If you are going to 'ping' the server you could deactivate the udp
ping by setting natping_interval to 0.
http://www.kamailio.org/docs/modules/1.5.x/nathelper.html#id2453019
Nevertheless, I would keep it active, and set ping_nated_only to 1, so
you just ping clients which are known to be behind NAT.
--
Saúl -- "Nunca subestimes el ancho de banda de un camión lleno de disketes."
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