Am 16.03.2011 15:06, schrieb David: > Hello, > > I have a Kamailio 3.0 server with two interfaces. 192.168.x.x and a > public interface. > > I send PUBLISH out on the private interface to my presence server. > > Everything else happens on the public address. > > I did not use the "listen=" option in the config, so Kamailio was > automatically detecting my interfaces to bind to.
I always specify explicitly the sockets, thus I do not know hwo the "auto" feature works. > Last night I had a provider sending packets in on TCP and Kamailio was > sending out on UDP. Unfortunately, it kept using the private interface > despite that the IP was unreachable on this interface. > > It looks like Kamailio uses the first interface it finds when converting > between TCP and UDP, and I believe that on the server, the private > interface was being listed first. > > I finally added listen= in kamailio with all 4 interfaces ( tcp/udp > public and tcp/udp private ). I listed the public UDP interface first, > restarted and the packets started going out on the public interface. > > Is this a feature or a bug ? Probably it is just by design. If you do not tell Kamailio which interface to use (force_send_socket) it somehow has to guess. If usually tries to use the same socket on which the message was received. Probably in case of protocol change that does not work. > > How does Kamailio decide which interface to use ? What if I sent a > packet to an IP that is only reachable on one interface? Either force the interface, or use mhomed=true (multihomed). Actually, I always thought that the interface on which the request will be sent is chosen by the OS (based on routing table) - Kamailio just decides which src-IP address to use in the SIP message. If you set mhomed=yes, then it opens a new socket to find out which IP will be choosen be the OS, close the socket, use the IP in the message header, and send it on the respective socket. > At the very least, I think that a note about this difficulty should be > included in the default config so that future users don't have the same > issue I did. Patches are welcome. regards Klaus _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
