Business Internet Glossary – Broadband Internet terminology explained

Business Internet – Glossary of Terms

Our glossary of business internet terminology helps you gain an understanding of the industry’s most common terms and definitions.

As businesses consumers, we should have some understanding of how we can transmit, protect and store our data. Yet sometimes it feels as though the information provided to help us understand business broadband internet packages is unduly complicated, veiled behind cryptic acronyms and tech-speak.

The Business Tech Weekly team has put together a series of business internet terminology to help you navigate through “tech-speak” when researching broadband internet suppliers and packages. Below you will find brief descriptions for many of the terminology and acronyms relating to business broadband and internet.

We realise the below terminology may not be exhaustive, and we endeavour to update this list this regularly. If you identify any business internet-related words which are unfamiliar and not listed below, please get in touch.

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Third Generation, commonly abbreviated to 3G. A mobile communications standard which allows mobile devices (computers, phones, and other portable internet-capable electronic devices) to access the internet wirelessly.


Fourth Generation, commonly abbreviated to 4G. A mobile communications standard designed to replace 3G.  4G allows higher speed wireless access to the internet than 3G.


Fifth Generation, commonly abbreviated to 5G. The next stage in mobile technology, i.e. the fifth generation (5G). Expected to be faster than 4G.  A mobile communications network which will support the demands of Internet of Things (IoT) devices and mobile device users. In the UK, 5G network was launched in 2019 by EE.


20th Century Network, commonly abbreviated to 20CN. 20CN provided broadband speeds of up to 8Mbps over standard copper. Superseded by BT’s 20Mbps 21CN network in the majority of locations.


21st Century Network, commonly abbreviated to 21CN.  Next-generation network (NGN) to bring UK’s telecoms network into the digital age.  Will allow the transition of BT’s network from PSTN to an Internet Protocol (IP) system – thereby enabling the national rollout of newer technology such as ADSL2 and FTTC (Fibre to the cabinet).  Approximately 92% of the UK is now served by the 21CN network.


ADSL, ADSL2+ – Asymmetric Digital Subscriber Line

Asymmetric Digital Subscriber Line broadband technology allows faster data transfer across standard copper telephone lines. A microfilter or modern telephone faceplate is required to make phone calls and have broadband internet connectivity at the same time.  This will allow you to operate both telephone and broadband connections simultaneously on the same line. ADSL lines can provide up 8Mb bandwidth. However, now ADSL2+ is available at almost all exchanges in the UK, providing improved data transfer rates with speeds of up to 17Mb.

Assured throughput

The performance of an internet connection.  Used to help ensure consistent performance. The assured throughput illustrates the average daily rate over 24 hours, which you are guaranteed..


Commonly used in reference to DSL broadband technology.  As in Asymmetric Digital Subscriber Line.  Asymmetrical broadband connections offer differing upload and download speeds, typically providing higher download speeds than upload speeds.


An indication of reliability. A system, broadband connection or network which is identified as high availability means it rarely fails.



Bandwidth signifies the maximum capacity of a connection, i.e. how much data can pass through the line at any one time.  Bandwidth is measured in Mbps (megabits per second).


The cable (either copper or fibre) on which the provided service operates on.  Frequently used in terms of leased lines, for example, the capacity of the bearer (or cable) determines the speed of the internet connection.

Bonded DSL

A DSL broadband solution for rural areas. Particularly for businesses experiencing connection speeds, or desiring to increase their current speeds. Bonded DSL bundles together up to four ADSL lines.


Buffering is the delay caused by the time it takes to download sufficient data to start streaming and maintaining the content.  An example of buffering is when there is a delay between clicking “play” on an online video, and the video starting to play. The duration you experience in buffering is relative to the speed of your connection to the internet.  Consequently, buffering will not occur provided your internet connections is fast enough.  With a poor internet connection, buffering can be expected to be experienced throughout streaming and not just at the start.



Cabinet refers to the green telecoms boxes commonly found in nearly every street in the UK.  This kerbside box is where the telecoms companies deliver broadband and telephony to your area. The cabinet is your point of contact with the local infrastructure.  From this box, the cabling is carried into your premises, thereby connecting you to the local, regional and national infrastructure.

Cloud computing

Cloud computing allows you to access, via the internet, a network of remote systems and servers to store and process data, instead of on storing the data on local servers or systems.  The use of cloud computing services provides on-demand availability of computing resources allowing flexible working since the applications, programmes, and even servers are available at any time and from anywhere via an internet connection. A simple example of a cloud service is online email services such as Gmail.


A type of data centre facility where organisations can rent space for their servers and other computing systems. Also known as a “co-lo”.  Typically, a co-lo provides a shared building and associated facilities such as bandwidth, cooling, physical security and power. In contrast, the customer provides servers and storage.  Customer data is stored and managed offsite by a co-location provider along with data from other customers too.

Computer hardware

A term used to describe the physical components related to a computer system.  The combination of hardware and software forms a usable computing system, with the hardware being instructed by the software to execute any command.


Configuration refers to the set-up and fine-tuning process for any device or system specific to your needs. Configuration is typically done to make sure the device or system works optimally per your particular circumstances.

Contention ratio

Also known as an HTTP cookie, are pieces of code which act as a marker to help websites recognise you when you revisit.  Cookies are sent by the website to be stored in the user’s web browser, either to remember information or to track browsing activity.  Most web browsers have an option to block cookies to varying levels.


Also known as a HTTP cookie, are pieces of code which act like a marker to help websites recongnise you when you revisit.  Cookies are sent by the website to be stored in the user’s web browser, either to remember information or to track browsing activity.  Most web browsers have an option to block cookies to varying levels.

CPU – Central Processing Unit

The CPU, acts like a brain for your device, carrying out most of the calculations, processes and executing instructions.


Data Centre

A data centre is a highly secure and resilient facility, within a building or group of buildings, to house servers, telecommunication and storage systems.  Data centre standards are specified by the Telecommunications Industry Association (TIA), which stipulate the minimum requirements for telecommunications infrastructure.


A precursor to broadband, dial-up was the primary method of connecting to the internet.  Dial-up internet access, in conjunction with a modem, used a conventional phone line (PSTN) to access the internet. The modems used with dial-up connections, decode and encode audio signals into data to transmit and receive data.


A domain name, such as, is the address of a website. Domain names can be purchased by businesses or individuals to obtain a personalised online identity, for example, a website and email address. Domain names are administered by the Internet Corporation for Assigned Names and Numbers (ICANN), via accredited domain name registrars, who grant the right to use a domain name.


Downstream, measured in Mbps, illustrates the amount of data which be downloaded via the internet per second. Also known as “download speed”, downstream also identifies the direction of traffic, referring to the data transferred to your computer.


Downtime refers to the period in which any given system, such as a hosted application, server or network is unavailable.

Digital subscriber line (DSL)

DSL is a family of technologies that are used to transmit digital data over conventional telephone lines.


EFM – Ethernet in the First Mile

With EFM, the connection between the premises and the exchange comprises of bundled copper pairs rather than fibre. EFM offers symmetrical speeds, but can only achieve speeds up to 10Mbps. EFM provides a very cost-effective type of leased line but is limited to certain areas which have been enabled for EFM.


The conversion of data, using an algorithm, into an unreadable format.  The data can only be read using the required encryption key. Encryption is often used to securely transfer confidential, personal and sensitive data across networks, between systems, or store it securely.


A method of sending data used in Local Area Networks (LANs).

EoFTTC  – Ethernet over FTTC

A superfast Ethernet connection provisioned over fibre broadband infrastructure.


This is the primary delivery point for telecommunication networks, including the internet, within your local area.



A strategy to building resiliency in computer systems and telecommunications networks whereby, in the event of failure, the service automatically switches over to a standby service.

Five nines

The term “five nines” refers to the figure of 99.999%.  This figure provides, in percentage terms, how consistently a service is available and in operation (uptime).

FTTC – Fibre to the cabinet

With FTTC, the connection between the exchange and the local cabinet is in fibre.  The remaining connection, the portion between the cabinet and the customer’s premises, is over copper.  FTTC connections offer speeds of ‘up to’ 38Mbit/s or 76Mbit/s.  In the UK, the majority of fibre broadband is FTTC.

FTTP – Fibre to the premises

With FTTP, as with FTTC, the connection between the exchange and the local cabinet is in fibre.  The remaining connection, between the local cabinet and customer premises, is also delivered over fibre.   FTTP broadband offers speeds of up to 1Gbit/s (i.e. 1,000Mbit/s). FTTP only constitutes a small portion of broadband connections.

FTP – File Transfer Protocol

A method and protocol for uploading and downloading data between two computers.

Full root access

Full root access provides full control of that server and is the most authoritative control possible over a server.

FUP – Fair Usage Policy

Some internet service providers (ISP), outline the usage limits (usage cap) for your internet broadband service. FUP is usually included in some broadband agreements.


Gbps – Gigabit per second

A unit to illustrate data transfer speed.  The value specifies the average number of bits or data blocks per unit through a data-transmission system per second. Often written as Gbps, or gigabits per second, most ISPs use the style Gbps.

GB – Gigabyte

Gigabyte is used to specify the size of computer files and memory capacity. Gigabyte is often written GB.  One GB comprises of 1,000 megabytes (MB), which consists of 1,000 kilobytes (KB), which consists of 1,000 bytes.  Depending on the type of file, the appropriate unit of measure will be used.  For example, a basic Word document may be specified in KB, while a video may be in GB.

Gigabit broadband

A broadband internet service which offers speeds of 1Gb or more. Most Gigabit broadband internet connections rely on FTTP connections. – at a rate of 1Gbps, a gigabit connection is very fast it, theoretically taking only 32 seconds to transfer a 4GB DVD.



See Computer Hardware

HA – High Availability

An approach to system design which aims to ensure a level of operational performance availability of a system or telecommunication network, usually uptime, for a higher period than usual.

Hosted PBX

A (PBX) phone system which resides on a remote system in a facility managed by a hosted service provider.


See Internet Hosting Service

HTTP – Hypertext Transfer Protocol

The foundation of data communication for the World Wide Web.  The fundamental component of HTTP is hypertext, which allows documents to include hyperlinks to other resources via a mouse click or by tapping the screen in a web browser.

HTTPS – Hypertext Transfer Protocol Secure

A more secure version of HTTP, HTTPS is a protocol which is used to communicate on the internet securely, typically used by webpages such as online banking.  Formerly using the Secure Sockets Layer (SSL), HTTPS now uses Transport Layer Security (TLS) to encrypt the communication protocol.


Incremental Backup

A technique which backs-up successive copies of the file.  This time and data-saving method, only backs-up the portion that has changed since the last backup copy was made, as opposed to backing up the entire content. If a full restoration of the whole data is required, the recovery process would require the last full backup in addition to all the incremental backups until the data is fully restored.

IMAP – Internet Message Access Protocol

One of the two most prevalent protocols for email retrieval, IMAP is used to retrieve email messages from a central email server over a TCP/IP connection.

ISDN – Integrated Services for Digital Network

ISDN is a set of communication specifications for concurrent digital transmission of voice, video, data, over a public switched telephone network (PSTN). ISDN usually provides a maximum of 128 kbit/s bandwidth in both upstream and downstream directions.  Superseded by broadband, the UK’s ISDN infrastructure will be retired by 2025.



Jitter describes the frequent variations in latency. A small constant fluctuation in latency is to be expected. Still, it can become problematic if the data packets are experiencing significant changes in latency, for example, jumping from 20ms to 300ms to 50ms to 170ms. Frequent jittering could be an indication of a problem with the internet connection either at the local network, the remote server link, or with your broadband ISP. Some troubleshooting will be required to determine the exact cause.


Kbps – Kilobits per second

A unit to illustrate data transfer speed.  The value specifies the average number of bits or data blocks per unit through a data-transmission system per second.  Kbps was commonly used to measure dial-up internet speeds.

KB – Kilobyte

Kilobyte is used to specify the size of computer files and memory capacity.  1 Kilobyte is equivalent to 1,000 bytes. The size of a basic Word document may be specified in KB.


A database or collection of resources which facilitate knowledge sharing and management. A knowledgebase will include common fault finding techniques and solutions, frequently asked questions and administrative procedures.



Measured in milliseconds (ms), latency is the time it taken to send data and receive a reply.  High latency is often described as “lag”.  Lag can often cause problems where there is a need for rapid communication. Most broadband internet services will, on typically have very low levels of latency. However, a satellite broadband connection, for instance, has a very high latency due to the time it takes to send and received data to and from the satellite.

Leased Lines

An uncontended (essentially un-shared) connection to the internet, or connection between two points.

Load Balancer

Typically a hardware device (network or server), which acts as load distributor to share the workload between machines, network links or other resources to reduce stress and to improve resilience.  A load balancer can be deployed as part of a high-availability solution.


MAC address – Media Access Control Address

Also known as the physical address, a MAC address is a unique identifier assigned to the network hardware component (NIC – network interface controller) of a device which is capable of connecting to a network.  MAC addresses comprise of six groups of two hexadecimal digits, either with or without separators (hyphens or colons). MAC addresses are primarily assigned by device manufacturers and typically includes a manufacturer’s organizationally unique identifier (OUI).

Mbps – Megabits per second

Similar to Gbps and Kbps, Mbps is a unit to illustrate data transfer speed.  The value specifies the average number of bits or data blocks per unit through a data-transmission system per second.  A 1Mb connection will be able to transfer 1MB (megabyte) of data in eight seconds.

MB – Megabyte

Along with GB and KB, MB or megabyte is used to specify the size of computer files and memory capacity.  1MB is equivalent to 1,000KB, although it’s still common to see it defined as 1,024KB (known as a Mebibyte – MiB).


A small piece of hardware which splits your telephone line into a phone link and broadband link, allowing both services to be used simultaneously on the same line. A microfilter typically plugs into your phone socket.

Modem – Modulator-demodulator

A hardware device which decodes and encode audio signals (analogue) into data (digital) to transmit and receive data.  Before broadband, modems were used to connect to the internet via a conventional phone line.

Mirrored Servers

Mirrored servers refer to two servers set-up in parallel and duplicated to one another for security and redundancy. As part of a failover system, the failure of one server will automatically trigger the remaining server to take the full load, thereby ensuring business continuity.



The term N1 refers to the ability to switch processing onto another server automatically, storage facility or application in case of failure. Predominately used when talking about redundancy or mirroring, N1 refers to a set up where two machines are running in parallel so that either one of the machines can take over if the other was to fail.

NOC – Network Operations Centre

The administrative, management and control centre for a telecommunications network.


OS – Operating system

System software which is design to manage the computer hardware and software resources, such as PCU, memory allocation, storage space, etc., and provide common services for application software.


Packet Loss

Packet loss occurs when an unstable or unreliable connection drops packets of data from reaching their destination. A high frequency of packet loss may lead to poor data transfer times and audio quality.

PSTN – Public switched telephone network

Also referred to as the Plain Old Telephone Service (POTS), PSTN is the collection of interconnected voice-oriented public telephone networks, which provide infrastructure and services for public telecommunication, either commercially or government-owned.

Proactive monitoring

A monitoring philosophy employed by Internet Service Providers (ISPs) which seeks to avoid the underlying conditions that lead to service faults and degradation.  ISPs will often use proactive monitoring to determine how your service is performing and identify any potential areas of risk, to try and troubleshoot and fix faults before they occur.

POP – Post Office Protocol

An alternative to the IMAP, POP is one of the two most prevalent protocols for the retrieval of email messages from a central email server.  POP removes the email message from the server, so while it is suitable for local access, POP is inadequate for email retrieval via multiple devices.

PBX – Private branch exchange

A PBX is a private organisation’s telephone exchange or switching system designed to share central office trunks internally installed devices such as a telephone, fax machine or modem.  The PBX also provides intercommunication between those internal telephones without the use of external lines. Each device connected to the PBX is referred to as an extension and has a designated extension number. PBX systems offered advantages such as cost savings for internal phone calls, hunt groups, call forwarding, and extension dialling.


QoS – Quality of Service

QoS refers to the overall performance of a network service.  To determine QoS, several factors of the network service are considered, such as availability, bit rate, jitter, packet loss, throughput, transmission delay, etc.


RAM – Random Access Memory

RAM is used by systems to typically used to store working data and can be read and changed in any order.


Redundancy entails having a fallback system or device ready to use if the primary system or device fails.  Redundancy is one of the ways of achieving resilience.

Replication servers

Similar to mirrored servers, replication servers entail more than one server working in tandem to provide resilience.  In case of failure, there is a seamless transfer of workload between the servers.


A networking hardware device which manages the traffic between computer networks, such as your business network and the internet.  Routers link networks together and connect networks to the internet.


A method of providing and maintaining a service as close to regular operation as possible despite threats and risks. Adding resilience to a system or network entails having backup systems and hardware available on standby.


SAN – Storage Area Network

A SAN storage system is a network of storage devices connected by a high-speed data link.

SDSL – Symmetrical Digital Subscriber Line

An alternative to ADSL, SDSL is a type of DSL which uses copper wires of the telephone network, providing synchronised upstream and downstream speeds (in contrast to ADSL which is asynchronous and has much faster download speeds).

SIP Trunk – Session Initiation Protocol Trunk
SLA – Service Level Agreement

An SLA defines the service – quality, availability, responsibilities – agreed between the service provider and the service user in plain language terms.  Internet service providers (ISPs) will include SLAs within their contracts to define the level of service being sold.


Software refers to the computer programs, data or instructions which essentially tell the computer hardware what to do and how. The combination of hardware and software forms a usable computing system, with the hardware being instructed by the software to execute any command.

SSL Encryption – Secure Socket Layer Encryption

Replaced by Transport Layer Security (TLS), both SSL and TSL are cryptographic protocols used secure communications over a computer network, for example, communications between a website server hosting a website and a web browser.

Static IP addresses

A fixed IP address which is provisioned to identify your computer on the internet.  Static IP addresses are generally used for email management, CCTV systems, accessing a desktop remotely, or running servers for websites, for example. Static IPs, do, however, increase the vulnerability from cyberattacks.

Symmetrical connection

A service, for example, SDSL, which provides the same upstream and downstream speeds.



Commonly employed by ISPsduring peak broadband usage times to deliberately slow down internet connections.  Throttling is also sometimes used against customers who may have breached their usage limits or fair usage policy (FUP).


A term used to refer to network or data traffic transmitted across a network.

Traffic management & traffic shaping

Traffic management, or traffic shaping, refers to controlling and managing network data traffic. Traffic management is used to improve performance, for example, the prioritisation of bandwidth-intense video streaming during peak periods. However, aggressive traffic management can be used to limit connections, causing a significant drop in performance for certain activities, such as file sharing.


The performance of an internet connection.  Used to help ensure consistent performance. The throughput illustrates the average daily rate over 24 hours.



A broadband connection which has only one customer.  An uncontended connection tends to provide much faster speeds.


Upstream (measured in Mbps), determines how much data can be uploaded to the internet per second. Also known as “upload speed”, upstream also identifies the direction of traffic, referring to the data transferred to from your computer to the internet.


A good measure of performance. Uptime relates the period of availability of a service or device. Uptime is commonly stated in percentages, i.e. five nines (99.999%).

Uniform Resource Identifier (URI)

URI identifies a particular resource to enable the representation of that resource over a network, such as the World Wide Web.  URIs have a specific syntax and are defined by specific protocols. Web addresses, a URL, is the most common form of URI.

URL – Uniform Resource Locator

URLs are a form of URI, and are used commonly to reference web pages (HTTP), but are also used for file transfer (FTP), email (mailto), database access (JDBC).


Measured in GB, usage is a measurement of the amount of data you’ve used for upstream and downstream data transmission.


VDSL, VDSL2 – Very High-Speed Digital Subscriber Line

VDSL is a type of DSL which is provisioned over copper telephone lines. VDSL offers faster transmission making it ideal for high definition video streaming or VoIP telephony. VDSL provides speeds of up to 52 Mbit/s downstream and 16 Mbit/s upstream.

Virtual Private Server (VPS) or Virtual Dedicated Server (VDS)

VPS and VDS have similar definitions.  VPS is a software-defined server, which is functionally comparable to a dedicated physical server.  Being software-defined, VPS’ can be created and configured quickly, and are scalable in terms of performance requirements, i.e. easily able to increase allocated memory, CPU/processing power and storage.  However, the fact that a VPS shares its underlying physical hardware with other VPSs, performance will be dependent on the workload of other VPSs.  The advantages of VPS, such as scalability, cost-effectiveness, resiliency, and ease of set-up and configuration, far outweigh the disadvantages for most businesses.


In virtualisation, the hardware, and the underlying infrastructure, is pooled into “clusters”, which is managed by specialist virtualisation software.  The virtualisation software separates the server component from the underlying hardware resources, allowing the creation of virtual machines (VPS) which act like their physical counterparts.  Since the underlying hardware is shared, virtualisation significant improves resiliency and uptime.

VoIP – Voice over IP

VoIP, also sometimes known as IP telephony, is a method of delivering voice communications over IP (internet protocol) networks, for example, the internet.

VPN – Virtual Private Networks

VPNs are used by businesses to allow remote workers to access internal company resources like software or files securely. VPN effectively extends the business network across a public network to transmit and receive data, as if the user’s device were connected directly to the business network.


WAN – Wide Area Networks

WANs are networks which span over a large area, offering metropolitan, regional or even country-wide computer networking.  WANs are typically used to securely transfer information between sites or offices over a wide geographical area.  WAN interconnectivity is typically provided via routers, with many LANs (local area networks) interconnected to form a WAN for a specific organisation or business.

Web Hosting

Web hosting allows businesses to make their website available on the World Wide Web.  Web hosting companies, or web hosts, provide space on a server owned or leased for use by customers.  In addition, the web host will provide internet connectivity (from the server to the internet).  The server is typically housed in a data centre or co-lo facility.

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