extensions.ael:

context default {
       300 => {
               Answer();
               Wait(1);
               Read(agent,agent-user);
               &queue-add(Helpdesk,${agent},${CALLERID(num)});
       };

       301 => {
               Answer();
               Wait(1);
               Read(agent,agent-user);
               &queue-remove(Helpdesk,${agent},${CALLERID(num)});
       };
};

macro queue-add(queuename, username, clid) {
       AddQueueMember(${queuename},Local/${username}@agents,,,);
       Set(DB(Location/${username})=SIP/${clid});
       switch(${AQMSTATUS}) {
               case ADDED:
                       Playback(agent-loginok);
                       Hangup();
                       break;
               case MEMBERALREADY:
                       Hangup();
                       break;
               default:
                       Hangup();
       };

};

macro queue-remove(queuename, username, clid) {
       RemoveQueueMember(${queuename},Local/${username}@agents);
       Noop(${DB_DELETE(Location/${username})});
       switch(${RQMSTATUS}) {
               case REMOVED:
                       Playback(agent-loggedoff);
                       Hangup();
                       break;
               case NOTINQUEUE:
                       Hangup();
                       break;
               default:
                       Hangup();
       };
};

context agents {
       705 => &delivercall();
       707 => &delivercall();
       668 => &delivercall();
       709 => &delivercall();
       710 => &delivercall();
       713 => &delivercall();
       715 => &delivercall();
       716 => &delivercall();
       729 => &delivercall();
       720 => &delivercall();
       721 => &delivercall();
       724 => &delivercall();
       678 => &delivercall();
};

macro delivercall() {
       Noop(User: ${MACRO_EXTEN} @ Device: ${DB(Location/${MACRO_EXTEN})} currently ${DEVSTATE(${DB(Location/${MACRO_EXTEN})})});
       if ("${DEVSTATE(${DB(Location/${MACRO_EXTEN})})}" = "INUSE") {
           Busy();
       } else {
               Dial(${DB(Location/${MACRO_EXTEN})});
       }
};

sip.conf:
genera
limitonpeer=yes

703
type=friend
username=703
secret=1234
host=dynamic
context=maxnet-default
callerid="AJ" <703>
amaflags=default
mailbox=703@default
qualify=no
port=5060
nat=never
dtmfmode=inband
record_out=Adhoc
record_in=Adhoc
call-limit=4


queues.conf:
Helpdesk
strategy=fewestcalls
timeout=20
retry=5
music=default
wrapuptime=30
joinempty=yes
timeoutrestart=yes
ringinuse=no
autofill=yes
context=queue_breakout