ISO 2110:1989

Information technology — Data communication — 25-pole DTE/DCE interface connector and contact number assignments

Specifies the 25-pin connector and assignment of connector pin number at the interface between data terminal equipment and data circuit-terminating equipment or automatic calling equipment. Applicable to voice band modems, public data network facilities, telegraph signal converters, and automatic calling equipment where CCITT Recommendations V.24 and V.28 are valid.