Telecommunications can involve a lot of technical jargon. This telecom glossary explains common telecom, VoIP, networking and broadband terms in simple language.
Whether you’re researching VoIP systems, SIP trunking, fibre broadband or network performance, this guide helps you understand the terminology used by telecom providers and IT teams.
Use the search tool below to quickly find a telecom term and see a clear explanation with no jargon.
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We’ve made a comprehensive list of the telecoms technical jargon below. Use the search tool to quickly search the telecom glossary of terms and view clear explanations.
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| Term | Explanation |
|---|---|
4G Backup# |
What is 4G backup? 4G backup means a business uses a 4G mobile connection as a standby internet service during outages. This is a common resilience feature for broadband, VoIP and business connectivity because it helps services stay live if the main line goes down. |
5G# |
What is 5G? 5G is the fifth generation of mobile connectivity, designed to offer faster speeds, lower latency and better support for many connected devices. Searches like 5G meaning or what is 5G in telecom usually refer to modern mobile networks used for phones, wireless broadband and connected services. |
10Gbps# |
What is 10Gbps? 10Gbps means ten gigabits per second and is used to describe very high-capacity network connectivity. This speed is common in core networks, data centre connections and high-demand business environments using fibre and dedicated services. |
ADSL# |
|
ANI# |
What is ANI? ANI stands for Automatic Number Identification. It is used to pass the caller’s number through telecoms systems. It often appears in contact centre, routing and billing setups where the network needs to identify the source of a call. |
API# |
What is an API? API stands for Application Programming Interface. It allows different systems to communicate and exchange data automatically. In telecoms, APIs are often used to connect phone systems, CRMs, SMS platforms, reporting tools and customer portals. |
Attenuation# |
What is attenuation? Attenuation means a signal gets weaker as it travels along a cable or line. In broadband and telecoms, higher attenuation can reduce speed and quality, especially on longer copper-based connections. |
Auto Attendant# |
What is an auto attendant? An auto attendant is the recorded menu callers hear when they ring a business phone number. It helps route calls without a receptionist answering each one, using options like press 1 for sales or press 2 for support. |
Bandwidth# |
What is bandwidth? Bandwidth is the capacity of a network connection, usually measured in Mbps or Gbps. Searches like bandwidth meaning or what is bandwidth in telecom usually mean how much traffic a connection can carry at once. |
Bitrate# |
What is bitrate? Bitrate is the amount of data used every second by a voice, video or media stream. Higher bitrate can improve quality, but it also uses more bandwidth, which matters in VoIP and video communication. |
Broadband# |
What is broadband? Broadband is the general name for internet connectivity services used by homes and businesses. It can include ADSL, FTTC, FTTP, cable and wireless services. Searchers looking for broadband definition usually mean a fast always-on internet service. |
BYOD# |
What is BYOD? BYOD stands for Bring Your Own Device. It means staff use their own phone, tablet or laptop for work. In telecoms, this often means using a business softphone or app on a personal mobile rather than a desk handset. |
Call Hunting# |
What is call hunting? Call hunting means a phone system tries a list of users or devices until a call is answered. This is common in sales and support teams where inbound calls should reach the next available person. |
Call Queue# |
What is a call queue? A call queue places callers in line when all agents are busy and connects them when someone becomes free. It is a core feature in support teams and contact centres, often with hold music, announcements and wait messages. |
Call Routing# |
What is call routing? Call routing is the process of sending incoming calls to the correct destination based on rules such as time, team, number dialled or availability. Searches like call routing meaning usually refer to business phone systems and cloud telephony. |
Call Transfer# |
What is call transfer? Call transfer is when a user sends a live call to another extension, team or number. This is one of the most common PBX features in business telecoms and is often paired with Busy Lamp Field and hunt groups. |
Carrier# |
What is a carrier? A carrier is a telecoms company that provides network services such as voice, mobile, data or internet connectivity. Some carriers own infrastructure directly, while others provide wholesale access or partner services. |
CDR# |
What is a CDR? CDR stands for Call Detail Record. It logs information such as time, duration, source, destination and call result. CDRs are useful for reporting, billing, troubleshooting and analysing telecom performance. |
CLI# |
What is CLI? CLI stands for Calling Line Identification. It is the caller number presented on an outbound call. Businesses often choose their CLI so customers see a main office number, local area number or direct dial number. |
Click-to-Call# |
What is click-to-call? Click-to-call lets users start a call directly from a website, CRM or software tool. It is popular in sales and support systems because it speeds up calling and reduces dialling errors. |
Cloud PBX# |
What is a cloud PBX? A cloud PBX is a business phone system that runs online rather than on hardware in your office. It usually includes features like extensions, voicemail, call routing and softphone apps without needing a traditional phone cabinet onsite. |
Codec# |
What is a codec? A codec is the method used to compress and decompress voice or video data so it can travel efficiently across networks. Different codecs affect quality, delay and bandwidth use, which is why codecs matter in VoIP and video calling. |
Copper Line# |
What is a copper line? A copper line is a traditional telecom connection using copper cabling for phone or broadband services. Older technologies like ADSL and part of FTTC rely on copper, which is more affected by distance and interference than full fibre. |
CRM Integration# |
What is CRM integration? CRM integration links a phone system with customer records so teams can see caller details, log calls and improve workflows. It is common with sales and service platforms such as HubSpot, Salesforce and similar systems. |
Cross Talk# |
What is cross talk? Cross talk is interference caused when signals from one line affect another nearby line. It can reduce broadband performance, especially on older copper services where many lines run close together. |
DDI# |
What is DDI? DDI stands for Direct Dial In. It is a number that routes directly to a person, extension or department without going through the main switchboard. People searching DDI meaning usually mean direct inward dial numbers in business telephony. |
DECT# |
What is DECT? DECT is a wireless phone standard commonly used for cordless office handsets. It allows users to move around a building while staying connected to the business phone system. |
Dial Plan# |
What is a dial plan? A dial plan defines how a phone system interprets and routes numbers such as extensions, local calls and international numbers. It helps determine what happens when users dial different patterns and is important in both hosted and onsite telephony. |
Downstream# |
What is downstream? Downstream means data flowing from the provider or internet to the user's device. Download speed is a downstream measure and affects activities like streaming, web browsing and receiving files. |
Ethernet# |
What is Ethernet? Ethernet is a networking standard used inside local networks and also in business-grade connectivity services. In telecoms, Ethernet often refers to dedicated or managed data services used by businesses for reliable connectivity. |
Extension# |
What is an extension? An extension is a short number used to reach someone internally within a business phone system. Extensions are one of the most common PBX features and are often linked with DDIs, voicemail and transfer features. |
Failover# |
What is failover? Failover means a system automatically switches to a backup connection or service when the main one stops working. This is important for business internet, VoIP and critical communications where downtime is costly. |
Fibre Broadband# |
What is fibre broadband? Fibre broadband uses fibre optic cable for some or all of the internet connection, usually giving better performance than copper-only services. It may refer to FTTC or FTTP depending on how much of the connection uses fibre. |
Firewall# |
What is a firewall? A firewall is a security system that monitors and controls network traffic entering and leaving a network. In telecoms and business connectivity, it helps protect internet, VPN and voice services from unwanted access or attacks. |
Fixed IP# |
What is a fixed IP? A fixed IP is an internet address that does not keep changing. Businesses often use fixed IP addresses for VPNs, remote access, hosted systems and services that need a stable public address. |
FTTC# |
What is FTTC? FTTC stands for Fibre to the Cabinet. Fibre runs to a street cabinet, then copper is used for the final part to the premises. Searches like FTTC meaning or what is FTTC broadband usually refer to part-fibre broadband. |
FTTP# |
What is FTTP? FTTP stands for Fibre to the Premises. Fibre runs all the way to the building with no copper last mile. This is why people searching FTTP meaning or what is FTTP often see it described as full fibre broadband. |
Full Fibre# |
What is full fibre? Full fibre means the connection uses fibre optic cable all the way to the premises. It is usually another way of describing FTTP and is associated with higher speeds and better long-term scalability. |
Gbps# |
What is Gbps? Gbps means gigabits per second and is a unit used to measure network speed. It is commonly used for fast fibre and business internet services, including gigabit broadband and high-capacity circuits. |
Geo Redundancy# |
What is geo redundancy? Geo redundancy means systems are replicated or backed up across more than one location. It improves resilience by reducing the risk that one site failure takes out the whole service. |
Handset# |
What is a handset? A handset is the physical phone device used on a desk or as a cordless unit for voice calls. Even with softphones becoming more common, handsets are still widely used in offices, warehouses and front-of-house environments. |
Hosted PBX# |
What is hosted PBX? Hosted PBX is a cloud-based business phone system managed by a telecoms provider rather than by hardware in your office. People searching hosted PBX meaning or what is hosted PBX usually want to know it provides features like extensions, voicemail, apps and routing over VoIP. |
Hunt Group# |
What is a hunt group? A hunt group is a set of phones or users that all belong to the same inbound number or department. The system can ring them in order, all together or by another chosen pattern. |
IP Address# |
What is an IP address? An IP address is the address used to identify a device on a network or the internet. Devices need IP addresses to communicate, and businesses often use fixed or static IPs for remote access and hosted services. |
IP PBX# |
What is an IP PBX? An IP PBX is a business phone system that uses internet protocol rather than traditional telephony circuits. It supports VoIP calls, extensions, softphones and internet-based features. |
ISDN# |
What is ISDN? ISDN is an older digital telecom service used for business telephony and data connections before modern IP services became common. It is often replaced by SIP and cloud-based voice platforms. |
IVR# |
What is IVR? IVR stands for Interactive Voice Response. It is the menu system callers interact with by pressing buttons or speaking choices. IVR is often used in customer service and routed calling environments. |
Jitter# |
What is jitter? Jitter is when data packets arrive at uneven times instead of a steady rhythm. In voice calls, too much jitter can make audio sound robotic, broken or choppy. |
Kbps# |
What is Kbps? Kbps means kilobits per second and is a lower speed measurement than Mbps or Gbps. It is more often seen in older services or smaller data rates than in modern broadband marketing. |
LAN# |
What is a LAN? LAN stands for Local Area Network. It is the local network inside an office, building or site. A LAN connects devices like phones, laptops, printers and switches within the same physical location. |
Latency# |
What is latency? Latency is the delay between sending data and getting a response back across a network. Searches like latency meaning or what is latency in networking usually refer to delay that can affect VoIP, video calls and gaming. |
Leased Line# |
What is a leased line? A leased line is a dedicated internet connection used only by one business rather than shared in the same way as standard broadband. People searching leased line meaning usually want to know it offers more consistent speeds, better uptime and stronger service levels. |
Mbps# |
What is Mbps? Mbps means megabits per second and is one of the most common units used to describe broadband speed. It tells you how much data can move per second, although real-world performance also depends on other factors like contention and throughput. |
MPLS# |
What is MPLS? MPLS stands for Multi Protocol Label Switching. It is a networking technology often used to connect multiple sites over a private managed network. It is commonly compared with SD-WAN in business networking discussions. |
Mobile Network# |
What is a mobile network? A mobile network is the wireless telecom infrastructure used for mobile calls, texts and data services. Modern mobile networks include 4G and 5G and can also support fixed wireless broadband in some cases. |
Multi-Site Connectivity# |
What is multi-site connectivity? Multi-site connectivity means linking several offices or locations together using services like SD-WAN, MPLS, VPNs or dedicated circuits. It is important for businesses with multiple sites sharing systems, voice services or cloud applications. |
NAT# |
What is NAT? NAT stands for Network Address Translation. It allows many devices on a local network to share a smaller number of public IP addresses. It is common on business and home networks, but it can affect some voice services if configured poorly. |
Network Resilience# |
What is network resilience? Network resilience describes how well a network continues to operate during faults, outages or disruptions. It usually depends on redundancy, failover, diverse routes and good monitoring. |
Number Porting# |
What is number porting? Number porting means transferring a phone number to a different telecoms provider. This lets businesses keep their existing numbers when moving to a new phone system or network service. |
Outbound Calling# |
What is outbound calling? Outbound calling means calls made by a business to customers, prospects or contacts rather than calls received from them. It is common in sales teams, customer service follow-ups and campaign work. |
Packet# |
What is a packet? A packet is a small chunk of data sent over a network, then reassembled at the other end. Voice and internet traffic are broken into packets so they can move efficiently through IP networks. |
Packet Loss# |
What is packet loss? Packet loss happens when some packets never reach their destination. Searches like packet loss meaning usually relate to poor call quality, buffering or unreliable internet performance. |
PBX# |
What is PBX? PBX stands for Private Branch Exchange. It is a business phone system that connects internal users and manages inbound and outbound calls. People searching PBX meaning or what is PBX usually want to understand modern business telephony. |
Peering# |
What is peering? Peering is when two networks connect directly to exchange traffic without sending it through a third-party transit provider. Good peering can improve performance and reduce the distance traffic needs to travel. |
Ping# |
What is ping? Ping is a simple network test that measures how quickly a response comes back from another device or service. People often use the word ping informally to mean latency. |
PoE# |
What is PoE? PoE stands for Power over Ethernet. It allows power and data to travel through the same network cable. This is useful for devices such as desk phones, wireless access points and cameras. |
Port# |
What is a port? In telecoms and networking, a port can mean a physical socket on hardware or a numbered service channel used by traffic. Both meanings are common depending on whether the discussion is about equipment or software traffic. |
POTS# |
What is POTS? POTS stands for Plain Old Telephone Service, meaning traditional analogue landline telephony. It is an older term that usually appears in discussions about legacy services being replaced by IP telephony. |
PSTN# |
What is PSTN? PSTN stands for Public Switched Telephone Network. It is the traditional phone network used for landline voice calls. Many telecom markets have been moving away from PSTN towards IP-based services. |
QA# |
What is QA? QA stands for Quality Assurance. In telecoms and contact centres it often means reviewing calls and processes to improve service quality. QA is frequently linked with call recording, scorecards and training. |
QoS# |
What is QoS? QoS stands for Quality of Service. It means prioritising certain kinds of network traffic over others. Voice calls are often prioritised over downloads so call quality stays clear and stable. |
Router# |
What is a router? A router is a device that sends data between networks, such as between a local business network and the internet. Routers are central to business connectivity and often work alongside firewalls and switches. |
Session Border Controller# |
What is a Session Border Controller? A Session Border Controller, often called an SBC, helps secure and manage voice traffic between networks. It is commonly used with SIP for security, interoperability and call control. |
SIP# |
What is SIP? SIP stands for Session Initiation Protocol. It is used to start, manage and end voice calls over IP networks. People searching SIP meaning or what is SIP in telecom usually want to understand how internet calling systems work. |
SIP Trunk# |
What is a SIP trunk? A SIP trunk connects a business phone system to external calling services using internet-based voice instead of old phone lines. People searching SIP trunk meaning usually mean a modern replacement for ISDN or PSTN business telephony. |
Softphone# |
What is a softphone? A softphone is an app that lets users make and receive business calls on a laptop, desktop or mobile device. It works like a business phone without needing a physical handset and is common in hosted telephony and hybrid work. |
Static IP# |
What is a static IP? A static IP is an IP address that stays the same over time instead of changing. It is useful for hosted systems, remote access and secure network configurations. |
Switch# |
What is a switch? A switch connects devices such as phones, PCs and printers within the same local network. It is a core network component inside offices and business sites. |
Teams Phone# |
What is Teams Phone? Teams Phone is the voice calling layer within Microsoft Teams, allowing users to make and receive external phone calls. It is often combined with Direct Routing or operator services from a telecoms provider. |
Throughput# |
What is throughput? Throughput is the real amount of data successfully transferred over a connection. It is different from raw bandwidth because network conditions, overhead and congestion affect what users actually see. |
Transit# |
What is transit? Transit means a network pays another provider to carry its traffic across the wider internet. It is different from peering, where networks exchange traffic more directly. |
Trunk# |
What is a trunk in telecoms? A trunk is a communications link that carries multiple calls or channels between systems or networks. In modern telecoms, the term often appears in SIP trunking rather than physical circuit trunks. |
UC# |
What is UC? UC stands for Unified Communications. It means combining calling, messaging, meetings and presence tools in one joined-up system. Businesses often use UC to reduce tool sprawl and improve staff communication. |
UCaaS# |
What is UCaaS? UCaaS stands for Unified Communications as a Service. It means cloud-based calling, messaging and collaboration tools delivered by subscription. It is one of the main models for modern business telecoms and collaboration platforms. |
Uptime# |
What is uptime? Uptime is the amount of time a telecom or internet service stays available and operational. It is often expressed as a percentage and matters heavily for business-critical services. |
Upstream# |
What is upstream? Upstream means data moving from the user outward to the internet or provider network. Upload speed is an upstream measure and affects cloud backups, video calls and sending files. |
Virtual PBX# |
What is a virtual PBX? Virtual PBX is another term for a hosted or cloud PBX service. It gives businesses PBX features without a traditional on-premise phone cabinet. |
VLAN# |
What is a VLAN? VLAN stands for Virtual Local Area Network. It allows one physical network to be divided into separate logical sections. Businesses often use VLANs to separate voice traffic from general data traffic. |
Voicemail to Email# |
What is voicemail to email? Voicemail to email sends voicemail messages to an email inbox, often as audio attachments or playable files. It makes messages easier to access, forward and store. |
VoIP# |
What is VoIP? VoIP stands for Voice over Internet Protocol. It means making phone calls over the internet instead of traditional phone lines. Searches like VoIP meaning, what is VoIP and VoIP phone system definition all point to modern internet-based business telephony. |
VPN# |
What is a VPN? VPN stands for Virtual Private Network. It creates a secure encrypted connection over the internet. Businesses use VPNs for remote staff access and site-to-site networking. |
WAN# |
What is a WAN? WAN stands for Wide Area Network. It connects sites or offices across towns, regions or countries. A WAN can use broadband, MPLS, SD-WAN, leased lines or other carrier services. |
WebRTC# |
What is WebRTC? WebRTC is a technology that allows voice, video and real-time communication inside a web browser. It is used in click-to-call, browser softphones and modern communication tools. |
Wholesale Line Rental# |
What is Wholesale Line Rental? Wholesale Line Rental is a model where a provider buys underlying line access from another provider and resells it. It has been common in telecom markets with shared infrastructure. |
Wi-Fi Calling# |
What is Wi-Fi calling? Wi-Fi calling lets a mobile phone make calls over Wi-Fi instead of relying only on the mobile signal. It is useful indoors where mobile coverage is weak but broadband is strong. |
Wi-Fi 6# |
What is Wi-Fi 6? Wi-Fi 6 is a newer wireless networking standard designed to improve speed and performance, especially with many devices connected. It is useful in busy homes, offices and shared environments. |
xDSL# |
What is xDSL? xDSL is a general term covering DSL broadband technologies such as ADSL and VDSL. These services use copper lines and are older than modern full fibre access. |
Zero Touch Provisioning# |
What is Zero Touch Provisioning? Zero Touch Provisioning means devices can be configured automatically when deployed, without manual setup on each one. This is especially useful for large deployments of routers, phones and network equipment across multiple sites. |
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