Good evening.I have succesfully configured mod_callcenter (queue, agent and tiers) in my freeswtich with agent behing a trunk sip (all the extension are reachable from FS but are not registered in it), all work as intended. So the simple configuration of the agent is:    <agent name="agent999" type="callback" contact="[call_timeout=10]sofia/gateway/gatewayName/999" status="Logged Out" max-no-answer="3" wrap-up-time="10" reject-delay-time="30" busy-delay-time="60" no-answer-delay-time="10" />All work well and i get the right agent status and agent state. But this work only for the inbound call routed to freeswitch, i haven't any information abount agent independent presence (For Example: if the agent dial and is in call with another agent) .So the internal database "think" that the agent is available and ready even if is in call and busy so the mod try to invite him obviously whitout success. I  try in the gateway to subscribe whit the presence of remote agent, and in some way update internal database with script lua or event_socket<include>   <gateway name="server_gw">    <param value="no-reg" name="username"/>     <param value="server.org" name="realm"/>     <param value="no-reg" name="password"/>     <param value="10.0.80.10:5060" name="proxy"/>     <subscriptions>         <subscription event="presence">             <param name="content-type" value="application/pidf+xml"/>             <param name="expire-seconds" value="60"/>             <param name="retry-seconds" value="30"/>             <param name="username-in-request" value="true"/>         </subscription>     </subscriptions>      ... I haven't found a way to subiscribe and receive the notifiy and publish event of prencence in the gateway (trunk sip) for a specific group of agent, in my example the extension 999 behind the trunk (but ideally all my call center agent), the subscribe is from and to "no-reg" for a contact gw+server_gw, i need to subscribe to someting like 999@server.org   SUBSCRIBE sip:sa@server.org:5060 SIP/2.0    Via: SIP/2.0/UDP 10.1.10.82:5080;rport;branch=z9hG4bKU3DyKZaHrg24p    Max-Forwards: 70    From: <sip:no-reg@10.0.80.10:5060>;tag=K3N8p1cKmS1vm    To: <sip:no-reg@10.0.80.10:5060>;tag=e340d29f4e69500c4c17ab56fb041ae6-7cd3    Call-ID: 1db94e51-298b-1234-1493-005056963714    CSeq: 85401361 SUBSCRIBE    Contact: <sip:gw+server_gw@10.1.10.82:5080;transport=udp;gw=server_gw>   Expires: 60    User-Agent: FreeSWITCH-mod_sofia/1.7.0+git~20151210T010223Z~85f8bca628~64bit    Accept: application/pidf+xml    Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY    Supported: timer, path, replaces    Event: presence    Content-Length: 0 There is way to subscribe through a trunk for presence or generate it via mod_event_socket ( i found only the NOTIFY event and not for SUBSCRIBE https://freeswitch.org/confluence/display/FREESWITCH/mod_event_socket#sendev...), or there are any other tools to probe the presence and don't do a "polling of busy call" for a call center application?thank you for all, and thanks indeed for the help receveived in the past month. Emiliano Olivier