I'm an OpenSER newbie and I realise this is probably a very fundemantal thing but I followed the installation tutorial and built some test users on a local MySQL database. Users can register correctly to the SER but they cannot call any other SIP users on the internet or anything else. I am not familiar with the architecture but what is required here?

I have access to a Audiocodes Mediant 2000 and would like to get users to be able to call real PSTN numbers.