The Teridian 73M2901CE single chip integrated circuit modem provides all the microprocessor control and modulation and demodulation functions required to implement a V.22 bis 2400 bps modem. Equipment intended to be connected to the Public Switched Telephone Network （PSTN） must comply with specific standards such as FCC part 68， CTR-21， JATE， etc. A certification process usually verifies conformity to those standards. Among the regulatory requirements， there are both maximum and minimum levels at which the modem may transmit. The normal default transmission levels for data and DTMF tones as measured on the line may be lower than desired when using the 3.3V 73M2901CE. Additional losses through the DAA could reduce the levels even further. The following information is provided to aid you in properly setting up the 73M2901CE to achieve the optimal transmit levels.