An implementation methods described by the ITU-T Recommendation T.38 specification for Fax over Internet Protocol (FoIP). Fax spoofing is used for facsimile transmissions over IP networks characterized by relatively long and unpredictable levels of packet latency that could cause a session between conventional fax machines to time out. Fax spoofing compensates for both increased latency and jitter by padding the line with occasional keep-alive packets to keep the session active, rather than allowing it to time out.Thereby,T.38 spoofs, or fools, the receiving device into thinking that the incoming transmission is over a real-time, synchronous voice network. See also facsimile, FoIP, jitter, latency, session, spoofing, and T.37.