Under Per User licensing, each user that connects via Remote Desktop needs a Windows Server CAL and a RDS CAL. In your example you would need 100 Windows Server CALs and 100 RDS CALs.
You may have a maximum of two Active Remote Desktop sessions for administrative purposes only. These administrative connections do not require CALs. To make an administrative connection you would use the /admin command line switch, like this:
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.