ok.. you look confused

let's say you have a remote server (let's call it A) you want to connect to, but you can't open firewall ports on the remote side, so you can't just ssh o vpn to the remote server.
with reverse tunneling, you have a outgoing ssh connection from the remote server (i.e. no need for open firewall ports if there's no outgoing filtering rules on the remote side) to your server or a server you can ssh to (let's call it B)
when you want to connect to A, simply ssh to B and then ssh to localhost:portofyourchoice... you will be redirected to A
no need of fixed ip on A side.. neither on B side if you use something like dyndns
obviously you need something to keep outgoing ssh connection up all the time; I'm quite sure you'll find some script example out there to do it
HTH