Abstract
Abstract
Security problems take an important part of computer network study in
which several techniques were developed for this purpose. Virtual Private
Networks (VPNs) are considered as an active form for providing secure networks.
The key feature of VPNs is that they are able to use public networks like the
Internet rather than rely on expensive private lines.
The aim of this paper is to design a VPN switch with the help of simulink
software provided by MATLAB 6.5. The VPN switch is a single hardware device,
it has the ability to support firewall, encryption, authentication, and data integrity
for secure tunneling across managed IP networks and Internet.
Introducing scrambling code within a VPN switch for encryption is
something new. The basic advantage of this method is to eliminate long headers,
which are usually dedicated for authentication and encapsulation in IPSec.
Therefore an increase in the bandwidth efficiency of the channel is expected.
Larger values of spreading factor show better probability of error and data
integrity in spite of the decrement in the bandwidth of the channel in some cases.
