Enhance Features and Performance of a Linux-based Content Switch
In this paper we present the design of a Linux-based content switch, discuss ways for improving the TCP delay binding and the lessons learnt from the implementation of the content switch. A content switch routes packets based on their headers in the upper layer protocols and the payload content. We discuss the processing overhead and the content switch rule design. Our content switch can be configured as the front end dispatcher of web server cluster and as a firewall. By implementing the http header extraction and xml tag extraction, the content switch can load balancing the request based on the file extension in the url and routes big purchase requests in XML to faster servers in e-commerce systems. The rules and their content switching rule matching algorithm are implemented as a module and hence can be replaced without restarting the system. With additional SMTP header extraction, it can be configured as a spam mail filter or virus detection/removal system. With IMAP/POP header extraction, it can be configured as a load balancer for email retrieval systems.