Specifications

Cell
The 53-byte basic information unit within an ATM network. The
user traffic is segmented into cells at the source and reassembled
at the destination. An ATM cell consists of a 5-byte ATM header
and a 48-byte ATM payload, which contains the user data.
Channel
A path for electrical transmission between two or more points.
Also called a link, line, circuit or facility.
Clock
A term for the source(s) of timing signals used in synchronous
transmission.
Congestion
A state in which the network is overloaded and starts to discard
user data (frames, cells or packets).
Data
Information represented in digital form, including voice, text,
facsimile and video.
Data Link Layer
Layer 2 of the OSI model. The entity, which establishes, maintains,
and releases data-link connections between elements in a
network. Layer 2 is concerned with the transmission of units of
information, or frames, and associated error checking.
dBm
A measure of power in communications: the decibel in reference
to one milliwatt (0 dBm = 1 milliwatt and -30 dBm = .001
milliwatt).
Decibel
See dB.
Diagnostics
The detection and isolation of a malfunction or mistake in a
communications device, network or system.
Differential Delay
Differential delay is caused when traffic is split over different lines
that may traverse shorter and longer paths. Products like the RAD
IMX-2T1/E1 inverse multiplexer compensate for any differential
delay (up to 64 msec) between the T1 lines, to properly
reconstruct the original stream.
Digital
The binary (“1” or “0”) output of a computer or terminal. In data
communications, an alternating, non-continuous (pulsating) signal.
E3
The European standard for high speed digital transmission,
operating at 34 Mbps.
Encapsulation
Encapsulating data is a technique used by layered protocols in
which a low level protocol accepts a message from a higher level
protocol, then places it in the data portion of the lower-level
frame. The logistics of encapsulation require that packets traveling
over a physical network contain a sequence of headers.
Ethernet
A local area network (LAN) technology which has extended into
the wide area networks. Ethernet operates at many speeds,
including data rates of 10 Mbps (Ethernet), 100 Mbps (Fast
Ethernet), 1,000 Mbps (Gigabit Ethernet), 10 Gbps, 40 Gbps, and
100 Gbps.
Flow Control
A congestion control mechanism that results in an ATM system
implementing flow control.