I have system with Kamailio v5.1 which needs to send OPTIONS packets to all active clients. Here is full Nathelper module configuration:

modparam("nathelper", "received_avp", "$avp(s:received)")

modparam("nathelper", "natping_interval", 30)

modparam("nathelper", "ping_nated_only", 0)

modparam("nathelper", "sipping_bflag", FLB_SIPPING)

modparam("nathelper", "sipping_from", "sip:pinger@kamailio.org")

It works fine if client is connected over UDP. But as soon as I will switch to TCP or register with client that uses WS, Kamailio stops generating OPTIONS.

Does anyone know if it is  correct behavior or something is wrong?

Thanks a lot!