Availability in network security

The principle of availability states that information should be available to authorized user at all the time.
Example :- due to intentional action of unauthorized user C, an authorized user A may not be able to contract a server computer B, as shown in diagram.
This would defeat the principle of availability. Such attack are known as interruption.

attack on availability

We're not around right now. But you can send us an email and we'll get back to you, asap.