Wikipedia says, "Internet Protocol Security (IPsec) is a protocol suite for secure Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session."
For IPSec, the 7705 SAR-8 supports VPRN when 8-port Gigabit Ethernet Adapter card, version 3, When we use Nokia Router to running IPSec, we need to service instance (Maybe we can use VPRN-VPRN or VPRN-IES), one service for public network (sometimes naming as untrusted zone) and the other one is for private network (sometimes naming as trusted zone).