TMI: Is there a tutorial for setting up sipx??

I've got an existing VoIP/IP-pbx network set up using Asterisk, with AudioCodes VoIP boxes. Because of certain missing features in Asterisk, I want to try out SipFoundry instead - but I'm lost in all the configuration screens, and I don't know how the things that sipXconfig is looking for, coorelate with the settings that I have in Asterisk. Is there a tutorial that will, for example, describe setting up a network which has, let's say, a T1 Voip box for PSTN and a handful of FXS boxes for phones?? That would be very useful here!!