Nortel Meridian 1 Option 11C, Administration And Maintenance

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Chapter 5 — ISDN BRI line and packet data implementation Page 189 of 492
Option 11C ISDN BRI Administration and Maintenance
To calculate the number of SILCs for a combination of terminals on a DSL,
follow the equations below:
Total SILC B-channel terminals ÷ (number of B-channel terminals per
DSLx 8) = SILCs
Total SILC D-channel terminals ÷ (number of D-channel terminals per
DSLx 8) = SILCs
If the result is a fraction, round it off to the next highest number. The larger
of the two results obtained from the above two equations represents the SILCs
for blocking conditions.
NT6D71 U Interface Line Card (UILC)
The UILC interface supports a two-wire point-to-point loop consisting of a
twisted pair engineered for 2B1Q line coding on the DSL. The Option 11
UILC card (NT6D71) is the same circuit card that is used by the rest of the
Meridian 1 product line. It supports the OSI physical layer (layer 1) protocol.
The UILC supports ANSI 2B1Q line encoding.
The UILC provides eight two-wire full duplex (not polarity sensitive) U
interfaces that are used to connect ISDN BRI compatible terminals over DSLs
to the Option 11 system. 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 km (16,405 ft).
The main functions of the UILC are:
— provide eight ISDN U interfaces that use 2B1Q encoding.
— 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 connection.
— perform activation and deactivation of DSLs.
— provide loopback control of DSLs.