User`s guide

D-16
Glossary
optical transmitter
A circuit that converts an electrical signal to an optical signal.
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).
packet processing engine module
High-performance component of the ATX bridge capable of
performing packet analysis/transfer at a high rate.
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.
PHY (Physical Layer Protocol)
FDDI standard that defines symbols, line states, clocking