Выражение встречается в следующем контексте:
An annunciator, a SCCP device that uses the Cisco Media Streaming Application service, enables Cisco CallManager to play pre-recorded announcements (.wav files) and tones to Cisco IP Phones and gateways. The annunciator, which works with Cisco Multilevel Precedence Preemption, enables Cisco CallManager to alert callers as to why the call fails. Annunciator can also play tones for some transferred calls and some conferences.
Заранее спасибо