ZyXEL Communications 792H manual VPN Screens

Prestige 792H G.SHDSL Router

	Table 14-8 VPN IKE: Advanced
LABEL	DESCRIPTION
Encryption	Select DES or 3DES from the drop-down list box.
Algorithm	When DES is used for data communications, both sender and receiver must know
	the same secret key, which can be used to encrypt and decrypt the message or to
	generate and verify a message authentication code. The DES encryption algorithm
	uses a 56-bit key. Triple DES (3DES) is a variation on DES that uses a 168-bit key.
	As a result, 3DES is more secure than DES. It also requires more processing power,
	resulting in increased latency and decreased throughput.
Authentication	Select SHA1 or MD5 from the drop-down list box. MD5 (Message Digest 5) and
Algorithm	SHA1 (Secure Hash Algorithm) are hash algorithms used to authenticate packet
	data. The SHA1 algorithm is generally considered stronger than MD5, but is slower.
	Select MD5 for minimal security and SHA-1 for maximum security.
SA Life Time	Define the length of time before an IKE SA automatically renegotiates in this field. It
(Seconds)	may range from 60 to 3,000,000 seconds (almost 35 days).
	A short SA Life Time increases security by forcing the two VPN gateways to update
	the encryption and authentication keys. However, every time the VPN tunnel
	renegotiates, all users accessing remote resources are temporarily disconnected.
Key Group	You must choose a key group for phase 1 IKE setup. DH1 (default) refers to Diffie-
	Hellman Group 1 a 768 bit random number. DH2 refers to Diffie-Hellman Group 2 a
	1024 bit (1Kb) random number.
Phase 2
Active Protocol	Use the drop-down list box to choose from ESP or AH.
Encryption	Select DES, 3DES or NULL from the drop-down list box.
Algorithm	When DES is used for data communications, both sender and receiver must know
	the same secret key, which can be used to encrypt and decrypt the message or to
	generate and verify a message authentication code. The DES encryption algorithm
	uses a 56-bit key. Triple DES (3DES) is a variation on DES that uses a 168-bit key.
	As a result, 3DES is more secure than DES. It also requires more processing power,
	resulting in increased latency and decreased throughput. Select NULL to set up a
	tunnel without encryption. When you select NULL, you do not enter an encryption
	key.

14-18 VPN Screens