In this illustration, separate Internet and Telephone network signals are sent to the central office and converge in a DSLAM server. From there they are sent in a single signal, marked "Existing phone line: 0-4KHz phone; 4-50KHz upstream data; 50KHz-1MHz downstream data." The signal hits a splitter and connects in one direction with the customer's home phone and in another direction to the customer's DSL modem and home PC.