Optimal redundancy allocation for high availability routers

Abstract

SUMMARYHow to optimally allocate redundant routers for high availability (HA) networks is a crucial task. In this paper, a 5-tuple availability function A (N , M, , , ) is proposed to determine the minimum required number of standby routers to meet the desired availability ( ) of an HA router, where N and M are the numbers of active routers and standby routers, respectively, and , , and are a single router's failure rate, repair rate, and failure detection and recovery rate, respectively. We have derived the availability function, and analytical results show that the failure detection and recovery rate ( ) is a key parameter for reducing the minimum required number of standby routers of an HA router. Thus, we also propose a High Availability Management (HAM) middleware, which was designed based on an open architecture specification, called OpenAIS, to achieve the goal of reducing takeover delay (1/ ) by stateful backup. We have implemented an HA Open Shortest Path First (HA-OSPF) router, which consists of two active routers and one standby router, to illustrate the proposed HA router. Experimental results show that the takeover delays of the proposed HA-OSPF router were reduced by 6, 37.3, and 98.6% compared with those of the industry standard approaches, the Cisco-ASR 1000 series router, the Juniper MX series router, and the Virtual Router Redundancy Protocol (VRRP) router, respectively. In addition, in contract to the industry routers, the proposed HA router, which was designed based on an open architecture specification, is more cost-effective, and its redundancy model can be more flexibly adjusted.

Dynamic connection provisioning with shared protection in IP/WDM networks

“…Grover intensively investigated service availability in ring optical networks. To and Neusy and Tsai et al analyzed a number of long‐haul network architectures from an unavailability point of view and have shown that self‐healing rings dual fed systems offer the highest level of survivability by eliminating service impacts caused by link cuts and other optical fiber components. The research studies in find out that partitioning a network into multiple domains increases the overall availability.…”

FDVRRP: Router implementation for fast detection and high availability in network failure cases

“…If a router fails, the routing functionalities should be seamlessly shifted from one router to another without any disruption of the internal network. A significant challenge has also been the allocation of redundant routers-when these routers exist-to achieve high availability [8].…”

Preventive start‐time optimisation of open shortest path first link weights for hose model

“…Emerging Internet applications such as voice-over-Internet protocol (VoIP), teleconferences and multi-party games are adversely affected if rerouting of the data packets occurs because of failures caused by optical fibre cuts, maintenance windows, router reboots, and so on [1][2][3]. Present traffic engineering methods, which are used to optimise link weights, need to recalculate a set of optimal link weights if network failures such as link failures occur.…”