Overlay protection against link failures using network coding

This paper introduces a network coding-based protection scheme against single and multiple link failures. The proposed strategy makes sure that in a connection, each node receives two copies of the same data unit: one copy on the working circuit, and a second copy that can be extracted from linear combinations of data units transmitted on a shared protection path. This guarantees instantaneous recovery of data units upon the failure of a working circuit. The strategy can be implemented at an overlay layer, which makes its deployment simple and scalable. The proposed strategy is an extension of the scheme presented in the work of Kamal (2006). The new scheme is simpler, less expensive, and does not require the synchronization required by the original scheme. The sharing of the protection circuit by a number of connections is the key to the reduction of the cost of protection. A preliminary comparison of the cost of the proposed scheme to the 1+1 protection strategy is conducted, and establishes the benefits of our strategy.