ADTRAN L768 User Manual
Page 20
Chapter 1: Understanding HDSL and the Express L768/L1.5
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Express L768/L1.5 User Manual
61202192L1-1
THE EXPRESS L768/L1.5
The Express L768/L1.5 is a standalone device that links two Local Area Net-
works (LANs) using a high-speed DSL two-wire or four-wire line. The Express
L768 has a two-wire interface and operates up to 768 kbits per second. The Ex-
press L1.5 has a four-wire interface and operates up to 1.536 Mbits per second.
The Express L1.5 is compatible with the Express L768 in a two-wire mode if
the rate is 768K and below.
See Figure 1-1 for an illustration of the Express L768/L1.5. The 10BaseT con-
nector operates at 10 Mbits per second half duplex and accepts standard eth-
ernet packets encapsulated using IEEE 802.3 or Ethernet II (DIX). Because the
10BaseT is a four-wire interface, a crossover switch permits the user to connect
to either a hub-concentrator or network interface card without the need for
special cabling. The maintenance port can connect to any asynchronous termi-
nal emulating a VT 100 terminal for configuration.
Figure 1-1
Express L768/L1.5
LI
EXPRESS L1.5
TX/RX
LOOP1
LOOP2
PWR
LINE
TEST
LI
EXPRESS L768
TX/RX
LOOP
LINK
PWR
LINE
TEST
L768
L1.5