ZyXEL Communications LTE5121, User Manual

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Chapter 16 VPN
LTE-5121 User’s Guide
156
16.5.1 IPSec Architecture
The overall IPSec architecture is shown as follows.
Figure 106
IPSec Architecture
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.
Key Management
Key management allows you to determine whether to use IKE (ISAKMP) or manual key
configuration in order to set up a VPN.
16.5.2 Encapsulation
The two modes of operation for IPSec VPNs are Transport mode and Tunnel mode. At the time of
writing, the LTE Device supports Tunnel mode only.