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Bring yourself up to speed with our introductory content.
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Bring yourself up to speed with our introductory content.
What are the different types of network cables?
The main types of network cables are coax, fiber optics, and shielded and unshielded twisted pair. As enterprises deploy new technologies, it's critical to select the right cables. Continue Reading
Variable Length Subnet Mask (VLSM)
Variable Length Subnet Mask (VLSM) is a subnet -- a segmented piece of a larger network -- design strategy where all subnet masks can have varying sizes. Continue Reading
network node
A computer network is a system of computers and computing devices that are connected via communication links. Continue Reading
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Seebeck effect
The Seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances. Continue Reading
dynamic multipoint VPN (DMVPN)
A dynamic multipoint virtual private network (DMVPN) is a secure network that exchanges data between sites/routers without passing traffic through an organization's virtual private network (VPN) server or router located at its headquarters. Continue Reading
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Definitions to Get Started
- CAPWAP (Control and Provisioning of Wireless Access Points)
- network performance monitoring (NPM)
- infrared radiation (IR)
- BGP (Border Gateway Protocol)
- CSU/DSU (Channel Service Unit/Data Service Unit)
- data streaming
- secure access service edge (SASE)
- Network Configuration Protocol (NETCONF)
delay-tolerant network (DTN)
A delay-tolerant network (DTN) is a network that's designed to operate effectively in extreme conditions and over very large distances, such as with space communications.Continue Reading
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.Continue Reading
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance)
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) is a protocol for carrier transmission in 802.11 networks.Continue Reading
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).Continue Reading
virtual network adapter
A virtual network adapter is software that operates like a physical network adapter within the host operating system (OS) or through an application installed on the endpoint or server.Continue Reading
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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...Continue Reading
flow routing
Flow routing is a network routing technology that takes variations in the flow of data into account to increase routing efficiency.Continue Reading
Ethernet
Ethernet is the traditional technology for connecting devices in a wired local area network (LAN) or wide area network (WAN).Continue Reading
big-endian and little-endian
Endianness is a term that describes the order in which a sequence of bytes is stored in computer memory.Continue Reading
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.Continue Reading
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.Continue Reading
data link layer
The data link layer is the protocol layer in a program that handles the moving of data into and out of a physical link in a network.Continue Reading
router
A router is a physical or virtual appliance that passes information between two or more packet-switched computer networks.Continue Reading
network hub
A network hub is a node that broadcasts data to every computer or Ethernet-based device connected to it.Continue Reading
computer hardware
Computer hardware is a collective term used to describe any of the physical components of an analog or digital computer.Continue Reading
network interface card (NIC)
A network interface card (NIC) is a hardware component, typically a circuit board or chip, which is installed on a computer so it can connect to a network.Continue Reading
What's the difference between internet and Ethernet?
Internet and Ethernet are two technologies that sound similar and provide connectivity, but the methods of providing connectivity differ significantly.Continue Reading
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.Continue Reading
Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP) is a standard that defines how to establish and maintain a network conversation by which applications can exchange data.Continue Reading
Class of Service (CoS)
Class of Service (CoS) is a way of managing traffic in a network by grouping similar types of traffic -- such as email, streaming video, voice over IP and large document file transfer -- together and treating each type as a class with its own level ...Continue Reading
User Datagram Protocol (UDP)
User Datagram Protocol (UDP) is a communications protocol that is primarily used to establish low-latency and loss-tolerating connections between applications on the internet.Continue Reading
Remote access vs. site-to-site VPN: What's the difference?
A remote access VPN connects remote users from any location to a corporate network. A site-to-site VPN, meanwhile, connects individual networks to each other.Continue Reading
modulation
Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal.Continue Reading
10BASE-T
10BASE-T is an Ethernet standard for local area networks and one of several physical media specified in the Institute of Electrical and Electronics Engineers (IEEE) 802.3 standard.Continue Reading
frequency-shift keying (FSK)
Frequency-shift keying (FSK) is a method of transmitting digital signals using discrete signals.Continue Reading
subcarrier
A subcarrier is a secondary modulated signal frequency modulated into the main frequency (the carrier) to provide an additional channel of transmission.Continue Reading
internet metering
Internet metering is a service model in which an internet service provider (ISP) keeps track of bandwidth use and charges users accordingly.Continue Reading
Address Resolution Protocol (ARP)
Address Resolution Protocol (ARP) is a procedure for mapping a dynamic IP address to a permanent physical machine address in a local area network (LAN).Continue Reading
subnet (subnetwork)
A subnet, or subnetwork, is a segmented piece of a larger network.Continue Reading
bottleneck
A bottleneck, in a communications context, is a point in the enterprise where the flow of data is impaired or stopped entirely.Continue Reading
CDN vs. cloud computing: What's the difference?
Content delivery networks and cloud computing architectures may appear to serve the same function. But each has a specific role to play when distributing content.Continue Reading
Telnet
Telnet is a network protocol used to virtually access a computer and to provide a two-way, collaborative and text-based communication channel between two machines.Continue Reading
URL (Uniform Resource Locator)
A URL (Uniform Resource Locator) is a unique identifier used to locate a resource on the Internet.Continue Reading
circuit switching
Circuit switching is a type of network configuration in which a physical path is obtained and dedicated to a single connection between two endpoints in the network for the duration of a dedicated connection.Continue Reading
thin client (lean client)
A thin client (or lean client) is a virtual desktop computing model that runs on the resources stores on a central server instead of a computer's resources.Continue Reading
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).Continue Reading
Ways to speed up white box networking adoption
Most organizations are slow to deploy new techniques, white box networking included. Experts explain why and offer advice on how to speed up adoption across enterprises.Continue Reading
Universal Service Fund (USF)
The Universal Service Fund (USF) is a United States government program that supports telecommunications access and affordability in rural and low-income communities.Continue Reading
Next Hop Resolution Protocol (NHRP)
Next Hop Resolution Protocol (NHRP) is an automated configuration technology that routes data on a distributed network by discovering the best routing path between endpoints.Continue Reading
transceiver
A transceiver is a combination transmitter/receiver in a single package.Continue Reading
100 Gigabit Ethernet (100 GbE)
100 Gigabit Ethernet (100 GbE) is an Ethernet standard that supports data speeds of up to 100 billion bits (gigabits) per second (Gbps).Continue Reading
edge router
An edge router is a specialized router located at a network boundary that enables an internal network to connect to external networks.Continue Reading
PSTN (public switched telephone network)
The public switched telephone network, or PSTN, is the world's collection of interconnected voice-oriented public telephone networks.Continue Reading
cloud networking
Cloud networking is when some or all of an organization's networking resources are hosted in the cloud.Continue Reading
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.Continue Reading
runbook
Runbooks are a set of standardized written procedures for completing repetitive IT processes within a company.Continue Reading
network visibility
Network visibility is an awareness of the components and data within an enterprise computer network.Continue Reading
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.Continue Reading
visitor-based networking (visitor-based network)
Visitor-based networking (VBN) is a computer network with high-speed internet access provided by an organization for temporary use by visitors, guests or other users in a public area.Continue Reading
wavelength
Wavelength is the distance between identical points (adjacent crests) in the adjacent cycles of a waveform signal propagated in space or along a wire.Continue Reading
top-of-rack switching
Top-of-rack switching refers to a distributed data center architecture where one or more Ethernet switches is installed in a rack, then uplinked using high-bandwidth fiber optic connections to a central, high-density distribution point.Continue Reading
VPN (virtual private network)
A virtual private network (VPN) is a service that creates a safe, encrypted online connection.Continue Reading
telecommunications (telecom)
Telecommunications, also known as telecom, is the exchange of information over significant distances by electronic means and refers to all types of voice, data and video transmission.Continue Reading
Service Profile Identifier (SPID)
In telecommunications, a Service Profile Identifier (SPID) is a number assigned by a phone company to a terminal on an Integrated Services Digital Network (ISDN) B-channel.Continue Reading
deep packet inspection (DPI)
Deep packet inspection (DPI) is an advanced method of examining and managing network traffic.Continue Reading
The role of smartNICs in modern enterprise networks
This chapter excerpt from 'Building a Future-Proof Cloud Infrastructure' looks at how smartNICs can support distributed services platforms for both cloud providers and enterprises.Continue Reading
How smartNIC architecture supports scalable infrastructure
In this Q&A, author Silvano Gai discusses how smartNICs can benefit enterprises by providing more granular telemetry and supporting distributed cloud infrastructure.Continue Reading
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.Continue Reading
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).Continue Reading
serial digital interface (SDI)
Serial digital interface (SDI) is a standard for digital video and audio transmission over coaxial or fiber optic cabling.Continue Reading
trunk (trunking)
A network trunk is a communications line or link designed to carry multiple signals simultaneously to provide network access between two points.Continue Reading
Point-to-Point Protocol over Ethernet (PPPoE)
Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol that facilitates communication between network endpoints.Continue Reading
1000BASE-T (Gigabit Ethernet)
1000BASE-T is Gigabit Ethernet -- 1 gigabit is 1,000 megabits per second (Mbps) on copper cables, using four pairs of Category 5 (Cat5) unshielded twisted pair (UTP) to achieve the gigabit data rate.Continue Reading
Server Message Block protocol (SMB protocol)
The Server Message Block protocol (SMB protocol) is a client-server communication protocol used for sharing access to files, printers, serial ports and other resources on a network.Continue Reading
dynamic port numbers
Dynamic port numbers, also known as private port numbers, are the port numbers that are available for use by any application to use in communicating with any other application, using the internet's Transmission Control Protocol (TCP) or User ...Continue Reading
customer proprietary network information (CPNI)
Customer proprietary network information (CPNI) in the United States is information that telecommunications services -- such as local, long-distance and wireless telephone companies -- acquire about their subscribers.Continue Reading
autonomous system (AS)
An autonomous system (AS) in networking is a collection of one or more associated Internet Protocol (IP) prefixes with a clearly defined routing policy that governs how the AS exchanges routing information with other autonomous systems.Continue Reading
CompTIA Cloud+ tips to troubleshoot cloud networks
The CompTIA Cloud+ exam covers a range of topics, including how to secure and troubleshoot cloud networks. Some of the first steps: Start simple, and isolate the problem.Continue Reading
domain name system (DNS)
The domain name system (DNS) is a naming database in which internet domain names are located and translated into Internet Protocol (IP) addresses.Continue Reading
stateful inspection
Stateful inspection, also known as dynamic packet filtering, is a firewall technology that monitors the state of active connections and uses this information to determine which network packets to allow through the firewall.Continue Reading
Real-time Transport Protocol (RTP)
Real-time Transport Protocol (RTP) is a network standard designed for transmitting audio or video data that is optimized for consistent delivery of live data.Continue Reading
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.Continue Reading
Synchronous Data Link Control (SDLC)
Synchronous Data Link Control (SDLC) is a transmission protocol used to synchronously transfer code-transparent, serial-by-bit data over a communications channel.Continue Reading
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.Continue Reading
signal-to-noise ratio (S/N or SNR)
In analog and digital communications, a signal-to-noise ratio, often written S/N or SNR, is a measure of the strength of the desired signal relative to background noise (undesired signal).Continue Reading
Virtualization concepts to study for CCNP and CCIE exams
In this Q&A, author Patrick Gargano discusses the importance of virtualization in networking and offers studying advice for aspiring CCNPs and CCIEs in preparation for the exams.Continue Reading
Explore virtualization study topics for CCNP, CCIE exams
Aspiring CCNPs and CCIEs will need to grasp one of networking's most important topics: virtualization. 'Day 7' from Patrick Gargano's '31 Days' explains the subject in detail.Continue Reading
Synchronous Digital Hierarchy (SDH)
Synchronous Digital Hierarchy (SDH) is a group of fiber optic transmission rates that transport digital signals with different capacities.Continue Reading
bit stuffing
Bit stuffing refers to the insertion of one or more bits into a data transmission as a way to provide signaling information to a receiver.Continue Reading
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
Power over Ethernet (PoE)
Power over Ethernet (PoE) is a technology for implementing wired Ethernet local area networks (LANs) that enables the electrical current necessary for operating each device to be carried by Ethernet data cables instead of standard electrical power ...Continue Reading
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.Continue Reading
How to set up a VLAN for enterprise networks
VLANs can secure and prioritize network traffic. To set up VLANs correctly, teams should understand concepts like VLAN tagging and subnets.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
QAM (quadrature amplitude modulation)
QAM (quadrature amplitude modulation) is a method of combining two amplitude modulation (AM) signals into a single channel.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
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
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
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
packet loss
Packet loss is when one or more transmitted data packets fail to arrive at their destination.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
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