Contributed by norman.
RTPProxy can be run on a different machine than SER.
For example, if the remote machine has an IP Address of 192.168.1.1 (which isn't the same machine that SER is running on):
On the RTPProxy machine start rtpproxy with the following command:
/usr/local/bin/rtpproxy -l 192.168.1.1 -s udp:*:12345
Note1: 12345 is the port that rtpproxy will listen on. The default, if not specified is 22222. Note2: There is a -f option that will keep rtpproxy in for foreground. This will offer you the ability to watch the execution of rtpproxy in realtime.
On the SER machine add the following line to your ser.cfg
modparam("nathelper", "rtpproxy_sock", "udp:192.168.1.1:12345")
This is just a simple example. More complex configurations are possible by building on the above.normannorman