In his "Cost Cutting by Rightsizing Network Reliability" report, Neil Rickard (vice president in Gartner Research) suggests that "Enterprises should grade their sites by reliability needs because this is the biggest factor driving WAN costs" and proposes three key findings:
- Combining multiple, less-expensive services in parallel can deliver the same levels of reliability at lower prices than a single, high-quality connection.
- Reducing the reliability target for a location by one "9" (for example, from 99.99% to 99.9% availability) will typically save 30% of the WAN costs for that site.
- Transition costs, such as installation charges for new services, will typically eliminate half of the first year's savings.
This statement is the traditional driver for hybrid networking: adding a secondary link over Internet would provide the expected availability improvement (basically an additional "9") sought by IT and network managers while being (most of the time) cheaper than a second MPLS access line.
Now that the "network centric" approach to business continuity has been accepted, it's time to take it from an "IT centric" or even "business centric" perspective. Once you have "continuous access to the network", you need "continuous application performance". This is more important that it seems at first thought; let's remember the application brownout formula (5' = 1%) that states that only 5 minutes of poor performance a day decrease the enterprise productivity by 1%.
On average, preventing application performance brownouts (like unexpected variations in response time, too long transfer delays, demoralizing login time, etc.) and ensuring a perfect user quality of experience have an impact of the same order of magnitude (may be even larger) as moving network availability from 99% up to 99.9% or even 99.99%, i.e. from plain domestic Internet quality to business grade reliability.
That requires the same agility to handle application flows in the space dimension (which network?) as in the time dimension (acceleration, priorization, shaping…). Autonomic networking, enabling a strong coupling between QoS and control, WAN optimization and dynamic WAN selection seems the perfect candidate to get these two birds with one stone: perfect [business continuity + application performance] in a world of unified hybrid networks.
Illustration: la grande famille – René Magritte (1898-1967)
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