<extension name="agent_login">
<condition field="${destination_number}" expression="^agent_login$">
<action application="set"
data="ignore=${callcenter_config(agent set status ${caller_id_number}@${sip_to_host} 'Available')}"
inline="true"/>
<action application="ring_ready"/>
<action application="pre_answer"/>
<action application="sleep" data="2500"/>
<action application="answer"/>
<action application="sleep" data="700"/>
</condition>
</extension>
But ringback is not generaded. Why is it posible?