User's Guide

Glossary
hwc_glossary.fm
Networking terms and abbreviations
9034530-02, March 2010
476 HiPath Wireless Controller, Access Points and Convergence Software V7.11, User Guide
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.
OSPF Open Shortest Path First, an interior gateway routing protocol developed for IP networks
based on the shortest path first or link-state algorithm. Routers use link-state algorithms to
send routing information to all nodes in an internetwork by calculating the shortest path to
each node based on a topography of the Internet constructed by each node. Each router
sends that portion of the routing table (keeps track of routes to particular network destinations)
that describes the state of its own links, and it also sends the complete routing structure
(topography). Using OSPF, a host that obtains a change to a routing table or detects a change
in the network immediately multicasts the information to all other hosts in the network so that
all will have the same routing table information. The host using OSPF sends only the part that
has changed, and only when a change has taken place. (RFC2328)
OUI Organizationally Unique Identifier (used in MAC addressing).
Packet The unit of data that is routed between an origin and a destination on the Internet or any other
packet-switched network. When any file is sent from one place to another on the Internet, the
Transmission Control Protocol (TCP) layer of TCP/IP divides the file into packets. Each packet
is separately numbered and includes the Internet address of the destination. The individual
packets for a given file may travel different routes through the Internet. When they have all
arrived, they are reassembled into the original file (by the TCP layer at the receiving end).
PAP Password Authentication Protocol is the most basic form of authentication, in which a user's
name and password are transmitted over a network and compared to a table of name-
password pairs. Typically, the passwords stored in the table are encrypted. (See CHAP).
PDU Protocol Data Unit. A data object exchanged by protocol machines (such as management
stations, SMUX peers, and SNMP agents) and consisting of both protocol control information
and user data. PDU is sometimes used as a synonym for “packet''.
PEAP PEAP (Protected Extensible Authentication Protocol) is an IETF draft standard to authenticate
wireless LAN clients without requiring them to have certificates. In PEAP authentication, first
the user authenticates the authentication server, then the authentication server authenticates
the user. If the first phase is successful, the user is then authenticated over the SSL tunnel
created in phase one using EAP-Generic Token Card (EAP-GTC) or Microsoft Challenged
Handshake Protocol Version 2 (MSCHAP V2). (See also EAP-TLS).
PHP server Hypertext Preprocessor
PKI Public Key Infrastructure
PoE Power over Ethernet. The Power over Ethernet standard (802.3af) defines how power can be
provided to network devices over existing Ethernet connection, eliminating the need for
additional external power supplies.
POST Power On Self Test, a diagnostic testing sequence performed by a computer to determine if
its hardware elements are present and powered on. If so, the computer begins its boot
sequence.
Term Explanation