TIA-470.230-C:2005 (R2012)

This standard defines the DTMF, Pulse Dial, and Flash network
signaling performance requirements for Customer Premises Equipment
(CPE) intended for connection to the Public Switched Telephone
Network (PSTN). These requirements should ensure compatibility and
satisfactory performance to the user in a high percentage of
installations.

Several performance measurement procedures are in use today,
each of which yields standardized measurement data that may be used
for the comparison of different products. This document may
reference only a single procedure or specific equipment, however
the intent is not to be all-inclusive. Any measurement procedure
and equipment that can result in an identical result is considered
valid.

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