PESO: low overhead protection for Ethernet over SONET transport

This paper addresses the issue of reliable transport of emerging data services in Ethernet over SONET (EoS) networks that require protection guarantees beyond standard best effort delivery. We argue that the current consensus of using Ethernet spanning tree and a SONET 1+1 protection, while providing reliability, is an inefficient use of resources. Instead, we claim that EoS opens novel opportunities for protection heretofore unavailable in other environments. In particular, the deployment of virtual concatenation and LCAS protocols enables "route splitting", creating a fundamentally new routing paradigm for circuit-switched environments. We propose a scheme called PESO, appropriate for EoS, with innovative routing, failure notification and switching components. More importantly, it is competitive with SONET protection without its 100% bandwidth overhead. We also suggest a enhancement in LCAS that can further improve PESO\´S switching time. PESO leverages the underlying protocols, making it extremely attractive to implement and use in practice.