Child porn filters to cut Aussie broadband speeds

The study was conducted by the Australian Communications and Media Authority to demonstrate advances in Internet content filtering technologies.

In a statement provided to iTnews, the Department of Broadband, Communications and the Digital Economy effectively confirmed that the scope of the study limits useful outcomes of the report.

“The ACMA report is based on a laboratory trial of ISP filtering technologies, within a network that would be used by a small ISP,” the spokesperson said.

“It is therefore necessary that the Government proceed with a real world live pilot to test how these filtering products work with ISPs of different sizes and network configurations.”

Department and industry have expressed opposing concerns that preliminary findings on the degradation of broadband network speeds caused by the content filters may be inflated, or underestimated, respectively.

Preliminary results from the ACMA study showed that five of the six filters tested degraded Internet throughput speeds by between 22 percent and 75 percent, or more.

Just introducing a filter to the test network -- without actively filtering any content -- resulted in up to 10 percent degradation.

But because the study did not distinguish between “inappropriate and innocuous content” appropriately, the Department is concerned that the reported outcomes of network degradation may be inflated.

“It is important to note that the tests did not specifically test filtering of a black-list independent of over-blocking and under-blocking,” the Department spokesperson said.

“The Government’s policy is to filter [only] a black-list of illegal content maintained by the ACMA.”

In addition, it has now emerged that the test network may have been operating at an “artificially constrained” traffic rate approximately half the speed of a dial-up modem, according to the Systems Administrators Guild of Australia (SAGE-AU).

This is potentially at odds with the Department’s position, as it implies the degradation results achieved may have been under-estimated.

"While it's probably true to say that filtering software doesn't present noticeable performance degradation when you've already artificially constrained the offered traffic rate to below dial-up speeds, it's difficult to see the relevance of that conclusion in a world where the Minister wants everyone in Australia to connect over 500 times faster," said Mark Newton, a SAGE-AU member.

Despite the results, Peter Coroneos, CEO of the Internet Industry Association (IIA), is urging industry to wait for the real world trial before casting further speculation and judgement.

“I believe that [the reported] level of degradation is unlikely to be acceptable even to government,” added Coroneos.