The Australian Competition and Consumer Commission (ACCC) has released a discussion paper about the service levels of the NBN Co in its wholesale contracts, as part of an inquiry into the company's standards.

Stakeholders are expected to answer questions from the paper, with a focus on connections, fixing faults and appointments.

It also asks about the access of retailers to rebates or compensation when the NBN Co does not meet its commitments.

As a wholesaler, the NBN Co's customers are the retailers directly and not the end-users of the network. If an NBN Co related issue occurs, the retailer is required to compensate end-user customers.

Nine of the 38 questions asked in the discussion paper relate to potential compensation.

When the submissions have been considered, the ACCC will then determine whether regulation is necessary, chairman Rod Sims said.

"NBN is now in its peak rollout phase and the ACCC is concerned that complaints about connecting to services, including missed appointments and having faults repaired, will continue to grow unless improvements are made now," he said.

"This inquiry will consider whether there are appropriate incentives for NBN Co to remedy service failures," Mr Sims said.

"The ACCC has heard industry concerns from ISPs that the service standards aren't adequate to ensure customers have a good experience connecting to and having faults repaired for NBN services."

The inquiry will consider whether specified service levels or non-price terms and conditions should be made in a final access determination.

While the inquiry isn't expected to be complete until December 2018, there could be action taken beforehand.

"We have the power to come up with interim orders early in the New Year," Mr Sims said.

"I'd be surprised if this [doesn't happen]."

When Mr Sims announced the inquiry he said there were particular concerns about a " high number of complaints from consumers around poor customer experiences, particularly in relation to customers connecting to NBN services and having faults repaired".

"One of the main focuses of our inquiry will be whether there are appropriate incentives for NBN Co to remedy service failures, along with the adequacy of compensation available to wholesale customers, to ensure consumers in turn are provided appropriate redress when things go wrong," he said.

Wholesale service standard levels are negotiated between the NBN Co and the retailers.

This includes performance objectives and operational targets and any requirements for the NBN Co to correct issues if standards are not met.

The ACCC is able to set regulated terms and conditions of access to NBN services.

The regulator previously expressed concern that NBN wholesale service standards were preventing customers from being able to obtain redress when connections were delayed or there were faults.

Submissions are expected to be made by 16 February.

The NBN Co previously said it would work constructively with the regulator on its inquiry and was "pleased to see the broad focus of the inquiry on the entirety of the supply chain, including wholesale and retail service levels".

Optus vice president regulatory and public affairs Andrew Sheridan said customers deserved consistent and quality service.

"There is scope to better align wholesale service standards with end users' expectations for retail service delivery and performance," he said.

"This inquiry provides an opportunity to identify and fix some issues which will, ultimately, improve the overall retail experience."

Retailers, community groups and communications bodies are expected to be among those making submissions.

Jennifer Duke