NEC Electra Elite 48/192 Features And Specifications Manual page 331

Issue 6
E - 28
When the station user is talking on a line that is to be dropped for
¥
911 - Cut Through, an alert tone is provided for 2 seconds before the
line is disconnected.
¥ Calls are dropped for 911 - Cut Through in the following priority:
1. Talking State
2. Holding State
3. Parked State
4. Conferencing, Live Record, or Live Monitoring State
Electra Elite
Emergency 911 - Cut Through