Heuristic routing is a system used to describe how deliveries are made when problems in a

network topology Network topology is the arrangement of the elements (Data link, links, Node (networking), nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, ...

arise.

Heuristic A heuristic or heuristic technique (''problem solving'', '' mental shortcut'', ''rule of thumb'') is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless ...

is an adjective used in relation to methods of learning, discovery, or problem solving.

Routing Routing is the process of selecting a path for traffic in a Network theory, network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched ...

is the process of selecting paths to specific destinations. Heuristic routing is used for traffic in the

telecommunications network A telecommunications network is a group of Node (networking), nodes interconnected by telecommunications links that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of circuit ...

s and

transport network A transport network, or transportation network, is a network or graph in geographic space, describing an infrastructure that permits and constrains movement or flow. Examples include but are not limited to road networks, railways, air routes ...

s of the world. Heuristic routing is achieved using specific

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

s to determine a better, although not always optimal, path to a destination. When an interruption in a network topology occurs, the software running on the networking electronics can calculate another route to the desired destination via an alternate available path. According to :

The heuristic approach to problem solving consists of applying human intelligence, experience, common sense and certain rules of thumb (or heuristics) to develop an acceptable, but not necessarily an optimum, solution to a problem. Of course, determining what constitutes an acceptable solution is part of the task of deciding which approach to use; but broadly defined, an acceptable solution is one that is both reasonably good (close to optimum) and derived within reasonable effort, time, and cost constraints. Often the effort (manpower, computer, and other resources) required, the time limits on when the solution is needed, and the cost to compile, process, and analyze all the data required for deterministic or other complicated procedures preclude their usefulness or favor the faster, simpler heuristic approach. Thus, the heuristic approach is generally used when deterministic techniques or are not available, economical, or practical.

Heuristic routing allows a measure of route optimization in telecommunications networks based on recent empirical knowledge of the state of the network. Data, such as

time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

delay, may be extracted from incoming messages, during specified periods and over different routes, and used to determine the optimum routing for transmitting data back to the sources.

IP routing

The

IP routing IP routing is the application of traffic routing methodologies to IP networks. This involves technologies, protocols, structure, administrations, and policies of the worldwide Internet infrastructure. In each IP network node, IP routing involv ...

protocols in use today are based on one of two algorithms: ''distance vector'' or ''link state''. Distance vector algorithms broadcast routing information to all neighboring routers. Link state routing protocols build a topographical map of the entire network based on updates from neighbor routers, and then use the Dijkstra algorithm to compute the shortest path to each destination. Metrics used are based on the number of hops, delay, throughput, traffic, and reliability.

Distance vector algorithms

* RIP uses number of hops, or gateways traversed, as its metric * IGRP uses bandwidth, delay, hop count, link reliability, load, and MTU * EIGRP uses the (DUAL) Diffusing Update Algorithm *

BGP Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous system (Internet), autonomous systems (AS) on the Internet. BGP is classified as a path-vect ...

uses the distance vector algorithm

Link state algorithms

* OSPF uses the Dijkstra algorithm.

References

* * * * {{DEFAULTSORT:Heuristic routing Heuristic algorithms Routing

IP routing

Distance vector algorithms

Link state algorithms

See also

References