On Amazon AWS Marketplace you can look for "OpenVPN Access Server". You'll see a number of results. One of these will simply be titled "OpenVPN Access Server". This Marketplace image is suitable for the BYOL licensing system as long as you do not use auto-scaling and do not change the instance type after activating a license key. If you do then the virtual hardware that the license key has locked to will change and the license key may become invalid. In such a case you will have to contact us through the support ticket system to request a license key reissue. With this licensing model you pay for the AWS instance itself and any license keys that you purchase through us and activate on your Access Server installation. If no license key is installed, the Access Server goes into a demonstration mode where all functions work without time limitations, but it will only allow 2 simultaneous VPN connections to be established. A license key unlocks more connections.
The other images for OpenVPN Access Server listed on AWS Marketplace will have an amount of "connected devices" specified. These function using the Amazon AWS tiered instance licensing model, and these are billed directly through the Amazon systems per the stated hourly charges. The costs are separated into software licensing costs and AWS instance costs. These are billed hourly. If you launch an OpenVPN Access Server (?? connected devices) type instance on Amazon AWS you will incur charges for the use of the software and charges for the use of the instance you've launched while the instance is actively running. If you stop the instance, you will stop incurring additional costs. It is therefore possible to use such a system on demand, or in other words to have an instance on cold standby ready to be launched when needed.