Open-access and digital-government objectives for the national broadband network (NBN) would be compromised under the Coalition's fibre-to-the-node (FttN) architecture because the technical limitations of VDSL technology would preclude the simultaneous delivery of services from more than one service provider, confidential NBN Co report has warned.
The report – prepared by NBN Co for the now Department of Communications to evaluate the issues a transition to the new government's NBN would raise – warns that “there would be interference from running two virtual circuits across the one VDSL service so the Network Termination Device (NTD) would likely be either a jack or a single port NTD.”
By contrast, NTDs currently being installed under the fibre-to-the-premises (FttP) rollout offer four ports.
The distinction is important because, under the current policy, the additional ports have been envisioned to allow NBN customers direct connections to multiple service providers; for example, government agencies could deliver a direct service to allow healthcare providers direct access to provide remote monitoring of, and assistance to, elderly shut-ins.
FttN's architecture “would therefore limit the end-user to only one service provider relationship,” NBN Co's assessment warned. “This could impact future innovation.”
Forcing all traffic over the one port would not only limit customers' interactions to just one retail service provider (RSP), but would also limit delivery of multiple services simultaneously. This is because such an elderly-care service, for example, would consume a significant portion of the FttN NBN connection, forcing all other traffic to fight for a share of the remaining traffic.
As already reported by ZDNet Australia, NBN Co's assessment warned that the performance characteristics of FttN technology would prevent NBN Co from guaranteeing the performance of high-speed services above 25Mbps.
Such services could, the assessment warned, only be delivered as “best-effort” services – known as Traffic Class 4 in NBN Co parlance – until detailed performance testing was conducted and the quality of the copper wiring in each premises addressed.
The report also noted the inability of an FttN architecture to deliver Traffic Class 2 and 3 quality of service (QoS) guarantees, which are crucial to the types of applications required by medium and large businesses. “FTTN solutions are unable to provide significant amounts of guaranteed bandwidth,” the report warns.
Turnbull has previously dismissed the report as "totally political" and out of date — despite subsequent evidence to the contrary — and has promised that details of his network's cost and technological models will be revealed soon.
Turnbull recently received the findings of the strategic review, but has delayed its release and defied calls by the Senate to make the document public. The report is now expected to be released tomorrow.