cc_CallAck( )

Description | Termination Event | Cautions | Example | Errors | See Also

Name:	int cc_CallAck(crn, newLineDev, msg_id)
Inputs:	CRN crn	call reference number
	LINEDEV newLineDev	new line device handle
	int msg_id	message id
Returns:	0 on success < 0 on failure
Includes:	cclib.h
Category:	Optional call handling
Mode:	asynchronous
Technology:	BRI/2; BRI/SC; PRI (all protocols)

Description

The cc_CallAck( ) function allows the application to send the first response to an incoming call, after the CCEV_OFFERED event is received, in asynchronous mode, or after cc_WaitCall( ) returns, in synchronous mode.

NOTE:

Controlling the first response to the incoming setup message is optional. The ISDN firmware assumes the control by default unless it is set up by the application (see the cc_SetEvtMsk( ) function description for details).

Parameter	Description
crn:	The call reference number. Each call needs a valid CRN.
newLineDev:	The new line device handle for the channel to be used for the call. This parameter is reserved for future use. Set newLineDev to 0.
msg_id:	The message ID, either CALL_PROCEEDING or CALL_SETUP_ACK. NOTE: Applications that require overlap receiving should set msg_id to CALL_SETUP_ACK.

The application can use this function to indicate one of the following conditions to the network:

1. The received setup message contains all the information necessary to set up the call. The application should use the function in one of the following ways:
   • cc_CallAck(crn, 0, CALL_PROCEEDING) if B channel is acceptable
   • cc_CallAck(crn, newLineDev, CALL_PROCEEDING) if a new B channel is desired.
2. The received setup message contains insufficient destination information. The application should use the function in one of the following ways:
   • cc_CallAck(crn, 0, CALL_SETUP_ACK) if the B channel is acceptable
   • cc_CallAck(crn, newLineDev, CALL_SETUP_ACK) if a new B channel is desired

Termination Event

• CALL_SETUP_ACK and CALL_PROCEEDING - indicate that the call setup message has been received.
• CCEV_TASKFAIL - indicates that a request/message was rejected by the firmware. Typically, this event is triggered by an incorrect function call during the call.

Cautions

None

Example

#include <windows.h>   /* For Windows applications only */  
#include <stdio.h>  
#include <errno.h>  
#include "srllib.h"  
#include "dtilib.h"  
#include "cclib.h"  
void main()  
{  
   LINEDEV   devhdl    = 0;  
   CRN       crn = 0;  
   char     *devname = "dtiB1T1";  
   if ( cc_Open( &devhdl, devname, 0 ) < 0 )   
   {  
      printf("Error opening device: errno = %d\n", errno);  
      exit(1);  
   }  
   if ( cc_WaitCall(devhdl, &crn, NULL, -1, EV_SYNC) < 0 )  
        procdevfail(devhdl);  
   /*   
    * The cc_CallAck() function needs to be called after   
    * cc_WaitCall and before cc_CallProgress(), cc_AcceptCall()  
    * and cc_AnswerCall()  
    */  
   if ( cc_CallAck(crn,0,CALL_PROCEEDING) < 0 )  
        callfail(crn);  
   printf("Accepting call\n");  
   if ( cc_AcceptCall(crn, 0, EV_SYNC) < 0 )  
        callfail(crn);  
   if ( cc_AnswerCall(crn, 0, EV_SYNC) < 0 )  
        callfail(crn);  
        .  
        .  
        .  
        .  
        .  
   if ( cc_DropCall(crn, NORMAL_CLEARING, EV_SYNC) < 0 )  
        callfail(crn);  
   if ( cc_ReleaseCall(crn) < 0 )  
        callfail(crn);  
   if ( cc_Close( devhdl ) < 0 )   
      printf("Error closing device, errno = %d\n", errno);  
}  
int callfail(CRN crn)  
{                  
        LINEDEV ld;  
         cc_CRN2LineDev(crn,&ld);  
         procdevfail(ld);  
}  
int procdevfail(LINEDEV handle)  
{  
        int reason;  
        char *msg;  
        reason = cc_CauseValue(handle);  
        cc_ResultMsg(handle,reason,&msg);  
        printf("reason = %x - %s\n",reason,msg);  
}

Errors

If the function returns a value < 0 to indicate failure, use the cc_CauseValue( ) function to retrieve the reason code for the failure. The cc_ResultMsg( ) function can be used to interpret the reason code. Error codes are defined in the files ccerr.h, isdnerr.h and isdncmd.h.

Error codes from the cc_CallAck( ) function include the following:

Error Code	Description
E_ISBADIF | ERR_ISDN_LIB	Bad interface number
E_ISBADTS | ERR_ISDN_LIB	Bad time slot

See Also

• cc_SetEvtMsk( )

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