The company said its participation in the trial will allow it to "objectively assess the technical viability of the filtering solution we have proposed to implement, not the relative merits of proposed legislation," which it notes is "more valuable to us than relying solely on third party information".

The ISP said its participation in the trial is not tantamount to backing the scheme, but only "legitimises our right to be able to comment authoritatively on the technical aspects of the viability of a proposed filtering implementation." It will test DSL, /Broadband DSL and Ethernet connections.

Optus director of government and corporate affairs Maha Krishnapillai said the telco will make a decision to participate in the trials after the initial six-week round is completed.

"We remain absolutely committed to working with the government in blocking illegal activity and helping in anyway we can, and we will wait to see the results of the trail," Krishnapillai said.

A spokesman in charge of the ISP's content filtering service said government policy will make or break the scheme.