2. Scope

2.1

This standard contains voice transmission performance and compatibility requirements for ISDN voice terminals intended for connection to a public integrated services digital network (ISDN). The requirements are based upon the characteristics of the evolving ISDN, including interworking connections to the present telecommunications plant.

These requirements should ensure satisfactory voice service to the user in a high percentage of installations, both initially and over some period of time, as ISDN service becomes more ubiquitous and as changes occur in telephone serving equipment. However, because of the wide range of central office switching equipment, PBX equipment, customer apparatus, and loop plant used in North America, conformity with this standard does not guarantee acceptable performance under all possible operating conditio ns. In general, where two levels of acceptability are specified (desirable and mandatory), compliance with the criteria in the desirable category implies a higher probability of acceptable performance or compatibility.

2.2

These requirements apply to terminals that encode and decode analog signals in conformance with ?-law (Ref A10). These re quirements apply also to a terminal connected to the integrated services compatible station (ICS) interface of an integrated services PBX (ISPBX) as specified in TIA PN 1993, ISPBX Loss Plan (Ref A11).

These requirements are not intended to describe specific requirements for the following types of digital voice terminal equipment: ISDN terminal adapters, ISDN cellular voice terminals, ISDN terminal speakerphones, and proprietary digital telephones designed to be connected to systems whose loss plan is different from TIA PN-1993.

2.3

An ISDN voice terminal complies with this standard if it meets these requirements when manufactured and can be expected to continue to meet these requirements when properly used and maintained.

2.4

This standard is limited to ISDN terminals employing a close-speaking microphone and an earphone that permit a single user to carry on a two-way real-time voice communication (handset typ e telephone). This standard is also limited to terminals with linear (noncarbon) technology transmitters.

2.5

The standard is intended to be in conformity with Part 68 of the Federal Communications Commission (FCC) Rules and Regulations (Ref A7), but is not limited to the scope of those rules. In the event that Part 68 requirements are more stringent than those contained in this standard, the provisions of Part 68 apply.

2.6

The terminal will also be subject to the applicable environmenta l conditions specified in EIA/TIA-571, Environmental Considerations for Telephone Terminals, (Ref A12).

2.7

The standard does not contain safety requirements. Compliance with the requirements of Safety Standards such as UL 1459, Standard for Telephone Equipment (Ref A5) and CSA C22.2 No. 225, Telecommunication Equipment (Ref A6) may be required in certain locations.