Abstract: Delay is measured associated with the transfer of voice signals involving a telephone connected to a PSTN carrier (e.g., non VoIP based) where the call is terminated by an operator agent using a workstation connected to a VoIP based network. A test tone is provided to the telephone causing a tone to be generated at a headset of the workstation. An oscilloscope measures the delay using an input of a first signal associated with the generation of the test tone at the telephone, and a second signal associated with the generation of the resulting tone at the headset. The tone at the headset can be looped back into the headset microphone, causing a return signal to be generated and measured. Once the overall delay is known, and the delay of certain elements are estimated, the delay associated with other network elements, including the workstation, can be determined.