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- Analog Signal
- Application layer
- Application or App
- Back End
- Black hole
- Cable modem
- CE Router
- Cellular network
- Cross Over Cable
- Dark fiber
- Datalink layer
- Dedicated line
- Default route
- Demarcation point
- Digital signature
- Domain Name
- ECC memory
- Edge computing
- End User
- EoF End of File
- EoL End of Life
- Expansion Card/Slot
- Layer 2 switching
- Layer 3 switching
- Layer 4 switching
- Leased line
- Line of sight
- Link Aggregation
- Load balancing
- Local address
- Mesh Network
- Micro Code
- Packet Loss
- Parity check
- Penetration Testing
- Physical Layer
- Token Ring
- Trasport Layer
- Tree Topology
- Trusted Certificate
- Tunneling protocol
- Twisted Pair
(Acknowledgement)- is an abbreviation used in networking for packets/signals which are used to “acknowledge” successful transmission. An ACK signal is sent after receiving the block of data, after which more data is sent once the host receives the ACK; if the host does not it either resends the data block or halts transmission.
(Access control list) – In a network an ACL refers to the rules applied on ports and IP addresses on the 3rd layer of networks such as hosts. see also RBAC
A device used to translate signals from one interface to another. See NIC
(Analogue to digital converter) – Usually in the form of an integrated circuit which converts analogue signals to digital. A crucial component used in software-defined radios. See also DAC
Number or unique label used to identify a device or process on the network. See also IP Address
2 networked devices in close proximity sharing a common media, i.e. an Ethernet Cat5 cable.
(Asymmetric digital subscriber line) – one of the types of DSL technologies, it focuses on download speed at the cost of slower upload speeds – hence “Asymmetric” DSL. ADSL2 can reach 20Mbps down 820Kbps up, while older ADSL technology offers 8Mbps down/384Kbps up.
When a router or service sends signals at specific intervals for other devices to keep them update on configuration/status information. See also: Beacon
(Advanced Encryption Standard)- is a specification for encrypting electronically stored data using symmetric key algorithms. It was adopted by the US government circa 2000, replacing the antiquated and compromised encryption standard at the time, DES. It is now the most commonly used symmetric-key algorithm, with hardware-accelerated AES ASIC’s permeating the consumer/enterprise market. See also: Symetric-key, Encryption
A program which has specific, well-defined tasks given to it such as background monitoring. See also: Client
(Artificial Intelligence)- Is when a machine exerts intelligence. This can involve accomplishing complex tasks that humans associate with intelligence, such as learning and problem solving. Self-driving cars, smart factories and machine analytics can be seen as form of applied AI.
a set of rules forming a step-by-step process used for calculating, data processing, analytics and automation logic.
(Arithmetic Logic Unit)- One of the two main components in a CPU, it’s in charge of performing mathematical calculations. See also: CU, CPU
(Amplitude Modulation)- is a technique using modulation on the amplitude of a wave, essentially transmitting data using the amplitude(highest value) of a wave. See also: FM, RF
The highest value of an analogue wave, it’s usually represented as the curve along the x-axis in a graph. See also: Frequency
- Analog Signal
The representation of information through a continuous signal, with variable physical quanties(i.e sound waves through air). Analog systems take advantage of the physical properties of the medium to convey information through it. Analog signals theoretically hold infinite resolution, though in practice effects from distortion and interference limit resolution, as opposed to digital systems with definite and finite values. See also: Digital, Binary
(American National Standards Institute)- An organization composed of voluntary corporate, government and professionals that coordinates activities related to setting and approving U.S. national standards.
A physical device designed for receiving and transmitting radio frequencies. Antennas serve to capture/transmit specific frequency ranges and are thus not interchangeable (i.e a 2.4GHZ antenna cant be used to transmit 5GHz signals).
(Application Program Interface)- Not unlike how GUIs make computers easier for end users, API’s help software developers simplify application building. By implementing a proper API, developers expose only the functions they need, and can abstract all the underlying processes(i.e. a search box and the underlying components).
(Access Point Name)- The identifier used in mobile networks to access the gateways between GPRS, GSM, 3G/4G cellular networks and packet switched networks(i.e the internet). It’s required for sending data from cellular network to packet switched networks & viceversa.
- Application layer
The 7th and top layer of the OSI model, and defined as the layer where user input/output occurs. It focuses on abstracting the underlying processes away from the end user. The protocols on this layerutilize process-to-process communication(I.E FTP, SMTP). See also: OSI
- Application or App
is computer software designed to help users perform specific functions and tasks. Also known as a computer program, examples include word processors, web browsers, media players and games.
The design which defines the structure and organization of a system. The architecture of a system is what sets its overall limits, efficiency and capabilities.
(Address Resolution Protocol) – protocol used in the IP suite, as its name suggests it is utilized for address resolution. It maps network addresses (e.g .IPv4) to physical ones (like MAC addresses). See also: IP Address, MAC
(Automatic Repeat reQuest)- A technique used in communications, where if an error is detected in the receivedtransmission, a re-transmission request is automatically sent until the data is received intact.
- Back End
In software, the Front end is used for presentation and user input/output; whereas the back end is encompasses the actual underlying processes, protocols and systems used to deliver data to/from the front end. See also: Front End, Infrastructure
The part of the network used to transmit data destined for different networks, providing a pathway for exchanging information between diverse networks.
(AKA backhaul network)- Many definition exist, the primary consensus of backhaul networks is that they are in charge of moving data to/from the network edge(i.e user device) to the core(backbone) of larger network like the internet.
is the group of electrical connectors that run in parallel to form a bus, commonly used in printed circuit boards(PCB). See also: Bus, PCB
In an analog system, it is the difference between the highest and lowest frequencies supported in a medium, measured in hertz(i.e. 4g uses 5-20 MHz of bandwidth). Also used to describe throughput capacity (i.e. my ISP provides 3Mbps of bandwidth). See a
is a signal with a very narrow frequency, so that it only transmits data through a specific part of the spectrum. Cellular networks and operators implement basebands dependent on things like spectrum licencing and usable spectrum .
in telecommunications, its used as the unit of measurement for symbol rate(or modulation rate), measured in symbols(pulses) per second. Specifically it deals with with the number of different symbol changes made per second in transmission medium. See also: Symbol
In a wireless network(iee 802.11 WLANs), beacon frames are transmitted every so often to advertise the presence of the wireless network.
(Border Gateway Protocol)- A standardized exterior gateway protocol, its a widespread protocol used for exchanging information between the innumerable amount of autonomous systems deployed (like routers & gateways). See also: MPLS, Gateway
a term used to describe the order in which bytes are stored in computer memory, Big endian orders bytes starting with the most significant bit. See also: Little-Endian
the language in which machines communicate(due to their on-off, transistor based composition). A binary number is any number expressed in base-2 using the symbols 1 and 0. See also: Hexadecimal, Octal
Single binary digit used in the binary numbering systems, a bit can either be a 1 or 0.
Speed at which bits are transmitted, commonly expressed in bits per second. See also: bps, bandwidth
- Black hole
An area of the network where traffic is dropped or discarded in a silent manner(doesn’t inform the source). This can be caused by a firewall, a” dead” ip address, or a filter.
A technique used in software which initially loads a small payload with just enough functionality so it can load the larger, main part of the program.
(bits per second)- the rate at which bits are transmitted per second, e.g 50bps. See also: kbps, mbps, gbps
a device which connects two network segments that share the same communication protocol, operating at layer 2 of the OSI model. A bridge mainly forwards, filters and floods incoming frames based on MAC addresses. See also: OSI, Switch, Router
Refers to a high-capacity transmission technique wich uses multiplexing to incorporate wide range of frequencies enabling large amounts of data to be transmitted at the same timeSee also: Narrowband, Baseband
a method of data transmission where packets are sent to all nodes on a network. See also: multicast, unicast
A GUI-centric application used for accessing websites. It works by parsing the hypertext data transmitted into graphical elements. See also: GUI, Application
(Berkeley Standard Distribution)- A term used to describe a variety of UNIX-like operating systems, based on UC berkely BSD OS. FreeBSD and OpenBSD being the most popular ones. See also: UNIX, Linux
storage area reserved for holding data in transit. Buffers can be used to compensate for differences in processing power/speed between devices. A buffer can also be used in video transmission to compensate for slow/unreliable connections by amassing enough of the transmission in a buffer before playback. See also: Stutter, Cache
In software development it can be used to describe pre-compiled applications ready for use. usage example: “You can download the x86 build of Firefox on their website”. See also: Compile, Source Code
In communications it means a group/sequence of signals sent closely together and counted as a single transmission.
Physical path through which signals are sent, usually composed of copper wiring or copper paths on a PCB.
a sequence of bits being worked on as a single unit. A byte contains 8 bits.
- Cable modem
a modulation and demodulation device that serves to translate a cable service providers WAN signal into more common LAN network technologies. See also: DSL Modem
An optimization technique that stores data used in previous processes so future applications/processes can access it faster. Cache is usually stored in high-speed re-writable media like RAM. See also: RAM
(channel associated signaling)- Is a technique where the signal information is encoded in the payload itself, this can result in lower bandwidth for the payload itself. The most popular form of CAS is known as robbed-bit signaling. See also: Channel
(Category 5 )- is a twisted-pair cable used in the structured cabling of computer networks(usually Ethernet based). CAT-5 cables can support up to 2.5GBASE-T, and are superceded by CAT-5e and CAT-6 cables.
(Cable TV)- an abbreviation often used for cable television broadcasting systems.
(Constant BitRate)- in telecommunications it relates to the quality of service for ATM networks. See also: VBR, bitrate. See also: VBR, Bitrate
(Country Code)- the nation-specific phone number prefix used for international calling.
(Code Division Multiple Access) – Is a channel access method employed by various RF network technologies. It allows multiple access to a single communication channel, allowing transmitters to share a band of frequencies simultaneously. To avoid interference between users, CDMA uses coding scheme for individual users, and other techniques like spread-spectrum to avoid further interference. See also: GSM, LTE
- CE Router
(Customer Edge Router)- A term now mostly synonymous with CPE, it comes from MPLS networks were the CE router is located at the absolute edge of the customer network, and serves as a gateway to connect to the provider’s network’s by connecting to the PE router through MPLS, border gateway protocol or similar technology. See also: MPLS, PE Router, BGP
- Cellular network
distinguished by the fact that the last link in the network(the one to/from the end user) is a wireless one. Cell towers are distributed in such a fashion as to provide wide coverage in a large geographical area, with each cell tower counting as a cell site or station. See also: Packet-switched Network
(Computer Emergency Response Team) – CERT can trace back its roots to the proliferation of malware and viruses. In 1988, after a computer worm shutdown a large portion of the internet, the first CERT was formed. Since then many county’s governments have amassed their own response teams(i.e US-CERT, CERT-MX).
Frequencies can be divided into specific channels of predetermined frequency ranges, which can transmitter/receiver matching and improve spectrum efficiency. See also: Baseband, RF
(Challenge-Handshake Authentication Protocol) – an authentication scheme used by point-to-point tunneling (PPP), it helps stop replay attacks by using a challenge-response system. See also: Authentication, Handshake
is a small block of unique data generated by putting a file through a lossy algorithm like MD5. it’s primary use is for data integrity checking purposes, as vulnerabilitiesin algorithms and the lossy nature make it unsuitable for real encryption. See also: MD5, SHA
A method used to transform plaintext data into unreadable messages, for the purpose of securing transmission of said data. See also: Encryption, AES, DES
(Command Line Interface)- A text based interface for users that allows them to interact and execute applications and by extension the operating system itself through special commands. Linux and windows both come with several flavors of CLI’s. See also: GUI, UI
A software program or node that connects to a server. See also: Server
Its a term that denotes the front end (client) and the back end (server), also known as distributed computing architecture. See also: Distributed computing, Server
(Consumer-Premise Equipment)- Network equipment that is located at the customer premise, it’s used to connect the service providers network to the customers – usually at the network edge. See also: Service Provider, Network edge
(Central Processing Unit) – more commonly known as a processor, they are essentially the brains of modern computers/systems. Their main components are ALU’s, CU’s and memory. Processors are in charge of doing the actual calculation(the ALU), reading instructions from memory and executing them(the CU and memory). See also: ALU, CU, memory
(Cyclical Redundancy Check) – is an error detecting code used in digital networks and storage. It works by appending a check value to raw data blocks(the check value is calculated based on polynomial long division), and if the check value doesn’t match the data block corruption can be detected and dealt with accordingly. See also: Checksum
- Cross Over Cable
Now a mostly obsolete cable configuration, it was used to connect two NIC’s or computers together before the existence of Automatic MDI/MDI-x. See also: NIC, Ethernet
(Carrier Sense Multiple Access with Collision Avoidance/Detection)- is a MAC protocol where nodes try to sense the existence of other transmissions/traffic before sending out transmissions itself. This is a technique used for shared mediums, such as RF cellular networks. Subsequent variations include improvements:
where a node immediately terminates any transmission once collision is detected, speeding up the re transmission.
Collision detection – where if a medium is busy with a transmission, it postpones the transmission at a random Collision avoidance – interval, greatly reducing the chances of simultaneous transmission.
(Channel Service Unit/ Data Service Unit)- is a device used to change from one digital signal to another. DSL modems and cable modems fall under this category as they change from WAN digital signals to LAN compatible signals. See also: DSL, WAN, LAN
A device that converts from digital to analog signals, usually in the form of an ICSee also: ADC, IC, Analog, Digital
- Dark fiber
It is Fiber optic cabling that has been laid and installed, but is not in use(hence dark). Service providers lay dark fiber in key location to speed up deployment times. See also: Fiber, Service Provider
quantities, symbols characters; it’s essentially any information that computers utilize.
A set of data specially structured for fast access and stored in computer or systemSee also: Storage, SQL
is a basic unit associated with data transfer in packet switched networks. The provide connection-less communication, where delivery and arrival times are not guaranteed. See also: UDP, PSN, TCP
- Datalink layer
The second layer in the OSI networking model, it deals with data transfers between nodes in a network(usually a LAN). It provides the means to transfer data and correct for things like collision. Protocols in this layer: Ethernet and PPP See also: OSI, Node
(decibel)- a logarithmic unit used to define the ratio between two physical quantities. Mainly used for measuring power/gai in acoustic vibrations, electronics and optics.
de-provisioning or disabling a device or service.
The opposite complementary function to encryption, its the act of taking encrypted data and through the use of reverse-algoriths and a key convert it into readable plaintext. See also: Encryption, Plaintext
- Dedicated line
As opposed to normal ISP lines, dediciated lines are meant for specific applications(such as voice) and offer application-specific benefits(latency, badwidth, etc). They usually come with a service-level agreement. See also: SLA, Leased line
- Default route
When no specific route can be determined(or is even specified) packet-switched networks can send the packets to predetermined default routes. See also: Router, Packet
It’s an important variable to take into acount when designing networks(especially WANs), while delays between adjacent nodes can be nearly insignificant, over long distances or after passing through several nodes the delay can become cumbersome. The term is mostly synonymous with latency, as both are a measurement of the time it takes for transmissions to reach their destination. See also: latency, ping
- Demarcation point
Term used by CSPs to define the location where public telephony networks end, and the customer’s wiring begins. See also: WAN, Infrastructure
A demodulator extracts the information carried by modulated carrier waves. It takes an analog signal and converts the information stored in the wave to digital binary data. See also: Modulator, ADC
This takes a multiplexed signal, and separates the various different signals that are encoded into it. See also: Multiplex, Broadband
(Data Encryption Standard)- A symetric-key algorithm for encrypting data, now superseded by AES after several vulnerabilities were discovered. See also: Symetric-key, Encryption, AES
(Dynamic Host Configuration Protocol) – DHCP is a standardized network protocol used to automate the detection of network configuration, with the end goal being plug-and-play network functionality. A DHCP server issues configurations to newly connected devices provisioning them for the network. See also: Plug and Play, Automation,
(Direct Inward Dialing)- is a telecommunication service offered by telephone companies to PSTN subscribers that use PBX systems. DID provides groups of phone numbers for people to call into the PBX systems. See also: PBX, VoIP, PSTN
- Digital signature
A mathematical technique that imposes an electronic signature onto documents, messages or plain data. The signatures are intentially made to be hard to replicate, mainly by using public-key cryptography. See also: Public-key, Authentication, Digital Certificate
(Direct Memory Access)- A function in certain computer systems that allow certain parts of the hardware to directly access system memory(RAM), instead of going through the processor and wasting clock cycles and bandwidth. See also: RAM, Memory
(Domain Name System)- A descentralized system made for resolving and associating a domain name(i.e. lanner-america.com) with its respective IP Address(i.e 126.96.36.199). Useful mainly for end users because it translates hard to remember public IP addresses(i.e. 188.8.131.52) to easily recognizable character-based names such as google.com.
(Data Over Cable Interface Specification)- An international telecom standard that allows broadband communications over existing CATV infrastructure/systems. See also: CATV, Cable Modem
- Domain Name
A unique identification string used to access servers by more memorable labels, instead of IP addresses. See also: Label, IP Address
Relevant in radio communications and mostly used to describe satellite communications, it denotes the link associated with downloading(receiving) information. See also: Uplink
(Dynamic Random Access Memory)- Uses capacitors to store information. By using a charging circuit, capacitors are capable of storing 1 and 0 bits as charged and discharged states respectively. Because capacitors are incredibly fast, inexpensive and dense, today the most commonly deployed type o ram is an improvement of DRAM known as synchronous DRAM. One of the downsides of using capacitors is that they lose their charge quickly, leading to volatile memory. See also: SDRAM, SRAM
(Digital Subscriber Line)- DSL has evolved over the years into a family of technologies offering various upload/download speeds correlating with maximum line distance. See: ADSL, VDSL, xDSL
(Extensible Authentication Program)- An authentication protocol widely employed on PPP and wireless connections. See also: PPP, Authentication, Wi-Fi
- ECC memory
(Error Correcting Code)- Stray particles from radiation(mainly CBR- Cosmic background radiation) are responsible for bits spontaneously changing states from 1 to 0 or viceversa. This can cause errors in the data stored on the RAM module, and for critical financial and scientific systems this is unacceptable. ECC RAM, for example, includes modules capable of detecting and correcting these errors. See also: Corruption
(Elliptic Curve Digital Signature Algorithm)- A variation of the DSA, both employ elliptic curve cryptography to employ powerfull encryption See also: DSA, Cryptography
- Edge computing
focuses on moving processing and computing from core networks closer to the source by using powerful hardware on the outmost part of the network – the edge.
(Electrically Erasable Programmable Read-Only Memory)- Memory that can be electrically erased and reprogrammed. See also: ROM, EPROM
(Electronic Freedom Frontier)- Non-profit organization providing funds for legal defense related to technologies, especially new technologies which open up new avenues for abuse and misuse against individuals.
Standards from the telecommunications industry association which focuses on physical cabling for commercial buildings.
Electronic mail is a term used to describe digitally stored messages transmitted over a shared resource such as a LAN or WAN.
(ElectroMagnetic Interference)- When radiation from powerlines, for example, interferes with other frequencies such as the ones used by cellular RF networks, this can lead to signal degredation/interference.See also: RF, Spectrum
Is the act of converting from one type of code to another. For example: English alphabet to Morse code, .WAV to . MP3 sound file conversion, DVDs to MP4 video files etc. See also: Code, Decode
A form of applied cryptography, encoding is the process of taking plaintext data and encoding it in such a way as t hide the original message from all but the intended recipient(s). This involves some form of secret, usually a key/password. See also: Decryption, Plaintext, Cryptography
- End User
Refers to the individual(s) that are intended to use the actual service/system.
The term can refer to any device(computer, node, phone, smartwatch, smart meter, etc) that is on a TCP/IP network.
- EoF End of File
A term commonly used to decribe the end of the data stream where information can no longer be read.
- EoL End of Life
A term used to describe a product/service that has reached the end of its lifecycle. Usually this means discontinued support, but may be extended by popular demand(example: Windows XP)
(Electronically Programmable Read-Only Memory)- Memory which can be written to electronically, but must be erased by other means(if even possible) such as though a small glass windows allowing photonic erasure. See also: EEPROM, ROM
(ElectroStatic Discharge)- Stored static electricity can cause damage to electronic components, such as ram modules.
A group of technologies used in LANs/MANs, it was standardized by IEEE into the 802.3 standard during 1983. Before Ethernet became the golden standard it is today, it competed with several other technologies such as FDDI and token ring. See also: FDDI, 802.3, IEEE
(European Telecommunications Standards Institute) -An independent non-profit organization dedicated to producing telecommunications standards that can be applied world-wide. They standardize technologies for both wired and wireless communication. See also: IEEE
- Expansion Card/Slot
A system designed to be expandable by using a modular approach. The motherboard houses the slot and bus will the expansion cards interface with it adding functionality.
A term mostly used in modern protocols that utilize a just-in-case technology, almost always a slower less error prone connection, to “fallback” on in-case the main connection experiences problems. It can refer to any system designed as a automatic backup to the main system. See also: Backup
- Fast Ethernet
Also known as 100BASE-T, it is an Ethernet standard providing up to 100mbps transmission rates, 10x more than the 10mbps offered by the original Ethernet standard. See also: 802.3, Gigabit Ethernet,
- Fiber Optic Cable
A fiber optic cable consists of 3 components: Core, Composed of glass or plastic fibers. Cladding, Material with a lower refraction index which keeps light at the core. Coating, Outer material which serves to protect the finished cable.
A firewall serves to filter unwanted traffic that could be potentially harmful. One of the main uses is as a barrier between the internet and LANs, or as a barrier to more critical systems in a zoned network. For a detailed description see Network security knowledgebase on Firewalls
(AKA flash storage) – A form of electronically erasable/write-able memory that is non-volatile (retains data while unpowered). The 2 types of flash can be divided by ones that USE NAN or NOR gates which offer trade-offs between density, power consumption and speed. See also:ROM, NAND, NOR
Used to refer the size, power-usage and overall impact of a device, such as a firewall which operates 24/7 nonstop (i.e this compact firewall has a really low footprint).
- Frame relay
An almost obsolete technology with the widespread adoption of superior Ethernet communications, it is still none-the less employed today in low-bandwidth use-cases due to its extremely low-cost. Speeds for this type of network hover around the 100kbits/s range.
(File Transfer Protocol)- A user layer protocol used to transfer files between nodes. See also: OSI, User-Layer
A data transmission systems that allows the transmission of data in both directions simultaneously (Example: phones are full-duplex, while walkie-talkie radios are half-duplex)See also: Half-duplex, line-of-sight
(Foreign Exchange Office)- Term used to describe ports using analog phone lines, This port is designated as the one on end devices such as the rj11 ports on phones.
(Foreign Exchange Station)- Term used to describe ports using analog phone lines, its responsible for the actual communications between the service provider and the subscriber(this is the phonejack port on the wall)
Serve as a middleman between 2 different network technologies such as LAN/WAN, wireless/wired etc. See knowledgebase IoT gateway
(Gigabyte) – Abreviation meaning Gigabyte or 1024 megabytes. See also: Byte, Kilobyte, Megabyte, Terabyte
(GigaBit Interface Converter)- A hot-swappable interface that allows transceivers to be plugged in and convert signals from media such as copper and optical. Made obsolete by the Small form-factor pluggable transceiver. See also: SFP, Transceiver
(Gigabit per Second)- Abbreviation that measures the speed of a transfer in 1 billion bit increments. See also: bps, mbps, tbps
- Gigabit Ethernet
An umbrella term describing the various Ethernet communication technologies that transmit at gbps speeds and higher. See also: 802.3, Fast Ethernet
(General Packet Radio Service)- a mobile data service standardized by ETSI and now maintained by the 3GPP, it extends GSM network capabilities allowing services like SMS/MMS, Always on internet, p2p and much more. See also: 3G, CDMA
(Global System for Mobile Communications)- A standard developed by ETSI to define the set of protocols used for the second generation of mobile networks. It has grown to become the most widely deployed mobile communication system worldwide, only recently being overshadowed by new LTE deployments. See also: LTE, CDMA
(Graphical User Interface)- Essentially the opposite of a text-based interface like the CLI, it employed objects and graphical elements to create a user interface that many people find more intuitive. See also: CLI, UI, UX
One of the most commonly used modern formats for video compression, distribution and recording.
In communications its a term used to describe the automated negotiation between systems(to synch the connection parameters/variables for connection) that goes on before regular communications take place. See also: Authentication
(AKA hashing function)- any function in a system that takes arbitrary data of variable size and maps it to data of fixed size. One popular use is for hash tables, where it speeds up data retrieval time significantly. Another use is in cryptography where passwords can be stored as a hash(MD5, SHA) to avoid plaintext weaknesses. See also: MD5, SHA, Database
(Hard Disk Drive or simply Hard Drive)- A term born from the fact that before mechanical platter based drives existed, there was “soft” storage like tape and floppy disks. In HDD’s, Data is stored on “hard” magnetic platters where bits can be written/erased by a header moving through the radius of a platter while it spins. The term has become so ubiquitous with general computer storage that many now use it to describe any main storage component in a system, even when the technology employed is a something different like a solid state drive. See also: SSD, Flash storage
Control information that is prepended to data before being transmittedSee also: TCP
The unit of measurement for frequency, part of the international system of units. It’s defined as 1 cycle per second and named after the first person to provide concrete evidence for the existence of electromagnetic waves, Rudolf Hertz. See also: decibel
Also known as a Man-In-the-Middle attack, it involves a third party taking control of communications between 2 entities and posing as 1 of the real entities to carry out further activities like eavesdropping, data altering and malware infection. See also: virus, malware, hack
A hop ca be defined as a section of the network between 2 nodes. Everytime data passes through a new device and onto another cable/network it is counted as a hop.
Is any device that has established a connection with the network and provides resources/services(i.e a computer using the IP suite can be known as an IP host). Taking the client/server model into mind, all servers are hosts but not all hosts function as servers. See also: client
In computer systems its defined as a capability to remove and connect parts while the machine is still on. Things like RAM and PCI cards usually need a reboot to work, while hard drives, USB devices and network connection are hot-swappable and can all be manipulated without needing to restart the system.
Now largely made obsolete by switches(outside of very niche applications), hubs or Ethernet hubs work by connecting various Ethernet devices into a single device(the hub) where one ports transmission are repeated to all the connected ports except the originating one. See also: Switch, Router, Bridge
(Input/Output)- Term used in computing to refer to the Input/output capabilities of a storage system(HDD, SDD), measured in operations per second (IOPS).
(Internet Corporation for Assigned Names and Numbers) A non-profit organization that is in charge of maintaining several important databases that define the namespaces of the internet. See also: Domain, DNS
(Internet Control Message Protocol)- A protocol included in the IP Suite , it enables nodes (mainly routers, switches) to send diagnostic/status information over the network. It differs from other protocols like TCP/UDP in that its primary use is to send control or operational information, not arbitrary data. See also: TCP, UDP, IP Suite
(Intrusion Detection System)- software or hardware system that focuses on monitoring the system for unwanted malicious activity, then reports back to another system, usually an SIEM or other primary network monitor See also: IPS, SIEM
(Institute of Electrical and Electronics Engineers)- not-for-profit organization that has published over 100 peer-reviewed journals in electrical, electronics engineering and computer science , and has defined hundreds of standards with over 900 actively employed all over the world. In networking, and even among its extensive standards portfolio, the 802 LAN/MAN standards are the most well known and employed. See also: 802, 802.3, 802.11
Develops many standards, with a large part of their portfolio in the IP suite, it’s an organization dedicated to making open standards and promoting the use of these open technologies. A parent organization of the nonprofit Internet Society.
A section of the electromagnetic spectrum between microwaves and visible waves. Commonly known as the source of thermal radiation seen through night-vision goggles. Its wavelength properties make it the idea choice for optical media such as fiber.
A software application(GUI/CLI based) or device (i.e HMI) designed to allow a user to interact and communicate with the machine. See also: CLI, GUI, HMI
In RF networks this can be caused by other sources of radiation or similar devices in close proximity, prompting technologies like CDMA with collision detection and avoidance to be developed. In wired media sources of EM radiation(i.e power lines) can also interfere with transmission and corrupt data. See also: CDMA, Baseband
The internet is the largest global network, interconnecting billions of devices all communicating through the IP Suite.
When systems or services can work together for an overall beneficial relationship.
Basically the opposite of a global network like the internet, its a smaller private network designed to be visible only to a specific group.
(Internet Protocol) – A suite of protocols defining end-end communications. They specify everything from how data should be sent formatted, labeled to how it should be transmitted, routed and received. Commonly named in conjunction with with TCP, as the TCP/IP suite. See also: Protocol, IPv4/v6
(Intrusion Prevention System)- While intrusion detection systems are limited to monitoring, IPS has response functions, i.e close a section of the network once an attack is detected. See also: Firewall, UTM
(Internet Protocol security)- Is a suite of protocols designed to secure communications using authentication, encryption and management technologies. It provides an end-to-end secure architecture operating up to the highest layers of the OSI model, the application layer. See also: TLS, SSH
The most widely employed version of the internet protocol suite, it offers a 32bit address space which has slowly become a limiting factor in the protocol. IPv6 adoption is currently low although most modern devices support it.
(Internet Relay Chat)- An application layer protocol used for text-based communications. Working on the client/server model, users connect to hosted chat rooms. Mainly used by people to engage in group discussion. See also:
(Integrated Services Digital Network) – Set of communication standards that make data transmission over previously voice-exclusive lines like the PSTN. It allows packet-switched digital networks to operate over circuit switch networks. See also: PSTN
(International Standards Organization)- standards focused body composed of over 163 national members(all experts in a field) that collaborate on developing new innovative international standards.
(Internet Society)- Non-profit organization providing leadership, support and education for internet related standards. It’s organizational motivation is “to promote the open development, evolution and use of the Internet for the benefit of all people throughout the world”
In information technology it can be used to describe any process which uses timing coordination as an integral component. Real-time information streams like voice calling and video broadcasting all rely on time coordinated transmission systems.
(Internet Service Provider) – The majority are privately owned companies that provide broadband internet communication services through a WAN technology like CableTV (DOCSIS), Fiber, DSL, 3G/4G etc. Many ISPs also count as CSPs(Communication service providers) as they provide POTS and enterprise WAN solutions like MPLS. See also: CSP, SP, POTS
(Information Technology) – Term that encompasses anything that has to do with computers and their manipulation/creation of data, it’s transmission, reception and everything else in between(i.e the hardware/software). See also: PC
(International Telecom union)- Special agency of the UN that is responsible for taking care of matters related to information technologies(primarily the communication technologies involved). The ITU has coordinated the worldwide shared use of RF spectrum, works to promote and improve network infrastructure in developing countries and takes part in setting relevant global standards.
(Interactive Voice Response)- A system with technology that enables it to interact with humans through the use of (usually prerecorded) voice and the unique dial tones buttons have. This enables businesses to easily filter calls to the pertinent areas through the use of IVR menus. See also: Automation
(Information Technology)- In IT it refers to the female end of an RJ-11 telephone connector. In entertainment it refers to the female 3.5mm audio connector.
In electronics and communication media, a jitter is a deviation from a constant or periodic signal. Jitter can be induced by EMI or simply crosstalk with other signals and lead to flickering in video displays, audio pops/degredation etc.
A conducting material in the form of a rectangle wide enough to latch onto 2 adjacent PINS on a PCB and bridge them together for the purpose of modifying the systems configuration. Widely used to reset low-level system configurations like the BIOS. See also: BIOS, PCB
(Kilobits Per Second)- A measure of data transfer speed. Modems, for example, are measured in Kbps. Note that one Kbps is 1,024 bytes.
- Keep alive
A message sent to another device with a previously established connection, it’s only purpose is to verify if the connection is still functional. See: TCP
- Key pair
In public-key cryptography the public key(the key used to decrypt) and the private key(used for encryption) are together referred to as the key pair.
(Layer 2 Tunneling Protocol)- A tunneling protocol supporting technologies like Virtual private networks using UDP. It offers no security measures on its own, rather technologies like IPsec are used in conjunction with L2TP to provide secure transport. See also: PPP, VPN
An identifier asigned to an object to differentiate from others. See also: MPLS
(Link Aggregation Control Protocol)- Protocol supporting link aggregation. See also: Link Aggregation
(Local Area Network)- Any computer network in a limited geographic area (up to very large buildings) qualifies as a LAN. See also: MAN, WAN, IEEE 802
A measure of the time it takes for something to complete, for computers this speed is measured in nano/milliseconds. In information technology this mainly involves the latency induced by transmissions over longer distances through media such as fiber/copper, and he intermittent nodes(routers, switches, access points). See also: Ping
- Layer 2 switching
following the OSI network model, traditionally switches operated at the second layer sending packets to destinations based on their MAC address.
- Layer 3 switching
Layer 3 switching, also know as routing, works by reading the IP header information instead of the MAC address to determine where the packet should go. See also: Router
- Layer 4 switching
Layer 4 switching build ontop of layer 3 switching by also reading data information like port numbers stored in the TCP header. This allows more advanced networking techniques like QoS to be employed now that these switches can distinguish different types of traffic. See also: Multi-layer switching
- Leased line
A communications line that has been rented out from a third party, largely used by businesses to reliably connect distant branches. These lines offer more reliability than traditional service providers because they come with a Service level agreement guaranteeing specific up-times and speeds. See also: CSP, SP
Local exchange carrier)- A term used in telecommunications to refer to the actual telephone company providing telephone service. See also: POTS
(Light-Emitting Diode)- a 2 pronged semiconducting diode that emits light at a specific wavelength when electricity is passed through it. Today their are used in everything from visual indicators in HMI’s, to HD displays incorporating millions of minuscule LED’s.
- Line of sight
A characteristic of electromagnetic radiation and sound waves, it takes into account the fact that the curvature of the earth limits the range of terrestrial transmission over long distances, providing viable communications up to the line of sight which is the horizon horizon.
- Link Aggregation
Its a term used to describe a technique in computer networking that increases resources by utilizing 2 or more different connections in a seamless manner. It works by essentially balancing traffic between multiple links providing added redundancy and bandwidth beyond the capabilities of a single link.
It refers to the order in which bits are stored. In little-endian schemes, the least-significant bit is stored first(the lowest address in the memory). See also: Big-Endian, memory, address
- Load balancing
A technique used in networking that intelligently balances traffic between available connections/resources to avoid overbearing a single connection or device causing congestion.
- Local address
IPv4 reserves several blocks of addresses exclusively for private networks(LANs) to use. These are: 192.168.0.0 – 192.168.255.255 (total of 65,536 IP addresses), 172.16.0.0 – 172.31.255.255 (total of 1,048,576 IP addresses), 10.0.0.0 – 10.255.255.255 (total of 16,777,216 IP addresses)
In programming, a loop is a sequence of instructions that can be carried out several times before triggering an exit function, or continue running indefinitely.
a term used to describe algorithms that do not remove/destroy any of the original file information. In multimedia, although lossless formats preserve the original quality of the content, they are not very suitable for internet transmission as they take up to much badnwidth.
Term used to differentiate between fundamentally different compression algorithms. Lossy algorithms do not care about preserving original data integrity to its fullest, but instead focus on maximizing compression by discarding information deemed unnecessary by the algorithm(example: music compression algorithms like mp3, which discard the frequencies above and below human hearing range).
(Long-Term Evolution)- Designed for the fourth generation of mobile networks, it is based on improvements over technologies from the previous generation(GSM/EDGE, HSPA/UMTS). Main improvements over the previous generation are the exponential increase in bandwidth(both upload/download speeds), low latency and increased spectrum efficiency.
(Media Access Control)- A unique identifier assigned to Network interface cards, it also contains organizational (manufacturer) information and configuration parameters. Switches/routers(working at the 2nd-layer of the OSI model) use these unique address to deliver frames to the appropriate interface. Composed of six octets, FF:FF:FF:FF:FF:FF being the final address(reserved as the broadcast address), it has a 48bit address space capable of 281,474,976,710,656 unique permutations. See also: IEEE, 802, Ethernet, OSI
(Metropolitan Area Network)- Larger than a LAN(Max size ~building), but smaller than a WAN(infinite span), it encompasses networks still limited to a geographic area but much larger than a LAN, like large campus or even a city-wide network. MANs can also be interconnected buildings, usually through a backbone line. See also: LAN, WAN
(MegaByte)- 1,000,000 bytes or 1,000 kilobytes.
1,000,00 bits per second
MD5 -A widely used algorithm, but vulnerabilities in its cryptographic functions have lead to its primary use as a simple data integrity checking hash. See also: SHA, Hash
Plural of medium, its used to describe the actual physical object used to transmit the signals. Fiber(optical), Wired(electrical) and Air(RFs) being the 3 media used to transmit their respective signals.See also: optical, RF
Singular of Media.
- Mesh Network
A highly interconnected network topology where every node cooperates in the distribution of data. This offers benefits like increased reliability using intelligent algorithms than can reroute paths upon detecting failure/congestion. See knowledgebase on Network Topology
In networking it can mean the strict control/monitoring of the amount of information passing through a connection(usually a service providers) for billing or other purposes.
- Micro Code
A technique in computing that uses an interpreter to translate high-level instructions into low-level circuit operations. This layer of abstraction allows programmers to build complex applications much more quickly and efficiently. In a more general view it can be seen as the base firmware built into a device. See also: BIOS, EFI, Interpreter
EM radiation in between 300Mhz and 300GHz, this broad range of frequencies offers usable spectrum for broadband point-to-point communications(requires line-of-sight). Since microwaves can be focused into narrow beams its widely employed by satellite communications to form uplinks/downlinks with high bandwidth. This frequency band includes the milimeter waves that are being tested for 5G usage. see also: line-of-sight, EM Spectrum
(Microprocessor without Interlocked Pipeline Stages) – A RISC based ISA supporting up to 4 cores, its primary use is in embedded systems such as routers, gateways,video game consoles/handhelds. See also: X86, RISC
(MOdulator-DEModulator)- A device capable of transforming or creating an analog signal(i.e carrier wave) from common digital transmissions used by networked devices, like Ethernet. Widely known examples include DSL modems that utilize the modulated analog signals in phone lines for broadband communications. See also: DOCSIS, DSL
(MultProtocol Label Switching )- An efficient technique used in high-performance networking that uses short path labels, instead of network addresses and complex routing tables. The architecture is protocol agnostic and allows the simultaneous usage of multiple protocols. See also: Router, switch
(Multiple Service Operator)- A term today reserved for communication service providers that operate a large number of cable television systems. See also: CSP, ISP
(Message Transfer Agent) – Any application that transfers messages based on a client/server model. E-mails for example operate on this principle, with the client being the sender and the mail server being a sort of electronic post office that delivers mail to the recipient. See also: E-mail
(Maximum Transmission Unit)- defined as the largest size a packet or frame can be in a packet/frame switched network. It’s defined in octets which the TCP uses to determine the maximum size of a packet before transmission.
A form of data transmission in which a single packet is transmitted to multiple points or addresses. See also: Broadcast, Unicast
Multiplexing involves takes multiple analog or digital signals, and combines them for transmission across a single medium(fiber/copper). De-multiplexing equipment splits the signal back into individual streams on the other side of the connection. see also: Demux, WAN
In RF communications, it describes radio communications constrained to a narrow band of frequencies( i.e 100-200hz). See also: Baseband, Broadband, Wideband
(Network Attached Storage) – A specialized file server built for providing fast access to its data through a network. See also: server, storage
(Network Address Translation) – Its a technique in networking that remaps one IP address space into another by modifying the information in the IP packet headers themselves. It has become a crucial tool due to the limited address space in IPV4, NAT allows networks to use only 1 public IP address for the entire private network. See also: IPv4, IP Address
C (Network Access Control) – A computer networking technique that increases security by using a set of protocols implementing a policy upon network nodes that attempt to connect to the network. As its name implies, its main goal is to control and limit access of the network and constrain devices/users to their permitted actions. See also: MAC
- Network Layer
The 3rd layer of the OSI network model, it is primarily concerned with forwarding packets through routers and paths. See also: OSI
(Network File System)- A distributed file system protocol that facilitates and speeds up access to files over a network.
(Network Interface Card/Controller) – The component in computers that allows them to connect to networks, oday the widespread adoption of Ethernet has made them a standard component on motherboards, with more advanced NIC options available in the form of (PCI) expansion module cards. NICs house the female connectors for network media such as CAT-5 RJ-45 cables and Fiber optic cables. See also: Cable, Media, PCI
(National Institute of Standards and Technology)- A measurement standards laboratory and non-regulatory agency of the United States Department of commerce. NIST supplies Standards reference materials used for accurately callibrating equipment.
- Node or
(AKA Network Node)- A term that encompasses communications equipment like routers, modems, switches and endpoints like smartphones, workstations. It essentially includes any electronic device on the network capable of creating, recieving and transimiting data over the network. See also: DTE, DCE
(Network Operating System)- Operating systems designed and built for computer networking. It can the the operating system installed on routers/switches (i.e. JUNOS) or simply a customized linux distribution like cumulus linux. See also: OS, BIOS
(Network Time Protocol)- One of the oldest internet protocols still in active use, it is a prtocol made to synchronize time between computers over packet-switched networks. It works by synchronizing systems to within several milliseconds of the UTC (Universal Coordinated Time).
(Non-Volatile Random Access Memory)- In contrast to RAM like DRAM and SDRAM, non-volatile RAM mintains its contents even after power has been removed. This technology does not come without any drawbacks, as NVRAM tends to have shorter lifecycles due to the finite number of erase/write cycles it supports as well as lower speed relative to volatile memory.
(Original Design Manufacturer)- An ODM is a company that designs and manufactures products for another company. This allows companies to produce devices withou having to build and run a factory of their own.
(Original Equipment Manufacturer)- to differentiate from ODMs, OEMs do not design the product, but instead help with the manufacturing processes. This means that if you already have a solid design and simply need someone to help manufacture it, an OEM is all that would be required.
(Out-of-the-box) – A term used to describe features or functionality (mainly in software) that works immediately after procurement/installation.
- Open Architecture
An architecture designed in a way that simplifies adding, upgrading and switching component. These system tend to use standardized components and connectors allowing third-parties to manufacture components for it.
(Communications) – The properties of light offer several advantages over electricity for communications. It is uperior in terms of spead, capacity, and distance, but other factors like cabling and equipment costs limit its universal adoption. With the advent of fiber optics, optical communication technologies have been steadily replacing network infrastructure (with al major backhaul links and intercontinental undersea cables being fiber optic).
(Open System Interconnect)- A network model that standardizes communication functions of a system, regardless of the underlying technology/architecture. Its end goal is to create interoperability between diverse networked systems with common standardized protocols. read more: knowledgebase OSI Network Model
(Open Short Path First) – A routing protocol used for IP networks, it uses algorithms to determine the shortest (available) path a packet can take.
(Open Source Software) – Computer software whos code has been made publicly available, and with a licence that allows others to modify and distribute the software freely. See also: Proprietary, Vendor
(Operational Technology) – Software/hardware that monitors and controls how devices operate, as opposed to information technology that focuses on data manipulation and trasnmission technologies. Cheap embedded processors have slowly been closing the gapps between these systems, as IT/OT technology is increasingly cheap to manufacture.
(Peer-to-Peer Network) – a distributed application architecture that uses peer’s resources to handle workloads and communications. Peers all take equal responsabilities and are equal participants in the network. Peers allot a dection of their computing, storage and networking(bandwidth) resources and make them directly available to other pers in the network. See also: Client/server, topology
- Packet Loss
This term is used to denote(in percentage) packets that are dropped, lost or become corrupted before reaching their destination, these packets become known as lost packets.
(Password Authentication Protocol) An authentication protocol based on a password, its been deemed insecure due to its transmission of plaintext passwords over the network,. CHAP and EAP both offer security and should be used in its place when possible. See also: CHAP, EAP, Authentication
- Parity check
Process for checking the integrity of a character. A parity check involves appending a bit that makes the total number of binary 1 digits in a character or word (excluding the parity bit) either odd (for odd parity) or even (for even parity).
ecret data value, usually a character string, that is used as authentication information.
Portion of a cell, frame, or packet that contains upper-layer information (data).
private branch exchange. Digital or analog telephone switchboard located on the subscriber premises and used to connect private and public telephone networks. See also: Voip
protocol control information. Control information added to user data to comprise an OSI packet. The OSI equivalent of the term header. See also header.
pulse code modulation. Technique of encoding analog voice into a 64-kbit data stream by sampling with eight-bit resolution at a rate of 8000 times per second.
- Penetration Testing
(AKA pen testing)- A security validation assessment process that involves a third party attempting to access the network via various illicit methods to test the level of secrutiny in the network.
- Physical Layer
Layer 1 of the OSI reference model. The physical layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems. Corresponds with the physical control layer in the SNA model. See also application layer, OSI
Process of carrying acknowledgments within a data packet to save network bandwidth.
(Public-key Cryptography )- Series of specifications published by RSA Laboratories for data structures and algorithm usage for basic applications of asymmetric cryptography
Any defined rule that determines the use of resources within the network. A policy can be based on a user, a device, a subnetwork, a network, or an application.
Post Office Protocol. Protocol that client e-mail applications use to retrieve mail from a mail server.
1. Interface on an internetworking device (such as a router). 2. In IP terminology, an upper-layer process that receives information from lower layers. Ports are numbered, and each numbered port is associated with a specific process. For example, SMTP is associated with port 25. A port number is also called a well-known address. 3. To rewrite software or microcode so that it runs on a different hardware platform or in a different software environment than that for which it was originally designed.
(power-on self test)- Set of hardware diagnostics that runs on a hardware device when that device is powered up.
Point-to-Point protocol- Successor to SLIP that provides router-to-router and host-to-network connections over synchronous and asynchronous circuits. Whereas SLIP was designed to work with IP, PPP was designed to work with several network layer protocols, such as IP, IPX, and ARA. PPP also has built-in security mechanisms, such as CHAP and PAP. PPP relies on two protocols: LCP and NCP. See also CHAP, LCP, NCP, PAP, and SLIP.
(Packets Per second)-a measure of the Number of packets per second.
Probe is an intrusive analysis technique that uses the information obtained during scanning to more fully interrogate each network device. The probe uses well known exploitation techniques to fully confirm each suspected vulnerability as well as to detect any vulnerabilities that cannot be found using nonintrusive techniques.
Refers to information (or other property) that is owned by an individual or an organization and for which the use is restricted by that entity.
Formal description of a set of rules and conventions that govern how devices on a network exchange information.
Creation of an active subscriber account, or modification of parameters for an existing subscriber account. Provisioning of a subscriber account includes subscriber account registration and device activation.
1. Entity that, in the interest of efficiency, essentially stands in for another entity.
2. Special gateways that relay one H.323 session to another.
( packet-switched network)- Network that uses packet-switching technology for data transfer. Sometimes called a PSDN. See also packet switching.
(Quality of Service)- A technique used in networking that prioritizes traffic based on a set of rules. Connection sensitive data like Voice/VoIP is given precedence over other traffic, keeping the quality of the overall service. Atleast a layer 4 switch/router is necessary,
(Quad Small Form-Factor Plugable Transceiver)- A standardized transceiver offering a hot-pluggable small form factor. IT quadruples the spead of the previous standards, SFP, See also SFP
A message sent with a request for information
(Redundant Array of independent Disks) – A storage virtualization technology that merges multiple physical media like HDD/SDD into a single logical unit, introducing benefits like added redundancy or performance increase depending on the configuration.
(Random Access Memory) – Fast, mostly volatile, memory that a computer uses to store actively used data (i.e application code, databases, operating systems)
A process that involves retrieving or regenerating corrupt, lost or incomplete information (through data storage or transmission media). See also: EMI, Corruption
A repeater is a simple transceiver(receiver/transmitter) that i used to re-transmit the signal typically using the same technology and media.This is done for range extending purposes and there exists various types of repeaters based on the media used, optical repeaters(extending fiber installations beyond its limits) , and Radio Frequency repeaters(i.e.WiFi repeaters). See also: Transmitter, Receiver, Transceiver
In computing it usually refers to a specific location where large amounts of data is stored, archived and maintained. It can be setup as a centralized distribution center for software(i.e. version control). See also: Database
(Radio Frequency) – Can refer to to the oscillation in a radio wave used to transmit information, or as a generic term to describe radio(wireless) communications. The ITU is the body that regulates the use of radio frequencies to prevent interferencee/misuse. See also: ITU, wireless
(Reduced Instruction Set Computing)- A processor design based on the logic that a simplified instruction sets should provide higher performance as the simple instructions use only 1 processor cycle to perform. Most modern processors operate on a RISC architecture, with Intel (the originator of the CISC architecture:x86) having switched to a RISC core architecture coupled with an x86 decoder. See also: CISC, Architecture
RJ-45 – An industry standard 8-pin connector commonly used in Ethernet LAN communications. See also: RJ-11, SFP
(Read only Memory) – A type of non-volatile memory used to store data in electronic devices. ROM is difficult if not impossible to right to (as many are permanently programmed during manufacturing), its primary use is to store basic critical software like firmware or BIOS. See also: volatile memory, RAM
- Root CA
A Root Certificate is a crucial component in a type of public-key cryptography scheme based on a chain of trust
Network nodes used to forward packets between networks. They utilize routing tables and operate on the 3rd level of the OSI model.
(Reverse Path Forwarding)- A technique used in multicast routing used to prevent loops. See also: mulitcast
Composed of the first letters of Rivest, Shamir and Adleman, they are the authors of RSA – one of the first viable public-key encryption system, and still in wide use.
(Real-time Clock)- A clock that keeps track of current time, usually backed up by a battery. This is used by electronics (like computers/servers) that need to keep an accurate track of time.
(Real-Time streaming Protocol) – Protocol used in time sensitive application like multimedia/communications systems that helps control the media servers. The protocol is useful for initiating and maintaining multimedia sessions between nodes.
(Round-trip time)- The length of time it takes for a transmision to be sent and acknowledged. Also knows as ping. See also: ping, ACK
a portion or division of a whole unit. In networking its usually used to describe a section of a network composed of 2 nodes and the medium connecting them.
Term used mostly in computer networking, a session is described as a maintained interaction between devices/systems with the purpose of exchanging information.
(Small Form-factor Pluggable) – A compact hot-pluggable transceiver using in networking equipment. It offers a modular approach to network interfaces and allows NICs to provide media-agnostic Input/Output. SFP is the successor to GBIC. See also: GBIC, QSFP
(Subscriber Identity Module) – Authentication technology that is used in umts/gsm and lte networks. It contains user identification information in a cryptographicaly secured module.
(Service Level Agreement)- An agreement used by service providers (mostly private line, MPLS) that specifies a constant minimum capacity , availability and maximum latency and packet loss percentage. See also: SP, ISP, CSP
Measure of capacity and speed of a line, in networking its measured in bits per second. See also: bps
(Telecommunication Industry Association)- a group accredited by the ASNI, it creates coordinated industry standards for a wide range of information and communication technologies.
In networking and computing, it refers to a parameter that sets the time limit for a process or transmission, wich is then enforced by the application/protocol.
Similar to an IP packet, its used to define the datagrams with recipient information that token ring network utilize.
- Token Ring
A network technology that uses a ring topology, where each connected node has the task of transmitting tokens (data packets) to the subsequent node until the tokens have reached their destinations.
The actual physical structure of a network(how the cables, nodes are arranged and interconnected). See more: Network topology Knowledge center
(Terms of Service)- rules set by a service provider that a user must agree with and abide by to use the service.
(Trusted Platform Module) – An international standard for crytpoprocessors, it comes in the form of a dedicated microcontroller whose sole purpose it to generate cryptographically secure keys.
A network diagnostics included in most modern operating systems, it displays routing information and transmission times accross a given IP network. See also: ping
(Transmitter/Receiver) -A device that can both transmit and recieve signals.
- Trasport Layer
4th layer of the OSI models, this layer include protocols that provide connectionless data streams, reliabity functions, flow fucntions and even multiplexing function. TCP is the most commonly used protocol in this layer. See also: OSI, TCP
- Tree Topology
A type of physical network topology that utilizes branched a sytem of leaves (nodes), branches(VLAN’s) and trunks(backbones, backhaul lines).
Malicous software that gains entry into systems through deception. It’s usually software that masquerades as a seamingly usefull or benevolant application.
- Trusted Certificate
An essential component of the chain of trust secure networking model, it relies on of third party trusted authorities issueing certificates to entities that pass a filter with certain criteria. See also: root key, public-key cryptography
- Tunneling protocol
A protocol that allows a device or user to access/provide/manage a service s that the network does not natively support. Tunneling protocols overcome disparities in network protocols by encapsulating a complete packet in a common protocol, essentially creating a virtual tunnel where information passes from one point to another.
- Twisted Pair
Cables that use pairs of same-circuit copper wires twisted together in such a way that it cancels electromagnetic interference. See also EMI, UTP
(Universal Asynchronous Reciever/Transmitter)- A device or component in a hardware device, it enables asynchronous serial communication with variable speeds. See also: asynchronous, transceiver
(User Datagram Protocol) – A simple protocol for data transmission included in the IP suite, it offers connectionless transmission with minimalist protocol function. UDP performs simple checksums to provide data-integrity and port numbers that can be assigned for different function on the same host/destination. It does not provide any authentication or handshake functions, so things like delivery, in-order transmission and duplication protection aren’t possible, that is where TCP steps in. UDP is used in applications where error-checking/correction aren’t exactly necessary, or are performed by another process in the application, thus avoiding potential overhead and performance hits. See also: TCP, Protocol
(User Interface)- An interface, either graphical(GUI) or text-based(CLI) that helps users to interact with a system and/or application. See also: application
(Universal Mobile Telecomunications System) – A technology developed for the 3rd generation of mobile networks by the 3GPP, UMTS defines a complete, functioning network system(this encompasses RF acces networks, core mobile backbone network, and authentication technologies (SIM to be exact). See also: 3GPP, SIM
A transmission technique that sends packets to a single detination/recipient. See also: Multicast, Broadcast
The amount of time a machine(usually a server) has remained online since the last reboot/shutdown. See also: Downtime, SLA
(Uniform Resource Locator)- A URL is composed of 2 elements, a protocol identifier(i.e. http://) and an address (i.e. google.com). URLs are used to easiliy refference webpages and link to them. See also domain name, link
(Universal Serial Bus)- An interface made to be universally adopted by device manufacturers as a standard power and communications capable interface. It’s widely implemented accross billions of devices, and there exists several generations of the standard retroactively compatible with eachother. Each generation provides incremental imporvements in maximum speed and power output, these standards are :
USB2: capacity- 480mbps power- 5V at 1.8A
USB3: capacity- 4.8Gbps power- 5V at 1.8A
USB3.1: capacity- 10Gbps power- 5V at 2A, 12v/20v at 5A
(Coordinated Universal Time)- The standard for time commonly used by systems globally. It’s manged by the timing centers in place around the world, hence coordinated. See also: NTP
(Unshielded Twisted Pair)- The most common type of copper cablingthat is used in computer networks, it is composed of un-shielded pairs of color-coded wires twisted together to prevent Electromagnetic interference. The twisted pairs creat a magnetic field that performs the function of the missing shielding, albeit to a lower extent.
( Very -high-bitrate Digital Subscriber Line)- Faster than ADSL, VDSL provides 52mbps download and 16mbps upload speeds. VDSL2 provides speeds greater that 100mbps at the cost of shorter maximum distance. See also: DSL, ADSL
Referring to the act of creating virtual instances of other systems, components and devices. There are various techniques that can accomplish this, but the end goal is to fabricate a near-identical copy through the use of software.
In computing, a computer virus behaves in much the same fashion as a biological one, both function by infecting a machine, compromising systems and self-replicating for further propogation. It is created much the same as normal software, but its real-world applications are mostly illicit and maliciuos in nature. See also: Hack, Zero-day
(Virtual Local Area Network) – By isolating sections of a LAN using network equipment, VLANs can be created. VLANs operate at the 2nd layer of the OSI model. See also: OSI
(Virtual Machine)- A virtual instance of a machine created by software capable of emulating the functions of physical computer hardware.
(Video on Demand) – A term used to describe media delivery systems that are capable of providing content on an a la carte basis, instead of using pre-programmed broadcast time schedules.
(Voice Over IP)- Both a group of technologies and a specific approach to voice-based communications, it derives its name from the fact that it transmits information over an IP capable network (such as the internet) instead of traditional phone lines. See also: PSTN, IP
(Virtual Private Network) – A technology that allows private networks to extend beyond geographically attached areas by tunneling traffic through a larger network, such as the internet. More detail: VPN Knowledge Center
(Wide Area Network)- Much larger than LANs, and even larger than MAN’s, WAN is a term used to describe network that are larger than cities, examples: state-wide networks, country-wide networks, global networks and even extraterrestrial networks. See also: LAN, MAN
(Wave-length Division Multiplexing)- A technique in optical communications that combines multiple infared signals with different wavelengths, and transmits them over fiber optic media. It does so through the use of several IR lasers independently modulated by a particular signal. See also: Muliplex
(Wireless Local Area Network)-A form of network used to connect computers and computer hardware together without cables. See also: RF
A group of workstations, servers and nodes on a LAN that are configured to communicate with each other.
Any computer in a network that people use to run software which interacts with other nodes on the network.
(Wireless Protected Access)- A wireless security technology employed by 80211 communication technologies.
(World Wide Web)- acronym defining the global network that is the internet.
Processor architecture invented by intel, its a CISC based architecture, and the industry standard processor for network computing in the server market.
Intels server oriented architecture.
- Zero Day
(Exploit)- There are unknown/undisclosed vulnerabilities in software(and even hardware) that can be used to gain privileged access to systems. It is known as 0-day because the nature of the exploit gives companies zero time to prepare for the attack. Malware that employs 0-day exploits is often extremely difficult if not impossible to mitigate. See also: Exploit, Virus
1021bytes OR 1,000,000,000,000,000,000,000 bytes OR 1000 exabytes OR 1 million petabytes OR 1 billion terabytes OR 1 trillion gigabytes.
Common file format used for compression. See also: Compression, Algorithm
In general computing, a zombie is a compromised device connected to a network allowing hackers to employ malicious activities from a remote location. See also: Botnet, hack