Users sitting on the end of long copper runs could potentially be stuck with a connection incapable of hitting the National Broadband Network's (NBN) mandated 25Mbps until well into the next decade.
In response to Senate Estimates Questions on Notice, NBN said of all its fibre-to-the-node (FttN) connections, as of June 18, 6 percent were within the 12-25Mbps download range, 29 percent sat between 25-50Mbps, 33 percent could hit 50-75Mbps speeds, and 32 percent were capable of 75-100Mbps speeds.
As NBN pointed out, these speeds are impacted by "co-existence profile settings", which makes FttN connections run slower due to needing to continue support for legacy services over copper, such as ADSL, during the 18-month migration window.
"Following switch-off of legacy copper services after this period, the Layer 2 attainable bitrate (speeds) will increase," NBN said. "The numbers also reflect the impact of other factors such as any in-home wiring issues, which can affect attainable speeds."
"Where the network is not capable of providing the minimum wholesale download speeds after coexistence has ended, NBN will take action to rectify any issues so that minimum standards are met."
According to NBN's July 2017 product roadmap [PDF], the company plans to be conducting co-existence migrations until June 30, 2022.
Until premises are migrated over, NBN has previously said it will only guarantee 12Mbps speeds.
"As we're upgrading the copper to be capable of faster speeds, we have to take steps to ensure the change in frequencies doesn't cause interference between the ADSL and VDSL services," an NBN spokesperson said in June 2015.
"Hence taking a cautious approach with our customers, the retail telecommunications companies, and guaranteeing the delivery of 12Mbps/1Mbps."
Writing in response to a question published on Friday, NBN also said the average attainable speed on FttN is 67.7Mbps down and 30.6Mbps up.
"FttN, by itself, with the copper loop lengths we are building with, will not give you gigabit per second," NBN CEO Bill Morrow told Senate Estimates in May.
"When we can upgrade them to FttC, and we use G.Fast capabilities with this little DPU [distribution point unit] that we put into the pit in front of your home, then that will give you up to a gigabit per second speed."
The CEO said at the time that fixed-wireless has the potential to surpass 1 gigabit per second once 5G arrives, but satellite would always lag behind.
"Satellite is not going to deliver that anytime in our tenure here," he said. "It was never designed for, even under the previous regime and previous policy, 8 percent of the nation was never going to see anything other than 25Mbps."
The company responsible for rolling out the NBN across the country maintains that all premises, including those currently classed as service class zero, will be able to order a service by July 2020.
For the week ending June 8, NBN said it had none of its planned fibre-to-the-distribution-point/curb (FttDP/C) network ready for service, but had 864,000 premises being designed and 2,770 being built.
In April, NBN said it would expand FttDP to 1 million premises across the country, with 400,000 coming from the footprint of the former Optus HFC network. A leaked NBN draft in November 2015 revealed that Optus' HFC network was not "fully fit for purpose".
At the time, NBN said it expects to launch commercial FttDP/C services in the first half of 2018, with 100,000 premises able to connect at that point.
The company also revealed on Friday that it had received almost 55,000 complaints over the financial year to June 15. Broken down, there were 20,500 installation issues, 13,500 equipment issues, 10,900 complaints related to appointments, and almost 10,000 deemed "restoration issues".