Telstra denies throttling customers on free data day

After a major outage knocked out large parts of Telstra's network last month, the telco was slammed for an entirely different reason yesterday as customers took advantage of a day of free data.

Over the course of the day, Telstra says customers churned through 2,686 TB of data -- equivalent to 3.4 million HD movies, and roughly 3 times the normal weekday traffic. That figure well and truly eclipsed the previous record for data usage in a single day, set just a month ago on Telstra's most recent Free Data Day.

It's been a tough couple of months for Telstra, which was hit with two major outages in as many months. The first, in February, was caused by what the telco called an "embarrassing human error" which knocked roughly 15 percent of its mobile customers off the network.

Telstra attempted to make peace by offering customers a free day of data, but just a month later it was back in the headlines after another outage, this time affecting roughly 50 percent of customers. For a company that places a great deal of value on its network, it was an embarrassing turn of events.

But in a sign that customers are getting used to the free data windfalls offered by Telstra, data usage yesterday was 46 percent higher than usage on February's free data day, when customers burned through 1,841 GB.

One Reddit user, DrRodneyMcKay took serious advantage of the free data, boasting that he'd used 994 GB of data during yesterday's free period, beating their previous record of 421 GB from the last data day. Compared to a "typical user," Telstra said 994 GB equated to about 40 years worth of use.

But it wasn't a total free for all.

Some customers took to social media yesterday to complain about download speeds, raising questions about whether Telstra's network was up to the challenge of offering free data across the country.

Telstra's management team explained that it had put "traffic balancing mechanisms" in place to give all customers a "fair go."

"It's actually a bit of software in the network that adjusts throughput at a group level," Telstra's group managing director of networks Mike Wright said of this mechanism. "If you're on one tower, and a large number of people are downloading huge amounts of traffic, it's just like everyone leaving your suburb at the same time -- you're going to run into congestion at the end of the street.

"Across the network generally, the cells performed very well, but there were some hot spots were people were clearly taking advantage of the day, and that meant some people slowed down."

We asked Wright whether Telstra in effect throttled its own customers.

"Arguably they throttled themselves," he said. "They shared the bandwidth that was available, and it meant that they all slowed down when they all tried to use it at once."