Specifications

Diagnostics
The detection and isolation of a malfunction or mistake in a
communications device, network or system.
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.
Frame
A logical grouping of information sent as a link-layer unit over a
transmission medium. The terms packet, datagram, segment, and
message are also used to describe logical information groupings.
Framing
At the physical and data link layers of the OSI model, bits are fit
into units called frames. Frames contain source and destination
information, flags to designate the start and end of the frame,
plus information about the integrity of the frame. All other
information, such as network protocols and the actual payload of
data, is encapsulated in a packet, which is encapsulated in the
frame.
Full Duplex
A circuit or device permitting transmission in two directions
(sending and receiving) at the same time.
G.703
An ITU standard for the physical and electrical characteristics of
various digital interfaces, including those at 64 kbps and 2.048
Mbps.
Gateway
Gateways are points of entrance and exit from a communications
network. Viewed as a physical entity, a gateway is that node that
translates between two otherwise incompatible networks or
network segments. Gateways perform code and protocol
conversion to facilitate traffic between data highways of differing
architecture.
Impedance
The combined effect of resistance, inductance and capacitance on
a transmitted signal. Impedance varies at different frequencies.
Interface
A shared boundary, defined by common physical interconnection
characteristics, signal characteristics, and meanings of exchanged
signals.