cc_DropCall( )

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

Name:	int cc_DropCall(crn, cause, mode)
Inputs:	CRN crn	call reference number
	int cause	reason for dropping the call
	unsigned long mode	synchronous or asynchronous
Returns:	0 on success < 0 on failure
Includes:	cclib.h
Category:	Call control
Mode:	synchronous or asynchronous
Technology:	BRI/2; BRI/SC; PRI (all protocols)

Description

The cc_DropCall( ) function allows the application to disconnect a call, specified by a CRN, at any time. The application must specify a reason for dropping the call. Valid causes are listed in Table 18.

Parameter	Description
crn:	The call reference number. Each call needs a CRN.
cause:	The reason for disconnecting or rejecting the call. The values listed in Table 18 indicate common causes for dropping a call.
mode:	Specifies asynchronous (EV_ASYNC) or synchronous (EV_SYNC) mode.

Table 18. cc_DropCall( ) Causes

Value	Description
ACCESS_INFO_DISCARDED	Access information discarded
BAD_INFO_ELEM	Information element nonexistent or not implemented
BEAR_CAP_NOT_AVAIL	Bearer capability not available
CALL_REJECTED	Call rejected
CAP_NOT_IMPLEMENTED	Bearer capability not implemented
CHAN_DOES_NOT_EXIST	Channel does not exist
CHAN_NOT_IMPLEMENTED	Channel type not implemented
CHANNEL_UNACCEPTABLE	Channel is unacceptable
DEST_OUT_OF_ORDER	Destination out of order
FACILITY_NOT_IMPLEMENT	Requested facility not implemented
FACILITY_NOT_SUBSCRIBED	Facility not subscribed
FACILITY_REJECTED	Facility rejected
INCOMPATIBLE_DEST	Incompatible destination
INCOMING_CALL_BARRED	Incoming call barred
INTERWORKING_UNSPEC	Interworking unspecified
INVALID_CALL_REF	Invalid call reference
INVALID_ELEM_CONTENTS	Invalid information element
INVALID_MSG_UNSPEC	Invalid message, unspecified
INVALID_NUMBER_FORMAT	Invalid number format
MANDATORY_IE_LEN_ERR	Message received with mandatory information element of incorrect length
MANDATORY_IE_MISSING	Mandatory information element missing
NETWORK_CONGESTION	Network congestion
NETWORK_OUT_OF_ORDER	Network out of order
NO_CIRCUIT_AVAILABLE	No circuit available
NONEXISTENT_MSG	Message type nonexistent or not implemented
NORMAL_CLEARING	Normal clearing
NO_ROUTE	Network has no route to the specified transient network, or the network has no route to the destination.
NO_USER_RESPONDING	No user responding
NUMBER_CHANGED	Number changed
OUTGOING_CALL_BARRED	Outgoing call barred
PRE_EMPTED	Call preempted
PROTOCOL_ERROR	Protocol error, unspecified
REQ_CHANNEL_NOT_AVAIL	Requested circuit/channel unavailable
RESP_TO_STAT_ENQ	Response to status inquiry
SERVICE_NOT_AVAIL	Service not available
TEMPORARY_FAILURE	Temporary failure
TIMER_EXPIRY	Recovery on timer expired
UNASSIGNED_NUMBER	Unassigned number
UNSPECIFIED_CAUSE	Unspecified cause
USER_BUSY	User busy
WRONG_MESSAGE	Message type invalid in call state or not implemented
WRONG_MSG_FOR_STATE	Message type not compatible with call state

Termination Events

• CCEV_DROPCALL - indicates that a DISCONNECT message has been sent to the network.
• 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

In order to release the call reference number, this function must be followed by a cc_ReleaseCall( ) to prevent a blocking condition or memory allocation errors.

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);  
   }  
   printf("Waiting for call\n");  
   if ( cc_WaitCall(devhdl, &crn, NULL, -1, EV_SYNC) < 0 )  
        procdevfail(devhdl);  
   if ( cc_AnswerCall(crn, 0, EV_SYNC) < 0 )  
        callfail(crn);  
      .  
      .  
      .  
      .  
      .  
   /* Drop the call */  
   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 < 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_DropCall( ) function include the following:

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

See Also

• cc_ReleaseCall( )
• cc_MakeCall( )
• cc_WaitCall( )

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