System and method for achieving path symmetry in an internet protocol (IP) based network

摘要

A system and method for improving network performance when communicating between a first site network and a second site network via an IP-based transport network. The site networks include a LAN, a plurality of host/media gateways (MGWs) connected to the LAN, and pairs of first and second Site Edge Routers (SERs) connected to the LAN for handling traffic from different host/MGWs. The SERs are configured as redundant backup pairs in which each SER in a given pair backs up the other SER in the pair. Each SER is connected to a different Provider Edge (PE) router in the transport network via a dedicated link that has sufficient spare capacity to carry traffic coming from both of the SERs in a given pair of SERs in case one of the SERs fails. The SERs provide preferred routing prefixes to the PE routers, thereby guaranteeing symmetric paths for bidirectional traffic.