Based On Transparent Bridge Spam Firewall Software System Design And Implementation

In the information society, network is the main way to publish information, but a large part of bandwidth of network is used to transfer garbage information.Though there are many solutions trying to resolve the problem, many are based on server or just plug-ins to the client, and don't work perfectly.How to establish an efficient and extensible framework to filter garbage information is a very important issue.The main content and innovation of the article can be concluded as two points:(1) The article describes a kind of extensible spam filtration firewall.The system uses netbirdge,iptables,netfilter to establish the real-time filter system.The system gets the IP packages, then completes IP and TCP protocol revivification to get the integrated information.Use double queue to store the information, also contain a thread pool to provide multithreads processing.When the judgment comes out, the information will be forwarded or discarded.(2) The system has the behavior-based filter using support vector machine, rules-based filter, improved bayes-based filter and is very extensible, new protocol and new algorithm can be added easily.The system is isolated from server and client,neither setted up in server nor to be a plug-in in client.It is in front of server,filtering the spam in real-time.So the spam can not arrive at server nor the client.The system can add or delete modules by changing the configure file over web.After the system finds the configure changed ,it'll reload the config automatically.Also it supports automatical upgrading,when there are new rule files,it'll download them and use the new ones immediately.The system can be configured as mail firewall before mail server,short message firewall before short message server and web pages firewall before web server.The system was used in labs, had passed the tests in Beijing huawei and got good respondence.