Page 1316 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

sites in general is hardware replacement supplies. There are

basically two options for hardware replacement supplies. One
option is to employ “in-house” replacement, whereby you store
extra and duplicate equipment at a different but nearby location
(that is, a warehouse on the other side of town). (In-house here
means you own it already, not that it is necessarily housed under
the same roof as your production environment.) If you have a
hardware failure or a disaster, you can immediately pull the

appropriate equipment from your stash. The other option is an
SLA-type agreement with a vendor to provide quick response and
delivery time in the event of a disaster. However, even a 4-, 12-, 24-
, or 48-hour replacement hardware contract from a vendor does
not provide a reliable guarantee that delivery will actually occur.
There are too many uncontrollable variables to rely on this second

option as your sole means of recovery.

Service Bureaus

A service bureau is a company that leases computer time. Service
bureaus own large server farms and often fields of workstations. Any

organization can purchase a contract from a service bureau to
consume some portion of their processing capacity. Access can be on
site or remote.

A service bureau can usually provide support for all your IT needs in
the event of a disaster—even desktops for workers to use. Your
contract with a service bureau will often include testing and backups
as well as response time and availability. However, service bureaus

regularly oversell their actual capacity by gambling that not all their
contracts will be exercised at the same time. Therefore, potential exists
for resource contention in the wake of a major disaster. If your
company operates in an industry-dense locale, this could be an
important issue. You may need to select both a local and a distant

service bureau to be sure to gain access to processing facilities during a
real disaster.

Cloud Computing