The term is also used analogously in the field of information technology to describe the build-up of data behind an I/O switch if the buffers are full and incapable of receiving any more data; the transmitting device halts the sending of data packets until the buffers have been emptied and are once more capable of storing information. It also refers to an algorithm for routing data according to congestion gradients (see backpressure routing).[2][3]