DIN ETS 300114-1997 公共电话转接网(PSTN).I类和II类基础规范.公共电话转接网标准调制解调装置规范
Public Switched Telephone Network (PSTN) - Basic Category I and Category II specifications for modems standardized for use on the PSTN; English version ETS 300114:1996
The document deals with the criteria for the approval of modems according to categories I and II. The basic attachment requirements for category I modems are defined, as well as attachment and test methods, which are applicable for more than one type of category II modems.