Datacom DM991C, Product Manual

Page: 15 / 89

Product Manual - DM991 Series V Family - 204.4092.08 15
3. G.SHDSL INTERFACE
The DM991S/SE modem G.shdsl interface presents connection through the screw connector block, as
seen in Table 5. The DM991C/CE modem G.shdsl interface presents connection through an RJ45 with
pinout as shown in Table 6.
Signal
screw connector
block
Port
TIP TX -1
RING TX -2
TIP RX -1
RING RX -2
A
B*
Table 5. DM991S/SE - G.shdsl Interface Pinout
* Only 4W modem
.
Signal Pin (RJ45) Port
TIP 4
RING 5
TIP 3
RING 6
A
B*
Table 6. DM991C/CE - G.shdsl Interface Pinout
* Only 4W modem.
The G.shdsl (G.991.2) standard specifies symmetrical connection to 2 wires for subscriber’s lines.
The handshake negotiations are done according to the ITU-T G.994.1 recommendation.
It can be configured as LTU (central) or NTU (user), always working as a cluster to other interfaces in the
equipment.
It can be configured to operate in quasi-synchronous, synchronous or automatic selection modes.
It can be configured to operate as per Annex A, B or with automatic selection, defined on recommendation
G.991.2.
It supports operation with rates up to 2,304 kbit/s per line, according to annexes A and B in standard
G.991.2.
It can carry from 1 to 36 64-kbit/s timeslots, with line channel alignment.
The interface range alternates according to the transmission rate, between 7,100m (for 192kbit/s on a
noise-free 0.4-mm line) and 4,100m (for 2,304kbit/s on a noise-free 0.4-mm line).
When configured as NTU, the interface accepts any rate, annex and frame type that the LTU indicates
during the handshake. The number of channels of the aggregate should always be the same or larger to
the sum of tributaries channels.
Only for DM991C/CE: The interface has primary protection - (sparklers) capable of supporting electrical
discharges according to the ITU-T K.21 recommendation.