DSL Advances

12.2. Inside Telephone Wiring and ADSL

As shown in Figure 12.1, the telephone distribution cable connects to the customer premises via a drop wire that typically consists of two to four pairs of wire. Starting in the year 2000, the industry widely adopted self-installation by customers using the splitterless customer premises configuration shown in Figure 12.2. The splitterless configuration uses the same pair of inside wires for POTS and ADSL data; this pair of wires is known as line-1 and connects to pins three and four of the telephone wall jacks. Despite being called “splitterless,” this configuration typically includes a line-sharing splitter at the central office end of the line.

Figure 12.1. Customer premises configuration with shared ...