# Performing low-level call control

The ADI service includes functions that enable applications to perform call control from the host. These functions are typically used with the NOCC (no call control) protocol. Their use is restricted when running other CAS protocols.

For example, all channel associated signaling (CAS) protocols reserve out-of-band signaling,
so ADI service functions that perform out-of-band signaling may not be available. For information about CAS protocols, refer to the NMS CAS for Natural Call Control Developer's Manual.

The following low-level control functions are available in the ADI service:

If you want to... | Then use...
--- | ---
Assert an out-of-band signaling pattern | adiAssertSignal
Pulse an out-of-band signaling pattern for a duration | adiStartPulse
Start detection of out-of-band signaling bits | adiStartSignalDetector
Stop detection of out-of-band signaling bits | adiStopSignalDetector
Query the current inbound out-of-band signaling bits | adiQuerySignalState
Start DTMF/pulse dialing of digits | adiStartDial
Stop DTMF/pulse dialing of digits | adiStopDial

The out-of-band signaling functions relate to either the physical out-of-band signal bits of digital protocols or the control of analog interface boards. In both cases, four signaling bits are addressed: A, B, C, and D, often written as ABCD, and defined by a bit mask (0x8, 0x4, 0x2, and 0x1, respectively). When using these functions, refer to the appropriate manual for your telephone line interface board.

adiStartDial and adiStopDial enable you to perform dialing operations when you are not running formal call control.