The Australian Competition and Consumer Commission (ACCC) has released a consultation paper detailing the proposal by the National Broadband Network (NBN) company to vary its Special Access Undertaking (SAU) in order to take into account the multi-technology mix (MTM), inviting submissions on key questions.

The SAU, originally submitted to the ACCC in 2013, governs the pricing and regulatory terms facing the NBN until 2040.

The MTM NBN model involves a mix of technologies including fibre to the premises (FttP), fibre to the node (FttN), fibre to the basement (FttB), and hybrid fibre-coaxial (HFC); the former SAU took into account only FttP.

According to the Variation to NBN Co Special Access Undertaking: Consultation paper [PDF], published on Wednesday, NBN said it also wants to expand the service description to include network technologies that may be implemented in future, such as fibre to the distribution point (FttDP) -- with which NBN said on Tuesday it will be replacing some FttN planned areas -- and to modify its rollout progress information requirements.

"The ACCC is especially interested in receiving feedback on industry's experience in accessing and re-supplying NBN services to date," ACCC Commissioner Roger Featherston said on Wednesday.

"Changes to the Special Access Undertaking are needed to accommodate services under the multi-technology NBN model. We want to be sure the commitments in the undertaking continue to promote competition in NBN markets and remain in the long-term interests of consumers."

Specifically, the questions for submissions involving broadband technologies are: Whether the proposed SAU descriptions define the FttN, FttB, and HFC networks accurately, and make clear NBN's commitments with regards to these networks; whether the proposed network definition extension will cover the inclusion of future technologies including FttDP; whether the proposed User Network Interface (UNI) definition is consistent with technical standards; whether accepted definitions of Layer 2 are consistent with NBN supplying access services to a UNI not located on a Network Termination Device (NTD) for FttN and FttB services; the extent to which defining the network boundary point provides certainties related to maintenance responsibilities; and whether the proposed definitions of the UNI and the Wholesale Broadband Agreement (WBA) network boundary point provide enough certainty for the network boundary point to be removed from the SAU.

On the issue of co-existence, the ACCC wants to hear thoughts on whether the current WBA provisions have been effective; whether any respondents have encountered co-existence issues with NBN or end users and how they were resolved; whether access seekers are informed sufficiently of NBN's co-existence arrangements; the extent to which the proposed co-existence timeframe for special services creates uncertainties for access seekers; and whether the inclusion of co-existence clauses in module 2 is appropriate.

In regards to remediation, the ACCC is encouraging submissions on whether the WBA provisions on remediation provide certainty on data rates; whether there have been any issues concerning remediation matters with either NBN or end users; whether access seekers and retail service providers (RSPs) are informed on NBN's remediation arrangements; and whether remediation clauses should be included in module 2.

The ACCC is also accepting submissions addressing the rollout information section on whether the SAU mandates that the NBN report enough detail on the nature, scope, timing, and frequency of the rollout; whether the proposed information commitments by NBN create a level playing field between Telstra and other RSPs; whether the SAU and voluntary arrangements are both flexible enough to adapt to RSP information requirements and also have enough certainty to commit to providing timely and relevant rollout information; whether RSPs are satisfied that NBN's proposal to provide voluntary rollout information outside the SAU will contain the same quality of information; whether the requirements under the agreements that access seekers must agree to in order to see rollout information are reasonable; whether it is appropriate to receive rollout information online, as proposed by NBN; whether NBN will provide necessary and timely rollout information despite its proposed commitment to make information available "where NBN Co is not restricted from doing so"; whether the rollout's "broad timeframes" by quarter are precise enough for RSPs to plan and market for; and whether receiving rollout progress information would enable greater competition for RSPs to supply NBN services.

Lastly, the ACCC wishes submissions to address: Stakeholders' views on whether an additional resolution advisor should be appointed; whether the resolution advisor may be a body corporate with at least one nominated person; whether the pricing and charges specification for FttN, FttB, and HFC services and installation provisions are appropriate; and any other issues raised by the SAU variation.

The ACCC first published NBN's proposed variations back in May, when the broadband company said it already offers FttN, FttB, and HFC technologies in an SAU-consistent manner -- the SAU variation is simply to formalise the process. However, several other amendments would see NBN forced to provide rollout progress information to access seekers, as well as changing the dispute resolution mechanism to allow a body corporate to be appointed as a resolution adviser.

"None of the changes which NBN proposes alter the underlying regulatory principles, structure, and incentives embedded in the SAU, which the ACCC has previously accepted as being reasonable, including being in the long-term interests of end users," NBN said in its supporting submission [PDF].

"NBN's changes are limited in scope and mechanical in nature; they represent an incremental change to reflect current policy settings.

"Fundamentally, the change to the MTM model does not change the underlying regulatory principles, structure, or incentives embedded in the SAU and they apply equally to the MTM as they do currently to the services and products under the SAU."

NBN submitted the proposed variation [PDF] on May 27 alongside prolific and supportive independent evaluations from professor Janusz Ordover and Dr Allan Shampine [PDF], Analysys Mason [PDF], and Dr Steven Bishop and professor Bob Officer [PDF].

The ACCC is accepting submissions on the proposed variation until August 26.

The regulator last month also gave final approval for NBN's revenue control alteration proposal, and deemed the company to have been compliant with pricing controls during 2014-15.