In this paper, we propose a High Availability Open Shortest Path First (HA-OSPF) router which consists of two OSPF router modules, active and standby, to support a high availability network. First, we used the continuous-time Markov chain (CTMC) to analyze the steady-state availability of an HA-OSPF router with one active router and N standby routers (1 + N redundancy model). Then, with the fai...

In this paper, the authors have focused on the stochastic analysis of an internet data center (IDC), which consists of a database main server connected to a redundant server. Observing the different possibilities of functioning of the system, analysis has been done to evaluate the various reliability characteristics of the system. The system can completely fail due to failure of redundant serve...

How 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 ro...

This paper is devoted to researching the routing reliability and router standby mechanism for smart and cooperation network. The method of updating and initiating the standby router has been also provided. With the aid of virtual interface, both the main router and standby router will be transparent to the network. Through Mini-Net simulated experiment, this paper has verified the mechanism. It...

Vol. 9 No. 3 1997 A DIGITAL router engineering team has refined and extended routing protocols to guarantee a five-second maximum loss-of-service time during a single failure in an Internet Protocol (IP) network. We use the term router cluster to describe our improved implementation. A router cluster is defined as a group of routers on the same local area network (LAN), providing mutual backup....

OSPF (Open Shortest Path First), which is used widely on networks, has a Router Dead Interval problem. If a (backup) designated router has stopped operation due to failure, the OSPF routers await a hello packet acknowledgment for the router dead interval to recognize that the designated router has ceased the operation. The Router Dead Interval is 40 sec This interval time is not only long for m...

layer is the third component, the optical switch, which interconnects the core routers via a switched optical network layer over WDM links. While new high-availability (so-called “non-stop routing”) core routers provide service resiliency at the packet layer, the optical layer provides lowest cost and highest level of resiliency at the physical layer against catastrophic network events such as ...

We propose data structures preparing shortest path routing, such as OSPF or ISIS, for link failure. Each router can in constant time determine an outgoing link on a shortest path to a destination avoiding any given failed link. This is used to avoid inconsistent forwarding in the period where router tables are updated following a link-

In this article we study approaches that can be used to minimise the convergence time, we also make a focus on microloops phenomenon, analysis and means to mitigate them. The convergence time reflects the time required by a network to react to a failure of a link or a router failure itself. When all nodes (routers) have updated their respective routing and forwarding databases, we can say the n...

We design a new language DRπ F in which we extend the language DRπ to handle node failure during communication. We have extended the reduction semantics of DRπ . For handling the node failure we describe two tables at router: One is routing table contains name mapping for forward travel of messages and other is a database of all active nodes at any router. Further we discuss the new node creati...