Metrics (networking)
Routing metrics are configuration values used by a router to make routing decisions. A metric is typically one of many fields in a routing table. Router metrics help the router choose the best route among multiple feasible routes to a destination. The route will go in the direction of the gateway with the lowest metric.
A router metric is typically based on information such as path length, bandwidth, load, hop count, path cost, delay, maximum transmission unit, reliability and communications cost.
Examples
A metric can include:- measuring link utilization
- number of hops
- speed of the path
- packet loss
- network delay
- path reliability
- path bandwidth
- throughput
- load
- maximum transmission unit
- administrator configured value
A metric can be considered as:
- additive - the total cost of a path is the sum of the costs of individual links along the path,
- concave - the total cost of a path is the minimum of the costs of individual links along the path,
- multiplicative - the total cost of a path is the product of the costs of individual links along the path.
Service level metrics
Router metrics are metrics used by a router to make routing decisions. It is typically one of many fields in a routing table.Router metrics can contain any number of values that help the router determine the best route among multiple routes to a destination. A router metric is typically based on information like path length, bandwidth, load, hop count, path cost, delay, MTU, reliability and communications cost.