asterisk users - Dec 2016 - app_queue missed calls per agent - caller hangup before timeout

hi,

i'm trying get report about missed calls per agent. i'm using queue_log 
and RINGNOANSWER event
but i found problem described here

---
https://www.thirdlane.com/forum/queue-log-problem

RINGNOANSWER only happens if the call TIMES OUT ringing the agent and it 
returns to the queue. If your agent has a 30 second timeout and the 
caller ABANDONS the call in 5 seconds it will log an ABANDON not a 
RINGNOANSWER.

This is the only time ast_queue_log is executed with RINGNOANSWER. The 
subsequent code of this function goes on to autopause the agent/member 
if autopause is enabled. Not something that happens when callers hang up 
when ringing the agents.

/*! \brief RNA == Ring No Answer. Common code that is executed when we 
try a queue member and they don't answer. */
static void rna(int rnatime, struct queue_ent *qe, char *interface, char 
*membername)
{
if (option_verbose > 2)
ast_verbose( VERBOSE_PREFIX_3 "Nobody picked up in %d ms\n", rnatime);
ast_queue_log(qe->parent->name, qe->chan->uniqueid, membername, 
"RINGNOANSWER", "%d", rnatime);
---


any tips howto detect missed calls where caller hangup before timeout?
tnx
Marek