Define Routing Algorithms

What is Routing Algorithms

Routing Algorithm can be differentiated based on several key characteristics. First, the particular goals of the algorithm designer affect the operation of the resulting routing protocol. Second, various types of routing algorithms exist, and each algorithm has a different impact on network and router resources. Finally, routing algorithms use a variety of metrics that affect calculation of optimal routes. The following sections analyze these routing algorithm attributes.

Usually Routing algorithms have one of these goals

• Rapid convergence
• Flexibility
• Robustness & Stability
• Optimality
• Simplicity and low overhead

Routing algorithms are usually flexible, which means that they should quickly and accurately adapt to a variety of network circumstances. Assume, for example, that a network segment has gone down. Routing algorithms will become aware of the problem, they will quickly select the next-best path for all the routes. It can also be programmed to adapt to changes in network bandwidth, router queue size, and network delay also.

Different types of Algorithms

• Single-path versus multipath
• Static versus dynamic
• Host-intelligent versus router-intelligent
• Flat versus hierarchical
• Link-state versus distance vector
• Intradomain versus interdomain

Routing Metrics

Routing table contains information  used by switching software to select the best route. Routing algorithms uses many different metrics to determine the best route. Sophisticated routing algorithms can use route selection on multiple metrics, combining them in a single (hybrid) metric. All the following metrics have been used by Routing Algorithms.

• Reliability
• Path Length
• Delay
• Load
• Bandwidth
• Communication cost