Is WAN Optimization Hardware Obsolete?

Reports of the death of WAN optimization appliances are much exaggerated

We recently received a copy of a Netex-commissioned white paper called "The Death of the WAN Optimization Hardware Appliance: R.I.P." The paper, by a firm curiously named Dragon Slayer Consulting, predicts that WAN optimization hardware will soon be as obsolete as the buggy whip because virtualized server appliances will render it moot. We believe this prediction is wrong. Here's why.

WAN optimization is unlike other functions that can chug along just as well in a virtual as in an actual appliance. Successful virtualization is predicated upon the assumption that the software running on the virtual appliance will consume a fraction of the allotted processing power. A mix of applications accessed by a mix of users creates a wide range of CPU utilizations, with low average utilization. Virtualization leverages the low average and wide distribution to run the same processes in few machines. However, the efficiency benefit must be significant enough to outweigh virtualization's overhead tax. Therefore successful virtualization needs an appropriate mix of applications.

WAN optimization, on the other hand, runs few processes which are very CPU intensive. This is particularly the case with network layer functions that must operate at 100 Mbps or often 1 Gbps. When this happens in a virtual server environment, performance takes such a nosedive that virtualization loses its attractiveness.

Of course virtual WAN optimization will work if there is very little traffic to process. But an enterprise cannot take the risk that the WAN circuit utilization will always remain low. How will you deal with serious traffic loads? If you never have much traffic, then why are you paying for a big WAN circuit in the first place? The router runs on hardware that must keep up with the WAN bandwidth. WAN optimization is the next thing in the path, and it must perform more functions than a router--at the same bandwidth!

Thus, we predict that WAN optimization appliances will continue to be a common sight in the networking landscape, and we do not expect to be placing flowers at on the WAN optimization appliance's grave any time soon.

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