3. ISDN Technology Overview
19
Table 3. Inbound Call Set-Up (Asynchronous Example)
Function/Event Action/Description
cc_WaitCall( ) Issued once after line device opened with
cc_Open( ).
CCEV_OFFERED Indicates arrival of inbound call and initiates
transition to Offered state
*cc_GetANI( ) Request caller ID information
*cc_GetDNIS( ) Retrieves DNIS digits received from the network
*cc_CallAck( ) Requests additional call setup information
*cc_AcceptCall( ) Issued to acknowledge that call was received but
called party has not answered.
*CCEV_ACCEPT Termination event - indicates call received, but not
yet answered; causes transition to Accepted state.
cc_AnswerCall( ) Issued to connect call to called party (answer
inbound call).
CCEV_ANSWERED Termination event - inbound call connected; causes
transition to Connected state.
* = Optional functions and events or maskable events
Table 4 illustrates a simple scenario for making an outbound call using the
asynchronous call establishment process. The items denoted by an asterisk (*) are
optional functions/events or maskable events that may be reported to the
application. For more detailed call scenarios, see Appendix A.