Equal-cost multi-path routing

About: Equal-cost multi-path routing is a research topic. Over the lifetime, 10472 publications have been published within this topic receiving 249362 citations.

A Length-Matching Routing Algorithm for High-Performance Printed Circuit Boards

Abstract: As the clock frequencies used in industrial applications increase, the timing requirements imposed on routing problems become tighter. Therefore, it becomes important to route the nets within tight minimum and maximum length bounds. Although the problem of routing nets to satisfy maximum length constraints is a well-studied problem, there exists no sophisticated algorithm in literature that ensures that minimum length constraints are also satisfied. In this paper, the authors propose a novel algorithm that effectively incorporates the min;max length constraints into the routing problem. The approach is to use a Lagrangian-relaxation (LR) framework to allocate extra routing resources around nets simultaneously during routing them. The authors also propose a graph model that ensures that all the allocated routing resources can be used effectively for extending lengths. Their routing algorithm automatically prioritizes resource allocation for shorter nets and length minimization for longer nets so that all nets can satisfy their min;max length constraints. This paper demonstrates that this algorithm is effective even in the cases where length constraints are tight, and the spacing between adjacent nets is small

A Review on Hierarchical Routing Protocols for Wireless Sensor Networks

Abstract: The routing protocol for Wireless Sensor Networks (WSNs) is defined as the manner of data dissemination from the network field (source) to the base station (destination). Based on the network topology, there are two types of routing protocols in WSNs, they are namely flat routing protocols and hierarchical routing protocols. Hierarchical routing protocols (HRPs) are more energy efficient and scalable compared to flat routing protocols. This paper discusses how topology management and network application influence the performance of cluster-based and chain-based hierarchical networks. It reviews the basic features of sensor connectivity issues such as power control in topology set-up, sleep/idle pairing and data transmission control that are used in five common HRPs, and it also examines their impact on the protocol performance. A good picture of their respective performances give an indication how network applications, i.e whether reactive or proactive, and topology management i.e. whether centralized or distributed would determine the network performance. Finally, from the ensuring discussion, it is shown that the chain-based HRPs guarantee a longer network lifetime compared to cluster-based HRPs by three to five times.

Methods and systems for hitless restart of layer 3 packet forwarding

Abstract: A method for hitless restart of layer 3 packet forwarding includes replicating some but not all state information from a master management service module to a slave management service module. The master management service module builds a layer 3 routing table by participating in layer 3 routing protocols. The layer 3 routing table is stored in memory. The master management service module builds a first layer 3 forwarding table and stores the forwarding information in hardware. A slave management service module receives a copy of the first layer 3 forwarding table from the master management service module. When the master management service module fails, the slave management service module initiates construction of a routing table by participating in layer 3 routing protocols. Packet forwarding is not interrupted because forwarding using hardware entries continues. The slave management service module links entries in the newly constructed routing table to those stored in the forwarding table.

Routing restorable bandwidth guaranteed connections using maximum 2-route flows

Abstract: Routing with service restorability is of much importance in Multi-Protocol Label Switched (MPLS) networks, and is a necessity in optical networks. For restoration, each connection has an active path and a link-disjoint backup path. The backup path enables service restoration upon active path failure. For bandwidth efficiency, backups may be shared. This requires that at least the aggregate backup bandwidth used on each link be distributed to nodes performing route computations. If this information is not available, sharing is not possible. Also, one scheme in use for restorability in optical networks is for the sender to transmit simultaneously on the two disjoint paths and for the receiver to choose data from the path with stronger signal. This has the advantage of fast receiver-initiated recovery upon failure but it does not allow backup sharing. In this paper, we consider the problem of efficient dynamic routing of restorable connections when backup sharing is not allowed. Our objective is to be able to route as many connections as possible for one-at-a-time arrivals and no knowledge of future arrivals. Since sharing cannot be used for achieving efficiency, the goal is to achieve efficiency by improved path selection. We show that by using the minimum-interference ideas used for nonrestorable routing, we can develop efficient algorithms that outperform previously proposed algorithms for restorable routing such as routing with the min-hop like objective of finding two disjoint paths with minimum total hop-count. We present two new and efficient algorithms for restorable routing without sharing, and one of them requires only shortest path computations. We demonstrate that both algorithms perform very well in comparison to previously proposed algorithms.