Definition - What does Metric mean?
A metric is a variable among the critical attributes of the route of a packet within a computer network. It has an unsigned value, so it can never be negative. Metrics are calculated for multiple routes to determine the best route. The route having the best metrics is usually the easiest and fastest path for delivering the packet.
The method used to calculate a metric differs from one network protocol to another. For example, Enhanced Interior Gateway Routing Protocol (EIGRP) has a metric ranging between zero and 4,294,967,295.
This term is also known as a routing metric.
Techopedia explains Metric
Routing tables in routers contain only routes with the lowest metrics. There is another important network attribute called link-state, which is used together with the metric to make the final decision regarding the best path.
To calculate the route metric, many different network parameters are used, including:
- Utilization per link.
- Actual path speed/bandwidth.
- Packet losses per link/path.
- Overall delay of a packet.
- Reliability of the path, calculated according to the history of outages.
- Router throughput.