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Enterprise network executives face several challenges in successfully migrating to advanced IP services. They must connect large, distributed organizations with optimized bandwidth to facilitate application performance. They must lower the number of circuits they support while dramatically reducing latency. They must respond to pressure to implement a voice over IP (VoIP) solution to add functionality and lower telecommunications costs, without any perceptible impact on the quality of the enterprise's voice capabilities. They must train and retain IT staff, often with insufficient budgets. Finally, they must find a cost-effective way to manage their new network.
The choices facing the network executive today tend to fall into two solutions: 1) build a management solution, or 2) outsource this work to a third party. When you think about this, you really have one solution with a choice of who will do the work. This is essentially two sides to the same coin, with the coin being an overlay network solution. As an overlay solution, there are common challenges to this approach that network executives encounter. This paper will explore the problems inherent in an overlay management approach and describe a new approach that allows for the management of the wide-area network to be not only offered as a service, but actually embedded in the network itself, resulting in several incremental benefits to the enterprise.
Current Solution: Overlay Management For Impartiality And Control
IT departments have a tendency to tackle network jobs themselves, thinking that the network management is really just an extension of their existing responsibilities. Many IT groups further believe that keeping the management "in-house" will minimize the budgetary impact.Typically, this "do-it-yourself" approach tends to become more difficult as the myriad of attendant tasks required to run an enterprise network create distractions, the costs of adding new capabilities stresses budgets, and the integration work involved in adding new sites or supporting a corporate merger become overwhelming.
On the other hand, outsourcing the overlay management network to a third party can reduce the work on the IT staff; but at a cost in terms of dollars and network management control. Overlay solutions are not cheap, nor are they something you can just buy once and then stop paying for. There is an ongoing maintenance component for the continued support, along with the potential costs of added (future) capabilities. More importantly, however, is the risk of not having control over your network. Depending on the approach taken, you could find yourself turning your network management over to a vendor and hoping they give your network the same priority your staff would.
Often overlooked in this debate over outsourcing vs. in-sourcing are the greater costs inherent in an overlay network approach. First, there is the latency added by collecting the session header information needed to assess network traffic performance. Some overlay management solutions use "agents" or "probes" to capture this information. However, some application performance must be diverted to these agents so that the information can be captured and analyzed, adding latency to the network traffic. Some "customer premise" routers have the ability to capture this information as the traffic is flowing through the device, but this data capture simply increases the processing time of these routers, thereby adding latency to the process. Regardless of the approach to data collection, there is a "latency tax"that is paid with an overlay solution.
Second, there are the costs of adding new locations to the network, and the headaches of integrating this new location into the overlay management solution. Some companies have found that this is where they begin to migrate from a "do it yourself" approach to an outsourced alternative. While all networks must be managed, few network executives get kudos from the senior team for this effort, and in fact often hear only the criticism when some aspect of the network performance is not delivered as promised.
Third, adding an additional (management) application to the network increases traffic that is competing with other network traffic. Since the server where the network traffic statistics are stored and analyzed is somewhere in the enterprise network, accessing that information simply puts additional strain on the corporate network. This "bandwidth tax" can be as much as 20% of available bandwidth, thereby reducing the bandwidth available for other applications.
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