Bandwidth throttling is a process by which the amount of bandwidth one or more clients connected to a server can use is limited in some way. This can be done in a number of ways, and often leads to the client user finding his or her download or upload speeds to that server reduced. The purpose of such throttling is typically to free up resources used by one client, to enable other clients to more effectively connect to the server. Bandwidth throttling is not necessarily a negative concept, though many Internet users protest its use by Internet service providers (ISPs).
The basic idea behind bandwidth throttling comes from the way in which a network is created and used by various people. A network of any kind, both local and wide area, is typically established with one of more hosts or servers, to which one or more clients connect. Someone using a computer to connect to the Internet and view a website, for example, is acting as a client and connecting to a host server that contains the information for that website. The term “bandwidth” refers to the speed at which the client is able to send and receive data to and from the host or server.
No matter how complex and powerful a server system is, there is some limitation as to the amount of data that can be sent between a host and one or more clients. Additional clients increase the workload on a single server, and eventually the bandwidth limit can be hit, which may impair the connections of clients to a server or even cause the server to crash. In order to avoid this situation, the administrator of a server can limit or reduce the amount of data being transmitted between the server and one or more clients. This, essentially, is bandwidth throttling, as the server reduces data transmission with clients.
Bandwidth throttling is often used by ISPs and other networks in a number of different ways. One of the most common uses is in peer-to-peer connections that clients can use to directly share data between each other. Throttling can be used to single out these types of connections, which often create heavy upstream and downstream bandwidth use, and reduce the amount of bandwidth afforded these users. Such throttling, in theory, then frees up bandwidth for other users on that network.
Opponents of bandwidth throttling argue that ISPs utilize these methods to limit the amount of bandwidth that paying customers can utilize. Many ISPs defend such throttling by stating that a small percentage of users account for an excessive amount of bandwidth, and that such limitations allow other paying customers to use the Internet without dealing with slowdown caused by clients using a large amount of bandwidth. Those in favor of network neutrality, or net neutrality, decry the use of bandwidth throttling, as they see it as a way in which ISPs can restrict Internet access and data distribution for paying customers.