Good evening fernando thanks very much for the link that you suggest me.
After I had read the differences between VPN Concentaror and ASA i would choice tha ASA, but I have a doubt; I don't underastand well, the politic of licensing about ASA, I'm interested about this model of ASA:
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...