Data VoIP Solutions

Preparing Your TCP/IP Data Network For Voice Traffic
By Bob Potter

As much as vendors would like you to believe, employing voice applications over your existing TCP/IP data network is certainly not as simple as plugging in VoIP-enabled phones and installing software to make them work. Combining voice and data networks into one seamless operation can be tricky.

Before you attempt to run voice communication over your TCP/IP network, familiarize yourself with the following key issues in order to avoid any unpleasant surprises.

Voice vs Data

VoIP enables the human voice to be sent over networks as data "packets". These packets are then reorganized into the human voice upon reaching their final destination. One would think that non-voice traffic travels over the network in the same manner as data traffic. After all, data is data, right?

Wrong. The reasons are that TCP/IP networks do not generally deliver "packets" of data in the same order, along the same route, or even within the same time frame. This is not a problem for normal data downloads or data transfer, but for voice conversations it is critical that "packet" information is transferred without packet loss or latency.

Bandwidth

It goes without saying that in order to run voice over a TCP/IP network, sufficient bandwidth is required. Most network services customers are familiar with the raw bandwidth of each of their connections. The key issue here is not to confuse "available" bandwidth with "total" bandwidth. For example, a T-1 devoted to data networking may have 1.5 Mb of raw bandwidth. That does not mean, however, that the entire 1.5 MB of bandwidth will be available for voice applications.

Packet Loss

Inherent in any network is the inevitability of "packet loss". Packet loss refers to the percentage of data packets that travel the network then fail to reach their final destination. Packet loss can be tested and measured using network analysis tools. If you test and determine a packet loss of 3% or more, your existing network will not successfully handle voice traffic.

Keep in mind that packet loss increases dramatically when a network is overloaded with traffic. In fact, a network may even become unusable for voice applications when approaching their maximum bandwidth capabilities.