Even with campuses across the country closed, AARNet is playing a vital role to support the research and education sector. Research traffic continues to move across the AARNet network and we are providing critical video and collaboration services for enabling remote working and learning.

Since the COVID-19 outbreak began it has been an extraordinarily busy time for the AARNet team. In response to the unfolding situation, we have performed a slew of upgrades to our network and services at a rapid pace. We have been working hard to support the universities and our other connected customers as they transition to this new way of working and learning.

Here’s how our race to upgrade the network and services has unfolded to date:

Connectivity to China

First, in mid-February, we more than tripled AARNet capacity to Chinese internet destinations via Hong Kong, to support increasing demand for video conferencing and remote learning for the thousands of international students impacted by travel restrictions and unable to return to Australia.

This is in addition to AARNet’s approximately 1Tbps of capacity between Sydney, Perth and Singapore on the Indigo submarine cable system, which was launched in 2019.

The graph below indicates the growth of traffic from January to March on one of our links to the Chinese internet.

Initial collaboration platform upgrades

When it became clear in early March that universities and schools were likely to shift online, we proactively doubled the capacity of the AARNet server infrastructure on which we host the Zoom videoconferencing service. We predicted an increase in demand for Zoom associated with online course delivery for students and remote working for staff.

Capacity upgrades to internet service providers

Around mid-March when working and learning from home was recommended by the Prime Minister, we saw a four-fold drop in inbound traffic towards institutions connected to the AARNet network. Fewer people were coming into campuses and accessing services from cloud providers over the AARNet network from there, since people were using their residential broadband providers to connect to service providers without touching the AARNet network.

As an example, the following graphs show the inbound traffic towards a mid-sized university campus, comparing 2019 to 2020. Traffic stepped up in 2020 as usual as semester started, but was followed by a “crikey” moment as traffic started to rapidly drop off:

What we started seeing then was a marked increase in outbound traffic headed towards internet service providers (ISPs) such as Telstra, TPG and Optus, as staff and students accessed resources hosted on campus from home, sometimes via virtual private networks. This was largely driven by a rapid increase in usage of services hosted on the AARNet network, including Zoom, Panopto and CloudStor.

The following graph shows the traffic outbound from that same mid-size university campus:

See below for a cross-section of AARNet’s traffic outbound towards users now working from their home connections across the Australian internet, indicative of the extent of this change:

This is a substantial divergence from our typical traffic patterns. Under normal circumstances, the largest flows on the AARNet network are from content providers such Google, Akamai, Microsoft, Amazon, or Apple, which are all either hosted within AARNet data centres or directly connected to our backbone. The next largest volume of traffic is typically that of private inter-campus links, followed by the big research traffic flows between university campuses and data-intensive facilities such as the National Computational Infrastructure or Pawsey Supercomputing Centre, or to international facilities such as the Large Hadron Collider at CERN in Geneva. All these flows typically dwarf the traffic flows to and from the residential internet in Australia.

As these outbound flows towards staff and students at home started to rise, our interconnects with the ISPs, which are typically underutilized, started to congest. We quickly began to divert traffic across less congested links and then engaged with the ISPs to increase the capacity of our busiest interconnects more than 10-fold in order to alleviate the congestion issue. We now have 100Gbps or multiple 10Gbps peering links in place to reach all Australian internet users, with further upgrades already planned. By the beginning of April 2020, we had increased our overall domestic capacity seven-fold.

Further collaboration platform upgrades

Uptake of Zoom for remote working and learning escalated very quickly and over the month of March we raced against the tide to boost the capacity of our Zoom infrastructure 20-fold to meet the demand from the universities. During the month of March, the total number of Zoom hours per day across all our university customers climbed from around 5,000 to close to 466,000; the total number of participants per day, climbed from just over 7,000 to just over 824,000; and the total number of meetings per day climbed from around 2,200 to over 68,000.

In the month of March, almost 360,000 staff and students used Zoom for the first time!

The number of concurrent connections to our Zoom servers increased by a factor of almost 50 over the month of March:

These Zoom users are relying heavily on the platform each day:

Looking forward…

While our network, services and highly dedicated teams were stretched to the limit some two weeks ago, we are pleased to report that all are performing at a high level and more than meeting peak demands. As always, we are continuously monitoring our network and services and will be making further upgrades to capacity as needed to support the universities and other AARNet customers.

We have responded to a massive change in our ecosystem and are now fine tuning and addressing additional needs to ensure that everyone, from Australia’s pandemic researchers to university staff, faculty and students, as well as K-12 students, all have the connectivity they need.

Importantly, whilst the focus has been on enabling teaching and learning to continue in these new and unusual circumstances, we can see that research traffic has continued to flow uninterrupted.

We know that Australian researchers are making an impact globally across all fields of study, and somewhere amid all those bits and bytes, Australian researchers are contributing to a better understanding, and hopefully a cure for COVID-19.

Author: David Wilde, AARNet’s Chief Technology Officer