Co-spanning tree restoration mechanism for metro Ethernet switched networks

Abstract

Ethernet, a popular technology in IT industry, with high transmission rate, simple maintenance, and compatibility with different types of links was invented for local and small-scale computer networks. However, current spanning tree-based Ethernet protocols do not meet the requirements for metro Ethernet networks in terms of network resilience. One of the most important weaknesses is slow re-convergence time in the event of a link failure when a new spanning tree must be reconstructed to ensure the survivability of networks. In this paper, we propose a co-spanning tree restoration (CSTR) mechanism for metro Ethernet switched networks to handle the link failures. Upon failure of a link on the network, a distributed failure restoration protocol will be activated to reconstruct the damaged spanning tree using a $$co\text {-}tree$$co-tree link. We explain the details of the protocol, including advertisement tables and fundamental reconfiguration processes. In addition, we propose a simple and effective solution for a double link failure and develop an optional feature to control unnecessary topology changes. The simulated results of CSTR on different network topologies show its features of efficiency and quick recovery.