dcb_estconf( )

Description | Cautions | Example | Errors | See Also

Name:	int dcb_estconf(devh,cdt,numpty,confattr,confid)
Inputs:	int devh	DCB/SC DSP device handle
	MS_CDT *cdt	pointer to conference descriptor table
	int numpty	number of parties in conference
	int confattr	conference attributes
	int *confid	pointer to the conference identifier
Returns:	0 on success -1 on failure
Includes:	srllib.h dtilib.h msilib.h dcblib.h
Category:	Conference Management
Mode:	synchronous

Description

The dcb_estconf( ) function establishes a conference of up to four parties. A conference is associated with a DSP and all DSP resources used by the conference are on that DSP. When dcb_estconf( ) returns successfully, confid will contain the conference identification number for use in all further modifications to that conference.

Parameter	Description
devh:	The DCB/SC DSP device handle.
cdt:	Pointer to the conference descriptor table.
numpty:	Number of parties in the conference.
confattr:	The conference attributes.
confid:	Pointer to the conference ID number.

The conference descriptor table is an array of the MS_CDT structure. The MS_CDT structure has the following format:

typedef struct {  
          int chan_num;      /* SCbus time slot number */  
          int chan_sel;      /* meaning of time slot number */  
          int chan_attr;     /* attribute description */  
} MS_CDT;

The chan_num field denotes the SCbus transmit time slot number of the device to be included in the conference. The chan_sel defines the meaning of the chan_num. At present, chan_sel must be set to the following value:

• MSPN_TS SCbus time slot number

chan_attr is a bitmask describing the conferee's properties within the conference. Valid choices are:

• MSPA_NULL No special attributes for conferee. The conferee hears
  everyone except the coach.
• MSPA_RO Conferee participates in conference in receive-only
  mode.
• MSPA_TARIFF Conferee receives periodic tone for duration of call.
• MSPA_COACH Conferee is a coach. Coach is heard by pupil only.
• MSPA_PUPIL Conferee is a pupil. Pupil hears everyone including
  coach.

Table 4. Valid Attribute Combinations

Pupil	Coach	Periodic Tone	Receive-only mode
			X
		X
		X	X
	X
X
X		X

NOTES:

1. Only one coach and one pupil are allowed in a conference at any time. Specifying more than one of either will cause unexpected results.

NOTES:

1. The default MSPA_NULL must be used if channel attributes are not specified.

NOTES:

2. Invalid attribute combinations may lead to unexpected results.

The The conference attribute parameter, conf_attr, is a bitmask describing the properties of the conference. The properties are in effect for all parties in the conference.

• MSCA_ND All parties in conference are notified by a tone if
  another conferee is added or removed from a
  conference.
• MSCA_NN If MSCA_ND is set, do not notify conferees if a
  conferee joins the conference in receive-only mode
  or as a monitor.
• MSCA_NULL No special attributes.

For MSCA_NN to have an effect, it should be ORed together with MSCA_ND.

The default MSCA_NULL must be used if the conference attribute is not specified.

For each member of a conference, the number of the SCbus time slot to listen to is returned in the chan_lts field of MS_CDT. The chan_attr field in the CDT structure is redefined as follows:

#define   chan_lts      chan_attr

NOTES:

1. Calling this function causes numpty resources to be used when the conference is successfully established.

NOTES:

2. This function may be used to establish a conference of up to 4 parties. You must use dcb_addtoconf( ) or dcb_monconf( ) to increase the size of the conference.

Cautions

This function fails when:

• An invalid device handle is specified.
• DSP resources are not available.

Example

#include <windows.h>  
#include <stdio.h>  
#include "srllib.h"  
#include "dtilib.h"  
#include "msilib.h"  
#include "dcblib.h"  
#include "errno.h"  
#define   NUM_PARTIES   2  
main()   
{  
   int  dspdevh;                        /* DCB/SC DSP Device handle variable */  
   int  tsdevh1, tsdevh2;               /* Time slot device handles */  
   MS_CDT  cdt[NUM_PARTIES];            /* Conference descriptor table */  
   SC_TSINFO tsinfo;                    /* Time slot information structure */  
   int  confid;                         /* Conference ID */  
   long scts;                           /* SCbus time slot */  
   /* Open DCB/SC board 1, DSP 2 device */  
   if ((dspdevh = dcb_open("dcbB1D2", 0) == -1) {  
      printf("Cannot open dcbB1D2. errno = %d", errno);  
      exit(1);  
   }  
   /* Open network board 1, time slot 1 */  
   if ((tsdevh1 = dt_open("dtiB1T1", 0)) == -1) {  
      printf( "Cannot open dtiB1T1: errno=%d", errno);    
      exit(1);  
   }  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &scts;  
   if (dt_getxmitslot(tsdevh1, &tsinfo) == -1){  
      printf("Error Message = %s", ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }  
   /* Set up CDT structure */  
   cdt[0].chan_num  = (int)scts  ;    /* scts is the time slot... */  
   cdt[0].chan_sel  = MSPN_TS    ;    /* ...returned from getxmitslot() */  
   cdt[0].chan_attr = MSPA_TARIFF;  
   /* Open board 1, time slot 2 */  
   if ((tsdevh2 = dt_open("dtiB1T2", 0)) == -1) {  
      printf( "Cannot open dtiB1T2: errno=%d", errno);    
      exit(1);  
   }  
   if (dt_getxmitslot(tsdevh2, &tsinfo) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   /* SCbus time slot to be conferenced */  
   cdt[1].chan_num  = (int)scts ;     /* scts is the time slot... */  
   cdt[1].chan_sel  = MSPN_TS   ;     /* ...returned from getxmitslot() */  
   cdt[1].chan_attr = MSPA_PUPIL;     /* Conferee may be coached later */  
   /* Establish conference */  
   if (dcb_estconf(dspdevh, cdt, NUM_PARTIES, MSCA_ND, &confid) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(dspdevh));  
      exit(1);  
   }  
   
   /* Do a listen() for the tsdevh1 to its conference signal */  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &cdt[0].chan_lts;  
   if (dt_listen(tsdevh1,&tsinfo) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }  
   
   /* Do a listen() for the tsdevh2 to its conference signal */  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &cdt[1].chan_lts;  
   if (dt_listen(tsdevh2,&tsinfo) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   /*   
    * Continue processing  
    */  
   /* Unlisten the time slots */  
   if (dt_unlisten(tsdevh1) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }  
   if (dt_unlisten(tsdevh2) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   if (dt_close(tsdevh1) == -1){  
      printf("Error closing tsdevh1\n");  
      exit(1);  
   }  
    if (dt_close(tsdevh2) == -1){  
       printf("Error closing tsdevh2\n");  
       exit(1);  
   }  
   /* Delete the conference */  
   if(dcb_delconf(dspdevh, confid) == -1) {  
      printf("Cannot delete conference %d. Error Message = %s", confid,  
	     ATDV_ERRMSGP(dspdevh));  
      exit(1);  
   }  
   /* Done Processing - Close device */  
   if(dcb_close(dspdevh) == -1) {  
      printf("Cannot close DSP dcbB1D2. errno = %d", errno);  
      exit(1);  
   }  
}

Errors

If the function does not complete successfully, it will return -1 to indicate an error. Use the Standard Attribute functions ATDV_LASTERR( ) to obtain the applicable error value, or ATDV_ERRMSGP( ) to obtain a more descriptive error message.

Refer to the error type tables found in Chapter 2 of this guide. Error defines can be found in dtilib.h, msilib.h or dcblib.h.

See Also

• dcb_addtoconf( )
• dcb_delconf( )
• dcb_monconf( )
• dcb_remfromconf( )
• dcb_unmonconf( )

Click here to contact Dialogic Customer Engineering