Software as a Service is an application provided by a provider over the Internet, and is also referred to as a hosted application. There is no need to purchase, install, or run applications on the user's computer. SaaS providers were previously referred to as application service providers (ASP). 

Serial Digital Interface is the standard specification for digital video interface with 270 Mb/s 

Subnet is the logical division of one network into several networks and a subnet mask is a value for representing the subnet. 

Region of Interest gives efficient video rates with optimized video quality. Frequently moving areas are keeping much better quality. On the other hands, less moving areas are dropping video rates.