A Security Gateway

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.

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