I must be one of those rare users who stand in the middle: I had used Asterisk before, but I didn't try to apply my Asterisk knowledge to learning FreeSWITCH, other than to make sure that all of the desirable features of my Asterisk configuration eventually had counterparts in my FreeSWITCH configuration.
The key for people coming from Asterisk is to learn the difference between the WHAT and the HOW. It's admittedly difficult, so any who've overcome the challenges and can help other new ones to make the transition are welcome to document their steps. My advice to Asterisk users who want their FS box to do something that their Asterisk box can do is this: separate the WHAT from the HOW. In other words, start at the top (WHAT) and work your way down, not at the bottom (WHAT). The top-down view is like this: Asterisk allows to SIP phones to talk to each other. The bottom-up viewpoint is this: I edited sip.conf, created these PEER entries, then I edited extensions.conf and added exten => foo... See the difference? Start at the top: ask yourself, WHAT does my Ast box do? Now, ask yourself, HOW does FS implement that feature? As much as I like the Rosetta Stone page (because I started it) I don't think that it is the first place to go when you are migrating from Asterisk. (Go there *after* you've played around with FS for a bit.) -MC