Thanks for your help. I've tried to set this parameters but still I was dropped of the room after a while. Here you can find the log when I was dropped.
19/07/2016 09:02:31: prof: DBG: Autoping: Sending ping request: prof_ping_17
19/07/2016 09:02:31: conn: DBG: SENT: <iq id="prof_ping_17" type="get"><ping xmlns="urn:xmpp:ping"/></iq>
19/07/2016 09:02:33: prof: DBG: iq stanza handler fired
19/07/2016 09:02:33: prof: DBG: Autoping: Pong handler fired: prof_ping_17.
19/07/2016 09:02:37: prof: DBG: Autoping: Sending ping request: prof_ping_18
19/07/2016 09:02:37: conn: DBG: SENT: <iq id="prof_ping_18" type="get"><ping xmlns="urn:xmpp:ping"/></iq>
19/07/2016 09:02:39: prof: DBG: iq stanza handler fired
19/07/2016 09:02:39: prof: DBG: Autoping: Pong handler fired: prof_ping_18.
19/07/2016 09:02:43: prof: DBG: Autoping: Sending ping request: prof_ping_19
19/07/2016 09:02:43: conn: DBG: SENT: <iq id="prof_ping_19" type="get"><ping xmlns="urn:xmpp:ping"/></iq>
19/07/2016 09:02:43: prof: DBG: Presence stanza handler fired
19/07/2016 09:02:43: prof: DBG: iq stanza handler fired
19/07/2016 09:02:43: prof: DBG: Autoping: Pong handler fired: prof_ping_19.
19/07/2016 09:02:48: prof: DBG: Autoping: Sending ping request: prof_ping_20
19/07/2016 09:02:48: conn: DBG: SENT: <iq id="prof_ping_20" type="get"><ping xmlns="urn:xmpp:ping"/></iq>
19/07/2016 09:02:48: prof: DBG: iq stanza handler fired
19/07/2016 09:02:48: prof: DBG: Autoping: Pong handler fired: prof_ping_20.