2011/6/10 Klaus Darilion klaus.mailinglists@pernau.at:
Kamailio performs NAPTR lookups, but chooses UDP. I do not know why.
You are fully right. I've captured DNS traffic and wireshark clearly shows a NAPTR record. And indeed kamailio prefers SIP over UDP with no reason (it should prefer TCP as my kamailio does not speak TLS):
$ host -t naptr oversip.net oversip.net has NAPTR record 5 50 "S" "SIPS+D2T" "" _sips._tcp.oversip.net. oversip.net has NAPTR record 10 50 "S" "SIP+D2T" "" _sip._tcp.oversip.net. oversip.net has NAPTR record 20 50 "S" "SIP+D2U" "" _sip._udp.oversip.net. oversip.net has NAPTR record 40 50 "S" "SIP+D2S" "" _sip._sctp.oversip.net. oversip.net has NAPTR record 50 50 "S" "SIPS+D2S" "" _sips._sctp.oversip.net.
Maybe kamailio is taking the "order" field of the NAPTR incorrectly and gives priority with higher values? I will check it ASAP.
Thanks a lot Klaus.