Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 135)

Acronyms and Definitions
Verilink Access System 2000: Basics Glossary-15
Digital Signal Level 3 DS3 is 28 DS1 signals assembled
with a two-step multiplexing
process. The 28 signals are
multiplexed into seven DS2
signals. The seven DS2 signals are
multiplexed into one DS3 signal.
Each multiplexing step uses bit
stuffing to manage the different
input frequencies, if required.
Comes in two formats: --M13
format (cannot provide end-to-end
path parity information). --C-
bit.format DS3 overhead (OH) bits
that provides alignment, error
checking, in-band
communications, and bit stuffing
control information. The overhead
bits are located in the first bit
position of every block.
DIM Verilink’s data interface module, a
type of connector interface
modules (CIM) used with Verilink
DIUs.
Direct Current See DC .
Discard Eligibility (DE) In frame relay networks, a bit used
to identify which frames to discard
if congestion occurs in order to
stay within the Committed
Information Rate.
DIU Verilink’s Data Interface Unit
(DIU) .
DLCI Data Link Connection Identifier. In
frame relay networks, a unique
value in the frame overhead bits
used to by the service provider to
direct the frame to the correct
endpoint. The DLCI identifies
which permanent virtual circuit
(PVC) will be used for that
particular frame.
DLS See Dual-line Shelf .
doubler Device used to regenerate signals
on HDSL copper pairs. Similar in
function to a T1 repeater.
drain Cabling term for a chassis ground
or shield ground.
drop and insert That process where a part of the
information carried in a
transmission is demodulated
(dropped) at an intermediate point
and different information is
entered (inserted) for subsequent
transmission.
DS0 See Digital Signal Level 0 .
DS1 See Digital Signal Level 1 .