Abstract: A telephone line analyzer provides automatic attenuation measurement of tie trunk lines and other telephone lines through measurement of the electrical level of a tone responder. The analyzer is primarily directed to testing telephone lines interconnected between trunk line selectable computerized private branch exchanges (PBXs) of the same user. The analyzer automatically dials a remote PBX through a desired tie trunk line; activates a remote tone responder; and measures and records the test results. The analyzer may also perform echo return loss measurements.The analyzer is user programmable and it can be set to initiate line tests at predetermined times so as to minimize interference with the normal telephone line activities of the user.