null Definitions
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E
extranet
An extranet is a private network that enterprises use to provide trusted third parties -- such as suppliers, vendors, partners, customers and other businesses -- secure, controlled access to business information or operations.
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F
fault management
Fault management is the component of network management that detects, isolates and fixes problems.
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fax
A fax -- short for 'facsimile' and sometimes called 'telecopying' -- is the telephonic transmission of scanned-in printed material, including text or images.
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FCAPS (fault, configuration, accounting, performance and security)
FCAPS (fault, configuration, accounting, performance and security) is a network management framework created by the International Organization for Standardization (ISO).
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FDDI (Fiber Distributed Data Interface)
FDDI (Fiber Distributed Data Interface) is a network standard that uses fiber optic connections in a local area network (LAN) that can extend in range up to 200 kilometers (124 miles).
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fiber optics (optical fiber)
Fiber optics, or optical fiber, refers to the technology that transmits information as light pulses along a glass or plastic fiber.
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fiber to the home (FTTH)
Fiber to the home (FTTH), also called fiber to the premises (FTTP), is the installation and use of optical fiber from a central point to individual buildings to provide high-speed internet access.
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fiber to the x (FTTx)
Fiber to the x (FTTx) is a collective term for various optical fiber delivery topologies that are categorized according to where the fiber terminates
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file server
A file server is a computer responsible for the storage and management of data files so that other computers on the same network can access the files.
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File Transfer Access and Management (FTAM)
File Transfer Access and Management (FTAM) is an OSI application Layer 7 protocol that standardizes how files are accessed and managed in a distributed network file system.
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firewall as a service (FWaaS)
Firewall as a service (FWaaS), also known as a cloud firewall, is a service that provides cloud-based network traffic analysis capabilities to customers as part of an overall cybersecurity program.
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fixed-length subnet mask (FLSM)
A fixed-length subnet mask (FLSM) refers to a type of enterprise or provider networking where a block of IP addresses is divided into multiple subnets of equal length (i.e., an equal number of IP addresses).
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flooding (network)
In a computer network, flooding occurs when a router uses a non-adaptive routing algorithm to send an incoming packet to every outgoing link except the node on which the packet arrived.
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flow routing
Flow routing is a network routing technology that takes variations in the flow of data into account to increase routing efficiency.
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frame relay
Frame relay is a packet-switching telecommunications service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between endpoints in wide area networks (WANs).
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frequency band
In telecommunications, a frequency band -- sometimes called a band -- refers to a specific range of frequencies in the electromagnetic frequency spectrum assigned to certain applications.
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frequency-division multiplexing (FDM)
In frequency-division multiplexing (FDM), multiple signals are combined for transmission on a single communications line or channel, with each signal assigned to a different frequency (subchannel) within the main channel.
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frequency-hopping spread spectrum (FHSS)
Frequency-hopping spread spectrum (FHSS) transmission is the repeated switching of the carrier frequency during radio transmission to reduce interference and avoid interception.
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frequency-shift keying (FSK)
Frequency-shift keying (FSK) is a method of transmitting digital signals using discrete signals.
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full-duplex
Full-duplex data transmission means that data can be transmitted in both directions on a signal carrier at the same time.
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What is FTP?
File Transfer Protocol (FTP) is a network protocol for transmitting files between computers over TCP/IP connections.
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G
Generic Routing Encapsulation (GRE)
Generic Routing Encapsulation (GRE) is a protocol that encapsulates packets in order to route various protocols over Internet Protocol (IP) networks.
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geo-blocking
Geo-blocking is blocking something based on its location.
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gigabit (Gb)
In data communications, a gigabit (Gb) is 1 billion bits, or 1,000,000,000 (that is, 10^9) bits. It's commonly used for measuring the amount of data that is transferred in a second between two telecommunication points.
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Gigabit Ethernet (GbE)
Gigabit Ethernet (GbE), a transmission technology based on the Ethernet frame format and protocol used in local area networks (LANs), provides a data rate of 1 billion bits per second, or 1 gigabit (Gb).
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GMPLS (Generalized Multiprotocol Label Switching or Multiprotocol Lambda Switching)
GMPLS (Generalized Multiprotocol Label Switching) is a networking technology that enables fast and reliable network switching of data flows on any type of network infrastructure.
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graceful degradation
Graceful degradation is the ability of a computer, machine, electronic system or network to maintain limited functionality even when a large portion of it has been destroyed or rendered inoperative.
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green networking
Green networking is the practice of selecting energy-efficient networking technologies and products and minimizing resource use whenever possible.
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GVRP (GARP VLAN Registration Protocol or Generic VLAN Registration Protocol)
GVRP (GARP VLAN Registration Protocol or Generic VLAN Registration Protocol) is a standards-based protocol that facilitates control of virtual local area networks (VLANs) within a larger network.
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H
HAProxy
HAProxy is a high-performance, open source load balancer and reverse proxy for TCP and HTTP applications.
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HDLC (High-level Data Link Control)
HDLC (High-level Data Link Control) is a group of protocols or rules for transmitting data between network points (sometimes called nodes).
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HELLO packet
A HELLO packet is a special data packet (message) that is sent out periodically from a router to establish and confirm network adjacency relationships to other routers in the Open Shortest Path First (OSPF) communications protocol.
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home server
A home server is a computer that functions as a server in a client-server home network.
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host (in computing)
A host is a computer or other device that communicates with other hosts on a network.
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I
ICMP (Internet Control Message Protocol)
ICMP (Internet Control Message Protocol) is an error-reporting protocol that network devices such as routers use to generate error messages to the source IP address when network problems prevent delivery of IP packets.
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IDSL
IDSL is a hybrid of a digital subscriber line (DSL) and integrated services digital network (ISDN) technology that transmits data slightly faster than ISDN but much slower than most DSL services.
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IEEE 802 wireless standards
IEEE 802 is a collection of networking standards that cover the physical and data link layer specifications for technologies such as Ethernet and wireless.
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IEEE 802.3
802.3, or IEEE 802.3, is a working group of standard specifications for Ethernet, a method of packet-based physical communication in a local area network maintained by the Institute of Electrical and Electronics Engineers.
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infrared radiation (IR)
Infrared radiation (IR), sometimes referred to simply as infrared, is a region of the electromagnetic radiation spectrum where wavelengths range from about 700 nm to 1 mm.
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ingress filtering
Ingress filtering is a method used by enterprises and internet service providers to prevent suspicious traffic from entering a network.
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international private leased circuit (IPLC)
An international private leased circuit (IPLC) is a point-to-point private line used by an organization to communicate between offices that are dispersed throughout the world.
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internet metering
Internet metering is a service model in which an internet service provider (ISP) keeps track of bandwidth use and charges users accordingly.
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IPTV (Internet Protocol television)
IPTV (Internet Protocol television) is a service that provides television programming and other video content using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, as opposed to broadcast TV, cable TV or satellite signals.
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IPv6 (Internet Protocol Version 6)
IPv6 is a set of specifications from the Internet Engineering Task Force that improves IPv4 by extending IP addresses from 32 bits to 128 bits.
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J
Joint Academic Network (JANET)
The Joint Academic Network (JANET) is an internal, high-speed computer network that links the U.K. education and research community.
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jumbo frames
A jumbo frame is an Ethernet frame, or data packet, with a payload greater than the standard size of 1,500 bytes.
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K
Kbps (kilobits per second)
In the U.S., Kbps stands for kilobits per second (thousands of bits per second) and is a measure of bandwidth (the amount of data that can flow in a given time) on a data transmission medium.
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keystone jack
A keystone jack is a female connector used in audio, video and data communications. It serves as a receptacle for a matching plug, which is a male connector of the same type as the jack.
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L
Layer Two Tunneling Protocol (L2TP)
Layer Two Tunneling Protocol (L2TP) is an extension of the Point-to-Point Tunneling Protocol (PPTP) used by an internet service provider (ISP) to enable the operation of a virtual private network (VPN) over the internet.
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Link Control Protocol (LCP)
In computer networking, Point-to-Point Protocol (PPP) provides a standard way to transport multiprotocol data over point-to-point links; within PPP, Link Control Protocol (LCP) establishes, configures and tests data link internet connections.
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load balancing
Load balancing is a technique used to distribute network traffic across a pool of servers known as a server farm.
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local area network (LAN)
A local area network (LAN) is a group of computers and peripheral devices that are connected together within a distinct geographic area, such as an office building or campus.
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location-based service (LBS)
A location-based service (LBS) is a software service for mobile device applications that requires knowledge about where the mobile device is geographically located.
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logical network
A logical network is a software-defined network topology or routing that is often different than the physical network.
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loose coupling
Loose coupling is an approach to interconnecting the components in a system, network or software application so that those components, also called elements, depend on each other to the least extent practicable.
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M
MAC address (media access control address)
A MAC address (media access control address) is a 12-digit hexadecimal number assigned to each device connected to the network.
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managed network services
Managed network services are networking applications, functions and services that enterprises outsource to be remotely operated, monitored and maintained by a managed service provider (MSP).
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Manchester encoding
In data transmission, Manchester encoding is a form of digital encoding in which a data bit's state -- 0 or 1 -- is represented by the transition from one voltage level to another.
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maximum segment size (MSS)
The maximum segment size (MSS) is the largest amount of data, specified in bytes, that a computer or communications device can handle in a single, unfragmented piece.
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maximum transmission unit (MTU)
The maximum transmission unit (MTU) is the largest size frame or packet -- in bytes or octets (eight-bit bytes) -- that can be transmitted across a data link.
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MDI/MDIX (medium-dependent interface/MDI crossover)
MDI/MDIX is a type of Ethernet port connection that uses twisted-pair cabling to link two networked devices.
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mean time to innocence
Mean time to innocence is the average elapsed time between when a system problem is detected and any given team's ability to say the team or part of its system is not the root cause of the problem.
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megabits per second (Mbps)
Megabits per second (Mbps) are units of measurement for network bandwidth and throughput. It is used to show how fast a network or internet connection is.
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megahertz (MHz)
Megahertz (MHz) is a unit multiplier that represents one million hertz (106 Hz). Hertz is the standard unit of frequency in the International System of Units (SI).
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metropolitan area network (MAN)
A metropolitan area network (MAN) is a computer network that is larger than a single building local area network (LAN) but is located in a single geographic area that is smaller than a wide area network (WAN).
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microsegmentation
Microsegmentation is a security technique that splits a network into definable zones and uses policies to dictate how data and applications within those zones can be accessed and controlled.
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millimeter wave (mmWave)
Millimeter wave (mmWave), also known as millimeter band, is a range of electromagnetic frequencies between microwaves and infrared.
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modulation
Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal.
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multi-user MIMO
Multi-user MIMO, or MU-MIMO, is a wireless communication technology that uses multiple antennas to improve communication by creating multiple connections to the same device at the same time.
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multiplexing
Multiplexing, or muxing, is a way of sending multiple signals or streams of information over a communications link at the same time in the form of a single, complex signal.
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Multiprotocol Label Switching (MPLS)
Multiprotocol Label Switching (MPLS) is a switching mechanism used in wide area networks (WANs).
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mutual exclusion (mutex)
In computer programming, a mutual exclusion (mutex) is a program object that prevents multiple threads from accessing the same shared resource simultaneously.
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N
NACK (NAK, negative acknowledgment, not acknowledged)
NACK, or NAK, an abbreviation for negative acknowledgment or not acknowledged, is a signal used by computers or other devices to indicate that data transmitted over a network was received with errors or was otherwise unreadable.
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NBASE-T Ethernet
NBASE-T Ethernet is an IEEE standard and Ethernet-signaling technology that enables existing twisted-pair copper cabling to exceed the cable's specified limit of 1 gigabit per second (Gbps) for distances of up to 100 meters.
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NBMA (non-broadcast multiple access)
Non-broadcast multiple access (NBMA) is one of four network types in the Open Shortest Path First (OSPF) communications protocol.
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near-end crosstalk (NEXT)
Near-end crosstalk (NEXT) is an error condition that can occur when connectors are attached to twisted pair cabling.
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Nessus
Nessus is a platform developed by Tenable that scans for security vulnerabilities in devices, applications, operating systems, cloud services and other network resources.
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net neutrality
Net neutrality is the concept of an open, equal internet for everyone, regardless of content consumed or the device, application or platform used.
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NetBIOS (Network Basic Input/Output System)
NetBIOS (Network Basic Input/Output System) is a network service that enables applications on different computers to communicate with each other across a local area network (LAN).
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network access control (NAC)
Network access control (NAC), also called network admission control, is a method to bolster the security, visibility and access management of a proprietary network.
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Network Address Translation (NAT)
A Network Address Translation (NAT) is the process of mapping an internet protocol (IP) address to another by changing the header of IP packets while in transit via a router.
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network analytics
Network analytics is the application of big data principles and tools to the data used to manage and secure data networks.
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network analyzer (protocol analyzer or packet analyzer)
A network analyzer -- also called a network protocol analyzer or packet analyzer -- is a software application, dedicated appliance or feature set within a network component used in network performance troubleshooting or to enhance protection against malicious activity within a corporate network.
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Network as a Service (NaaS)
Network as a service, or NaaS, is a business model for delivering enterprise WAN services virtually on a subscription basis.
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network assurance
Network assurance is the method of validating whether services and policies configured on and across network appliances appropriately align with operational goals.
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network automation
Network automation is a methodology in which software automatically configures, provisions, manages and tests network devices.
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network configuration management (NCM)
Network configuration management is the process of organizing and maintaining information about all of the components in a computer network.
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Network Configuration Protocol (NETCONF)
The Network Configuration Protocol (NETCONF) is an Internet Engineering Task Force (IETF) network management protocol that provides a secure mechanism for installing, manipulating and deleting the configuration data on a network device such as a firewall, router or switch.
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network downtime
Network downtime refers to inaccessibility to part or all of a network due to the failure of hardware, software or some combination of the two.
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network engineer
A network engineer is a technology professional who has the necessary skills to plan, implement and oversee the computer networks that support in-house voice, data, video and wireless network services.
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network fabric
'Network fabric' is a general term used to describe underlying data network infrastructure as a whole.
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network functions virtualization (NFV)
Network functions virtualization (NFV) is a network architecture model designed to virtualize network services that have traditionally run on proprietary, dedicated network appliances.
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network hub
A network hub is a node that broadcasts data to every computer or Ethernet-based device connected to it.
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network interface card (NIC)
A network interface card (NIC) is a hardware component, typically a circuit board or chip, installed on a computer so it can connect to a network.
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Network layer
Located at Layer 3 of the Open Systems Interconnection (OSI) communications model, the primary function of the network layer is to move data into and through other networks.
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network management
A cornerstone of all computing is the ability to connect one machine, system or device to another -- enabling what is known as a computer network.
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network management system
A network management system, or NMS, is an application or set of applications that lets network engineers manage a network's independent components inside a bigger network management framework and performs several key functions.
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network monitoring
Network monitoring, also frequently called network management, is the practice of consistently overseeing a computer network for any failures or deficiencies to ensure continued network performance.
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network node
A computer network is a system of computers and computing devices that are connected via communication links.
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network operating system (NOS)
A network operating system (NOS) is a computer operating system (OS) that's designed primarily to support workstations, PCs and, in some instances, older terminals that are connected on a local area network (LAN).