Free pbx and extensions on public IPs

Hello Everyone,

I am having a dilemma and really would appreciate any help.

I am trying to set up my freepbx on a public IP address with 2 extensions also on public IPs. Both extensions can ring each other but as soon as the other extension answers the call you get the message “server failure”

I know public IPs are a security risk. Don’t worry this is just part of a test we are carrying out.

Thanks for your help in advance.

Check your directmedia settings

http://www.voip-info.org/wiki/view/Asterisk+sip+canreinvite