Draytek Vigor2620 LTE Series User Manual page 237

Item
IPSec Security Method
After finishing all the settings here, please click OK to save the configuration.
Vigor2620 Series User's Guide
Description
This group of fields is a must for IPSec Tunnels and L2TP with
IPSec Policy when you specify the remote node. Check the
Medium, DES, 3DES or AES box as the security method.
Medium-Authentication Header (AH) means data will be
authenticated, but not be encrypted. By default, this option is
invoked. You can uncheck it to disable it.
High(ESP-Encapsulating Security Payload) means payload
(data) will be encrypted and authenticated. You may select
encryption algorithm from Data Encryption Standard (DES),
Triple DES (3DES), and AES.
Local ID - Specify a local ID to be used for Dial-in setting in the
LAN-to-LAN Profile setup. This item is optional and can be
used only in IKE aggressive mode.
225