Network
Glossary
10BASE-T
IEEE
networking standard for 10 Mbps twisted-pair Ethernet cabling.
100BASE-TX
IEEE networking standard for 100 Mbps twisted-pair
Ethernet cabling; also called Fast Ethernet.
100BASE-FX
IEEE networking standard for Ethernet which
runs on multimode fiber optic cabling at 100 Mbps. This
is one version of Fast Ethernet.
1000BASE-SX
IEEE networking standard for a variant of
Gigabit Ethernet which runs on multimode fiber optic cable
at an 850 nm wavelength.
1000BASE-LX
IEEE networking standard for a variant of
Gigabit Ethernet which runs on multimode and single mode
fiber optic cable at a 1330 nm wavelength.
1000BASE-T
IEEE networking standard for a variant of
Gigabit Ethernet which runs on unshielded twisted pair
cable.
2002
FrontPage Server Extensions
These extensions are how Web developers using Microsoft’s FrontPage program
communicate with the web server.
Access
Control Lists
Database that describes the type of access
each user has to a service.
Access
Profiles
Access profiles control all aspects of
remote management of switches. An access profile can
consist of a list of IP addresses and net masks. Each
remote management method can be independently assigned
to an access profile. The remote management methods under
access profile control include SNMP Read, SNMP Read/Write,
Web, Telnet and SSH2 access.
Address
A set of characters that identifies an individual
network node.
Address
Table
The database maintained by a switch of
all addresses it has learned and the switch ports through
which these addresses can be reached. It is used by the
switch to make packet forwarding and filtering decisions.
Analog
Web/FTP Log Analyzer
A program that tracks and logs activity, on a website.
Anonymous
FTP
A way of anonymously logging into servers and transferring files.
Apache
Web Server
A program that displays the contents of a website when someone visits the site.
Also known as just Apache.
Application
Switching
A Layer 4-7 data center networking device
with the intelligence to detect different applications,
and assign each of the requisite network resources and
services for customer billing.
ASIC
Application-Specific Integrated Circuit.
A chip designed for a particular application. ASICs are
commonly used in networking devices to maximize performance
with minimum cost.
ASP
Application Service Provider. A business
that hosts software applications on its own servers within
its own facilities. Customers can access these applications
via private lines or the Internet.
ATM
Asynchronous Transfer Mode. Cell-based network
technology capable of transmitting data, voice, video,
and frame-relay traffic.
Auto-negotiating
Two-part process by which a network device
automatically senses the speed and duplex capability of
another device.
Autosensing
Process during which a network device automatically
senses the speed of another device.
Backbone
Interconnection in a LAN or WAN between
subnetworks or workgroups. The high-speed connection to
lower-speed subnets. For example, a Gigabit Ethernet backbone
connected to Fast Ethernet subnets.
Backplane
Bus or switching matrix that resides within
a switch or hub chassis; all traffic crosses the backplane
at least once.
Backup
/ Restore Functionality
The ability for a website administrator or webmaster to make a backup of their
website or to restore a previous version.
Bandwidth
The maximum amount of data that can be transmitted
in a fixed amount of time; usually expressed in bits-per-second
or bytes-per-second.
BGP
Border Gateway Protocol, an Internet protocol
that enables groups of routers (called autonomous systems)
to share routing information so that efficient, loop-free
routes can be established. BGP is commonly used within
and between Internet Service Providers (ISPs). The protocol
is defined in RFC 1771.
BGP4
An extension of the Border Gateway Protocol,
an Internet protocol that enables groups of routers (called
autonomous systems) to share routing information so that
efficient, loop-free routes can be established. BGP is
commonly used within and between Internet Service Providers
(ISPs).
Bidirectional
Rate Shaping
A hardware-based technology that enforces
traffic policies, tracks usage, and manages traffic concurrently
by routing data packets to the logical ingress queue
and processing policies in a bidirectional fashion. Also
referred to as bandwidth by the slice.
BIND
Domain Name Server
Berkeley Internet Name Domain. Allows a server to look up the IP address of
a Domain Name.
BLEC
Building Local Exchange Carrier. A type
of service provider that offers Internet access and data
network services for multi-tenant buildings owned by commercial
and residential real estate firms.
Broadband
The
high-bandwidth communications infrastructure, or big pipes,
that enable faster data transmissions and future applications
for the Internet economy.
Broadcast
Message forwarded to all devices within
a network. Broadcasts exist at Layer 2.
Category
5 (CAT5)
Networking standard certifying that a
copper wire cable can carry data at up to 100 Mbps. See
also UTP.
Chipset
A set of integrated hardware circuits, such
as application-specific integrated circuits (ASICs), which
perform a particular function. They are commonly used in
networking devices to maximize performance with minimum
cost.
CGI
Common
Gateway Interface. Where programs are stored that are activated
when someone clicks on a button or icon on a webpage. Also
known as (CGI Bin)
CGI
Scripting
The programs used to interact between web server and web browser when someone
clicks a button on a webpage.
CLI
Command Line Interface. An interface that
allows the user to interact with the operating system by
entering commands and optional arguments.
Client
A device or software that requests information from another device or software.
Client/Server
Distributed computing model where desktop
clients can access and share information resources from
multiple servers.
Collapsed
Backbone
LAN architecture in which the subnetwork
interconnection is concentrated within a Layer 3 switch
or router.
Collision
Concurrent Ethernet transmissions from two
or more devices on the same segment.
Co-location
Placing equipment owned by a customer in
another company's secured facility. Co-location facilities
offer the space for equipment, security, and other services,
as well as interconnections and Internet access for installed
equipment.
Concentrator
Device used in a LAN to combine transmissions
from a cluster of clients and/or servers; often called
a hub.
COPS
The Common Open Policy Service protocol
is used with RSVP and policy-based networking for the communication
between a network device and an authoritative policy management
entity. Typically, this is a policy server or call admission
control server process. It defines the transport and formatting
of data used in this communication.
Data-link
Layer
See Layer 2.
Dedicated
Server
A server that is dedicated to a single customer.
Destination
Address
The IP or MAC address of the node that is to receive the packet.
DHCP
Dynamic Host Control Protocol. An effective
way to dynamically assign and reuse a fixed number of IP
addresses when there are more devices on the network than
addresses available. A DHCP server dynamically assigns
IP addresses to devices requesting them. These address
assignments expire after a time specified by the network
manager. The DHCP server then reassigns these addresses
to other devices as needed. DHCP is an extension to BOOTP
in which the address assignments are static.
DHTML
Dynamic HTML is a name for a set of technologies Web developers use to create
Web pages that update themselves on the fly.
DiffServ
An IETF standard developed to help solve
IP quality problems. DiffServ operates at Layer 3 and allows
out-of-band negotiation. DiffServ relies on traffic conditioners
sitting at the edge of the network to indicate each packet's
requirements.
DNS
Domain Name System (or Service). The system
of assigning each domain name a unique address so that it can
be located on the Internet.
Duplex
A communication mode in which a device can
send and receive over data the same link. The device can
operate in full-duplex and half-duplex.
Dynamic
Link Context System
The Dynamic Link Context System allows
policy-setting based on user names or desktop devices,
and automatically maps them to lower-layer addresses.
DVMRP
The Distance Vector Multicast Routing Protocol
is used for the communication and distribution of multicast
routing table information. It is based on the RIP protocol
used in unicast routing. See IETF document draft-ietf-dvmrp-v3-07.
Enterprise
Desktop Switch
An Enterprise Desktop Switch combines
the low cost and simplicity of a stackable edge device
with the enterprise-class features found in more expensive
chassis-based switches.
Equal
Cost Multipath Routing (ECMP)
Distributes network traffic
across multiple high-bandwidth links to increase performance.
As many as four links may be involved in an ECMP link
and traffic is shared on an IP source/destination address
session basis.
ERP
Enterprise Resource Planning. A business
management system that integrates all facets of the business,
including planning, manufacturing, sales, and marketing.
As the ERP methodology has become more popular, software
applications have emerged to help business managers implement
ERP.
Ethernet
A local area network used for connecting
computers, printers, workstations, terminals, servers,
etc. within the same building or campus. An IEEE networking
standard, originally developed by Xerox, for transmitting
data at 10 Mbps.
E-mail
Gateway
A PC on the network that sends and receives email and/or faxes for everyone
on the LAN.
Exabyte
(EB) A unit of measure for physical data storage on a storage device (1000
Petabytes = 1 Exabyte).
Extranet
A secure web site for customers or suppliers
rather than the general public. It can provide access to
paid research, current inventories and internal databases,
virtually any information that is private and not published
for everyone. An extranet uses the public Internet as its
transmission system, but requires passwords to gain access.
Fast
Ethernet
An IEEE networking standard for transmitting
data at 100 Mbps. See 100BASE-TX also.
Fault-tolerance
The ability of a device to prevent or recover
from network and internal failures. Key elements of fault
tolerance include hot-swappable modules, redundant load-sharing
power supplies, passive backplanes, and redundant cooling
systems.
FDDI
Fiber Distributed Data Interface. An ANSI
networking standard for 100 Mbps fiber-optic LANs; widely
used as a backbone technology to interconnect several Ethernet
or Token Ring networks.
File
Manager
A graphical interface that allows website administrators or webmasters to manipulate
their site’s files and also set file permissions on those files.
Filter
An action of the switch to discard certain
types of data packets.
Firmware
Software routines that are permanently written
onto read-only memory.
Flash®
A bandwidth friendly and browser independent animation technology. Lets you
display dynamically enhanced animations on a webpage.
FTP
File Transfer Protocol. Lets you transfer files across the Internet. Allows
more functionality and security than TFTP (Trivial File Transfer Protocol).
Full-duplex
The communication mode in which a device
simultaneously sends and receives over the same link, doubling
the bandwidth. A full-duplex 100Mbps connection has 200Mbps
of bandwidth. A full-duplex 1000Mbps connection has 2000Mbps
of bandwidth.
Fully
Redundant Power Source
Multiple power supplies on a single server. If one fails the other continue
to power the server.
GBIC
Gigabit Interface Connector. The physical
connection to Gigabit Ethernet media.
Gbps
Gigabits per second.
Generated
Web Logs
Text files that display the traffic on a website.
GIF
Graphics Interface Format. A format used to make pictures or images viewable
on a computer. These files end with the extension: “.gif”.
Gigabit
Ethernet
Networking standard for transmitting data
at 1000 Mbps.
Gigabyte
(GB) A unit of measure for physical data storage on a storage device (1000
Megabytes = 1 Gigabyte).
Half-Duplex
The communication mode in which a device
is capable of either sending or receiving, but not simultaneously.
Hardware
Address
A device?s physical or media access control
(MAC) address.
Header
Special information contained in the beginning
of a frame.
Host
Any entity on the network that can initiate
a transmission. A router, a server or a workstation.
HTML
HyperText Markup Language. The programming language that is used to produce
web pages.
HTTP
Hypertext Transfer Protocol. Defines how
messages are formatted and transmitted, and what actions
Web servers and browsers should take in response to various
commands. Defines how requests for HTML and graphics files
which make up a web page are handled between the web server
and the client browser.
HTTPS
Hypertext Transfer Protocol Secure Socket Layer. A protocol developed for transmitting
private documents via the Internet.
Hub
An unintelligent network device that sends
one signal to all of the stations connected to it.
ICMP
Internet Control Message Protocol. The part
of the IP protocol that handles error and control messages.
The switch issues ICMP messages to report IP datagram problems
back to the their source.
IGMP
Internet Group Management Protocol. A protocol
that hosts use to keep local routers informed of their
membership in multicast groups. When all hosts leave a
group, the router no longer forwards datagrams that arrive
for the group.
IGMP
Snooping
IGMP Snooping provides a method for intelligent
forwarding of multicast packets within a Layer 2 broadcast
domain. By snooping IGMP registration information, a
distribution list of workstations is formed that determines
which end-stations will receive packets with a specific
multicast address.
IEEE
802
Set of Institute of Electrical and Electronic
Engineers standards for defining methods of access and
control on LANs.
Internet
The Internet is made up of more than 65
million computers in more than 100 countries covering commercial,
academic and government endeavors.
Intranet
An in-house web site that serves the employees
of the enterprise. Although intranet pages may link to
the Internet, an intranet is not a site accessed by the
general public.
IP
Internet Protocol. The standard on how information,
files, video, email, etc. (packets) travel through the
Internet. A Layer 3 (network layer) protocol that contains
addressing information and control information that allow
packets to be routed.
IP
Based
A term used for a website that is located on a server by an IP address, for
example, 101.12.14.3 would be an IP address.
IPX
Internetwork Packet Exchange. A networking
protocol used by the Novell? NetWare? operating systems.
Like UDP/IP, IPX is a datagram protocol used for connectionless
communications.
ISO
International Standards Organization.
JPEG
Joint Photographic Experts Group. A compressed image or picture. A compression
technique for use with images (pictures). These images files end with the
extension: “.jpg”.
Kilobyte
(KB) A unit of measure for physical data storage on a storage device (1000
bytes = 1 Kilobyte).
Latency
Any delay introduced into the network that
prevents packet forwarding at wire speed.
LAN
Local Area Network. A network of computers
/ servers that are connected in a fixed location, i.e.
a business or home. A network where computers are connected
in close proximity, such as in the same building or office
park; a system of LANs connected at a distance is called
a wide-area network (WAN).
Layer
1
The first, or physical, layer of the open
systems interconnection (OSI) model. Delivers data across
a network link. This layer must regulate signaling and
keep the signal strong. Hubs, repeaters and concentrators
operate at Layer 1. All packets received are repeated
on the wire.
Layer
2
The second, or data-link layer, of the
open systems interconnection (OSI) model. The media access
control (MAC) layer. Transmits packets across a Layer
1 physical link by reading the hardware or MAC source
and destination addresses in each packet. Switching operates
at Layer 2. Switches have a forwarding table of the hardware
addresses of the devices connected to them. When packets
arrive, the switch reads the Layer 2 address and if it
matches one in the table, forwards it to that port. Otherwise,
it forwards or ?floods? the packet to all ports.
Layer
3
The third, or routing, layer of the open
systems interconnection (OSI) model. The network layer
routes data to different LANs and WANs based on network
address.
Layer
4
The fourth, or transport, layer of the
open systems interconnection (OSI) model. It encompasses
network services that provide end-to-end management of
a communications session.
Layer
7
The seventh, or application, layer of
the open systems interconnection (OSI) model. It defines
the services that directly support applications such
as software for network management, electronic mail or
file transfers.
Link
Aggregation
The grouping of multiple network links
into one logical high bandwidth link. By grouping four
100 Mbps Ethernet connections into one logical link,
you can create up to 800 Mbps of bidirectional throughput
between the server and the switch.
MAC
Media Access Control. Layer 2 of the open
systems interconnection OSI model. The data-link layer
responsible for scheduling, transmitting and receiving
data on a local area network.
MAC
Address
Media Access Control address. The unique
physical address of each device's network interface card.
Macromedia®
Software company that develops Web authoring programs and Graphics manipulation
programs.
Majordomo
Mailing List Server
A program which automates the management of Internet mailing lists and discussion
forums.
MAN
Metropolitan Area Network, a data network
designed for a town or city. In terms of geographic breadth,
MANs are larger than local area networks (LANs), but smaller
than wide area networks (WANs). MANs are usually characterized
by very high-speed connections using fiber optical cable
or other digital media.
Mbps
Megabits per second.
Megabyte
(MB) A unit of measure for physical data storage on a storage device (1000
Kilobytes = 1 Megabyte).
Meshed
Topology
A network built with a mixture of different
network topologies. For example a high bandwidth backbone
network that connects to a collection of slower segments.
MIB
Management Information Base. A database
of information that the switch makes available to network
management systems. For example, traffic statistics and
port settings.
Miva
Merchant
A dynamic browser based storefront development and management system that allows
you to create and administrate your online store from anywhere in the world.
Modperl
for Apache
Perl language scripts that interact between the browser and Apache web server
with more functionality than CGI scripts.
MPLS
Multiprotocol Label Switching. A switching
protocol that integrates Layer 2 information about network
links into Layer 3 in order to simplify and improve IP
packet exchange.
Multicast
A packet, or transmission, destined for
many clients.
Multimode
Fiber Cable
Fiber cable with a wide core. Light is
reflected along the core at multiple angles, and is propagated
along multiple paths, each path with a different length
and hence a different time to traverse the fiber. These
multiple angles or modes cause the signal elements to
spread out in time, so that distortions occur that limit
the distance over which the integrity of the light signal
can be maintained. Multimode fiber is the predominant
type of LAN fiber installed within buildings and is less
expensive than single mode fiber.
MySQL
Database / phpMyAdmin
Software with a graphical user interface to manipulate and setup a database.
Name
Based
A term used for a website that is located on a server by it’s domain
name, for example, somecompany.com would be the name used to locate the website.
NIC
Network Interface Card. An expansion board
which goes into a workstation or server and provides the
connection to a network.
Non-blocking
A switch's ability to transmit and receive
packets on all ports simultaneously, at wire speed.
OC
Optical Carrier, used to specify the speed
of fiber optic networks conforming to the SONET standard.
OC-1 = 51.85 Mbps, OC-3 = 155.52 Mbps, OC-12 = 622.08 Mbps,
OC-24 = 1.244 Gbps, OC-48 = 2.488 Gbps, OC-96 = 4.976 Gbps,
OC-192 = 9.6 Gbps and OC-255 = 13.21 Gbps
OpenSSH
Secure Shell
Provides support for secure remote login, secure file
transfer, and secure TCP/IP.
Over-subscription
Over-subscription or over-subscription ratios
deal specifically with points in a network where bottlenecks
occur. The impact of improper over-subscription ratios
is congestion, which causes packet loss. Over-subscription
ratios are calculated by adding the potential bandwidth
requirements of a particular path and dividing the total
by the actual bandwidth of the path. Although a ratio larger
than 1:0 is considered over-subscribed, it does not necessarily
mean congestion will occur.
OSPF
Open Shortest Path First. A routing protocol
that maintains a map of all other routers and the networks
to which they connect. Sends short messages asking whether
a neighbor is alive and reachable. More efficient, scalable
than vector-distance routing protocols that maintain tables
of all known destinations and number of hops to reach them.
Packet-over-SONET
A metropolitan area network (MAN) or wide
area network (WAN) transport technology that carries IP
packets directly over SONET transmission without any data
link facility such as ATM in between. Packet-over-SONET
is intended to transmit data at the highest rates possible,
because SONET has a smaller packet header overhead than
ATM (28 bytes out of an 810-byte frame compared with 5
out of a 53-byte ATM cell).
Petabyte
(PB) A unit of measure for physical data storage on a storage device (1000
Terabytes = 1 Petabyte).
PHP
Hypertext Preprocessor for Apache
A widely-used general-purpose scripting language that is especially suited
for Web development and can be embedded into HTML.
PIM
Dense Mode
Protocol Independent Multicast Dense Mode.
A multicast protocol similar to DVMRP in that it uses
Reverse Path Forwarding but does not require any particular
unicast protocol.
PIM
Sparse Mode
A multicast protocol that works by defining
a rendezvous point that is common to both sender and
receiver. Sender and receiver initiate communication
at the rendezvous point, and when flow begins it occurs
over an optimized path.
Policy-Based
Quality of Service (QoS)
A network service that provides the ability
to prioritize different types of traffic and manage bandwidth
over a network.
POP
Point of presence. The point where a long
distance carrier connects to a local phone company or to
a user if a local company is not involved. For online services
and Internet service providers, the POP is the local exchange
users dial into via modem.
POP3
Post Office Protocol. Used to retrieve electronic mail from a mail server.
POP3
+ Imap Server
A program that runs on a server that allows you to send and receive email with
a desktop client like Outlook.
Port
(Software). An interface between to sources.
Port
Density
Number of ports, either physical or logical,
per network device.
Port
Mirroring
A switching feature that allows one port?s
media access control (MAC) layer data to be replicated
to another port for monitoring by a network analyzer.
ProFTPD
FTP Server
Program that runs on the server that controls the FTP processes. It is configurable
to allow you more flexibility in functions and performance.
Protocol
A set of rules governing the format of messages that are exchanged between
computers and people.
Python
Python is an interpreted, interactive, object-oriented programming language.
It is often compared to Tcl, Perl, Scheme or Java.
Queue
Multiple tasks, messages, calls or packets waiting for network response.
QWERTY
A type of keyboard. Gets it’s name from the top row of letter keys from
left to right.
RAID
5 Data Security - Redundant Array of Independent (or Inexpensive) Disks, a
category of disk drives that employ two or more drives in combination for
fault tolerance and performance. RAID disk drives are used frequently on
servers but aren’t generally necessary for personal computers.
RADIUS
Remote Authentication Dial-In User Service,
an authentication and accounting system used by many Internet
Service Providers (ISPs). When you dial in to the ISP you
must enter your username and password. This information
is passed to a RADIUS server, which checks that the information
is correct, and then authorizes access to the ISP system.
RAN
Regional area network. A data network that
interconnects businesses, residences and governments in
a specific geographic region. RANs are larger than local
area networks (LANs) and metropolitan area networks (MANs),
but smaller than wide area networks (WANs). RANs are usually
characterized by very high-speed connections using fiber
optic cable or other digital media.
Redundant
PHY
One of the most effective, least costly
and simplest ways to achieve link redundancy with sub-second
recovery is by using redundant physical connections,
also called redundant PHY (pronounced `f? With this type
of redundancy, there is typically an active primary link
and a standby secondary link. For example, a single gigabit
port may have two physical connections. If the primary
link fails, the secondary link takes over in less than
one second.
Remote
Login
Allows a website owner to remotely login to their site administration tools
from anywhere via the Internet.
RIP
Routing Information Protocol. A protocol
defined by RFC 1058 that specifies how routers exchange
routing table information. With RIP, routers periodically
exchange entire tables.
RMON
Remote Monitoring. A network management
protocol that allows network information to be gathered
at a single workstation.
Routing
The process of delivering a message across
a network or networks.
Router
A network device that forwards packets to
destinations based on Layer 3 IP addresses. A router implements
various protocols to maintain information on the location
of other routers. A router reads the Layer 3 network address
information in every packet that it receives and determines
whether it should be dropped or forwarded. If it is to
be forwarded, the router looks in its routing table to
find the best route between a sender and receiver.
RSVP
Resource Reservation Protocol. An IETF standard
used to provide quality of service by reserving bandwidth
before packet transfers to insure its availability.
Secure
Shell (SSH)
Secure Shell is a program to log into
another computer over a network, to execute commands
in a remote machine, and to move files from one machine
to another. It provides strong authentication and secure
communications over insecure channels. SSH protects a
network from attacks such as IP spoofing, IP source routing,
and DNS spoofing. An attacker who has managed to take
over a network can only force SSH to disconnect. He or
she cannot play back the traffic or hijack the connection
when encryption is enabled.
Secure
Web (SSL)
Secure Sockets Layer. A packet transporting technology for authentication and
data encryption between a web server and a web browser.
Segment
Section of a network that is bounded by
bridges, or switches; dividing an Ethernet into multiple
segments is a common way to increase bandwidth on a LAN.
Sendmail
SMTP Server
Simple Mail Transfer Protocol. A transfer protocol for sending email between
servers.
Server
A shared computer on a network that can be accessed by more than one PC at
a time.
Server
Side Includes
Programming script that is encoded into the webpage code which sends information
from the web browser to the web server.
Shared
Hosting
Multiple websites on a single server sharing the same software.
Single
Mode Fiber Cable
Fiber with a relatively narrow diameter,
through which only one mode will propagate. Carries higher
bandwidth than multimode fiber, but requires a light
source with a narrow spectral width.
SNMP
Simple Network Management Protocol. A standard
for gathering statistical data about network traffic and
the behavior of network components; SNMP uses management
information bases (MIBs), which define what information
is available from any manageable network device.
Snooping
Looking into the packet to obtain information.
SONET
Synchronous Optical Network, a standard
for connecting fiber-optic transmission systems. SONET
defines interface standards at the physical layer of the
OSI model. The standard defines a hierarchy of interface
rates that allow data streams at different rates to be
multiplexed. SONET establishes Optical Carrier (OC) levels
from 51.8 Mbps (about the same as a T-3 line) to 9.2 Gbps.
With the implementation of SONET, communication carriers
throughout the world can interconnect their existing digital
carrier and fiber optic systems. The international equivalent
of SONET, standardized by the ITU, is called SDH.
Source
Address
The IP or media access control (MAC) address
of the node issuing the packet.
Spanning
Tree
A process used to eliminate redundant
data routes and increase network efficiency.
SquirrelMail
Web-based Email
A program that allows you to check, delete and compose email from your web
browser.
Store-and-forward
Switching feature where the receiving port
receives the entire incoming frame and stores it in the
buffers before forwarding it to the destination port.
Switching
Fabric
A term used to specify the maximum bandwidth
of a switch at the backplane.
Subnet
Addressing
A method that a manager can use to span
multiple physical networks using a single IP network
address. Local routers and intelligent switches use extensions
of the IP network address to identify and route traffic
to local, physical segments.
Subnet
Mask
A number that a manager enters to tell
the switch how to filter incoming packets. For example,
a subnet mask of 255.255.0.0 for the address 192.3.1.254
tells the switch to only accept traffic destined for
IP addresses that begin with 192.3. All other packets
are dropped.
Switch
A network device that filters and forwards
packets between LAN segments and or desktops.
TCP/IP
Transmission Control Protocol/Internet Protocol.
The suite of communications protocols used to connect hosts
on the Internet.
T1/E1
A dedicated, point-to-point digital connection
configured to carry voice or data traffic, widely used
for private networks as well as interconnections between
an organization's PBX or LAN and the telco.
Telnet
A program that connects your PC to a device
on the network. You can then enter commands through the
Telnet program and they will be executed as if you were
entering them directly on the device’s console. The
protocol within the TCP/IP protocol suite which provides
a terminal emulation function.
Terabyte
(TB) A unit of measure for physical data storage on a storage device (1000
Gigabytes = 1 Terabyte).
TFTP
Trivial File Transfer Protocol. A simple form of the File Transfer Protocol
(FTP) and has no security features unlike FTP.
TLD
Top Level Domain. The right-most label in a domain name. For example, the TLD
of somewhere.com is the “.COM”.
Tomcat
4
The “container” that is used to hold the instructions for the web
server on how to handle the Java scripting language.
Topology
The physical or logical layout, or configuration
of a network.
Transparent
LAN Service (TLS)
A communications service from a local
telephone company or common carrier that links remote
LANs together.
Transparent
Web Cache Redirection
The ability to redirect web traffic using
Layer 4 criteria, such as HTTP Port 80, at wire speed
to one or more load-shared ports across several web cache
servers without the reconfiguration of browser applications.
UDP
User Datagram Protocol. A protocol for describing
how messages reach application programs within a destination
computer. A connectionless protocol that, like TCP, runs
on top of IP networks.
Uplink
A connection from a lower to higher device.
A hub to a switch, a switch to a router, a router to a
server.
Unicast
A packet destined for only one address.
URL
Uniform Resource Locator. The global address of documents and other resources
on the World Wide Web. “www.somewhere.com” is a URL.
UTP
Unshielded Twisted Pair. Cabling with wires
that are twisted around each other; the individual wires
are uninsulated. See also Category 5.
Vacation
Auto
Responder/Email – A means to automatically
reply to incoming email.
VBR
Variable Bit Rate. A network process of generating packets of information at
a random, bursty manner rather than continuously.
VDSL
Very High Speed Digital Subscriber Line.Transmits
data in the 10 Mbps-55Mbps range over short distances,
usually between 1000 and 6000 feet, over voice-grade wire.
VID
VLAN
Identifier. A number identifying a specific VLAN.
Virtual
Hosting
Multiple websites on a single server each having its own software. For example;
each website has its own operating system and web tools software but all the
websites are on the same physical server.
Virtual
Hosting Tools
Software based functions that allow you to manage multiple websites on a single
server.
VLAN
Virtual LAN. Computers or other Local Area
Networks that are connected via software rather than by
wire. Makes it seem like a LAN. A logical, not physical,
group of devices, defined by software. VLANs allow network
administrators to resegment their networks without physically
rearranging the devices or network connections.
Voice-grade
Wiring
The term generally refers to analog lines
with the bandwidth required to transmit human voice,
typically about four thousand Hertz (4KHz).
VoIP
Voice Over Internet Protocol. Allows you to send voice communications via a
data network.
Virtual
Private Network (VPN)
A private network that is configured within
a public network.
W3C
World Wide Web Consortium. Develops interoperable
technologies (specifications, guidelines, software, and tools)
to lead the Web to its full potential. Sets the Internet standards.
WAN
Wide Area Network. A computer network that
spans a relatively large geographical area. Typically,
a WAN consists of two or more local-area networks (LANs)
in multiple locations. A network that uses telecommunications
technology to connect computers or networks over long distances.
WDM
Wavelength Division Multiplexing. A type
of multiplexing developed for use on optical fiber. WDM
modulates each of several data streams onto a different
part of the light spectrum.
Web
Hosting
Placing a customer's web page or web site
on a commercially owned web server. A single server can
hold hundreds or even thousands of small web sites, while
larger web sites use a dedicated server or multiple servers.
WINS
Windows Internet Naming Service. A system
that determines the IP address associated with a particular
network computer.
Wire
Speed
The
theoretical, maximum rate at which packets can be transmitted
and received on a network interface.
Workgroup
Collection of computers that are grouped
for sharing resources such as data and peripherals.
WWW
World Wide Web. The Internet.
WWW2
Another used name or extension on Domain Name servers instead of www.
XML
Extensible Markup Language. A very flexible text format programming language
designed to meet the challenges of large-scale electronic publishing.
X-Terminal
A networked desktop that displays software applications which are running on
a networked server.
Y2K
Year 2000 (2Kilo’s (2 x 1000 = 2000)). Year 2000 bug. What would happen
when your computer hit the year 2000.
Yottabyte
(YB) A unit of measure for physical data storage on a storage device (1000
Zettabytes = 1 Yottabyte). May the force be with you!
Zettabyte
(ZB) A unit of measure for physical data storage on a storage device (1000
Exabytes = 1 Zettabyte).
Zero
Code Suppression
Line coding scheme used for transmission clocking. Zero line suppression substitutes
a 1 in the 7th bit of a string of 8 consecutive zeros.
ZIP
A file compression format. A format that takes a file and shrinks it up to
90% of it’s original size to save spac
