Kevin Scott of Forrest Reef near Orange said he was one of many customers around Australia who will be forced to use a slower package, creating problems for using FaceTime, streaming content and downloading and uploading from the internet.

Mr Scott said he found out about the downgrade when he received a note from his internet provider, Optus, saying he would be downgraded.

"The NBN fixed wireless Speed Pack 3 will be decommissioned from December 2019," the Optus message said.

It said he would be moved to "the next fastest option," which is the much slower Speed Pack 2, from November 12.

"It's just a hell of a downgrade from what we had," he said.

"We are talking about what [speed] we used to get with our old phone lines.

"FaceTime will be difficult, so will HD [high definition] downloads."

Optus has confirmed the downgrading which it said was due to the NBN changing its fixed network access services.

It said its affected customers would be able to leave their contracts without having to pay exit fees.

Mr Scott said fixed wireless networks existed in rural areas where the cabling used in cities, including Orange, was not provided.

He said users shared access to an antenna which sends out the internet signal for about eight kilometres.

Mr Scott said he had been told the fastest package was being removed because the NBN could not deliver the claimed speeds to users.

He said it was another case of country people getting a worse deal than people in the capital cities.

"It's going to affect every rural person," he said.

"Why do we have to suffer for so long?" Mr Scott said.

NBN announced the changes in a statement last December and said the fixed wireless access services would be upgraded.

"Following the regulatory changes in 2020, the company will be able to reallocate capacity to enable better utilisation of existing spectrum," it said.

"This will see the expected maximum potential download speed on the Fixed Wireless Plus product increase to up to 75Mbps [mega bits per second], with upload speeds up to 10Mbps."

Mr Scott said he was unsure whether this would improve the internet speed for his home and his farm business.

An Optus spokeswoman said the change had followed NBN's actions.

"Our wholesale supplier, NBN, is making changes to their fixed wireless access service," she said.

"Optus will move customers to the next readily available speed pack that we offer.

"Those customers impacted will be offered the opportunity to exit out of their contracts with no fees.

"This will not affect customers on other NBN plans or services."

She said anyone with an urgent enquiry could contact Optus.

The changes will also affect customers of other internet providers.

The Australian Competition and Consumer Commission said the NBN was working to improve the fixed wireless service.

"The original design of the fixed wireless network has been unable to meet higher take-up rates and changing usage patterns," it said.

"This has contributed to ongoing congestion issues affecting parts of the fixed wireless network."

The ACCC advises affected customers to talk to their internet provider about the changes and look at ways of reducing downloading at peak times.

It suggested users download streaming services the night before they planned to watch them to eliminate buffering and dropouts of the stream.