NBN has failed in court action brought last year against TPG subsidiary Pipe Networks.
NBN had sought a court declaration that Pipe was engaging in misleading and deceptive conduct. The TPG subsidiary was accused of misleading the owners of so-called multi-dwelling units about the telco's right to access power to run equipment stationed in MDUs.
The case centred on the right of TPG subsidiary Pipe Networks to plug its fibre-to-the-basement equipment into power outlets in the apartment blocks where it was rolling out FTTB.
NBN Co took Pipe to court in October last year.
Justice Kunc ruled today in the Supreme Court of NSW that the Telecommunications Act 1997 "does authorise Pipe, its employees and contractors to install the telecommunications equipment including by plugging it into a power socket and drawing power from the premises' power supply without the consent of the owner or occupier".
The parties will return to court to determine orders and allocation of costs.
"We took action against Pipe Networks because the Telecommunications Act was ambiguous," an NBN spokesperson said.
"We wanted the law clarified and we are very pleased to get clarification. That clarification is that the Telecommunications Act empowers carriers to plug their equipment into a power source on the property of a land owner without consent and draw power to operate that equipment."
The government-owned company (which recently ditched the 'Co' from its name) is still considering the impact of the judgement.
"Our initial view is that this decision will help the rollout of the NBN network over the coming years," the spokesperson said.
"We are very pleased to have been successful in these proceedings," TPG's general counsel, Tony Moffatt, said in a statement.
"Carrier rights have been in place since competition was introduced to the telecommunications market and were designed to place all competitive carriers in an equal position.
"This judgment is important for the industry and confirms that TPG, NBN and all other carriers have an equal entitlement to install and operate equipment in buildings, including by using electricity."
"This is an excellent win for consumers of telecommunications services in Australia, whether they be residential or business customers," said Reggie Naik, Pipe Networks' head of fibre operations
"Our fibre optic network and FTTB products will bring great benefits to consumers and we are proceeding with our rollout as quickly as we can. We hope that this case will quell the effects of the misinformation that has been given to strata managers about Pipe's FTTB installations."
TPG's rollout of FTTB had previously threatened to damage NBN by delivering super-fast broadband to areas where there were significant margins or the opportunity for a low-cost rollout.
NBN is protected by anti-cherry-picking laws; however, TPG managed to skirt around the restrictions by extending its existing networking within limits allowed by the relevant legislation.
The government last year stepped in to mandate that carriers offering services that will potentially compete with the NBN will be forced to have separate wholesale and retail arms and offer wholesale services to other telcos at the same price as their retail arm.
TPG temporarily withdrew its FTTB products while it moved to comply with the new licence condition imposed by the federal government. It returned the service to market again earlier this year.
NBN launched its FTTB offering earlier this year.