TIA-470.330-C:2012

This standard provides performance requirements for Customer
Premises Equipment (CPE) incorporating a Telephone Answering Device
(TAD) and intended for analog wireline connection to the Public
Switched Telephone Network (PSTN). Devices meeting these
requirements should ensure compatibility and satisfactory
performance to the user in a high percentage of installations.

A TAD may be a stand-alone device or may be integrated into CPE
with other features such as a handset for voice communication
(ITAD). Only TADs or ITADs using digital means of storing voice
messages are covered by this standard. Older devices using analog
storage technology, such as cassette tapes, are not covered. Only
requirements relevant to TAD functions are included in this
standard. Other requirements that may also be relevant to CPE
having TAD functions may be found in other standards of the TIA-470
series.

The voice transmission requirements in this standard only apply
to TADs operating in a hands free, speakerphone-like mode.
Transmission requirements that might be applicable to recording
outgoing messages, listening to recorded messages, etc, using the
handset of an ITAD may be covered in a future revision of this
standard.

This document proposes or references at least one measurement
procedure for each technical requirement. However, these procedures
are not exclusive. Any measurement procedure and equipment that can
result in an identical measurement is considered valid.

While the procedures may call out specific test points within
the requirements, the full range of the requirements takes
precedence.