A standards-based security suite that operates transparently and may eliminate the need for proprietary firewall mechanisms in some applications. IPsec also provides for encapsulation of the secured IPv6 packets inside IPv4 datagrams, in consideration of both the increasing need for security and the long-term transition process to IPv6. IPsec is described in IETF RFC 2401 and, in the context of the OSI Reference Model, runs at the Network Layer (Layer 4). See also datagram, encapsulate,, firewall, IETF, IPv4, IPv6, Network Layer, OSI Reference Model, and packet.