The Dropbox Server is the device that is sent to the client. The Dropbox Client is the machine the consultant uses to interact with the Dropbox Server. The Dropbox Relay proxies all communications. It can be in a dedicated lab environment or in the cloud.
For the current deployment configuration, the Dropbox Server will create four (4) reverse SSH tunnels to the Dropbox Relay upon boot. The Dropbox Client can then connect to these tunnels for SSH, VNC, HTTP proxy, or SOCKS proxy purposes.