Greeting the caller, reporting that all the operators are busy at the moment, plays music during waiting in queue, requests to stay on the line as the next available operator will pick up exactly your call.
The service for determining from which number a client has called. This helps to decide how to answer on the incoming call. A telephone company sends DNIS number to the telephone client’s system during establishing connection. As a rule, DNIS number consists from 4 to 10 digits.