Protection against link errors and failures using network coding

TL;DR

This paper introduces a network coding scheme that provides robust protection for multiple bidirectional unicast connections against adversarial errors and failures, using a minimal number of shared protection paths.

Contribution

It presents a novel network coding-based protection scheme that guarantees correction of errors and failures with a fixed number of protection paths, independent of the number of connections.

Findings

Errors can be corrected with 4n_e protection paths.

Protection against n_e errors and n_f failures requires 4n_e + 2n_f paths.

Protection path count is independent of the number of unicast connections.

Abstract

We propose a network-coding based scheme to protect multiple bidirectional unicast connections against adversarial errors and failures in a network. The network consists of a set of bidirectional primary path connections that carry the uncoded traffic. The end nodes of the bidirectional connections are connected by a set of shared protection paths that provide the redundancy required for protection. Such protection strategies are employed in the domain of optical networks for recovery from failures. In this work we consider the problem of simultaneous protection against adversarial errors and failures. Suppose that n_e paths are corrupted by the omniscient adversary. Under our proposed protocol, the errors can be corrected at all the end nodes with 4n_e protection paths. More generally, if there are n_e adversarial errors and n_f failures, 4n_e + 2n_f protection paths are sufficient. The number of protection paths only depends on the number of errors and failures being protected against and is independent of the number of unicast connections.