Customer dial pulse receiver

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A customer dial pulse receiver, or CDPR, is equipment in a telephone switch that receives digits dialed from a subscriber. Although the term refers to dial pulses, the same equipment may also be used to receive DTMF digits. In stored processor controlled switches, this is accomplished using a hardware DSP.


On 1ESS and 1AESS, CDPRs were frequently subject to crosstalk, such that subscribers could hear other people dialing digits during a call[1]. This kind of crosstalk was more common on newer 1AESS systems than on the original 1ESS systems[2].


  1. Doorbell, Evan. "The (1A ESS) Centrex Quirks of '83, part 1, 2:05-2:15".
  2. Doorbell, Evan. "The (1A ESS) Centrex Quirks of '83, part 1, 2:10-2:19".