Bandwidth throttling

Bandwidth throttling is a method of ensuring a bandwidth intensive device, such as a server, will limit ("throttle") the quantity of data it transmits and/or accepts within a specified period of time. For website servers and web applications, bandwidth throttling helps limit network congestion and server crashes, whereas for ISP's, bandwidth throttling can be used to limit users' speeds across certain applications (such as BitTorrent), or limit upload speeds.

A server, such as a web server, is a host computer connected to a network, such as the Internet, which provides data in response to requests by client computers. Understandably, there are periods where client requests may peak (certain hours of the day, for example). Such peaks may cause congestion of data (bottlenecks) across the connection or cause the server to crash, resulting in downtime. In order to prevent such issues, a server administrator may implement bandwidth throttling to control the number of requests a server responds to within a specified period of time.

When a server using bandwidth throttling has reached the allowed bandwidth set by the administrator, it will block further read attempts, usually moving them into a queue to be processed once the bandwidth use reaches an acceptable level. Bandwidth throttling will usually continue to allow write requests (such as a user submitting a form) and transmission requests, unless the bandwidth continues to fail to return to an acceptable level.

Likewise, some software, such as peer-to-peer (P2P) network programs, have similar bandwidth throttling features, which allow a user to set desired maximum upload and download rates, so as not to consume the entire available bandwidth of his or her Internet connection.