Távközlési műszaki tudományok és távközlési rendszerek
In order to evaluate the expected availability of a service, a network administrator
should consider all possible failure scenarios under the specific service availability
model stipulated in the corresponding service-level agreement. Given the increase
in natural disasters and malicious attacks with geographically extensive impact, considering
only independent single link failures is often insufficient. In this paper, we build
a stochastic model of geographically correlated link failures caused by disasters,
in order to estimate the hazards a network may be prone to, and to understand the
complex correlation between possible link failures. With such a model, one can quickly
extract information, such as the probability of an arbitrary set of links to fail
simultaneously, the probability of two nodes to be disconnected, the probability of
a path to survive a failure, etc. Furthermore, we introduce a pre-computation process,
which enables us to succinctly represent the joint probability distribution of link
failures. In particular, we generate, in polynomial time, a quasilinear-sized data
structure, with which the joint failure probability of any set of links can be computed
efficiently.
