The pulse dialing method, or pulse method for short, is a method for dialing and connecting a phone number over the telephone network. The acronym for the pulse method is IWF. In the early age of the telephone a "miss operator" still manually connected the phone calls, and the pulse dialing method was one of the first methods which allowed the subscriber to communicate the respective telephone number to the automatic exchange directly. The pulse method was later replaced by so-called multi-frequency signaling, or MF for short. Another term for multi-frequency signaling is DTMF (dual-tone multi-frequency). Many telephone systems today still support both pulse dialing and multi-frequency signaling via their analog connections.