Delay.The total time required for a signal to travel from one point to another, generally from a transmitter through a network to a receiver. Propagation delay, a fundamental factor in latency, is dependent on the nature of the electromagnetic signal, as not all signals travel through a medium at the same speed. Propagation delay also is influenced by the distance between the two points, the density of the medium, the presence of passive devices such as loading coils that might increase the impedance of the medium. Latency also is affected by any processing time associated with devices such as repeaters, transponders, concentrators, multiplexers, switches, and routers as they variously transmit and retransmit, amplify and reamplify, time and retime, shape and reshape, code and decode, compress and decompress, encrypt and decrypt, and otherwise process signals and manipulate data. Latency also is affected by any time that data packets spend in queues due to issues of network congestion and any time required to retransmit packets errored or lost in transit. See also jitter.