Synopsis:

       SMfeedlisten(chan1_id,chan1_type,chan2_id,chan2_type)

Arguments:

       chan1_id                – The channel into which the feed will be fed

       chan1_type                - The channel type (TYPE_VOX, TYPE_VMP, TYPE_TDM)

       chan2_id                -  The channel whose feed to listen to 

       chan2_type                - The channel type (TYPE_VOX, TYPE_VMP, TYPE_TDM)

Description:    This function makes the channel specified by the arguments chan1_id and chan1_type 'listen' to the datafeeds provided by the channel specified by the arguments chan2_id and chan2_type.  

The specified channels can be one of the following types as defined in aculab.inc:

const TYPE_VOX=0;

const TYPE_VMP=1;

const TYPE_TDM=2;

Channel types TYPE_VMP and TYPE_TDM must be have been previously created using the appropriate functions (SMcreateVMP() or SMcreateTMD()),   whereas TYPE_VOX channels are allocated at startup.

The first time a TYPE_VOX, TYPE_VMP, or TYPE_TDM channel is used as a feed (i.e as chan2_id and chan2_type arguments) then the datafeed for that channel is created and stored in the internal structure associated with that channel.

For example,  if you make a VMP channel listen to a VOX channel datafeed then any prompts or tones played on that VOX channel will be output by the VMP channel.            For Example:

     int vox_chan, port, chan, vmp_chan, module_id;

    vox_chan=1;

    module_id=0;

    port=0;

    chan=1;

    vmp_chan=SMcreateVMP(module_id);

    // The vmp_chan will now listen to the vox_chan datafeed

    SMfeedlisten(vmp_chan,TYPE_VMP,vox_chan,TYPE_VOX);

    // Wait for an inbound call (using the newly created VMP when we accept)

    CCenablein(port,chan);

    while(1)

           x=CCwait(port,chan,WAIT_FOREVER,&state);

           if(state eq CS_INCOMING_CALL_DET)

                CCalerting(port,chan);   // send INCOMING_RINGING event

           else if(state eq CS_WAIT_FOR_ACCEPT)

                vmp_chan=SMcreateVMP(module_id);

                // specify a codec on the vmp channel

                SMsetcodec(vmp_chan,0,G711_ALAW);

     

     

                CCclrparms(port,chan,PARM_TYPE_ACCEPT);

                CCsetparm(port,chan,PARM_TYPE_ACCEPT,CP_IPTEL_VMPRXID,vmp_chan);

                CCsetparm(port,chan,PARM_TYPE_ACCEPT,CP_IPTEL_VMPTXID,vmp_chan);

                CCsetparm(port,chan,PARM_TYPE_ACCEPT,CP_IPTEL_CODECS,vmp_chan);

                CCaccept(port,chan);

           endif endif

     endwhile

     // play a prompt which because of the above SMfeedlisten() will be heard by the caller..

     SMplay(vox_chan,"TEST.VOX");

     ... etc

To make a full duplex connection then make each channel listen to the other:

    // The vmp_chan will now listen to the vox_chan datafeed

    SMfeedlisten(vmp_chan,TYPE_VMP,vox_chan,TYPE_VOX);

    // The vox_chan will now listen to the vmp_chan datafeed

    SMfeedlisten(vox_chan,TYPE_VMP,vox_chan,TYPE_VMP);

For IP to TDM calls then the datafeeds from the VMP and the TDM can be connected as follows:

     int vox_chan, port, chan, vmp_chan, module_id;

    vox_chan=1;

    module_id=0;

    e1port=0;

    e1chan=1;

    ipport=8;

    ipchan=1;

    tdm_chan=CCcreateTDM(e1port,e1chan);    // Get a TDM endpoint for an E1 channel

    vmp_chan=SMcreateVMP(module_id);        // Create a VMP channel

    // specify a codec on the vmp channel

    SMsetcodec(vmp_chan,0,G711_ALAW);

   

    // Wait for an inbound call on IP channel(using the newly created VMP when we accept)

    CCenablein(ipport,ipchan);

    while(1)

           x=CCwait(ipport,ipchan,WAIT_FOREVER,&state);

           if(state eq CS_INCOMING_CALL_DET)

                CCalerting(ipport,ipchan);   // send INCOMING_RINGING event

           else if(state eq CS_WAIT_FOR_ACCEPT)

                // specify a codec on the vmp channel

                SMsetcodec(vmp_chan,0,G711_ALAW);

     

     

                CCclrparms(ipport,ipchan,PARM_TYPE_ACCEPT);

                CCsetparm(ipport,ipchan,PARM_TYPE_ACCEPT,CP_IPTEL_VMPRXID,vmp_chan);

                CCsetparm(ipport,ipchan,PARM_TYPE_ACCEPT,CP_IPTEL_VMPTXID,vmp_chan);

                CCsetparm(ipport,ipchan,PARM_TYPE_ACCEPT,CP_IPTEL_CODECS,vmp_chan);

                CCaccept(ipport,ipchan);

           endif endif

     endwhile

    // Now make outbound call on E1 port/channel

    x=CCmkcall(e1port,e1chan,"123456"."987654");

    while(1)

           x=CCwait(e1port,e1chan,WAIT_FOREVER,&state);

           if(state eq CS_OUTGOING_RINGING)

                applog("Outgoing ringing")   // send INCOMING_RINGING event

           else if(state eq CS_CALL_CONNECTED)

                break;

           else if(state eq CS_CALL_DISCONNECTED)

                // clear down the calls here and restart..

                cleardown_calls();

                restart;

           endif endif

     endwhile

    // ** Now connect the feeds from the VMP and TDM endpoint to make

    // ** a full duplex connection to connect the conversations from the IP to E1 calls  

    // The vmp_chan will now listen to the tdm_chan datafeed

    SMfeedlisten(vmp_chan,TYPE_VMP,tdm_chan,TYPE_TDM);

    // The tdm_chan will now listen to the vpm_chan datafeed

    SMfeedlisten(tdm_chan,TYPE_TDM,vpm_chan,TYPE_VPM);

    // The conversations are now connected..

    etc

Returns:   Upon success it returns 0, otherwise a negative error code.