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Australian Government Coat of Arms - NetAlert program Australian Government Net Alert

Protecting Australian Families Online

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Background

The primary aim of this project was to measure the performance impact of applying server based Internet content filtering applications and appliances to an Internet feed in both live and controlled environments to determine:

  • any degradation of speed/performance,
  • the typical filtering accuracy achieved and finally
  • the effect of filtering on the user experience when using broadband Internet services.

The trial assessed the effect of the filters on the overall performance of the network including the stability of the system, the impact on data rates and latency effects.

Another key component of the trial was the measurement of user perceptions of the filtered service, including their impressions of the impact of the filtering on the quality of the service. The object of this element of the trial was to better understand the likely impact of server-level filtering on consumer take-up of broadband.

NetAlert Limited (NetAlert) commissioned a scoping study for the trial late 2004. RMIT TestLab (TestLab) reviewed the viability, processes and procedures to be associated with the proposed trial. The scoping study confirmed that very little independent assessment has been conducted on performance degradation of broadband Internet performance when using Internet content filters. In particular, there appears to have been no research conducted into the user experience when accessing broadband Internet services using server based content filters.

NetAlert was consulted on the scoping study. Australian Broadcasting Authority (now the Australian Communications and Media Authority (ACMA)) and Telstra provided assistance to NetAlert.

In order to better understand the actual performance degradation of server based filters, NetAlert issued an expression of interest in early 2005 for an independent assessment of server based filter accuracy, performance degradation and the effect of this degradation on Internet users. RMIT Training Pty Ltd (RMIT) was awarded the tender to undertake the trial and RMIT TestLab – a division of RMIT Training Pty Ltd, conducted the testing.

In order to provide an opportunity for filter vendors to take part in the trial, an advertisement requesting expressions of interest was placed in The Australian Newspaper on 19 April 2005, inviting participation. However, only one vendor responded to the advertisement, hence other vendors were contacted and invited to participate.

No filter vendor was able to provide a product that was specifically designed for Internet Service Provider (ISP) usage. At least one vendor had an ISP based Internet content filter listed in its catalogue but the product was not locally available within the project timescale. As a consequence, the filters supplied by vendors and used in the trial were designed for use at an enterprise level. The project commenced using these products as they would provide an indication of performance and accuracy in an environment that would be similar to that of a smaller ISP.

Whilst there are server based content filters available that are designed for ISP use, this segment of the market has been slow to develop. Because of the potential for very large numbers of users it is usual that only low overhead filtering techniques, such as checking requested URLs against a blacklist, are really viable for server based filters.

In managing the filter trial process, NetAlert consulted with ACMA. Telstra provided technical assistance during the course of the trial.

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