Page420 of 544 NT6D71UILC line card
553-3011-100 Standard14.00 January 2002
Functional description
Each U interface provides two B-channels and one D-Channel and supports
one physical termination. This termination may be to a Network Termination
(NT1) or directly to a single U interface terminal. Normally this physical
termination is to an NT1, which provides an S/T interface that allows up to 8
physical terminals to be connected. The length of a DSL depends on the
specific terminal configuration and the DSL wire gauge, however, it should
not exceed 5.5 km (3.3 mi).
The main functions of the UILC are:
•provide eight ISDN U interfaces conforming to ANSI standards
•support point-to-point DSL terminal connections
•provide channel mapping between ISDN BRI format (2B+D) and
Meridian 1 bus format
•multiplex 4 D-channels onto one timeslot
•perform activation and deactivation of DSLs
•provide loopback control of DSLs
Micro Controller Unit (MCU)
The MCU coordinates and controls the operation of the UILC. It has internal
memory, a reset and sanity timer, a serial control interface, a maintenance
signaling channe l, and a digital pad.
The memory consists of 32 K of EPROM that contains the UILC operating
program and 8 K of RAM used to store interface selection and other functions
connected with call activities.
The reset and sanity timer logic resets the MCU.
The serial control interface is an IPE bus used to communicate with the U
transceivers.
IPE interface logic
The IPE interface logic consists of a Card-LAN interface, an IPE bus
interface, a maintenance signaling channel interface, a digital pad, and a clock
converter.