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• Plain Old Telephone Service (POTS)

  Plain Old Telephone Service (POTS) refers to the traditional, analog voice transmission phone system implemented over physical copper wires (twisted pair). Continue Reading

• 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. Continue Reading

• network operations center (NOC)

  A network operations center (NOC) is a centralized place from which enterprise information technology (IT) administrators -- either internal or third party -- supervise, monitor and maintain a telecommunications network. Continue Reading

• conductance

  Conductance is an expression of the ease with which electric current flows through materials like metals and nonmetals. Continue Reading

• connectionless

  In telecommunications, connectionless describes communication between two network endpoints in which a message can be sent from one endpoint to another without prior arrangement. Continue Reading

• Definitions to Get Started

  • What is shielded twisted pair (STP) and how does it work?
  • What is ping and how does it work?
  • What is 1000BASE-T (Gigabit Ethernet)?
  • What is DHCP (Dynamic Host Configuration Protocol)?

  • What is Routing Information Protocol (RIP)?
  • What is data center interconnect (DCI)?
  • What is streaming network telemetry?
  • What is network traffic?

  View All Definitions

• session border controller (SBC)

  A session border controller (SBC) is a dedicated hardware device or software application that governs the manner in which phone calls are initiated, conducted and terminated on a voice over Internet Protocol (VoIP) network.Continue Reading

• dense wavelength-division multiplexing (DWDM)

  Dense wavelength-division multiplexing (DWDM) is an optical fiber multiplexing technology that is used to increase the bandwidth of existing fiber networks.Continue Reading

• 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.Continue Reading

• carrier-to-noise ratio

  In communications, the carrier-to-noise ratio, often written as CNR or C/N, is a measure of the received carrier strength relative to the strength of the received noise.Continue Reading

• What is packet loss in networking?

  Packet loss is when one or more transmitted data packets fail to arrive at their destination.Continue Reading

• split horizon

  Split horizon is a method used by distance vector protocols to prevent network routing loops.Continue Reading

• Enhanced Interior Gateway Routing Protocol (EIGRP)

  Enhanced Interior Gateway Routing Protocol (EIGRP) is a network protocol that enables routers to exchange information more efficiently than earlier network protocols, such as Interior Gateway Routing Protocol (IGRP) or Border Gateway Protocol (BGP).Continue Reading

• star network

  A star network is a local area network (LAN) topology in which all nodes -- personal computers (PCs), workstations or other devices -- are directly connected to a common central computer that is often referred to as a hub.Continue Reading

• Spanning Tree Protocol (STP)

  Spanning Tree Protocol (STP) is a Layer 2 network protocol used to prevent looping within a network topology.Continue Reading

• sliding window (windowing)

  The sliding window (windowing) technique is used by Transmission Control Protocol (TCP) to manage the flow of packets between two computers or network hosts.Continue Reading

• 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.Continue Reading

• Network observability vs. monitoring: What's the difference?

  Traditional network monitoring is useful for collecting data about network issues. But network observability can add further insights into network health and end-user experience.Continue Reading

• 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.Continue Reading

• system administrator (sysadmin)

  A system administrator (sysadmin) is an information technolog professional who supports a multiuser computing environment and ensures continuous, optimal performance of IT services and support systems.Continue Reading

• coded orthogonal frequency-division multiplexing (COFDM)

  Coded orthogonal frequency-division multiplexing (COFDM) is a telecommunications modulation scheme that divides a single digital signal across 1,000 or more signal carriers simultaneously.Continue Reading

• ADSL (Asymmetric Digital Subscriber Line)

  ADSL (Asymmetric Digital Subscriber Line) is a technology that facilitates fast data transmission at a high bandwidth on existing copper wire telephone lines to homes and businesses.Continue Reading

• 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.Continue Reading

• beamforming

  Beamforming is a type of radio frequency (RF) management in which a wireless signal is directed toward a specific receiving device.Continue Reading

• 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.Continue Reading

• 5G core network functionality driven by SDN, NFV

  To reap the full benefits of 5G, operators are using SDN, NFV and network slicing to build out core network functionality.Continue Reading

• An introductory overview of 5G network capabilities

  In this Q&A, author William Stallings discusses 5G services, such as network slicing and QoS, and other topics covered in his book, '5G Wireless: A Comprehensive Introduction.'Continue Reading

• Test your knowledge in this 5G QoS quiz

  In this quiz, test your knowledge of network slicing, QoS, and other technologies and practices related to 5G networking.Continue Reading

• 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.Continue Reading

• asymmetric communications

  Asymmetric communications is a term pertaining to any system in which the data speed or quantity, when averaged over time, is different in one direction from the other.Continue Reading

• 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.Continue Reading

• preboot execution environment (PXE)

  Preboot execution environment (PXE), pronounced pixie, is a set of standards that enables a computer to load an operating system (OS) over a network connection.Continue Reading

• SYN scanning

  SYN scanning is a tactic that a malicious hacker can use to determine the state of a communications port without establishing a full connection.Continue Reading

• Stream Control Transmission Protocol (SCTP)

  Stream Control Transmission Protocol (SCTP) is a connection-oriented network protocol for transmitting multiple streams of data simultaneously between two endpoints that have established a connection in a network.Continue Reading

• port

  A port in computing has three main uses, each as a type of receptacle in networking, computer hardware and software.Continue Reading

• 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).Continue Reading

• 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.Continue Reading

• passive optical network (PON)

  A passive optical network (PON) is a system commonly used by telecommunications network providers that brings fiber optic cabling and signals all or most of the way to the end user.Continue Reading

• American Wire Gauge (AWG)

  American Wire Gauge (AWG) is the standard way to denote wire size in North America.Continue Reading

• committed information rate (CIR)

  Committed information rate (CIR) is the guaranteed rate at which a Frame Relay network will transfer information under normal line conditions.Continue Reading

• BOOTP (Bootstrap Protocol)

  BOOTP (Bootstrap Protocol) is an internet protocol that lets a network user automatically be configured to receive an IP address and have an operating system booted without user involvement.Continue Reading

• anti-replay protocol

  The anti-replay protocol provides Internet Protocol (IP) packet-level security by making it impossible for a hacker to intercept message packets and insert changed packets into the data stream between a source computer and a destination computer.Continue Reading

• time-to-live (TTL)

  Time-to-live (TTL) is a value for the period of time that a packet, or data, should exist on a computer or network before being discarded.Continue Reading

• Switched Multimegabit Data Service (SMDS)

  Switched Multimegabit Data Service (SMDS) is a public, packet-switched service aimed at enterprises that need to exchange large amounts of data with other enterprises over the wide area network on a nonconstant or bursty basis.Continue Reading

• What does the 0.0.0.0 IP address mean and why is it used?

  One of a few special-purpose addresses, IP address 0.0.0.0 has several applications in networking. It stands in as a placeholder address, identifies a default route and more.Continue Reading

• What is the network edge and how is it different from edge computing?

  The network edge is where an enterprise network connects to third-party network services. Edge computing is a distributed architecture that processes data closer to end users.Continue Reading

• How to use iPerf3 to test network bandwidth

  In this in-depth tip, learn how to use iPerf3, a network testing tool to measure throughput and benchmark your WAN links to ensure effectivity.Continue Reading

• 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.Continue Reading

• 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.Continue Reading

• customer premises equipment (CPE)

  Customer premises equipment (CPE) is telecommunications and information technology equipment kept at the customer's physical location rather than on the service provider's premises.Continue Reading

• encoding and decoding

  Encoding and decoding are used in many forms of communications, including computing, data communications, programming, digital electronics and human communications.Continue Reading

• The differences between PAP and CHAP

  PAP uses a two-way handshake to authenticate client sessions, while CHAP uses a three-way handshake. Both authentication processes are common, but one is more secure.Continue Reading

• optoisolator (optical coupler or optocoupler)

  An optoisolator (also known as an optical coupler, photocoupler, optocoupler) is a semiconductor device that transfers an electrical signal between isolated circuits using light.Continue Reading

• token ring

  A token ring is a data link for a local area network (LAN) in which all devices are connected in a ring or star topology and pass one or more tokens from host to host.Continue Reading

• Snort

  Snort is an open source network intrusion detection system (NIDS) created by Sourcefire founder and former CTO Martin Roesch.Continue Reading

• Static vs. dynamic routing: What is the difference?

  Static routing uses preconfigured routes to send traffic to its destination, while dynamic routing uses algorithms to determine the best path. How else do the two methods differ?Continue Reading

• poison reverse

  In a computer network that uses the Routing Information Protocol (RIP) or other distance vector routing protocol, poison reverse is a loop avoidance process.Continue Reading

• 12 official practice questions for the CCNA 200-301 exam

  These practice questions for CCNA 200-301 lay out what readers need to know about network security and IP routing in the LAN, from 'CCNA 200-301 Official Cert Guide, Volumes 1 and 2.'Continue Reading

• Five-nines availability: What it really means

  Learn what five-nines availability means and discover the steps enterprises should take to make sure network services are fully accessible.Continue Reading

• How to calculate network bandwidth requirements

  Figuring out how to calculate bandwidth requirements is vital to ensuring your network runs smoothly, and it's best to use the correct formula from the beginning.Continue Reading

• bus network

  A bus network is a local area network (LAN) topology in which each node -- a workstation or other device -- is connected to a main cable or link called a bus.Continue Reading

• 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.Continue Reading

• ping sweep (ICMP sweep)

  A ping sweep (also known as an ICMP sweep) is a basic network scanning technique used to determine which of a range of IP addresses map to live hosts (computers).Continue Reading

• cognitive radio (CR)

  Cognitive radio (CR) is a form of wireless communication in which a transceiver can intelligently detect which communication channels are in use and which ones are not.Continue Reading

• CRC-4 (Cyclic Redundancy Check 4)

  CRC-4 (Cyclic Redundancy Check 4) is a form of cyclic redundancy checking -- a method of checking for errors in transmitted data -- that is used on E1 trunk lines.Continue Reading

• 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.Continue Reading

• Uuencode (Uuencode/Uudecode)

  Uuencode (also called Uuencode/Uudecode) is a popular utility for encoding and decoding files exchanged between users or systems in a network.Continue Reading

• crosstalk

  Crosstalk is a disturbance caused by the electric or magnetic fields of one telecommunication signal affecting a signal in an adjacent circuit.Continue Reading

• 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).Continue Reading

• phase-locked loop (PLL)

  A phase-locked loop (PLL) is an electronic circuit with a voltage or voltage-driven oscillator that constantly adjusts to match the frequency of an input signal.Continue Reading

• near-end crosstalk (NEXT)

  Near-end crosstalk (NEXT) is an error condition that can occur when connectors are attached to twisted pair cabling.Continue Reading

• 10 Gigabit Ethernet (10 GbE)

  10 Gigabit Ethernet (10 GbE) is a telecommunication technology that offers data speeds up to 10 billion bits per second.Continue Reading

• spectrum analyzer

  A spectrum analyzer is a device that measures and displays signal amplitude (strength) as it varies by frequency within its frequency range (spectrum).Continue Reading

• virtual routing and forwarding (VRF)

  Virtual routing and forwarding (VRF) is a technology included in Internet Protocol (IP) network routers that enables multiple instances of a routing table to exist in a virtual router and work simultaneously.Continue Reading

• Time Division Multiple Access (TDMA)

  Time Division Multiple Access (TDMA) is a digital modulation technique used in digital cellular telephone and mobile radio communication.Continue Reading

• 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).Continue Reading

• Signaling System 7 (SS7)

  Signaling System 7 (SS7) is an international telecommunication protocol standard that defines how the network elements in a public switched telephone network (PSTN) exchange information and control signals.Continue Reading

• 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.Continue Reading

• bits per second (bps or bit/sec)

  In data communications, bits per second (bps or bit/sec) is a common measure of data speed for computer modems and transmission carriers.Continue Reading

• CCNA certification

  Cisco Certified Network Associate (CCNA) is a technical certification that Cisco offers for early-career networking professionals.Continue Reading

• bandwidth (network bandwidth)

  Network bandwidth is a measurement indicating the maximum capacity of a wired or wireless communications link to transmit data over a network connection in a given amount of time.Continue Reading

• An introduction to Go network programming

  This chapter excerpt from 'Network Programming with Go' dives into logging and metrics, while also providing Go code examples and best practices.Continue Reading

• Best practices and strategies for logging in Go

  Author Adam Woodbeck discusses how network teams can use the Go programming language for logging and metrics. One tip: Log prudently, and use metrics generously.Continue Reading

• How to secure your home Wi-Fi network in 7 steps

  When securing your home Wi-Fi, update devices regularly, change passwords consistently, turn off unused services and inspect outdoor network equipment.Continue Reading

• Hybrid network vs. hybrid network infrastructure

  Hybrid networks and hybrid network infrastructure blend different kinds of equipment, geographic locations, network ownership and technology disciplines.Continue Reading

• Ansible vs. Terraform vs. Vagrant: What's the difference?

  Ansible, Terraform and Vagrant are common infrastructure automation platforms with specific use cases, benefits and drawbacks. But choosing a platform doesn't need to be confusing.Continue Reading

• 4 attributes key to network-as-a-service model

  For a network-as-a-service model to work for the enterprise, it needs to offer four key attributes: an application-specific, elastic, secure and personalized VPN.Continue Reading

• What does a network infrastructure upgrade project involve?

  Explore the steps organizations must take to upgrade their network infrastructure, including how to tell if an upgrade is necessary and how to evaluate resources for the project.Continue Reading

• Wi-Fi 6 rollout requires careful review of network devices

  Wi-Fi 6 is just one part of the overall enterprise network. Organizations need to evaluate several network components to ensure a smooth Wi-Fi 6 deployment.Continue Reading

• 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.Continue Reading

• 3G (third generation of mobile telephony)

  3G refers to the third generation of cellular technology that enables mobile telephony.Continue Reading

• CDMA (Code-Division Multiple Access)

  CDMA (Code-Division Multiple Access) refers to any of several protocols used in second-generation (2G) and third-generation (3G) wireless communications.Continue Reading

• Test your knowledge of socket programming in Python

  In this quiz, review the fundamentals of socket programming in Python, including port scanning, TCP and UDP, and how to enable different methods from the socket module.Continue Reading

• Explore this ultimate socket programming guide for beginners

  In this socket programming guide preview, learn how sockets work, the role of socket programming in enterprise networks and the ins and outs of socket programming in Python.Continue Reading

• How to get started with socket programming for beginners

  To understand socket programming for beginners, basic network and security concepts are critical -- and having Python skills won't hurt, either. Learn more in this expert Q&A.Continue Reading

• orthogonal frequency-division multiplexing (OFDM)

  Orthogonal frequency-division multiplexing (OFDM) is a method of data transmission where a single information stream is split among several closely spaced narrowband subchannel frequencies instead of a single wideband channel frequency.Continue Reading

• 5 steps to conduct network penetration testing

  Enterprises that want to ensure competent network security strategies should look at how they can implement penetration testing, considering red teams and physical pen tests.Continue Reading

• 5 benefits of Wi-Fi 6 for enterprise networks

  In a perfect world, Wi-Fi 6 could introduce several benefits to business networks. But real-world conditions could curb the wireless technology's true potential.Continue Reading

• OSI model (Open Systems Interconnection)

  OSI (Open Systems Interconnection) is a reference model for how applications communicate over a network.Continue Reading

• Get started with network penetration testing for beginners

  Authentication, patching and configuration are among the most common vulnerabilities found through network penetration testing. Learn more in this free chapter excerpt.Continue Reading

• Advice on how to learn network penetration testing skills

  As beginners learn network penetration testing skills, they should remember these expert tips: Pay attention to what the client wants, and stick to offense, not defense.Continue Reading