Blocking Content on the Internet: a Technical Perspective

作者:Philip McCrea Bob Smart Mark Andrews


Executive Overview

This report provides some insights into the technical aspects of blocking material which is delivered over the Internet. It focuses on what can be done to block Content which has already been identified by some party as being illegal or offensive. The report does not address the desirability or otherwise of Content blocking on the Internet. Content blocking on the Internet can take place at two distinct levels:

♦ at the application level – e.g. blocking a particular web page or ftp site by specifying the URL of the site (or a particular page or file within a site), or by blocking an entire news group.

♦ at the packet level – this requires routers to examine the IP address of the sender of a packet, and compare it with a supplied ‘black list’.