cc_CallState( )

Description | Cautions | Example | Errors | See Also

Name:	int cc_CallState(crn, state_buf)
Inputs:	CRN crn	call reference number
	int* state_buf	pointer to requested state number
Returns:	0 on success < 0 on failure
Includes:	cclib.h
Category:	System tools
Mode:	synchronous
Technology:	BRI/2; BRI/SC; PRI (all protocols)

Description

The cc_CallState( ) function retrieves the state of a call associated with a particular call reference number (CRN). The call state, which is stored in the firmware, changes only when a valid message is sent or received during a given state. For more on call states, see Section 3.3. ISDN Call Control States.

Parameter	Description
crn:	The call reference number. Each call needs a CRN.
state_buf:	The pointer to the location where the state value is returned. The supported states are as follows:   CCST_ACCEPTED - An inbound call was accepted; the call is in the Accepted state.   CCST_ALERTING - The call is waiting for the destination party to answer; the call is in the alerting state (call alerted sent or received)   CCST_CONNECTED - An inbound or outbound call was connected; the call is in the Connected state.   CCST_DIALING - An outbound call request was received; the call is in the Dialing state.   CCST_DISCONNECTED - The call was disconnected from the network; the call is in the Disconnected state.
	CCST_IDLE - The call is not active; the call is in the Idle state.   CCST_NULL - The call was released; the call is in the Null state.   CCST_OFFERED - An inbound call was received; the call is in the Offered state.

Cautions

Due to normal process latency time, the state value acquired may not reflect the current state of the call. The state retrieved will be associated with the last event received by the application.

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";  
   int state;  
   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);  
   /*   
    * using cc_CallState(crn, &state) to retrieve the current   
    * call state from the firmware.  
    */   
      if ( cc_CallState(crn,&state) < 0 )  
           callfail(crn);  
      if(state == CCST_DISCONNECTED)  
      {  
            if ( cc_DropCall(crn, NORMAL_CLEARING, EV_SYNC) < 0 )  
                 callfail(crn);  
            if ( cc_ReleaseCall(crn) < 0 )  
                 callfail(crn);  
            exit(1);  
      }  
   }  
      .  
      .  
      .  
      .  
      .  
   /* Drop the call */  
   if ( cc_DropCall(crn, NORMAL_CLEARING, EV_SYNC) < 0 )  
        callfail(crn);  
   if ( cc_ReleaseCall(crn) < 0 )  
        callfail(crn);  
   /* Close the device */  
   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_CallState( ) function include the following:

Error Code	Description
ERR_ISDN_LIB | E_ISBADIF	Bad interface number
ERR_ISDN_LIB | E_ISBADTS	Bad time slot
ERR_ISDN_LIB | E_ISCALLRELATED	Call related event

See Also

None

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