ZyXEL Communications 2864 Series, Руководство пользователя, Страница: 135 / 267

12–1
Chapter 12
LEASED-LINE OPERATION
A leased line is a permanent telephone line connection between two fixed points. It
can be dedicated copper wires or a leased telephone circuit from the telephone com-
pany. The 2864L model supports 4-wire and 2-wire leased lines. 4-wire leased lines
use one pair of wires to transmit data and a second pair to receive. 2-wire leased
lines transmit and receive on the same pair of wires.
Connecting to a Leased Line
The leased-line model 2864L has a separate jack/terminal for a leased-line connec-
tion. The normal dial-up line models have only a phone jack for dial-up line con-
nections. On these models, connect to a 2-wire leased line using the same jack.
For the 2864L, the default line type is dial-up line (DL). It includes a separate
leased-line jack. The leased line must be connected to the jack labeled
LEASED LINE
(located at the rear of the modem) for leased-line operation. You can set the 2864L
for leased-line operation by typing commands from the terminal or by selecting it
from the front panel. The leased-line phone jack pin assignments are shown in Ap-
pendix B.
The rack mount model has both dial-up and leased-line terminal connectors on the
rear panel of the rack it is mounted on.
Line Type
For the normal dial-up line only models, only 2-wire leased lines can be used and
the same phone jack is used for both dial-up and leased-line connections. The dial
backup feature is not available in this case.
Menu AT-Command Description
2W LEASED
AT&L1
The modem is connected to a 2-wire leased
line; the line plug should be plugged into the
jack assigned
LEASED LINE on the rear panel.
4W LEASED
AT&L2
The modem is connected to a 4-wire leased
line. Plug the line into the
LEASED LINE jack.