Ipsec Algorithms; Key Management; Encapsulation; Figure 126 Ipsec Architecture - ZyXEL Communications P-662H-61 User Manual

Figure 126 IPSec Architecture

15.2.1 IPSec Algorithms

The ESP (Encapsulating Security Payload) Protocol (RFC 2406) and AH (Authentication
Header) protocol (RFC 2402) describe the packet formats and the default standards for packet
structure (including implementation algorithms).
The Encryption Algorithm describes the use of encryption techniques such as DES (Data
Encryption Standard) and Triple DES algorithms.
The Authentication Algorithms, HMAC-MD5 (RFC 2403) and HMAC-SHA-1 (RFC 2404,
provide an authentication mechanism for the AH and ESP protocols. Please see
on page 221for more information.

15.2.2 Key Management

Key management allows you to determine whether to use IKE (ISAKMP) or manual key
configuration in order to set up a VPN.

15.3 Encapsulation

The two modes of operation for IPSec VPNs are Transport mode and Tunnel mode.
P-662H/HW-D Series User's Guide
Chapter 15 Introduction to IPSec
Section 16.2
217