Struggling to understand how this value relates to how often OPTIONS packets are sent.... I've got this in my internal.xml: <param name="all-options-ping" value="true"/> <param name="nat-options-ping" value="true"/> <param name="unregister-on-options-fail" value="true"/> <param name="registration-thread-frequency" value="5"/> But I don't see any OPTIONS messages going to my registered SIP handset: freeswitch@internal> show registrations reg_user,realm,token,url,expires,network_ip,network_port,network_proto,hostname,metadata 1129301,176.9.31.72,fbbb6ffb2e8e3c9d@192.168.1.203,sofia/internal/sip:1129301@84.92.90.149:33888;transport=udp,1402068621,84.92.90.149,33888,udp,hzhmay14a.dmclub.net, And i've done this: sofia profile internal siptrace on Feel I'm banging my head against a brick wall on this!