The survey of current IPFRR mechanisms

Abstract

The primary idea of the IP Fast Reroute (IPFRR) technology is to reduce the network recovery time after a link or router failure within an ISP network. The key feature of existing IPFRR mechanisms for reaching low recovery time is the usage of pre-computed alternative backup paths. These alternative backup paths have to be pre-calculated before a network failure will occur. The calculation of the alternative backup path utilizes the specific information about destination networks, and thus most of existing IPFRR mechanisms are dependent on the distance-vector routing protocols (RIP, EIGRP). Other IPFRR mechanisms requires an additional information about the network topology, and therefore strongly depend on the usage of link-state routing protocols (OSPF, IS-IS). The paper is focusing on the analysis of existing IPFRR mechanisms and is identifying and presenting theirs primary problematic areas.