ADTRAN 1200070L2, 1200070L1 user manual Isdn Overview, Express XL/XLT

Chapter 1

Understanding ISDN and

the Express XL/XLT

ISDN OVERVIEW

The Integrated Services Digital Network (ISDN) is a public or private switched digital network. ISDN is an international standard for digital communica- tions, allowing a full range of enhanced services supporting voice, data, and image applications through standard interfaces over a single telephone wire. ISDN provides a means of integrating these services and modernizing com- munication networks for information movement and management efficiency.

THE EXPRESS XL/XLT

The Express XL/XLT is a standalone device that links two Local Area Net- works (LANs) using a high-speed ISDN public network or leased two-wire line. Optionally, the Express XLT has a plain old telephone service (POTS) connector that is used for voice/modem applications

See Figure 1-1 for an illustration of the Express XL/XLT. The 10BaseT connec- tor operates at 10 megabits 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.

				ExpressXL
			TEST
RX TX	LI COL JAB	ERR	LNK B1 B2 LOOP	PWR
				SELECT TEST

Figure 1-1

Express XL/XLT

61200.070L1-1 Express XL/XLT User Manual 7