NBN Co is piloting a new line speed monitoring process with select retail service providers (RSPs) that will alert the company when a line falls 20 percent below the maximum speed it is capable of.

Chief network engineering officer Peter Ryan told a parliamentary committee that the company began piloting the new process at the end of June, and hoped to eventually use it across its entire network.

“In the NBN network, the moment a new customer plugs a modem in, we can then do a test which calculates what the true line speed is, regardless of what [retail] service they’ve bought,” Ryan said.

“For example, the line may be capable of 80Mbps but the customer has bought a 50Mbps plan.

“What we then do [is that] we’ve built a capability where we can monitor degradation of that line speed.

“At the moment, we’re just working out what the right threshold of degradation is before we react and send a truck.”

For the purpose of the pilot, NBN Co has set a 20 percent degradation threshold, but this could change before the process is deemed production-ready.

“So when the [actual] speed versus the attainable line speed ... degrades by 20 percent, then we’d roll a truck to investigate what the problem is,” Ryan said.

The truck roll would occur regardless of what retail plan the customer was signed up to.

So, in Ryan’s example where the user has a line capable of 80Mbps and has only paid for 50Mbps, and the line speed degrades by 20 percent, NBN Co would still want to know the cause of the issue, despite it not impacting the user.

“We’ll still react even if the line speed is still above the retail product that’s actually been purchased,” Ryan said.

Ryan indicated that the pilot involves “a number of RSPs trying to finetune exactly the way this [new process] works.”

“We’ll work with RSPs and end users to work out what the optimum [threshold] percentage should be set at so we can continue to deliver a very good customer experience,” he said.

“Then, as we finetune this and get our processes industrialised so we can run this at the scale we need to, we will roll it out across the network.”

The company has a separate process that is “constantly looking at services that are unable or will not meet the minimum of 25/5 post coexistence” in the fibre-to-the-node (FTTN) footprint.

During coexistence, FTTN and ADSL services connect into the same infrastructure. FTTN services are purposely degraded during this period so as not to cause interference with existing copper-based services.

“So after we remove all the existing ADSL lines off the pillar, what we then do is try and identify which lines aren’t delivering those [minimum peak] speeds,” Ryan said.

The last time NBN Co published numbers on this issue, it said six percent of activated FTTN services couldn’t achieve a peak rate of 25Mbps.

Those services, therefore, did not meet the company’s statement of expectations (SOE) commitments, and would have to be either remediated or offered an alternative access technology.

Accurate line speed measurement data was a problem for NBN Co and especially its retail service providers throughout last year.

Many RSPs were rebuked by regulators for “overcharging” customers, which occurred when customers were sold retail services above the maximum attainable speed that their line could support.

An iTnews investigation at the time suggested line speed data provided by NBN Co to RSPs during the sale process was not fit for purpose, and was one of the key contributors to the overcharging issue.

Since then, NBN Co has put considerable effort into improving its network assurance functions through the use of machine learning and now the development of new processes.