Home Network Glossary

📶 Broadband Terms

ADSL, FTTC, FTTP, bandwidth, latency, and more

📡 Wi-Fi & Networking

Router, mesh, DNS, IP address, ethernet, and more

☎️ VoIP & Phone

VoIP, SIP, PSTN, Digital Voice, PBX, and more

🏠 Smart Home & IoT

Matter, Zigbee, Z-Wave, IoT, smart hub, and more

ADSL Asymmetric Digital Subscriber Line

The oldest widely used broadband technology in the UK, delivered entirely over copper telephone wires. Maximum download speeds are typically 10–24Mbps and are heavily affected by how far your home is from the local telephone exchange. Upload speeds are much slower than download speeds — hence asymmetric. ADSL is being phased out as full fibre rolls out across the UK.

→ See also: FTTC, FTTP, Openreach

ATA Analogue Telephone Adapter

A small device that plugs into your broadband router and provides a standard telephone socket, allowing you to use an existing analogue handset with a VoIP service. An ATA is often the cheapest and simplest way for households to keep using their existing phone after the UK landline switch-off.

→ See also: VoIP, Digital Voice, PSTN Switch-Off

Bandwidth

The maximum amount of data that can be transmitted over your internet connection at any one time, usually measured in Mbps or Gbps. Think of it as the width of a pipe — the wider it is, the more data can flow through simultaneously. A higher bandwidth means more devices can use the internet at once without slowing each other down.

→ See also: Mbps, Gbps, Download Speed

Broadband

A general term for any high-speed internet connection that is always on and significantly faster than the old dial-up connections. In the UK, broadband is delivered via several different technologies including ADSL, FTTC, FTTP, and cable. The term covers both the technology and the service package your provider sells you.

→ See also: ADSL, FTTC, FTTP, ISP

Cat5e / Cat6 / Cat6a Ethernet Cable Categories

Different grades of ethernet cable used to connect devices to your router or network switch. Cat5e supports speeds up to 1Gbps over short distances. Cat6 supports 1Gbps reliably and reduces interference. Cat6a supports 10Gbps and is ideal for future-proofing a home network. For most homes, Cat6 is the recommended choice for any new wired installations.

→ See also: Ethernet, Router, Switch

Contention Ratio

The number of users sharing the same portion of network capacity at any one time. A higher contention ratio means more users are sharing the same bandwidth, which can lead to slower speeds at busy times — particularly in the evenings. Residential broadband typically has higher contention ratios than business broadband, which is why business connections tend to be more consistent.

→ See also: Bandwidth, Peak Time Slowdown

DECT Digital Enhanced Cordless Telecommunications

The wireless standard used by most cordless home telephone handsets in the UK. DECT phones communicate with a base station plugged into your phone line or router. Most modern DECT phones are compatible with VoIP services either directly or via an ATA adapter, making them suitable for use after the UK landline switch-off.

→ See also: ATA, VoIP, Digital Voice

DHCP Dynamic Host Configuration Protocol

The system your router uses to automatically assign an IP address to every device that connects to your network. When your phone, laptop, or smart TV joins your Wi-Fi, DHCP is what gives it an address so it can communicate on the network. You rarely need to think about DHCP — it works automatically in the background on virtually all home routers.

→ See also: IP Address, Router, DNS

Digital Voice

The name BT and several other UK providers use for their VoIP home telephone service. It works in the same way as a traditional landline from the user's perspective — same number, same handset — but the calls travel over your broadband connection rather than the copper telephone network. Digital Voice is the replacement service for households affected by the UK landline switch-off.

→ See also: VoIP, PSTN, The UK Landline Switch-Off page

DNS Domain Name System

The internet's address book. When you type a website address like google.com into your browser, DNS translates that human-readable name into a numerical IP address your device can actually use to find the website. Your broadband provider operates DNS servers automatically — but you can optionally switch to alternative DNS providers like Cloudflare or Google for potentially faster browsing or improved privacy.

→ See also: IP Address, Router, ISP

Download Speed

The rate at which data travels from the internet to your device, measured in Mbps. This affects how quickly web pages load, how smoothly video streams, and how fast files download. For most households download speed is the most important broadband metric — though upload speed matters increasingly for home workers and content creators. See our Broadband Speed Checker page to test yours.

→ See also: Upload Speed, Mbps, Latency

Ethernet

A wired network connection using a physical cable — typically a Cat5e or Cat6 cable — to connect a device directly to your router or network switch. Ethernet connections are faster, more stable, and more secure than Wi-Fi, making them ideal for devices that need a reliable connection — smart TVs, games consoles, desktop computers, and VoIP phones. If you are experiencing Wi-Fi issues, testing via ethernet is always the first recommended step.

→ See also: Cat5e / Cat6, Router, Wi-Fi

Firewall

A security system that monitors and controls incoming and outgoing network traffic based on predetermined rules. Your broadband router includes a built-in firewall that protects your home network from unauthorised access from the internet. Most home users never need to configure their firewall — the default settings on modern routers provide adequate protection for typical home use.

→ See also: Router, NAT, IP Address

FTTC Fibre to the Cabinet

A broadband technology where fibre optic cable runs from the telephone exchange to the green street cabinet near your home, but the final connection from the cabinet to your property remains copper wire. Typical speeds are 30–80Mbps. FTTC is the most common broadband type in the UK but is being gradually replaced by full fibre FTTP as the Openreach rollout progresses.

→ See also: FTTP, ADSL, Openreach, Is It Worth Upgrading? page

FTTP Fibre to the Premises

Full fibre broadband — where a pure fibre optic cable runs all the way from the telephone exchange directly into your home or business with no copper in the chain. FTTP delivers speeds from 100Mbps up to 1Gbps or more, is more reliable than copper-based connections, and is unaffected by distance from the cabinet or exchange. It is the UK government's target technology for the majority of UK premises.

→ See also: FTTC, ADSL, Openreach, Is It Worth Upgrading? page

Gbps Gigabits per second

A unit of internet speed equal to 1,000 Mbps. Full fibre broadband packages at the top tier are often described as 1Gbps — meaning one gigabit per second. At this speed you could download a full HD film in under 30 seconds. For most UK households 100–500Mbps is more than sufficient — 1Gbps is useful for very large households or businesses with extremely high data demands.

→ See also: Mbps, FTTP, Download Speed

Guest Network

A separate Wi-Fi network broadcast by your router that gives visitors internet access without connecting them to your main home network. Devices on the guest network cannot see or communicate with devices on your main network — so your computers, NAS drives, and smart home devices remain private. Most modern routers support guest networks and they are worth enabling if you regularly have visitors connecting to your Wi-Fi.

→ See also: Router, Wi-Fi, SSID

Hotspot

A physical location or device that provides wireless internet access. A mobile hotspot is created when you share your smartphone's mobile data connection via Wi-Fi — useful when you have no fixed broadband available. Public hotspots are found in cafes, libraries, hotels, and transport hubs. Always exercise caution on public hotspots as they may not be secure — avoid accessing banking or sensitive accounts without a VPN.

→ See also: Wi-Fi, Mobile Data, VPN

IoT Internet of Things

The collective term for everyday physical devices that connect to the internet to send and receive data — smart speakers, smart thermostats, security cameras, connected doorbells, smart lighting, and more. IoT devices typically connect via Wi-Fi, Zigbee, or Z-Wave and are controlled through apps or voice assistants. The average UK home now has over 10 connected IoT devices.

→ See also: Smart Home, Zigbee, Z-Wave, Matter, Wi-Fi

IP Address Internet Protocol Address

A unique numerical label assigned to every device connected to a network. There are two types relevant to home networking — your public IP address, assigned by your ISP and visible to websites you visit, and your private IP addresses, assigned by your router to each device on your home network. Most home users have a dynamic public IP address that changes periodically rather than a fixed static one.

→ See also: DHCP, DNS, Router, ISP

IPv4 / IPv6

The two versions of the Internet Protocol currently in use. IPv4 uses a format like 192.168.1.1 and has a limited number of available addresses — most of which are now in use globally. IPv6 uses a longer format and provides a virtually unlimited number of addresses, future-proofing the internet for the billions of connected devices now in use. Most UK broadband providers now support IPv6 alongside IPv4.

→ See also: IP Address, ISP, Router

ISP Internet Service Provider

The company that provides your broadband internet connection — BT, Sky, Virgin Media, Vodafone, TalkTalk, and similar companies are all ISPs. Your ISP connects your home to the wider internet and is responsible for the speed, reliability, and support of your connection. Most UK residential ISPs use the Openreach network, though Virgin Media operates its own separate cable infrastructure.

→ See also: Openreach, Broadband, UK Provider Comparison page

Latency

The time it takes for data to travel from your device to a server and back again, measured in milliseconds. Also referred to as ping. Low latency means faster responses — important for online gaming, video calls, and real-time applications. High latency causes noticeable delays and lag. Full fibre connections typically have lower latency than copper-based connections, and wired ethernet connections have lower latency than Wi-Fi.

→ See also: Ping, Download Speed, Ethernet, Broadband Speed Checker page

Leased Line

A dedicated, symmetric internet connection provided exclusively to a single business — not shared with other users. Unlike residential or standard business broadband, a leased line guarantees the same upload and download speed at all times with a higher service level agreement. Leased lines are significantly more expensive than standard broadband and are typically used by businesses with very high or very consistent internet demands.

→ See also: Business Connectivity, Bandwidth, Contention Ratio

Matter

An open smart home connectivity standard developed by the Connectivity Standards Alliance, backed by Apple, Google, Amazon, and Samsung among others. Matter allows smart home devices from different manufacturers to work together seamlessly — regardless of whether you use Alexa, Google Home, Apple Home, or Samsung SmartThings as your primary ecosystem. Devices with the Matter logo are interoperable across all compatible platforms.

→ See also: Smart Home, IoT, Zigbee, Z-Wave, Thread

Mbps Megabits per second

The standard unit for measuring broadband speed in the UK. The higher the number, the faster the connection. Note that broadband speeds are measured in megabits while file sizes are typically shown in megabytes — there are 8 megabits in one megabyte. So a 100Mbps connection downloads a 100 megabyte file in approximately 8 seconds, not 1 second.

→ See also: Gbps, Download Speed, Upload Speed, Broadband Speed Checker page

Mesh Wi-Fi

A whole-home Wi-Fi system that uses multiple access points — called nodes — placed around your home to create a single seamless network. Unlike Wi-Fi extenders which create separate networks, mesh systems work together intelligently so your devices automatically connect to the nearest and strongest node as you move around. Mesh systems are particularly effective in larger homes, properties with thick walls, or multi-storey houses where a single router cannot provide adequate coverage throughout.

→ See also: Router, Wi-Fi Extender, Access Point, SSID

MU-MIMO Multi-User, Multiple Input, Multiple Output

A Wi-Fi technology that allows a router to communicate with multiple devices simultaneously rather than one at a time. Older routers without MU-MIMO take turns serving each device — causing slight delays that add up in busy households. MU-MIMO routers divide their antennas into separate streams for multiple users, improving overall network efficiency. Look for MU-MIMO support when choosing a new router for a household with many connected devices.

→ See also: Router, Wi-Fi, Bandwidth

NAT Network Address Translation

A process performed by your router that allows multiple devices on your home network to share a single public IP address. When any device on your network sends data to the internet, NAT translates the private IP address of that device into your public IP address — and reverses the process for incoming data. NAT also acts as a basic security layer by hiding your individual device addresses from the public internet.

→ See also: IP Address, Router, Firewall

Ofcom

The UK's communications regulator — the Office of Communications. Ofcom regulates TV, radio, telephone, and broadband services in the UK. They set the rules that broadband providers must follow, including minimum speed guarantees, switching processes, and protections for vulnerable customers during the landline switch-off. If you have a complaint about your broadband or phone provider that you cannot resolve directly, Ofcom's approved Alternative Dispute Resolution schemes can help.

→ See also: ISP, Broadband, One Touch Switching

One Touch Switching

A streamlined broadband switching process introduced in the UK in 2023 for customers moving between providers that use the Openreach network. Under One Touch Switching your new provider manages the entire switch on your behalf — you do not need to contact your existing provider to cancel. The switch happens automatically on an agreed date with minimal service interruption. Virgin Media switches work differently and may still require direct contact with both providers.

→ See also: ISP, Ofcom, Openreach, UK Provider Comparison page

Openreach

The BT Group division that owns and maintains the UK's national telephone and broadband network infrastructure — including the copper telephone network being retired and the full fibre FTTP network being built to replace it. Openreach is a wholesale provider — it does not sell directly to consumers but provides network access to ISPs like BT, Sky, TalkTalk, Vodafone, and others. The quality of your broadband line is largely determined by Openreach, regardless of which provider you are with.

→ See also: FTTP, FTTC, ISP, PSTN

PBX Private Branch Exchange

A telephone system used within a business that manages internal and external calls. Traditional PBX systems used physical hardware on-site. Modern hosted or cloud PBX systems deliver the same functionality over the internet — routing calls, managing extensions, voicemail, and auto-attendant features — without requiring any on-site equipment. Cloud PBX is now the standard recommendation for small and medium businesses migrating away from traditional phone lines.

→ See also: VoIP, SIP, Business Connectivity section of the Knowledge Hub

Ping

A measurement of how quickly your connection responds to a request, shown in milliseconds. The lower the ping the better — under 20ms is excellent, 20–60ms is good for everyday use, and over 100ms may cause noticeable lag in gaming or video calls. The term comes from sonar technology — like a sound ping sent out and returned, your device sends a small packet of data and measures how long it takes to get a response back.

→ See also: Latency, Download Speed, Broadband Speed Checker page

PSTN Public Switched Telephone Network

The UK's traditional copper wire telephone network that has carried voice calls for over a century. The PSTN is being permanently retired by BT Openreach and replaced with VoIP-based Digital Voice services. The switch-off is being rolled out exchange by exchange across the UK and is targeted for full completion by 2027. See our dedicated UK Landline Switch-Off page for a full guide on what this means for you.

→ See also: VoIP, Digital Voice, Openreach, The UK Landline Switch-Off page

Router

The device that connects your home network to the internet and distributes that connection to all your devices via Wi-Fi and ethernet. Your broadband provider supplies a router as part of your package — though you can often replace it with a higher-performance third-party model. Your router assigns IP addresses to devices via DHCP, provides a firewall, broadcasts your Wi-Fi network, and manages all traffic flowing in and out of your home network. Restarting your router is always the recommended first step when troubleshooting any connectivity issue.

→ See also: Wi-Fi, Ethernet, DHCP, Firewall, IP Address

SIP Session Initiation Protocol

The most widely used protocol for establishing and managing VoIP calls over the internet. SIP handles the signalling — setting up, maintaining, and ending calls — while separate protocols carry the actual voice data. SIP trunking is commonly used by businesses to connect a hosted PBX phone system to the public telephone network over a broadband connection, replacing traditional ISDN lines. Most VoIP desk phones and softphone apps support SIP as standard.

→ See also: VoIP, PBX, Digital Voice, Softphone

Smart Home

A home in which everyday devices — lighting, heating, security, appliances, and entertainment systems — are connected to the internet and can be controlled remotely via a smartphone app or voice assistant, or automated based on schedules and conditions. Smart home devices communicate using various wireless protocols including Wi-Fi, Zigbee, Z-Wave, and Thread. The Matter standard is helping to bring greater interoperability between devices from different manufacturers.

→ See also: IoT, Matter, Zigbee, Z-Wave, Thread, Wi-Fi

Softphone

A software application installed on a computer, tablet, or smartphone that enables VoIP calls — effectively turning your device into a telephone. Softphones display a virtual keypad, support call handling features like hold and transfer, and can be configured to ring on your business or home number. They are widely used by remote and hybrid workers as an alternative to a physical desk phone. See our VoIP page in the Knowledge Hub for a full breakdown of softphone options.

→ See also: VoIP, SIP, PBX, VoIP page in the Knowledge Hub

SOGEA Single Order Generic Ethernet Access

A broadband-only version of FTTC that does not require a traditional voice telephone line to be active. As the UK moves away from copper voice services, SOGEA allows providers to deliver part-fibre broadband without the overhead of maintaining a phone line. Performance is broadly the same as FTTC — 30–80Mbps typically — but it is supplied as a single broadband-only product, which can be slightly simpler and cheaper to manage.

→ See also: FTTC, FTTP, PSTN, Is It Worth Upgrading? page

SSID Service Set Identifier

The technical name for your Wi-Fi network name — what you see in the list of available networks when you connect a new device. Your router broadcasts one or more SSIDs. Most modern routers broadcast separate SSIDs for 2.4GHz and 5GHz bands, though many newer routers combine these into a single SSID and handle band selection automatically. You can change your SSID to anything you like via your router's settings page.

→ See also: Router, Wi-Fi, Guest Network, 2.4GHz / 5GHz

Thread

A low-power wireless mesh networking protocol designed specifically for smart home devices. Thread creates a self-healing mesh network — if one device goes offline, traffic automatically reroutes through other devices. It is more reliable and lower latency than Wi-Fi for smart home use and does not require a central hub in the traditional sense. Thread is a core transport layer for the Matter smart home standard and is supported by Apple HomePod, Google Nest, and Amazon Echo devices among others.

→ See also: Matter, Smart Home, Zigbee, Z-Wave, IoT

Upload Speed

The rate at which data travels from your device to the internet, measured in Mbps. Upload speed affects video calls, sending large files, cloud backups, live streaming, and remote desktop connections. On ADSL and FTTC connections upload speeds are much lower than download speeds — often 5–20Mbps even on faster packages. Full fibre FTTP connections offer dramatically better upload speeds, which is one of the strongest arguments for upgrading if you work from home regularly.

→ See also: Download Speed, Mbps, FTTP, Broadband Speed Checker page

UPS Uninterruptible Power Supply

A battery backup device that keeps your router and connected equipment running during a power outage. Particularly relevant for households transitioning to VoIP Digital Voice — unlike traditional copper landlines which can work without mains power, VoIP phones require your router to be powered and online. A basic UPS suitable for keeping a home router running costs from approximately £30–£80 and provides several hours of backup depending on the model.

→ See also: VoIP, Digital Voice, Router, The UK Landline Switch-Off page

VoIP Voice over Internet Protocol

The technology that allows voice telephone calls to be made and received over a broadband internet connection rather than a traditional copper telephone line. VoIP converts your voice into digital data packets, transmits them over the internet, and reassembles them at the other end. Services like WhatsApp calls, FaceTime, Zoom, and Microsoft Teams all use VoIP technology. In the UK, VoIP is becoming the standard for all home and business phone services as the copper PSTN network is retired. See our VoIP page in the Knowledge Hub for a comprehensive guide.

→ See also: SIP, Digital Voice, PSTN, ATA, Softphone, VoIP page in the Knowledge Hub

VPN Virtual Private Network

A service that encrypts your internet connection and routes it through a server in a location of your choice, masking your IP address and location from websites and services you visit. VPNs are used for privacy, security on public Wi-Fi networks, accessing region-restricted content, and by businesses enabling secure remote access to company systems. Consumer VPN services are widely available at low monthly cost — though they do reduce connection speed to some degree due to the additional routing involved.

→ See also: IP Address, Hotspot, DNS, Firewall

Wi-Fi

The wireless technology that allows devices to connect to your home network and internet without physical cables. Wi-Fi uses radio waves broadcast by your router across one or more frequency bands — typically 2.4GHz and 5GHz, with newer Wi-Fi 6 and 6E routers also supporting 6GHz. Wi-Fi speed and reliability are affected by distance from the router, physical obstacles like walls and floors, interference from other devices, and the number of connected devices sharing the network.

→ See also: Router, Mesh Wi-Fi, Ethernet, SSID, 2.4GHz / 5GHz

Wi-Fi 5 / Wi-Fi 6 / Wi-Fi 6E / Wi-Fi 7

The generational naming system for Wi-Fi standards. Wi-Fi 5 (802.11ac) is found in most routers from 2015 onwards and supports speeds up to around 3.5Gbps. Wi-Fi 6 (802.11ax) improves performance in congested environments with many devices and adds better efficiency and security. Wi-Fi 6E extends Wi-Fi 6 into the 6GHz band for less interference. Wi-Fi 7 (802.11be) is the latest generation offering significantly higher speeds and lower latency — increasingly found in premium routers from 2024 onwards. For most UK households Wi-Fi 6 represents the current sweet spot of performance and value.

→ See also: Router, Wi-Fi, Mesh Wi-Fi, MU-MIMO

Wi-Fi Extender / Repeater

A device that receives your existing Wi-Fi signal and rebroadcasts it to extend coverage into areas your router cannot reach. Extenders are a low-cost solution for small coverage gaps but have limitations — they typically create a separate network name that devices must manually switch between, and the repeated signal is generally slower than the original. For whole-home coverage in larger properties a mesh Wi-Fi system is usually a more effective solution than multiple extenders.

→ See also: Mesh Wi-Fi, Router, SSID, Access Point

2.4GHz / 5GHz Wi-Fi Frequency Bands

The two main radio frequency bands used by Wi-Fi. The 2.4GHz band has longer range and better penetration through walls but is slower and more prone to interference from other devices like microwaves and baby monitors. The 5GHz band is faster but has shorter range and struggles more with solid obstacles. For devices close to the router — laptops, phones in the same room — 5GHz is preferable. For devices further away or in adjacent rooms — smart home devices, security cameras — 2.4GHz is often more reliable.

→ See also: Wi-Fi, Router, SSID, Mesh Wi-Fi

Zigbee

A low-power wireless communication protocol widely used by smart home devices — particularly smart lighting, sensors, and switches. Zigbee devices form a mesh network where each device acts as a repeater for others, extending the range of the network without additional infrastructure. Zigbee requires a compatible hub or gateway — such as Amazon Echo, Samsung SmartThings, or a dedicated Zigbee hub — to connect to the wider internet and your smart home apps. Many Zigbee devices are now also compatible with the Matter standard.

→ See also: Z-Wave, Matter, Thread, Smart Home, IoT

Z-Wave

A wireless protocol used primarily for smart home automation — similar in purpose to Zigbee but operating on a different radio frequency, typically 868MHz in Europe, which reduces interference with Wi-Fi networks. Z-Wave devices also form a mesh network and require a compatible hub. Z-Wave is known for reliability and strong interoperability between certified devices from different manufacturers. Like Zigbee, many Z-Wave devices are gaining compatibility with the Matter standard over time.

→ See also: Zigbee, Matter, Thread, Smart Home, IoT