When all queue operators are busy, the call is not caught in the RDD as having arrived at the queue. How to catch missed ones?

Question

Asterisk

There is a server on FreePBX 2.2 asterisk 1.8 A
queue for 20 operators, where calls from a large number of incoming trunks flow

announce-frequency=0 
announce-holdtime=no 
announce-position=no 
autofill=yes 
autopause=no 
autopausebusy=no 
autopausedelay=1 
autopauseunavail=no 
eventmemberstatus=yes 
eventwhencalled=yes 
joinempty=yes 
leavewhenempty=no 
maxlen=0 
memberdelay=0 
monitor-type=mixmonitor 
music=default 
penaltymemberslimit=0 
periodic-announce-frequency=0 
queue-callswaiting=silence/1 
queue-thereare=silence/1 
queue-youarenext=silence/1 
reportholdtime=no 
retry=1 
ringinuse=yes 
servicelevel=15 
setinterfacevar=yes 
strategy=ringall 
timeout=15 
timeoutpriority=app 
timeoutrestart=no 
weight=0 
wrapuptime=0 
member=Local/[email protected]/n,0,federal1,hint:[email protected] 
member=Local/[email protected]/n,0,federal 2,hint:[email protected] 
member=Local/[email protected]/n,0,federal3,hint:[email protected] 
member=Local/[email protected]/n,0,federal4,hint:[email protected] 
member=Local/3[email protected]/n,0,federal5,hint:[email protected] 
member=Local/[email protected]/n,0,federal6,hint:[email protected] 
member=Local/[email protected]/n,0,federal7,hint:[email protected] 
member=Local/[email protected]/n,0,federal8,hint:[email protected] 
member=Local/[email protected]/n,0,federal9,hint:[email protected] 
member=Local/[email protected]/n,0,federal10,hint:[email protected] 
member=Local/[email protected]/n,0,federal11,hint:[email protected] 
member=Local/[email protected]/n,0,federal12,hint:[email protected] 
member=Local/[email protected]/n,0,federal13,hint:[email protected] 
member=Local/[email protected]/n,0,federal14,hint:[email protected] 
member=Local/[email protected]/n,0,federal15,hint:[email protected] 
member=Local/[email protected]/n,0,federal16,hint:[email protected] 
member=Local/[email protected]/n,0,federal17,hint:[email protected] 
member=Local/[email protected]/n,0,federal18,hint:[email protected] 
member=Local/[email protected]/n,0,federal19,hint:[email protected] 
member=Local/[email protected]/n,0,federal20,hint:[email protected] 
member=Local/[email protected]/n,0,federal21,hint:[email protected]

Everything can be seen from the config.
The problem is the following.
It is necessary to catch the missed ones, at the moment it is implemented in this way. (queue settings below)
Code:

select calldate,clid,src,duration from cdr where (calldate like '{$date}%' and dcontext='ext-queues' and LENGTH(dstchannel)<2 and dst='{$a}') or (calldate like '{$date}%' and dcontext='app-announcement-4' and clid like '%SPB%')";

For example, one of the gateways in St. Petersburg
That is, in this case, a missed call is considered to have entered the queue but did not go further.
Analyzing the statistics, I saw this thing

Array ( [phone] => ***[town] => ufa [clid] => UFAPERSONAL [regionalname] => serj [queue] => 3471111 [desc] => ufa personal ***) 06:18:44gate 2246450 
accepted 2199 accepted by queue 1284 answered by members 1013 unanswered by members 271

2200 calls came to the gateway, 1284 queue answered
. This happens in several situations.
1) Call arrival when all operators are busy and the subscriber hangs up without waiting until someone is free, no entry is made in the RDD
2) This is already a jamb of the ringall strategy, the second call does not reach the operators until someone has accepted the first one.
I ask for help in resolving the problem.
The task is to keep track of all missed calls so as not to lose customers.
Thank you very much in advance.

Answer 1

1. you can catch through AMI or in the queue logs
   you can write your events to the log app_QueueLog
   
2. you don't need to use ringall it to handle a small flow of calls where the number of free operators is greater than the number of pending calls. rrmemory is usually a more profitable strategy.