Method and apparatus for telephone line testing

At a customer node of a public switched telephone network comprising a telephone line associated with a customer premises, a method of qualifying said customer node for digital communication services with a modem connected to said telephone line at said customer premises, the method comprising the steps of:

• transmitting with said modem a first plurality of test signals on said telephone line within a frequency range of approximately 0 Hz to 5 MHz;
• measuring a second plurality of response signals with said modem received in response to said first plurality of test signals;
• and
• generating an output value as a function of said first plurality of test signals and said second plurality of response signals indicative of the electrical characteristics of said customer node.

At a customer node of a public switched telephone network comprising a modem at said customer node connected to a telephone line, a method of qualifying said customer node for digital communication services, the method comprising the steps of:

• generating test signals on said telephone line within a frequency range of approximately 0 Hz to 5 MHz;
• generating a first plurality of values as a function of the amplitude, phase and delay of response signals received in response to said test signals;
• generating a second plurality of values indicative of the line voltages between the tip and ring, tip and ground, and ground and ring connections, respectively of said telephone line;
• generating a third plurality of values indicative of the resistance between the tip and ring, tip and ground, and ring and ground connections, respectively of said telephone line;
• generating a fourth values indicative of the capacitance between the tip and ring connection of said telephone line;
• generating a fifth value indicative of the background noise in at least one frequency band between approximately 0 Hz and 5 MHz;
• and
• generating an output value as a function of said first, second, third, fourth and fifth values indicative of the electrical characteristics of said customer node.