Attachments to the Public Switched Telephone Network (PSTN) Basic Attachment Requirements for Modems Standardized for Use on the PSTN (Candidate NET 20)
"This ETS specifies the technical characteristics to be met by modems seeking approval for connection to the PSTN. Clauses of this ETS also define the approval criteria for certain features which may be provided by some Category II modems@ but the requirements in these parts are only mandatory when invoked by a modem specific ETS. The term ""modem"" in the context of this ETS includes all physical implementation practices for voice band modems which are galvanically connected to the PSTN. NOTE: This implies that certain types of modems@ e.g. acoustically coupled and cordless modems@ are outside the scope of this ETS. This ETS also contains descriptions of the tests to be performed in order to confirm compliance with the functional requirements contained herein. A general description of the test conditions and test requirements for Clause 4 is given in Annex A and for Clause 5 in Annex B. Annex C describes the testing facilities which a testing laboratory may need to provide. Annex D indicates additional equipment@ or software@ that applicants may need to provide in order that testing to Category II can be achieved."