Hi, I have a remote extension( Cisco SPA504G ) that connects to our FreeSWITCH server across the internet. I am using a typical double nat scenario as per wiki and the remote extension registers properly against the right profile. The remote extension via a dialplan can dial any of the extensions that are local to the FS boxes network successfully with no problems However when we dial out to the remote extension we get a "Cannot locate any authentication on credentials to complete an authentication request for realm '<our external domain>' I have tried using both the default force register options and also setting up another directory realm as well. When looking at the log you see the originate attempting to connect to the appropriate ip/port of the external phone, but after it "entering state [calling]" it fails with the above error. Just to test I have installed the 3cx softphone client on the remote network, and it can be dialled with no problems. The difference being that the 3cx seems to register a port in the dynamic range (eg 52789) where as the cisco phone uses the 5090 port Has anyone struck that issue before Thanks Bob