Explain importance of modems used in data transfer and list some of the V-series recommendations.
The series also describes a variety of DCEs using different type modulation techniques and operating at different type speeds by using either a leased public switched telephone network or dial-up line Examples of DTE-DCE interface standards and other standards related to data transmission on public switched telephone network are:
V.5 For synchronous data transmission, standardization of data signaling rates in the PSTN
V.24 DTE-DCE interface and control signals
V.28 DTE-DCE electrical characteristics for unbalanced double-current interchange circuits.
V.53 Limits for the preservation of telephone type circuits utilized for data transmission.