B-8
Glossary
OSI (Open Systems Interconnection)
Refers to the OSI reference model, a logical structure for network
operations. OSI is the internationally accepted framework of
standards for internetwork communication.
packet
A group of bits including data and control elements arranged in a
specific format that are transmitted and switched as a composite
whole. Control elements include a source address, destination
address, frame control and status indicators, and a Frame Check
Sequence (FCS).
PDU (protocol data unit)
The portion of a datagram that contains the data associated with a
particular protocol.
peer-to-peer
Term used to describe data transmission between entities in the
same sublayer of the OSI model.
physical layer
Layer 1 of the OSI model. Defines and handles the electrical and
physical connections between systems.
power budget
The difference between transmit power and receiver sensitivity,
including any safety margins.
PPP (point-to-point protocol)
A protocol for transmitting datagrams (IP or MAC packets) over a
serial point-to-point link (e.g., the out-of-band management port).
pps (packets per second)
Unit of measure used to express packet data throughput. 18 pps is
approximately equal to 9600 bps.
propagation delay
The time it takes for a signal to travel across a network.