Ringing out is the act of dialing from an internal PBX or private telephone system to an external number on the Public Switched Telephone Network (PSTN). This usually requires dialing a specific prefix, such as 9, to seize an outside trunk line before entering the destination number. Telecom administrators monitor ring-out traffic to track trunk utilization and prevent toll fraud.
Check the dial plan rules, because the lobby phone shouldn't be able to ring out to international numbers.
Related terms
PBX
A private telephone network used within a company or organization.
Trunk call
A historic long-distance telephone call routed through major intercity exchanges.
PSTN
The global infrastructure of circuit-switched telephone networks operated by national and regional carriers.
Prefix
The initial digits of a telephone number that route the call to a specific geographic region or service type.