Number of user connections handled varies greatly dependant on what is happening on the appliance.
Testing has been completed with 200 simultaneous logins on a single appliance with no significant issues. If user logins are staggered then it works better.
If there are a lot of check and change actions happening, then users may notice minor performance degradation, with possible time outs when getting a login token and they will be prompted to try again.
In a cluster of 5 with a load balancer set up, 1000 simultaneous logins has been successfully tested
Once a user has logged in and has an authentication token we can support 1000's of users logged in simultaneously.