scope:

This standard provides specifications for DS3 (nominal 44.736 Mbit/s) interfaces between telecommunication carrier networks and customer installations and DS3 interfaces within customer installations. In this standard, the telecommunication carrier network is referred to as the Network and the customer premises wiring and equipment as the Customer Installation (CI). The interface between the Network and the CI is referred to as the Network Interface (NI). The NI is the same as the demarcation point defined in Part 68 of the FCC Rules and Regulations.

This standard establishes requirements at the NI for compatible operation between the network and the CI. It also establishes requirements within the CI for compatible operation between customer equipment. Equal level network-to-network DSX-3 interfaces are specified in T1.102-1993 (R1999), Digital Hierarchy - Electrical Interfaces.

The requirements in this standard are written to establish a functional and practical interface. Compliance with them provides a satisfactory interface in most installations. If problems arise that have not been addressed in this standard, they should be resolved through the cooperation of the customer, carrier, and equipment supplier.

Two types of signals normally exist at DS3 interfaces:

- Normal operating signals; and

- Maintenance signals.

This standard does not cover signals that occur as a result of the environment (e.g., power line induced voltages and currents, and transients caused by lightning).

A full duplex DS3 electrical interface, based on current digital network facilities, is described in this standard. Signals provided by the customer and the network to the equal level NI described in this standard must meet the same criteria as those provided by carriers to the DSX-3 cross-connect frame in network-to-network interfaces, except as otherwise stated.

The non-equal level NIs defined in this standard may be referenced for carrier network-to-carrier network interfaces when applicable. In such cases, the CI specifications would apply to one carrier network and the network specifications would apply to the other carrier network. The physical connection between the networks in such cases would be in a manner mutually agreed upon by the carriers, but not necessarily the plug and jack described in this standard.