Some enterprise VOIP systems are all but unusable from the time they are implemented because nobody took the time to properly profile the existing network. Before implementing a VOIP system, a thorough application impact study should be completed. Knowledge Center contributor Tim McCreery offers five critical steps enterprises should take to ensure a successful VOIP system implementation.

Traditional
telephone services have typically gained a reputation of providing
excellent voice quality and superior reliability. Consequently,
users take for granted that their phone systems will provide high
quality with virtually no downtime. Yet many voice over IP (VOIP)
installations fail to meet these expectations, primarily because
organizations have not adequately evaluated their network
infrastructure to determine whether it can adequately support
applications that are very sensitive to latency, packet loss, jitter
and other similar performance factors.
VOIP requires a steady, predictable packet delivery rate in order to
maintain quality. Jitter, which is variation in packet delivery
timing, is the most common culprit that reduces call quality in
VOIP systems. Jitter causes the audio stream to become broken,
uneven or irregular. As a result, the listener's experience
becomes unpleasant or intolerable.
The end results of packet loss are similar to those of jitter but
are typically more severe when the rate of packet loss is
high. Excessive latency can result in unnatural conversation flow
where there is a delay between words that one speaks versus words that
one hears. Latency can cause callers to talk over one another and
can also result in echoes on the line. Hence, jitter, packet loss and
latency can have dramatic consequences in maintaining normal and
expected call quality.
Some VOIP systems are all but unusable from the time they are
implemented because nobody took the time to properly profile the
existing network. Before implementing VOIP, a thorough application
impact study should be completed.