VPND – Virtual Private Network Daemon

vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm with a key length of up to 576 bits (may be downgraded to a minimum of 0 bits to suit any legal restrictions)

Release Notes v1.1.4 : More configuration options, VoIP optimizations for SIP phones, and minor fixes.


Or read more in here : http://vpnd.linuxsys.com/