kamailio proxy server can't find other server

Question

We are running two proxy server, we need to connect A server to B server.

but A server can't find B server because B server sip domain only register TCP!

only answer dig _sip._tcp.serveraddress SRV, not answer dig _sip._udp.serveraddress.

our dns server admin say, sorry we can't support udp.

how to fix kamailio source for support tcp dns?

Answer 1

The latest version (at this time 4.1.2) should try all the protocols.

You can try to play with dns proto preference global parameters, giving a higher priority to tcp, see:

• http://www.kamailio.org/wiki/cookbooks/4.1.x/core#dns_parameters

As example:

dns_tcp_pref=50