WAN Terms and Acronyms
HSIM-W87 User’s Guide
C-3
DSX-1 —
Short-haul version of DS1(coaxial cable being used as the
media defines it as short-haul) by definition, coaxial cable is short-haul.
DSX-3 —
Short-haul version of DS3 (coaxial cable being used as the
media defines it as short-haul) by definition, coaxial cable is short-haul.
DTE —
Data Terminal Equipment, equipment that originates and
terminates data transmission such as a computer or printer (see DCE).
E-1 —
European digital signal level 1. Similar to T1 but provides 32
channels (2.048 Mbps) instead of 24 channels (1.544 Mbps).
ESF —
Extended Super Frame. A new T1 framing standard (see D4
framing) that uses 24 T1 frames, thus allowing individual identification of
the channel and signaling bits.
EXZ —
Excessive Zeros, an EXZ is the occurrence of any zero string
length equal to or greater than 3 for B3ZS, or greater than 4 for HDB3.
Fractional T1 —
Use of a portion (less than the full 24 channels) of a T1
line.
Frame Relay —
A network protocol that allows for many point-to-point
virtual connections over a single access channel.
HDB3 —
High Density Bipolar 3, used with E-1, a bipolar coding
method that does not allow more than 3 consecutive zeros.
HDLC —
High-Level Data Link Control, layer 2 (link layer) full-duplex
protocol derived from SDLC.
INV. HDLC —
A form of zero suppression in which all zeros in the
HDLC packet are changed to ones and all ones are changed to zeros.
ISDN —
Integrated Services Digital Network. Allows point-to-point
connections at 64 Kbps or 128 Kbps when necessary and disconnects the
line when not in use. With this service the user only pays for the time
connected.
JBZS —
Jam Bit-Zero Suppression, a form of zero suppression that
places a one in the seventh bit of a timeslot. Reduces the effective
throughput to 56 Kbps.
