15.12 Satellite-Based Restoration

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Satellite carriers offer shared network restoration arrangements, whereby traffic is routed off failed terrestrial facilities and carried over previously contracted satellite links. There are, however, limitations associated with such arrangements, including the long lead time (a minimum of 24 hours) required to place backup satellite circuits into operation and the associated high cost.

Some very small aperture terminal (VSAT) vendors offer a complete restoration package that includes equipment, data recovery services, and an emergency procedures plan that is implemented in the event of a data communications failure. At least two types of services are offered on a subscription fee basis: on-call or dedicated. With on-call service, the vendor stores the necessary equipment at its headquarters under a constant test environment so that the backup devices are ready for immediate delivery to the customer’s site. Data recovery takes place within 24 hours from the time that vendor receives the customer’s emergency call. With dedicated service, the equipment is in constant standby operation at either the vendor’s headquarters or the customer’s host facility, or it is shared between both locations. This dedicated standby arrangement allows for network restoration in a matter of minutes.

Included in the subscription fee are all of the necessary satellite transponders, receivers, and VSAT dishes, which are provided by the vendor. The disadvantage of this arrangement, however, is that it is tantamount to the customer having redundant facilities in place, just waiting for a disaster to occur. Under abnormal network conditions, these redundant facilities would not be a disadvantage, but under normal networking conditions, the customer must still pay whether or not the equipment and service are ever used.



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LANs to WANs(c) The Complete Management Guide
LANs to WANs: The Complete Management Guide
ISBN: 1580535720
EAN: 2147483647
Year: 2003
Pages: 184

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