Performance And Security; Availability; Configuring Pptp And L2Tp - SMC Networks ELITECONNECT SMC2502W User Manual

VPN tunneling encrypts user data that passes between a client and the network.
Only those networks subject to snooping by unauthorized individuals need
encryption. Even those networks might be adequately protected by WEP
encryption.
If your network is subject to unauthorized interception of data and if WEP is
inadequate to protect this data, you should consider using VPN Security.

Performance and Security

Encryption and decryption of data imposes a computational load on both a client
computer system and the WLAN Access Manager. Encrypting and decrypting data
could slow data throughput by a factor of five or more. Although a more secure
algorithm is generally thought to be slower, that is not necessarily the case.
3-1 shows the various possible encryption algorithms and their relative
performance.
Table 3-1 Algorithms and their Relative Performance
Encryption algorithm
128-bit RC4
56-bit DES
168-bit DES
Blowfish
CAST

Availability

As previously mentioned, the availability of a client is an important part of the
selection of an algorithm to use for VPN Security.
PPTP, L2TP/IPSec, and pure IPSec clients known to interoperate with the WLAN
Secure Server VPN Security:
Table 3-2 Availability of Algorithms on Platforms
Algorithm
PPTP
L2TP/IPSec
IPSec
3.2

Configuring PPTP and L2TP

Configuration of PPTP and L2TP is done in two stages. The first stage configures
the WLAN Access Manager or WLAN Secure Server, and the second stage
configures the Rights Manager location, which is part of the WLAN Secure Server,
that allows (or requires) PPTP and L2TP.
3-4
Strength
good
fair
excellent
good
good
Platform
Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000,
Windows XP, Windows CE, and other vendors
Windows 2000, Windows XP
SafeNet, Netscreen, PGP, Certicom Movian
SMC EliteConnect WLAN Security System User Guide
Encryption speed
good
fair
slow
good
good
Table 3-2 shows availability of
Table