A SECURITY GATEWAY

ABSTRACT
In the context of computer networking, an application-level gateway (also known as ALG or application layer gateway) consists of a security component that augments a firewall or NAT employed in a computer network. It allows customized NAT traversal filters to be plugged into the gateway to support address and port translation for certain application layer "control/data" protocols such as FTP, Bit-Torrent, SIP, RTSP, file transfer in IM applications etc. In order for these protocols to work through NAT or a firewall, either the application has to know about an address/port number combination that allows incoming packets, or the NAT has to monitor the control traffic and open up port mappings (firewall pinhole) dynamically as required. Legitimate application data can thus be passed through the security checks of the firewall or NAT that would have otherwise restricted the traffic for not meeting its limited filter criteria.
TABLE OF CONTENTS
TITLE PAGE CERTIFICATION PAGE DEDICATION ACKNOWLEDGEMENT ABSTRACT TABLE OF CONTENTS
CHAPTER ONE INTRODUCTION STATEMENT OF PROBLEMS PURPOSE OF THE STUDY IMPORTANCE OF THE STUDY DEFINITION OF TERMS ASSUMPTION OF THE STUDY
CHAPTER TWO LITERATURE REVIEW ALG SERVICE IN MICROSOFT WINDOWS
CHAPTER THREE UNIFIED SECURITY GATEWAY DEPLOYMENT KEY FEATURES SECURITY
CHAPTER FOUR INSTANT MESSAGING COMPLIANCE MANAGEMENT
CHAPTER FIVE CONCLUSION 5.1 LIMITATION OF THE STUDY 5.2 SUGGESTION FOR FURTHER RESEARCH 5.3 REFERENCES