group call

        <extension name="group call">
                <condition field="destination_number" expression="^group_sip_((?=[0-9]*$)(?:.{10}))$">
                        <action application="ring_ready"/>
                        <action application="set" data="ringback=%(2000, 4000, 440.0, 480.0)"/>
                        <action application="sleep" data="3000"/>
                        <action application="answer"/>
                        <action application="sleep" data="500"/>

<!--
                        <action application="set" data="conference_auto_outcall_prefix={group_confirm_key=1,group_confirm_file=conference/8000/welcome_press_1_2_join.wav}"/>
                        <action application="playback" data="conference/8000/conf-welcome.wav"/>
-->

                        <action application="set" data="conference_auto_outcall_announce=/usr/share/freeswitch/sounds/en/us/callie/conference/8000/conf-welcome.wav"/>
                        <action application="set" data="conference_auto_outcall_timeout=30"/>
                        <action application="set" data="conference_auto_outcall_flags=none"/>
                        <action application="set" data="conference_auto_outcall_profile=default"/>

                    <!--
                        here I am doing conference_set_auto_outcall logic
                    -->
                        <action application="set" data="group_id=$1"/>
                        <action application="python" data="group_sip"/>

                        <action application="sleep" data="500"/>
                        <action application="conference" data="$1@default"/>
                        <action application="hangup"/>
                </condition>
        </extension>