IT and Telecoms Jargon Explained
Plain-English definitions of the terms your IT, broadband, phone and mobile suppliers use.
This glossary from Indigo Unified Communications, a Glasgow IT and telecoms provider, explains 60 terms businesses meet when buying IT support, cyber security, broadband, leased lines, phone systems and business mobiles. Each entry says what the term means, why it matters to your business, and where to read more. It is written and reviewed by our Glasgow team, who support organisations of 10 to 500 staff across Scotland.
Broadband, leased lines and connectivity
SoGEA (Single Order Generic Ethernet Access)
SoGEA is fibre-to-the-cabinet broadband supplied without a phone line attached. You pay for the data connection only, and any calls run over the internet instead. It matters because traditional line-plus-broadband packages are being withdrawn before the PSTN closes on 31 January 2027. SoGEA costs about £32 a month with Indigo. Business connectivity →
FTTP (Fibre to the Premises)
FTTP, also called full fibre, runs a fibre optic cable all the way into your building, with no copper in the connection. It's faster and more reliable than part-copper broadband. Ofcom reported in November 2025 that 71% of Scottish homes can get full fibre. With Indigo, FTTP costs £32–£50 a month depending on speed. Business connectivity →
FTTC (Fibre to the Cabinet)
FTTC runs fibre to the green street cabinet, then uses the existing copper phone line for the last stretch into your building. Speeds fall the further you are from the cabinet. Many businesses still use it. Where it depends on a phone line, it has to move to SoGEA or full fibre before the copper network closes. Business connectivity →
ADSL (Asymmetric Digital Subscriber Line)
ADSL is the oldest type of broadband, carried entirely over a copper phone line from the telephone exchange. Speeds are slow and drop with distance. ADSL depends on the analogue phone network, so it stops working when the PSTN closes on 31 January 2027. Any business still on ADSL should plan a move to SoGEA or full fibre now. PSTN switch-off check →
Leased line
A leased line is a private, dedicated internet connection for your business alone. Upload and download speeds are the same, the bandwidth isn't shared with neighbours, and it comes with a guaranteed fix time. Indigo supplies fibre Ethernet up to 10Gbps with a 5-hour fix, from £200 a month depending on area. Installation typically takes 30–90 working days. What is a leased line? →
EFM (Ethernet in the First Mile)
EFM is a leased line delivered over several copper lines bonded together rather than fibre. It's slower than fibre Ethernet but still dedicated, with equal upload and download speeds and a guaranteed fix time. Indigo supplies EFM at up to 20Mbps with a 7-hour fix. It suits sites where fibre isn't available or would take too long to install. Leased lines explained →
EoFTTC (Ethernet over FTTC)
EoFTTC is a business-grade Ethernet service that uses the same street cabinet and copper line as FTTC broadband, but with a business service level and a guaranteed fix time. Indigo supplies EoFTTC at up to 80Mbps with a 7-hour fix. It's a lower-cost step up from broadband when you need more reliability but a full fibre leased line isn't justified. Business connectivity →
Contention
Contention means sharing. Standard broadband is contended: many customers share the same capacity, so speeds can drop at busy times. A leased line is uncontended, so the bandwidth you pay for is yours alone. If your office slows every afternoon or your card machines time out at peak times, contention may be part of the reason. Leased lines explained →
Static IP address
A static IP address is a fixed internet address for your connection that doesn't change. Businesses need one to run remote access, some phone systems, CCTV viewing, VPNs or servers that other people connect to. Most business broadband and all leased lines can include static IPs. Ask for them when ordering, because adding them later can mean a reconfiguration. Business connectivity →
SD-WAN (Software-Defined Wide Area Network)
SD-WAN is software that manages several internet connections and sites as one network. It sends each type of traffic over the best available line and switches instantly if one fails. SASE (Secure Access Service Edge) adds security to the same platform. Indigo uses Cato Networks for SD-WAN and SASE, including for construction firms with many site cabins. Business connectivity →
Failover
Failover is a backup internet connection that takes over automatically when your main line fails. It might be a second broadband line, a 4G or 5G router, or satellite. For businesses that take card payments, run cloud phones or rely on Microsoft 365, failover keeps work going while the main line is being fixed. Business connectivity →
4G/5G router
A 4G or 5G router connects a site to the internet over the mobile network, using a data SIM instead of a fixed line. It's useful for construction sites, temporary offices, events and as backup for a fixed line. With Indigo, 4G and 5G site connectivity is usually live within 2–3 working days, depending on signal at the site. Business connectivity →
LEO satellite (Starlink)
Low Earth orbit (LEO) satellite broadband, such as Starlink, uses satellites orbiting much closer to Earth than older satellite services, so delays are far shorter and video calls work. It suits remote sites with no fibre and weak mobile signal. Indigo offers satellite for remote sites and has used Starlink with SD-WAN to connect construction site cabins. Business connectivity →
Business WiFi and networks
WiFi 6, 6E and 7
These are generations of the WiFi standard. WiFi 6 handles many devices at once better than older WiFi. WiFi 6E adds the 6GHz band, which is less crowded. WiFi 7 adds more capacity again. Your devices and access points both need to support a standard to benefit, so newer WiFi helps most in busy offices and venues. Business WiFi →
Access point
An access point is the device on a ceiling or wall that broadcasts WiFi. Most offices need several, placed where people actually work, not where cabling is easiest. Too few, or badly placed, access points are the most common cause of slow WiFi. Indigo installs Ubiquiti UniFi access points, managed centrally so they can be monitored and updated remotely. Business WiFi →
VLAN (Virtual Local Area Network)
A VLAN splits one physical network into separate, isolated networks. Businesses use VLANs to keep staff devices, guest WiFi, card payment systems and CCTV apart, so a problem or intruder on one can't reach the others. Keeping card payments on their own network is a basic requirement of the payment card security standard (PCI DSS). Business WiFi →
Captive portal
A captive portal is the login page guests see before they can use your WiFi. It can show your branding, ask visitors to accept terms of use, and limit how long or how much each guest can use. Venues, hotels and offices use captive portals to keep guest access separate and controlled. Business WiFi →
Phone systems and the PSTN switch-off
PSTN (Public Switched Telephone Network)
The PSTN is the UK's traditional copper phone network, used for landlines, alarm lines, fax, lift lines and some card machines. Openreach closes it on 31 January 2027 and new analogue lines are no longer sold. Anything still connected to it needs moving to a digital service before then. The PSTN switch-off explained →
ISDN (Integrated Services Digital Network)
ISDN is an older digital phone service that runs over the same copper network as the PSTN, often used to connect an office phone system to several lines. It closes along with the PSTN on 31 January 2027. Businesses with an ISDN-connected phone system usually move to SIP trunks or a hosted phone system. PSTN switch-off check →
VoIP (Voice over Internet Protocol)
VoIP means making phone calls over an internet connection instead of a copper phone line. Every modern business phone system, whether hosted in the cloud or on SIP trunks, uses VoIP. Call quality depends on a reliable internet connection, so it's worth checking your broadband before you switch. VoIP vs traditional phone systems →
SIP trunk
A SIP trunk is a virtual phone line delivered over your internet connection, connecting a phone system such as 3CX to the public phone network. It replaces ISDN lines. Indigo prices both SIP and fully hosted options at every review, because SIP usually becomes more cost-effective at around 30 users, depending on numbers and the features you need. Hosted telephony →
Hosted telephony
Hosted telephony is a business phone system that runs in the cloud, so there's no phone system box in your office. Staff can take calls on desk phones, mobiles or laptops wherever they work. Indigo supplies 8x8, 3CX and Microsoft Teams Phone. Fully hosted telephony starts from about £10 per user per month for a single handset. Hosted telephony →
UCaaS (Unified Communications as a Service)
UCaaS combines phone calls, video meetings, chat and sometimes contact centre features in one cloud service, paid for per user each month. Instead of separate systems for calls and meetings, staff use one app on their desk phone, laptop and mobile. Hosted phone systems such as 8x8 and Microsoft Teams Phone are examples. Hosted telephony →
Microsoft Teams Phone
Microsoft Teams Phone adds a full business phone number and phone system features to Microsoft Teams. Staff make and take external calls in the same app they already use for chat and meetings, on a laptop, mobile or desk phone. It suits businesses already standardised on Microsoft 365. Indigo supplies Teams Phone alongside 8x8 and 3CX. Hosted telephony →
Number porting
Number porting moves your existing phone numbers from one provider to another, so customers keep calling the same numbers. For landline numbers, ports are scheduled by Openreach and happen between 9am and 5pm, as they do for every provider. Indigo installs new phones during working hours and runs them alongside the old system, so there's no downtime. Hosted telephony →
DECT (Digital Enhanced Cordless Telecommunications)
DECT is the standard used by cordless business phones. A DECT base station connects to your phone system and handsets roam around the building within range. DECT suits warehouses, shop floors, venues and care settings where staff move about but mobiles aren't practical. DECT handsets work with hosted phone systems as well as on-site ones. Hosted telephony →
Auto attendant
An auto attendant answers incoming calls with a recorded message and menu, such as "press 1 for sales, 2 for support". It sends callers to the right person or team without a receptionist, and can play different messages outside opening hours. Most hosted phone systems include auto attendants and let you change messages and routing yourself. Hosted telephony →
Hunt group
A hunt group is a set of phones that ring for one number, such as a sales or support line. Calls can ring all phones at once, in order, or to whoever has been free longest. Hunt groups make sure calls are answered by whoever is available rather than going to one person's voicemail. Hosted telephony →
Business mobiles
eSIM
An eSIM is a SIM built into the phone, set up by downloading a profile instead of inserting a plastic card. It makes activating or moving a line quicker, because nothing needs posting out, and lets one phone hold more than one number. It's useful for remote staff and for adding a line to a tablet or laptop. Business mobiles →
PAC code (Porting Authorisation Code)
A PAC code lets you keep your mobile number when you switch network. For one number, text "PAC" to 65075 and your provider must send the code immediately or within two hours. A PAC is valid for 30 days, and the number normally moves within one working day. Businesses with 25 or more numbers ask their provider directly. Business mobiles →
Spend cap
A spend cap limits how much a mobile line can be charged beyond its monthly bundle. Set at zero, it stops out-of-bundle charges, such as roaming, premium-rate calls or extra data, unless you approve them. Indigo sets every line's spend cap at zero, which is one way businesses typically save about 20% on mobile costs over the contract. Business mobiles →
Roaming
Roaming is using your mobile abroad on another country's network. Since the UK left the EU, many UK networks charge for roaming in Europe as well as further afield, often as a daily fee. For staff who travel, roaming can be one of the biggest surprises on a business mobile bill unless bundles and spend caps are set up properly. Mobile bill review →
WiFi calling
WiFi calling lets a mobile make and receive normal calls and texts over a WiFi connection when mobile signal is weak. It's useful in buildings with poor indoor coverage, such as basements, steel-framed offices and rural sites. The phone, the network and the tariff all need to support it, and calls use your normal number and bundle. Business mobiles →
Rugged phone
A rugged phone is a mobile built to survive drops, dust, water and cold, often with a bigger battery and a screen that works with gloves. For construction and outdoor teams it usually costs less over its life than replacing broken standard handsets. Indigo supplies a large range of rugged phones and tablets. Business mobiles →
Cyber security
MFA (Multi-factor authentication)
MFA means proving who you are with a second check, such as an app prompt or code, as well as your password. A stolen password alone is then not enough to get into your email or systems. It's one of the simplest and most effective protections any business can turn on. Why you should enable MFA →
Passkey
A passkey replaces a password with a sign-in secured by your device, confirmed by fingerprint, face or PIN. There's nothing to type, so there's nothing for a fake login page to steal. Microsoft, Google and Apple accounts all support passkeys. For businesses, they make phishing much harder and reduce password resets. Cyber security →
Phishing
Phishing is a fake email, text or call designed to trick someone into clicking a link, entering a password or making a payment. The UK Government's Cyber Security Breaches Survey 2025/2026 found phishing was the most common attack, reported by 38% of businesses. Email filtering, MFA and staff training all reduce the risk. Phishing explained →
BEC and payment diversion fraud
Business email compromise (BEC) is when criminals take over or imitate a real email account, often a supplier's, and use it to divert payments. A typical example is an email in a genuine thread saying the supplier's bank details have changed. Always confirm new bank details by phone, using a number you already hold. Payment diversion fraud →
Ransomware
Ransomware is malicious software that encrypts a business's files and systems, then demands payment to unlock them. It often gets in through a phishing email, a stolen password or an unpatched system. The best defences are MFA, prompt security updates (patching), endpoint detection and response, and backups kept separate so they can't be encrypted too. How ransomware infects a network →
EDR (Endpoint detection and response)
EDR is security software on each laptop, desktop and server that watches for suspicious behaviour, not just known viruses, and can isolate a device automatically. Traditional antivirus only spots known threats. Indigo uses Kaseya 365 Endpoint for EDR across its managed IT packages. Cyber security →
SOC (Security operations centre)
A SOC is a team of security analysts who watch alerts from your systems around the clock and respond to threats as they happen, including at night and weekends when attacks often start. Indigo's Platinum and Charity packages include a 24/7 SOC, provided through RocketCyber, that spots and responds to threats for you (managed detection and response). Cyber security →
SIEM (Security information and event management)
A SIEM collects logs and security events from firewalls, servers, Microsoft 365 and devices in one place, then flags patterns that suggest an attack. On its own it produces alerts, not action, so it needs people watching it. Smaller businesses usually get the benefit through a security operations centre service rather than running a SIEM themselves. Cyber security →
Cyber Essentials
Cyber Essentials is the UK Government-backed certification showing a business has five basic technical controls in place: firewalls, secure configuration, user access control, malware protection and security updates. Central government suppliers handling personal data must hold it, and many other buyers and insurers ask for it. Indigo is Cyber Essentials certified. Cyber Essentials explained →
Cyber Essentials Plus
Cyber Essentials Plus covers the same five controls as Cyber Essentials, but an independent assessor tests your systems instead of relying on a self-assessment. It gives customers and insurers stronger evidence. Indigo holds Cyber Essentials Plus. We include Cyber Essentials support in our Platinum package, and any business can buy it separately. Our accreditations →
ISO 27001
ISO 27001 is the international standard for an information security management system: the policies, risk assessments and controls an organisation uses to protect information, checked by an external auditor. Larger customers and public bodies often ask suppliers for it. Indigo is ISO 27001:2022 certified for managed IT services, business mobiles, hosted telecoms and connectivity. Our accreditations →
Zero trust
Zero trust is a security approach that doesn't trust any user or device just because it's on the office network. Every sign-in is checked, using identity, device health and location, and people get access only to what they need. In Microsoft 365, conditional access and device management through Intune are the usual building blocks. Cyber security →
Patching
Patching means installing the security and bug fixes that software makers release for operating systems, applications and devices. Unpatched systems are one of the most common ways attackers get in, and keeping software up to date is one of the five Cyber Essentials controls. Indigo patches and monitors devices through Datto RMM as part of managed IT support. Managed IT support →
Penetration test
A penetration test is a controlled, authorised attempt to break into your systems to find weaknesses before criminals do. A vulnerability scan is the automated, lighter version that looks for known weaknesses. Both produce a report of what to fix. Indigo uses vPenTest for vulnerability testing, and customers and insurers increasingly ask for evidence of testing. Cyber security →
Microsoft 365 and devices
Microsoft 365 Business Premium
Microsoft 365 Business Premium is Microsoft's plan for organisations of up to 300 users. It includes the Office apps, email and Teams, plus security tools: Intune device management, Entra ID P1 with conditional access, and Defender for Business. Indigo's Platinum package includes Business Premium, and the Charity package includes Business Premium licences. IT support packages →
Intune and MDM (Mobile device management)
MDM lets a business manage laptops, phones and tablets centrally: enforce passwords and encryption, push apps and settings, and wipe a lost device remotely. Microsoft Intune is Microsoft's MDM, included in Microsoft 365 Business Premium. Cyber insurers increasingly expect devices to be managed this way. Indigo rolls out Intune for clients as part of managed IT support. Managed IT support →
Entra ID
Entra ID, formerly Azure Active Directory, is the Microsoft service that holds your users' accounts and controls sign-in to Microsoft 365 and many other apps. It's where MFA, conditional access and single sign-on are set up. Getting Entra ID right means one secure account per person, and access removed in one place when someone leaves. Cyber security →
SharePoint
SharePoint is the part of Microsoft 365 that stores and shares company files, intranets and document libraries, usually accessed through Teams or File Explorer. It often replaces an old office file server. Set up well, with sensible permissions and folder structure, it lets staff work on the same files from any site without a VPN. Managed IT support →
Copilot
Copilot is Microsoft's AI assistant. Copilot Chat is included with Microsoft 365 business plans and answers questions using the web and files you give it. The paid Copilot licence adds AI inside Word, Excel, Outlook and Teams that can use your company's emails and files. Before switching it on, check file permissions, because Copilot can surface anything a user can already access. Managed IT support →
Backup vs sync
Sync keeps the same file up to date in several places, such as OneDrive on your laptop and in the cloud. If a file is deleted or encrypted by ransomware, sync copies that change everywhere. A backup is a separate copy you can restore from. Indigo backs up Microsoft 365 data with Datto SaaS Protection in its managed IT packages. IT support packages →
IT support and contracts
Break-fix vs managed IT
Break-fix IT means paying an engineer only when something goes wrong. Managed IT means a fixed monthly fee covers support, monitoring, patching and security, so problems are prevented as well as fixed. Break-fix looks cheaper until something serious happens. Managed IT gives predictable costs and a provider who is paid to keep things working. What managed IT support includes →
SLA (Service level agreement)
An SLA is the part of a contract that sets out measurable service promises, such as response times, fix times, support hours and what happens if they're missed. Always check what an SLA actually measures: a fast "response" isn't a fix. Indigo's leased lines have 5-hour or 7-hour fix times, and every support ticket gets a first response in under 30 minutes. Managed IT support →
First response time
First response time is how long it takes for a person to start working on your support request after you log it. It's different from resolution time, which depends on the problem. Every Indigo ticket gets a first response in under 30 minutes; in September 2026 our average was 13 minutes across 1,854 tickets. Managed IT support →
RMM (Remote monitoring and management)
RMM is software an IT provider installs on your computers and servers to monitor their health, install updates and fix problems remotely. It spots issues such as a full disk or failed update before users notice. Indigo uses Datto RMM and manages more than 2,000 devices (endpoints) this way. Managed IT support →
PSA (Professional services automation)
A PSA is the system an IT provider uses to log and track support tickets, contracts, time and billing. For customers, it means every request gets a ticket number, a record of what was done and reporting on response times. Indigo uses Autotask PSA for its service desk. Managed IT support →
Onboarding
Onboarding is the handover period when a new IT provider takes over: documenting your systems, installing monitoring and security tools, collecting passwords and fixing urgent issues. It should be planned, not rushed. At Indigo, onboarding takes about 2 weeks and is included in our managed IT packages. When you switch mid-contract, we usually cover overlap costs or buy out the old contract. IT support packages →
Frequently asked questions
What's the difference between broadband and a leased line?
Broadband is shared with other users, so speeds can vary at busy times, and repairs have no guaranteed fix time. A leased line is a dedicated connection for your business alone, with equal upload and download speeds and a guaranteed fix time. Indigo's fibre Ethernet leased lines have a 5-hour fix and start from £200 a month depending on area.
Which of these services does the PSTN switch-off affect?
The switch-off on 31 January 2027 affects anything that uses the copper phone network: analogue landlines, ISDN, ADSL and broadband that needs a phone line, plus alarm lines, fax machines, lift lines and some card machines. Each needs moving to a digital service, such as SoGEA, full fibre, SIP trunks or hosted telephony. Our free PSTN switch-off check shows what's affected.
What's the difference between Cyber Essentials and Cyber Essentials Plus?
Both cover the same five technical controls. Cyber Essentials is a self-assessment, verified by a certification body. Cyber Essentials Plus adds an independent assessor testing your systems directly, so it's stronger evidence for customers and insurers. Indigo holds both certificates, includes Cyber Essentials support in the Platinum package, and helps any business get certified.
Can Indigo explain what our current IT and telecoms setup includes?
Yes. A technology assessment from Indigo Unified Communications reviews your IT support, cyber security, connectivity, phones and mobiles, then explains in plain English what you have, what's at risk and what it costs. Our Glasgow team supports businesses of 10 to 500 staff across Scotland, and website enquiries get a reply the same working day.