Multi-Path BGP (MBGP): A Solution for Improving Network Bandwidth Utilization and Defense against Link Failures in Inter-Domain Routing

Border Gateway Protocol version 4 (BGP-4) is the routing protocol for inter-domain routing in the Internet. Although BGP-4 is a scalable distributed routing protocol, BGP propagates only the selected best path for a destination to other autonomous systems. This property and long convergence delay in BGP have been known to cause serious inefficiency in network resource utilization and vulnerability to link failures. This paper proposes and describes a new routing protocol, MBGP (Multi-path BGP), to solve the problems by dynamically utilizing concurrent multiple BGP paths in today's Internet without routing loops. MBGP is designed to co-exist with the existing BGP routers. Performance analysis indicates that MBGP has O(N) processing overhead for each MBGP message. Concurrent inter-domain multi-path routing by MBGP with these advantages will enhance the efficiency in the future Internet.