Should VoIP Deployments Over WANs Be a Headache?

IT managers face a complex task when deploying VoIP because they can not afford deterioration in the quality of voice services or enterprise applications using the network.


Voice over IP (VoIP) is finally gaining traction in the enterprise world. It has been hyped for quite a while, but its adoption by large enterprises has been limited so far. However, deploying a VoIP-ready network is on the minds of every conscientious network manager.

It is not surprising that the adoption of VoIP has been timid once one looks at the numerous pre-requisites of a successful VoIP deployment over a WAN. From a network perspective, VoIP is a very demanding application. Not only is it real time but it also has meshed flow traffic patterns. The smallest deterioration in network performance in terms of jitter or packet loss will be immediately felt by the end-users who are used to the quality of traditional telephony.

Furthermore, while deploying VoIP over a WAN, network managers have to worry not only about the performance of VoIP but also about the impact of VoIP on other critical business flows – such as your ERP systems or applications provided via thin clients.

One solution offered to network managers by telecom service providers is to buy a dedicated class of service for VoIP over an MPLS network. By doing so, in essence, network managers are trading two physical networks for two – and sometimes more if they acquire several classes of service -- virtual networks. This approach protects other applications’ performance from the damage that could have been inflicted by the VoIP flow as well as guarantee to a certain extend the performance of the VoIP flow itself. However, it stills requires a fair amount of preparation to be rolled-out properly. To name but a few issues:

  • The VoIP call patterns must be precisely identified
  • Bandwidth utilisation must be predicted and traffic peak accounted for
  • Congestion points in the WAN must be recognised

This exercise usually leads to bandwidth over-provisioning that -- compounded with the premium that service providers usually ask for a dedicated class -- increases the overall cost of a VoIP deployment. The original promise of VoIP, lower cost, is then put into question. In addition, with only a dedicated class, network managers have no troubleshooting tools to know of and re-mediate any quality deterioration.

What should network managers do? Many have been torn between refusing to roll out – or at least delay – VoIP over the WAN or biting the bullet and accepting the costs and complications related to VoIP deployment.

The good news is that there is a third option. It consists of deploying traffic management tools that optimise meshed flows in real time. This kind of available technology allocates bandwidth dynamically guaranteeing the performance of critical applications such as VoIP without requiring dedicated bandwidth allocation. In addition, it provides real-time voice quality indicators, such as the MOS score, allowing network managers to troubleshoot in real time before a problem spreads into the entire network.

Traffic management tools can be precious allies for network managers who would like to easily and cost effectively deploy VoIP over a common WAN. Thus when assessing how to avoid VoIP deployment headaches, it makes sense to consider their use.

Mike Bailey, is country manager of Ipanema Technologies, a provider of business network optimisation solutions

For more information, our sister site Techworld has a comprehensive VoIP resource page.

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