Multi-Tech Systems MTASR3-200 - Manual (Page 82)

RASFinder User Guide
MTASR3-200 82
W
Wide Area Network (WAN): 1. A network that provides communication services to a geographic area larger than that
served by a local area network or a metropolitan area network, and that may use or provide public communication facilities.
2. A data communications network designed to serve an area of hundreds or thousands of miles; for example, public and
private packet-switching networks, and national telephone networks. Contrast with local area network (LAN).
Wide Area Telecommunications Service (WATS): A low-cost toll service offered by most long distance and local phone
companies. Incoming (800 call service, or IN-WATS) and outgoing WATS are subscribed to separately, but over the same
line.
X
X.25: ITU-T’s definition of a three-level packet-switching protocol to be used between packet-mode DTEs and network
DCEs. X.25 corresponds with layer 3 of the 7-layer OSI model.
Y
Yellow Alarm: An error indication sent by the T1 device when it has not gotten a receive signal, or cannot synchronize on
the receive signal received. Contrast “Red Alarm” and “Blue Alarm”.
Z
Zero Byte Time Slot Interchange (ZBTSI): A method for allowing 64K bps unrestricted user data (allowing all 0s in the
user data). An alternative to (but not as popular as) B8ZS.