Routing table

About: Routing table is a research topic. Over the lifetime, 16589 publications have been published within this topic receiving 336842 citations. The topic is also known as: routing information base & RIB.

An optimal probabilistic forwarding protocolin delay tolerant networks

Abstract: Due to uncertainty in nodal mobility, DTN routing usually employs multi-copy forwarding schemes. To avoid the cost associated with flooding, much effort has been focused on probabilistic forwarding, which aims to reduce the cost of forwarding while retaining a high performance rate by forwarding messages only to nodes that have high delivery probabilities. This paper aims to provide an optimal forwarding protocol which maximizes the expected delivery rate while satisfying a certain constant on the number of forwardings per message. In our proposed optimal probabilistic forwarding (OPF) protocol, we use an optimal probabilistic forwarding metric derived by modeling each forwarding as an optimal stopping rule problem. We also present several extensions to allow OPF to use only partial routing information and work with other probabilistic forwarding schemes such as ticket-based forwarding. We implement OPF and several other protocols and perform trace-driven simulations. Simulation results show that the delivery rate of OPF is only 5% lower than epidemic, and 20% greater than the state-of-the-art delegation forwarding while generating 5% more copies and 5% longer delay.

Dynamic wavelength routing using congestion and neighborhood information

Abstract: We present two dynamic routing algorithms based on path and neighborhood link congestion in all-optical networks. In such networks, a connection request encounters higher blocking probability than in circuit-switched networks because of the wavelength-continuity constraint. Much research has focused on the shortest-path routing and alternate shortest-path routing. We consider fixed-paths least-congestion (FPLC) routing in which the shortest path may not be preferred to use. We then extend the algorithm to develop a new routing method: dynamic routing using neighborhood information. It is shown by using both analysis and simulation methods that FPLC routing with the first-fit wavelength-assignment method performs much better than the alternate routing method in mesh-torus networks (regular topology) and in the NSFnet T1 backbone network (irregular topology). Routing using neighborhood information also achieves good performance when compared to alternate shortest-path routing.

Method for routing packets in a packet communication network

Abstract: A packet network routing method and system based on geographic coordinate identifiers is described. Each node in a network is uniquely identified by absolute geographical coordinates or by a code indicating absolute location in an external coordinate-based reference system (node coordinates), and such absolute geographical coordinates or the equivalent are employed as part of a packet identifier for each packet generated for use in making routing decisions. The node coordinates of a local node and its neighboring nodes and the packet coordinates are used by means at each node through which a packet is routed for determining a desired forwarding route of a data packet. The routing may be prioritized according to preselected criteria, preferably achieving maximum forward progress using the least amount of power. The packet routing protocol according to the invention requires no routing directory or table to perform data routing. Each node of the network collects in a table or is otherwise provided with information about the quality of communication between itself and its neighboring nodes. When a data packet has been received at a node, it is routed further through the network based on criteria derived from the history of communication between the local node and its neighbors.

Apparatus and method for unilateral topology discovery in network management

Abstract: A system for reducing the cost of network managment by using a proxy agent and subchannel communications so fewer SNMP licenses and fewer protocol stacks are needed. Subchannel communication is achieved in a plurality of different embodiments. Embodiments having single subchannel transceivers, multiple transceivers, single multiplexer and multiple multiplexers are disclosed. An NMS process using routing table CRC to automatically detect when the NMS topology information is incorrect and automated topology discovery is disclosed. A process for automated discovery of redundant cables during automated topology discovery is disclosed.

Survivable lightpath routing: a new approach to the design of WDM-based networks

Abstract: Network restoration is often done at the electronic layer by rerouting traffic along a redundant path. With wavelength-division multiplexing (WDM) as the underlying physical layer, it is possible that both the primary and backup paths traverse the same physical links and would fail simultaneously in the event of a link failure. It is, therefore, critical that lightpaths are routed in such a way that a single link failure would not disconnect the network. We call such a routing survivable and develop algorithms for survivable routing of a logical topology. First, we show that the survivable routing problem is NP-complete. We then prove necessary and sufficient conditions for a routing to be survivable and use these conditions to formulate the problem as an integer linear program (ILP). Due to the excessive run-times of the ILP, we develop simple and effective relaxations for the ILP that significantly reduces the time required for finding survivable routings. We use our new formulation to route various logical topologies over a number of different physical topologies and show that this new approach offers a much greater degree of protection than alternative routing schemes such as shortest path routing and a greedy routing algorithm. Finally, we consider the special case of ring logical topologies for which we are able to find a significantly simplified formulation. We establish conditions on the physical topology for routing logical rings in a survivable manner.