[Freeswitch-users] gateway setup example ?

Hi, I'm presently running a partial PBX using Kamailio and SEMS and I am interested in changing to freeswitch but I'm a bit overwhelmed by the many configuration files. My present setup is an upstream gateway providing DID services and outgoing services based on my IP only - no authentication. My internal phone network is based on three digit extensions. I need freeswitch to accept incoming DID calls and distributed them to mapped internal extensions - and take internal extension outgoing calls and send them as full national number calls via the upstream gateway. Is there a reference setup or tutorial somewhere that covers this scenario? Thanks, -- Jeremy Ardley