Resiliency can be defined as the ability to recover from a network
failure or issue, whether it is related to a disaster, link, hardware,
design, or network services. Diversity relates to having alternative
choices in the event that the primary source is unable to render the
desired service.
sources can prevent some power failures. A site could connect one power system to the local
power grid and another to an uninterruptible power supply.
connected network.
data center can protect the company from potential power failures. Organizations could locate
a redundant data center in another city, or in a part of the same city that is at some distance from
the primary data center. All back-end services can be duplicated, and transactions coming in
from remote offices can be sent to both data centers. This configuration would require duplicate
WAN links from all remote offices, duplicate network hardware, duplicate servers and server
resources, and leasing another building. Because this approach is so costly, it is typically the
last step taken by companies that want the ultimate in fault tolerance.
attractive alternate design. Instead of full duplication, you could duplicate several selected
critical servers and links to those servers.
with the medium and its link to each individual end station. Under this classification, media
components might include network interface controller failures, lobe or attachment unit
interface (AUI) cable failures, transceiver failures, hub failures, and all failures associated with
media components such as the cable or terminating devices.