Capacity and Disaster Recovery Planning for an Internet Connection that Can Become Unsatisfactory
Figure 2: Performance of North American routers
Figure 3: Performance of one router located in Elkhorn, Wisconsin, U.S.A
In Figure 3, a momentary period of slightly sluggish performance shortly before 2:00 p.m. can be seen in the performance of one router. This was not a serious problem. However, serious problems did exist elsewhere. For example, in one of the two Vancouver, Canada servers shown in Figure 2, the Current Index was 0.
Global companies with disaster recovery plans in place are often able to failover their entire systems to servers based in other regions of the world. But, even global companies are vulnerable.
For all the power of modern computing and satellites, most of the world's communications still rely on submarine cables to cross oceans. The Web site http://www.telegeography.com/products/map_cable/index.php contains a good deal of useful information on underwater cables and other network resources.
When two cables in the Mediterranean were severed earlier this year, it was put down to a mishap with a stray anchor. Since then, a third cable has been cut, this time near Dubai. That, along with new evidence that ships' anchors were not to blame, has sparked theories about more sinister forces that could be at work.
And, an even more recent report now states a fourth cable has been cut, in a different location than the other two cable locations.
When India initially lost as much as half of its Internet capacity earlier this year, traffic was quickly rerouted, but a day or two elapsed before the country was reported to have regained 90% of its usual capacity. The outage also reveals that the effects of such outages are anything but neutral; their effects vary widely depending on the size and resources of the user.
In addition to the kinds of problems discussed above, another, the loss of connectivity that's software related, warrants mentioning. Users recently experienced problems with Windows Genuine Advantage (WGA) authentication. Users of both Windows XP and Windows Vista could not validate their installations using WGA.
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