Companies are converging their IP VPNs at an ever increasing rate. Currently over 600 Orange Business Services customers use their VPNs to transport voice and data. Some use a do-it-yourself model; others use a fully managed model. If you're looking for value, however, the fully managed approach is the less costly and higher quality alternative. That's because of the costs and effort associated with the three major components of a convergence strategy:

• operation, administration and management
• interconnection between IP and TDM PBXs and the PSTN
• VoIP security

The costs involved include capital equipment costs and ongoing management costs. By employing a managed service, enterprises can save equipment purchase costs because the service provider buys the equipment. Determining this capitol savings can be straightforward. However, ongoing management costs for "do-it-yourselfers" are often hidden and are generally underestimated. Often, some costs are avoided for the short term because some element of convergence is ignored, like capacity management or security. These costs can be avoided for a time but can lead to serious consequences if left permanently unattended.

This paper takes a look at these three major costs and some reasons for choosing a managed solution.