Event	Description
Incoming Call	The network is offering a call.
Answering Call	AG Access is answering the incoming call.
Rejecting Call	AG Access is not answering the call. This occurs for two reasons: either the application commanded it or the protocol forced it due to an application timeout.
Placing Call	AG Access has seized an outbound line and is delivering the destination address. This indicates that you need not expect an incoming call due to a race condition.
Call Connected	Inbound: The network connection is established. Outbound: The network connection is established and any other connection criteria have been satisfied (e.g., modem tones detected).
Call Disconnected	The remote party has disconnected or the network has rejected a placed call (e.g., busy tone detected).
Call Released	The network connection and all AG Access resources allocated to this call have been released.
Blocking	Call establishment is disabled. Inbound calls are rejected and outbound calls are prevented.
Unblocking	Call establishment is re-enabled.
Placing Second Call	AG Access has placed the main call on hold and is delivering the destination address of a third party.
Second Call Connected	The third party has answered the call.
Second Call Disconnected	The third party is unavailable or has hung up.
Out of Service	The line is not available for use. Either the network is blocking calls or the line and associated hardware are not configured properly.
In Service	The line has returned to normal.

3.2 Call Control Events

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When performing call control functions, AG Access must process events received from the network. AG Access translates the network physical events into generic call control events. These events fall into two classes, informational and transitional, which are discussed in the following two sections. Actual event names for use in 'C' programming are defined in uppercase letters with an ADIEVN_ prefix. Refer to Appendix B in the AG Access Function Reference Manual for a complete listing of events.

3.2.1 Informational Events

Informational events do not require any action by the application. The protocol error event, ADIEVN_PROTOCOL_ERROR, provides information about abnormalities on the line including false seizure, too many incoming digits, or premature answer while dialing. Other informational events are generated only if you enable them.
The parameter ADICALLCTL eventmask dictates which optional informational call control events are generated. This parameter is discussed in detail in Section 3.4.2, Call Control Mask Parameters.
The following table provides a summary of optional informational events: Event Description Seizure The network has seized the line (inbound). Call Proceeding The destination address has been delivered. Remote Alerting Ring tone has been received from the network. Remote Answer The call is connected to the network.

Event	Description
Seizure	The network has seized the line (inbound).
Call Proceeding	The destination address has been delivered.
Remote Alerting	Ring tone has been received from the network.
Remote Answer	The call is connected to the network.

3.2.2 Transitional Events

Transitional events are generated when the call state changes. They are generated because AG Access needs the application to choose an action (e.g., incoming call response) or acknowledge that an application command is proceeding (e.g., placing call). The following table provides a summary of transitional events which comprise the majority of call control functionality (actual event names for use in `C' programming are defined in uppercase with ADIEVN_ prefixes): Event Description Incoming Call The network is offering a call. Answering Call AG Access is answering the incoming call. Rejecting Call AG Access is not answering the call. This occurs for two reasons: either the application commanded it or the protocol forced it due to an application timeout. Placing Call AG Access has seized an outbound line and is delivering the destination address. This indicates that you need not expect an incoming call due to a race condition. Call Connected Inbound: The network connection is established. Outbound: The network connection is established and any other connection criteria have been satisfied (e.g., modem tones detected). Call Disconnected The remote party has disconnected or the network has rejected a placed call (e.g., busy tone detected). Call Released The network connection and all AG Access resources allocated to this call have been released. Blocking Call establishment is disabled. Inbound calls are rejected and outbound calls are prevented. Unblocking Call establishment is re-enabled. Placing Second Call AG Access has placed the main call on hold and is delivering the destination address of a third party. Second Call Connected The third party has answered the call. Second Call Disconnected The third party is unavailable or has hung up. Out of Service The line is not available for use. Either the network is blocking calls or the line and associated hardware are not configured properly. In Service The line has returned to normal.
Within this chapter, any references to the "connected event" or "disconnected event" pertain to the context defined above.

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