Availability: Difference between revisions
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imported>Howard C. Berkowitz No edit summary |
imported>Howard C. Berkowitz No edit summary |
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'''Availability''' of an information service means that authorized users can depend on being able to use it whenever it is needed. In U.S. law, a definition is "Ensuring timely and reliable access to and use of information." <ref>44 USC 3542</ref> | {{subpages}} | ||
'''Availability''' of an information service, in the context of [[information security]] means that authorized users can depend on being able to use it whenever it is needed. In U.S. law, a definition is "Ensuring timely and reliable access to and use of information." <ref>44 USC 3542</ref> | |||
To specify availability in detail, however, can be quite complex. For example, if a service is offered only during normal business hours between 9 and 5, the service fails at 4, is repaired at 11, and is working the next morning, has it been unavailable for: | To specify availability in detail, however, can be quite complex. For example, if a service is offered only during normal business hours between 9 and 5, the service fails at 4, is repaired at 11, and is working the next morning, has it been unavailable for: | ||
Revision as of 13:31, 30 September 2009
Availability of an information service, in the context of information security means that authorized users can depend on being able to use it whenever it is needed. In U.S. law, a definition is "Ensuring timely and reliable access to and use of information." [1]
To specify availability in detail, however, can be quite complex. For example, if a service is offered only during normal business hours between 9 and 5, the service fails at 4, is repaired at 11, and is working the next morning, has it been unavailable for:
- 1 hour, the period of outage during business hours
- 7 hours, the actual period the service was unusable if someone attempted to use it
- 17 hours, the perceived period of outage if someone saw it fail and left for the day, not knowing he could respect it in the morning
References
- ↑ 44 USC 3542