- answering machine
- automatic dialing
- calling procedure
- call string
- called party
- call
- call charge
- calling party
- charge
- exchange
- extension
- extension number
- ext
- face panel
- guard circuit
- head set
- line loop
- linesman
- local network
- longitudinal circuit
- misdial
- operator
- party line
- period
- private line
- put through
- receiver
- redial
- ringer
- return call
- ring back
- ring up
- sidetone
- signal component
- subscriber
- subscription
- supervision
- switchboard
- switchboard operator
- switchboard line
- telephone extension
- telephone subscriber