Hello. I'm using almost default kamailio.cfg with nathelper, rtpproxy, PSTN dialing and other default features. I have following scheme:
FXS gateway -> (NAT) -> Kamailio -> FreeSwitch
Voice calls work perfectly, no one-direction sound and so on.
But with fax machine there was a problem. In wireshark I saw UDPTL from FS to Kamailio IP, and no UDPTL at all to FXS gw. I've guessed that something's wrong with a re-INVITE request processing in Kamailio. I've added this to WITHINDLG route:
else if ( is_method("INVITE") ) { record_route();
}
And problem was magically solved, T.38 now works OK. Is this OK solution or this may break something elsewhere?
Thanks.
Hello,
On 02.08.17 12:02, Yu Boot wrote:
Hello. I'm using almost default kamailio.cfg with nathelper, rtpproxy, PSTN dialing and other default features. I have following scheme:
FXS gateway -> (NAT) -> Kamailio -> FreeSwitch
Voice calls work perfectly, no one-direction sound and so on.
But with fax machine there was a problem. In wireshark I saw UDPTL from FS to Kamailio IP, and no UDPTL at all to FXS gw. I've guessed that something's wrong with a re-INVITE request processing in Kamailio. I've added this to WITHINDLG route:
else if ( is_method("INVITE") ) { record_route();}
And problem was magically solved, T.38 now works OK. Is this OK solution or this may break something elsewhere?
a re-INVITE should be get record route re-enforced, so likely you deal with some broken CPE. Anyhow, doing the record_route() there should be harmless for the other CPEs, so can be taken as an easy fix.
Cheers, Daniel
-
Daniel-Constantin Mierla -
Yu Boot