The period of time when a communication network becomes inoperative is referred to as:

The period during which a communication network becomes inoperative is called downtime, the stretch when the system is not working.

Time fit is not an established term for network outage and describes no recognised phase of operation.

Uptime is the opposite, the period during which the network is running and available.

Load time means how long content takes to load, not the span for which the whole network is down.

Downtime is measured to judge a system's reliability and availability.

Minimising downtime is a key goal of network maintenance.