secure connection with IPSEC etc.

Hello list I have to connect two lan's via ISDN. Certainly the connection should be secure. I think about a linux-box in each lan with ISDN-cards, which act as routers with a VPN-connection beetween them. Now I am looking for some information about these things (ISDN, VPN and how to bring them together). So I want you to ask which kind of VPN-implemantation (CIPE, FREESWAN) would you use or maybe you can tell me some sources of information about this. I've already gone through the HOWTO's and the Manual-pages. TIA Guido PS: I'm sorry that this is not a"real" question. Maybe you can sent me the information directly and not via the list. -- ----------------- Guido Tschakert SRC GmbH, SysAd -----------------