Can an 'AMS Extended' key be used on AWS?

We are running Adobe Media Server on AWS, and we want to run AMG and the Leg Service API.

If we purchase one or more licenses of 'Adobe Media Server 5 Extended', can we use AMG within EC2, either on our Adobe AMI server or a standalone EC2 instance?

Is the 25 'SIP ports' a limit on concurrent calls or unique SIP registrations or both?

Thanks in advance for any information you can share.