Typical CPE Configuration
This is a typical CPE configuration for both T1 data, and T1 voice. This diagram can be sent to the customer to educate them on how the equipment will likely be connected. The LEC usually drops off a "Smart Jack" in a wiring closet, and terminates a cable to a wall-mounted biscuit. The RJ48x has automatically goes into Loopback mode when the cable is unplugged. The DB60 pin plug shown is a proprietary Cisco V.35 connector.
Also shown are the areas of responsibility - which come into play during a trouble call.