Research On Realization Of IPSec Protocol

IPSec（Internet protocol security）is a network security agreement of industrialstandard,which provides transparent security services for IP network and prevents the TCP/IPcommunication from being eavesdropped or malicious modification. Protecting the safety ofIP data table and providing preventive measures against network attacks are the twofundamental objectives.Currently, comparied to the other network security technologies, IPSec-based VPN(Virtual Private Network) protocol technology is capable of providing more completesystem security measures. Moreover, IPSec VPN gateway based on this protocol can be usedto build virtual private network or intranet. VPN represents the most extensive form ofnetwork evolution nowadays, by combining the performance advantages of traditional datanetwork with structural merits of shared data network.With IPSec，VPN can easily ensurethe safety of off-site network communication.The main purpose of this paper is to design a security gateway dedicated to virtualprivate network whose netwok layer exploits IPSec. The IPSec protocol mainly consists ofthree parts: which are security protocols, Internet Key Exchange (IKE) and encryption. Firstlythe paper analyzes the VPN network applications and the architecture of IPSec protocol,describes the functions and relationship of the various components of the IPSec protocol, andthen studies the relevant agreements of the various components. Secondly the VPN and IPSecare combined to establish a secure gateway system.In addition, this paper also digs into therole of the security gateway in the the Femto (home base station) system, illustrates the designspecification of the security gateway’s hardware and software architecture,improves the datastream processing, SA (Security Association), SP (security policy)，and completes the designof the memory management module.Finally, the data record of experiential testing of IPSec security gateway is shown at the last chapter.By analyzing the data information, this paper illustrates the performance situationand gives advice for the future improvement.