Did you experience problems with Zoom in January? Here is an explanation of why it happened, and what has been done to prevent it from happening again.

SUNET: Swedish University Network - sunet.se

NORDU.net: company owned by SUNET together with their counterparts in Norway, Denmark and Finland - nordu.net

At the beginning of the year, many of us experienced problems with Zoom. Sound hacked or meetings could not be carried out, people were thrown out of group rooms, chats stopped working and some other things. The reason for this can be summarized as a much larger increase in use than expected.

During the autumn, a maximum of 150,000 users in the Nordic region were simultaneously connected in meetings on a given day. Now in the spring, 290,000 users suddenly appeared at the same time in a system built for 240,000.

Originally, before Corona, the system was dimensioned for 80,000 concurrent users, which was double what was actually used then. When Corona swept over us and we basically from one day to another went over to distance teaching and working, the number of users hit the ceiling in a flash. A temporary agreement was concluded with Zoom to redirect traffic via Amazon's server halls in Stockholm, which could resolve the emergency situation.

Since then, NORDU.net, which via SUNET is our supplier of the service, has invested large sums of money in expanding its capacity. When the temporary agreement on extra server capacity expired at the turn of the year, everyone was moved back to NORDUnet's expanded network. But no one could predict that we would increase so sharply by the start of the spring semester.

In addition to this, there were some problems with how the load was distributed in NORDUnet's new network, which led to some experiencing major problems while others coped better. In addition, Zoom had also encountered problems in its service, which was not linked to our specific solution, which resulted in, among other things, login problems. Both the distribution of load and Zoom's own problems are now solved.

SUNET and NORDU.net are further increasing their capacity and now have a total capacity of 300,000 simultaneous users, soon to be 360,000. The goal is for capacity to be twice as large as demand.