special handling and
prioritization on a network that might be jammed at
times with bulk file transfers or employees catching up
on the latest YouTube has to offer, it is critical to be
able to judge how the network performs at different
times.
Analyses
that use a snapshot approach often miss crucial
indicators, such as sporadic capacity shortages caused
by bulk file transfers or a scheduled backup that occurs
off-hours. Conversely, businesses may get a false
impression from a snapshot view. For instance, if a
large data replication occurred during the snapshot
window, an organization might mistakenly conclude that
they need more bandwidth to support their voice traffic
and needlessly invest resources.
Software
agents issue a variety of network test packets emulating
different application protocols, packet sizes, packet
spacing, and quality of service levels to mirror
conditions under a variety of circumstances including
real-time client transactions. By mirroring a variety of
traffic types and situations, these test scenarios
pinpoint the source of problems like latency, jitter,
and packet loss.
Ideally,
the network assessment should provide the information IT
managers need to get the end user view of voice quality.
Network assessments often use a mean opinion score
(MOS), an objective five-point standard scale in which a
perfect call quality merits a five and the poorest
performance rates a one.
A
network assessment service should provide a thorough
analysis of the statistical results to isolate any
potential problem sources whether they are related to
switch configuration, queuing methods or network
congestion. And because the test also looks at WAN
links, it helps IT managers assess whether service
providers are delivering appropriate service levels to
support adequate voice quality. IT managers can use this
information to identify potential problem sources and
make adjustments in advance of a deployment.
Conducting
this kind of wide-ranging assessment prior to an IP
telephony deployment is the best way to ensure a
successful transition to convergence. But network
infrastructures are anything but static so experts
advise businesses that maintain exceptional performance
to continue to evaluate the performance of their
network. Only then can a company be confident that they
are getting the maximum benefit from their investment.
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