Data cap

A data cap, often erroneously referred to as a bandwidth cap, is an artificial restriction imposed on the transfer of data over a network. In particular, it refers to policies imposed by an internet service provider in order to limit customers' usage of their services; typically, exceeding a data cap would require the subscriber to pay additional fees based on whether they have exceeded this limit. Implementation of a data cap is sometimes termed a fair access policy, fair usage policy, or usage-based billing by ISPs. U.S. ISPs have asserted that data caps are required in order to provide a "fair" service to their respective subscribers. The use of data caps has been criticized for becoming increasingly unnecessary, as decreasing infrastructure costs have made it cheaper for ISPs to increase the capacity of their networks to keep up with the demands of their users, rather than place arbitrary limits on usage. It has also been asserted that data caps are meant to help protect pay television providers that may also be owned by an ISP from competition with over-the-top streaming services. Although often referred to as a "bandwidth cap", it is not the actual bandwidth (bits per second) that is limited, but the total amount of data downloaded per month. Generally, each user of a network is expected to use high speed transmission for a short time, for example to download a megabyte web page in less than a second. Continuous usage, such as when or streaming videos can seriously impair service for others. In DSL, where the core network is shared but the access network is not, this concept is less relevant. However, it becomes more relevant in cable internet, where both the core network and the access network are shared, and on wireless networks, where the total network bandwidth is also relatively narrow. In 2016, U.S. provider Comcast offered a service plan with a data cap of 1 terabyte. At contemporary data consumption rates, each member of a family of four would need to separately watch 100 movies in a month to approach the cap.