Returns an event buffer to the NMS ISDN API.

DWORD isdnReleaseBuffer ( CTAHD ctahd,
void *buffer )

ctahd Context handle associated with a D channel, returned by ctaCreateContext.

buffer Pointer to the event buffer.

• SUCCESS
• CTAERR_INVALID_CTAHD
  The context handle is invalid.
• CTAERR_INVALID_STATE
  An ISDN protocol stack instance is not started on the specified context, or an instance is starting or stopping on the context.
• ISDNERR_INVALID_BUFFER
  The buffer submitted is not a valid buffer.

None.

This function indicates to the stack that the application has finished processing an event buffer (described by the CTA_EVENT buffer and size fields) and is returning that buffer to the NMS ISDN API. The event ID for ISDN events is ISDNEVN_RCV_MESSAGE.

Note: The application must return every event buffer to the NMS ISDN API as soon as possible, or the API will time out and stop passing events to the application.

DWORD sample_process_events (CTAHD ctahd)
{
CTA_EVENT     event;
ISDN_MESSAGE *imsg;
ISDN_PACKET  *ipkt;
BYTE         *data;
DWORD         ret;
char          errortext[40];
 
#define EVENT_CODE(from, code)       ((from<<8)|code)
...
/*
** Protocol already started
** Application may have sent messages to stack
*/
...
/*
** Application waiting for events
*/
myWaitForEvent( ctahd, &event);

/*
** Got event ISDN_RCV_MESSAGE
** If the event value field is not SUCCESS, then
** the event was not received successfully.
*/
if( event.value != SUCCESS )
{ 
    ctaGetText(ctahd, event.value, errortext, 40);
    printf("RCV_FAIL: %s\n", errortext);
    return MY_ERROR_RCV_FAILED;
}

/*
** NOTE: all asynchnous events have the 
** msg->userid field is ISDN_USERID_ASYNC
*/
ipkt = (ISDN_PACKET *) event->buffer;
imsg = &ipkt->message;
data = ipkt->data;

printf("from: %c  code=%c  to=%c   id=%d len=%d\n",
        imsg->from_ent, 
        imsg->code,
        imsg->to_ent,
        imsg->add.conn_id,
        ipkt->data_len);

switch(EVENT_CODE(imsg->from_ent, imsg->code) )
{
    case EVENT_CODE(ENT_ACU, CONN_CO):
        /*
        ** Call is now connected
        */
        printf("Connected on conn_id: %d\n",imsg->add.conn_id);
        break;

    case EVENT_CODE(ENT_ACU,ACU_CLEAR_CO):
        /*
        ** Call is now cleared
        */
        printf("Cleared on conn_id: %d\n", imsg->add.conn_id);
        break;
...

    default:
        printf("Unprocessed message: %c %c\n", imsg->from_ent, 
                imsg->code);
        break;
}
/*
** Processing is done, release the buffer as soon as possible
*/
ret = isdnReleaseBuffer( ctahd, event.buffer );
if( ret != SUCCESS )
{
    ctaGetText(ctahd, event.value, errortext, 40);
    printf("RELEASE_FAIL: %s\n", errortext);
    return  MY_ERROR_RELEASE_FAILED;
}
...
}