[asterisk-dev] Originated Calls and Progress Detection

[Whit Thiele]

Hi,

 

I am trying to accomplish something specific in the asterisk code base and
was looking for some feedback on a better direction to take:

 

When using the manager "Originate" command, a there is a call to the method
__ast_request_and_dial which goes into a while loop until the call is either
answered (AST_STATE_UP) or hits the timeout.

 

During this while loop, I want to detect what is happening on the channel
itself an try to determine if it is actually ringing, playing a SIT tone (or
message) and therefore be able to accurately determine the final disposition
of a failed call. 

 

My first attempt (which is very much a hack) times the difference in
receiving frames during the ast_waitfor() call  in an attempt to determine
if there is actually Ringing and how many rings in total:

 

Here is the code for the modified ast_waitfor:

 

int ast_waitfor(struct ast_channel *c, int ms, int *dif)

{

        int oldms = ms; /* -1 if no timeout */

 

        ast_waitfor_nandfds(&c, 1, NULL, 0, NULL, NULL, &ms);

        int diz = oldms - ms;

        *dif = diz;

        ast_log(LOG_DEBUG, "WAIT DIF WAS '%d' \n",diz);

        if ((ms < 0) && (oldms < 0))

                ms = 0;

        return ms;

}

 

 

Here is the section in ast_request_and_dial:

 

// snip

 

int span = 0;

int ringcount = 0;

int isValidTO = 0;

                while (timeout && chan->_state != AST_STATE_UP) {

                        struct ast_frame *f;

                        span = 0;

                        res = ast_waitfor(chan, timeout, &span);

                        if (res <= 0) /* error, timeout, or done */

                                break;

                        if (timeout > -1)

                                timeout = res;

 

                        if (span > 500)

                                ringcount++;

 

                        if (ringcount > 3){

                                isValidTO = 1;

                                /* ast_log(LOG_DEBUG, "THIS IS A VALID
CALL\n"); */

                                 *outstate = AST_CONTROL_RINGING;

                        }else{

                                *outstate = AST_CONTROL_CONGESTION;

                                /* ast_log(LOG_DEBUG, "NOT SURE THIS IS A
VALID CALL\n"); */

 

                        }

 

// end snip

 

 

Obviously, this is NOT the way to accomplish this task. I need some
direction on how to hook up some sort of DSP to try to determine the
progress of these Manager originated calls while they are being dialed. 

 

Regards,

 

Whit

 

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