Hirschmann RS20 Reference Manual page 217

Glossary
O
Open Shortest Path First. A link-
state (algorithm used by the router to
determine the current topology of a
network), Interior Gateway
(distributes routing information
between routers belonging to a
single Autonomous System) routing
protocol. This protocol's algorithm
determines the shortest path from its
router to all the other routers in the
network. This protocol is rapidly
replacing RIP on the Internet.
Open Systems Interconnection.
OSI is a seven (7) layer architecture
model for communications systems
developed by the ISO for the
interconnection of data
communications systems. Each
layer uses and builds on the
services provided by those below it.
Operating System Application
Programming Interface. OSAPI is
a module within the System Support
software that provides a set of
interfaces to OS support functions.
OS. Operating System.
OSAPI. See "Operating System
Application Programming Interface"
on page 217.
OSI. See "Open Systems
Interconnection" on page 217.
OSPF. See "Open Shortest Path
First" on page 217.
217
P
PDU. See "Protocol Data Unit" on
page 218.
PHY. The OSI Physical Layer: The
physical layer provides for
transmission of cells over a physical
medium connecting two ATM
devices. This physical layer is
comprised of two sublayers: the
Physical Medium Dependent (PMD)
sublayer, and the Transmission
Convergence (TC) sublayer.
PIM-DM. See "Protocol
Independent Multicast – Dense
Mode" on page 218.
PMC. Packet Mode Channel.
Port Mirroring. Also known as a
roving analysis port. This is a
method of monitoring network traffic
that forwards a copy of each
incoming and outgoing packet from
one port of a network switch to
another port where the packet can
be studied. A network administrator
uses port mirroring as a diagnostic
tool or debugging feature, especially
when fending off an attack. It
enables the administrator to keep
close track of switch performance
and alter it if necessary. Port
mirroring can be managed locally or
remotely. An administrator
configures port mirroring by
assigning a port from which to copy
all packets and another port where
those packets will be sent. A packet
bound for or heading away from the
CLI L2B
Release 4.0 11/07