User guide

HiPath Wireless Standalone 802.11n AP User Guide D-9
NTP Network Time Protocol, an Internet standard protocol (built on top
of TCP/IP) that assures accurate synchronization to the
millisecond of computer clock times in a network of computers.
Based on UTC, NTP synchronizes client workstation clocks to the
U.S. Naval Observatory Master Clocks in Washington, DC and
Colorado Springs CO. Running as a continuous background client
program on a computer, NTP sends periodic time requests to
servers, obtaining server time stamps and using them to adjust the
client's clock. (RFC1305)
OFDM Orthogonal frequency division multiplexing, a method of digital
modulation in which a signal is split into several narrowband
channels at different frequencies. OFDM is similar to conventional
frequency division multiplexing (FDM). The difference lies in the
way in which the signals are modulated and demodulated. Priority
is given to minimizing the interference, or crosstalk, among the
channels and symbols comprising the data stream. Less
importance is placed on perfecting individual channels.
OFDM is used in European digital audio broadcast services. It is
also used in wireless local area networks.
OID Object Identifier.
OPSEC OPSEC (Open Platform for Security) is a security alliance
program created by Check Point to enable an open industry-wide
framework for interoperability of security products and
applications. Products carrying the ‘Secured by Check Point’ seal
have been tested to guarantee integration and interoperability.
OS Operating system.
OSI Open System Interconnection. An ISO standard for worldwide
communications that defines a networking framework for
implementing protocols in seven layers. Control is passed from
one layer to the next, starting at the application layer in one
station, down through the presentation, session, transport,
network, data link layer to the physical layer at the bottom, over
the channel to the next station and back up the hierarchy.
OSI Layer 2 At the Data Link layer (OSI Layer 2), data packets are encoded
and decoded into bits. The data link layer has two sublayers:
the Logical Link Control (LLC) layer controls frame
synchronization, flow control and error checking
The Media Access Control (MAC) layer controls how a computer
on the network gains access to the data and permission to
transmit it.
OSI Layer 3 The Network layer (OSI Layer 3) provides switching and routing
technologies, creating logical paths, known as virtual circuits, for
transmitting data from node to node. Routing and forwarding are
functions of this layer, as well as addressing, internetworking,
error handling, congestion control and packet sequencing.
Term Definition