Common Network Terms

Modern business networks combine copper cabling, fibre optics, Ethernet switches, wireless access points and connected devices. This glossary explains the most useful networking terms customers are likely to encounter when planning, upgrading or troubleshooting a network.

=> Ethernet and Network Speeds

Ethernet is the most widely used technology for connecting devices within a wired local area network. Common Ethernet speeds include Fast Ethernet at 100Mbps, Gigabit Ethernet at 1Gbps, Multi-Gigabit Ethernet at 2.5Gbps or 5Gbps, and 10 Gigabit Ethernet at 10Gbps.

The speed available depends on the network switch, connected device, cable category, cable length and installation quality. Multi-Gigabit Ethernet is increasingly important for modern wireless access points, workstations, servers and network-attached storage because it provides more than 1Gbps without always requiring a complete replacement of existing cabling.

 

=> Network Switches: Unmanaged, Smart Managed and Managed

A network switch connects computers, servers, printers, wireless access points, IP cameras and other Ethernet devices on the same network. Unlike an older hub, a switch learns which device is connected to each port and forwards data only where it is required.

An unmanaged switch provides straightforward plug-and-play connectivity. A smart managed switch adds selected features such as VLANs, monitoring and Quality of Service. A fully managed switch provides greater control, security, redundancy and troubleshooting capabilities, making it more suitable for larger or business-critical networks.

 

=> Router, Default Gateway and Firewall

A router connects separate networks and directs data between them. In a typical business network, the router connects the internal local area network to the internet.

The default gateway is the router address that devices use when communicating with a destination outside their own local network. A firewall inspects and controls the traffic passing between networks according to defined security rules. These functions may be provided by one physical appliance, although larger networks often use separate routers, firewalls and security platforms.

 

=> IP Address, IPv4 and IPv6

An Internet Protocol address identifies a device or network interface so that data can be delivered to the correct destination.

IPv4 uses 32-bit addresses, usually displayed in a format such as 192.168.1.20. IPv6 uses 128-bit addresses and was developed to provide a much larger address space, simpler address configuration and other improvements for modern networks. Many organisations now operate IPv4 and IPv6 together using a dual-stack configuration.

 

=> DHCP and DNS

Dynamic Host Configuration Protocol, or DHCP, automatically provides devices with settings such as an IP address, subnet mask, default gateway and DNS server. This avoids having to configure every computer, phone or network device manually.

Domain Name System, or DNS, translates human-readable names into IP addresses. For example, DNS allows a user to enter a website address rather than having to remember the numerical IP address of its server. DHCP and DNS problems are common causes of devices appearing connected while being unable to access network services or the internet.

 

=> Bandwidth, Throughput, Latency and Jitter

Bandwidth is the maximum amount of data a connection is designed to carry, such as 1Gbps or 10Gbps. Throughput is the amount of useful data that is actually transferred after allowing for network overhead, congestion and device limitations.

Latency is the time taken for data to travel through the network. Jitter is the variation in that delay between packets. High bandwidth is valuable for large file transfers, but low latency and low jitter are particularly important for video conferencing, VoIP, remote control, cloud applications and other real-time traffic.

 

=> Category 6 and Category 6A Cabling

Cat6 and Cat6A are common twisted-pair copper cabling categories used for Ethernet networks. Both normally use eight conductors arranged as four twisted pairs and are commonly terminated with RJ45-compatible connectors.

Cat6 supports Gigabit Ethernet over a channel of up to 100 metres. It may support 10 Gigabit Ethernet over shorter distances, but performance can depend on cable length, installation quality and alien crosstalk. Cat6A is designed to support 10GBASE-T over the full 100-metre channel, making it the preferred option for new installations that require reliable 10Gbps performance or greater future capacity.

 

=> U/UTP, F/UTP and S/FTP Shielding

These abbreviations describe how the twisted pairs inside a network cable are protected against electromagnetic interference.

U/UTP has no overall shield and no individual pair shielding. It is commonly described simply as UTP and is suitable for many normal office installations.

F/UTP has an overall foil screen surrounding the unshielded twisted pairs.

S/FTP has an overall braided screen, with each individual pair also protected by foil.

Shielded cabling can be beneficial near electrical equipment, machinery, power cables or other sources of interference. However, the cable, connectors, patch panels and earthing arrangements must form a correctly designed shielded system.

 

=> Power over Ethernet: PoE, PoE+ and PoE++

Power over Ethernet allows compatible devices to receive electrical power and network data through the same Ethernet cable. Typical powered devices include wireless access points, VoIP phones, IP cameras, access-control equipment, digital signage and AV devices.

IEEE 802.3af is commonly called PoE, while IEEE 802.3at is known as PoE+. IEEE 802.3bt introduced higher-power four-pair operation, commonly marketed as PoE++ or 4-pair PoE. Type 4 equipment can supply up to 90 watts from the power sourcing equipment, with a lower amount available to the powered device after cable losses.

When selecting a PoE switch, check both the output supported by each port and the switch’s total PoE budget. A switch may support high-power PoE on an individual port without having enough total capacity to supply that level simultaneously across every port.

 

=> Virtual LAN and Network Segmentation

A Virtual Local Area Network, or VLAN, divides one physical switched network into separate logical networks. Devices can be grouped according to department, function or security requirement rather than simply by where they are physically connected.

For example, a business might use separate VLANs for employees, guest Wi-Fi, IP cameras, VoIP phones and building-management equipment. Traffic moving between VLANs must normally pass through a router, Layer 3 switch or firewall where access rules can be applied. VLANs improve organisation and can strengthen security, but they must be configured correctly throughout the switches, wireless system and routing infrastructure.

 

=> Link Aggregation, LAG and LACP

Link aggregation combines multiple physical Ethernet connections into one logical connection. It can increase the total capacity available between switches, servers or storage devices while also providing resilience if one of the physical links fails.

A Link Aggregation Group is usually abbreviated to LAG. Link Aggregation Control Protocol, or LACP, allows compatible devices to negotiate and manage the aggregated connection automatically.

Link aggregation does not normally multiply the speed of one individual data transfer. Instead, traffic from multiple devices or sessions is distributed across the available links according to the equipment’s load-balancing method.

 

=> Rapid Spanning Tree Protocol

Redundant links between network switches can improve reliability, but uncontrolled Layer 2 loops can create broadcast storms, duplicate frames and severe network disruption.

Spanning Tree Protocol identifies redundant paths and places selected links into a non-forwarding state until they are required. Rapid Spanning Tree Protocol, or RSTP, is a faster development of the original protocol and can restore connectivity more quickly following many network changes or link failures.

RSTP remains an important managed-switch feature wherever multiple switches are connected with redundant paths. It should be deliberately configured rather than treated as a substitute for correct network design.

 

=> Quality of Service

Quality of Service, or QoS, allows network equipment to identify and prioritise particular types of traffic. It is commonly used to give greater priority to delay-sensitive services such as VoIP, video conferencing, live video, control traffic and business-critical applications.

QoS is most noticeable when a network connection becomes congested. It can ensure that important traffic is processed before less urgent transfers such as software downloads or backups. QoS does not create additional bandwidth, and it must be configured consistently across the relevant switches, routers, wireless access points and connected systems.

 

=> Wi-Fi 6, Wi-Fi 6E and Wi-Fi 7

Wi-Fi 6 is based on IEEE 802.11ax and is designed to improve wireless efficiency, capacity and performance where many devices are connected. It operates in the established 2.4GHz and 5GHz frequency bands.

Wi-Fi 6E extends Wi-Fi 6 into the 6GHz band, providing access to additional wireless spectrum where local regulations and compatible equipment allow it.

Wi-Fi 7 introduces features including Multi-Link Operation, wider channels of up to 320MHz in supported markets and 4K QAM. These features can provide higher throughput, lower latency and more reliable performance. Businesses installing Wi-Fi 6E or Wi-Fi 7 access points should also check whether their switches, cabling and PoE budgets can support the increased wired uplink and power requirements.

 

=> Fibre Optic Cabling and SFP Transceivers

Fibre optic cable carries data as light rather than electrical signals. It provides high bandwidth, electrical isolation and greater transmission distances than conventional copper cabling.

OS2 singlemode fibre is normally selected for longer-distance links, building backbones and telecommunications connections. OM3, OM4 and OM5 are multimode fibre categories commonly used for shorter, high-speed connections within buildings and data centres.

Many switches use removable transceiver modules so that the required fibre type, connector and distance can be selected. Common formats include SFP for Gigabit connections, SFP+ for 10 Gigabit Ethernet, SFP28 for 25 Gigabit Ethernet, QSFP+ for 40 Gigabit Ethernet and QSFP28 for 100 Gigabit Ethernet. The module must be compatible with the switch, network speed, fibre category, connector type and optical wavelength used at the opposite end.

 

=> Single Pair Ethernet

Single Pair Ethernet, or SPE, carries Ethernet communications over one twisted pair rather than the four pairs normally found in standard structured network cabling.

SPE is being developed primarily for operational technology, industrial automation, building controls, sensors and other connected edge devices. It can reduce cable size and simplify the connection of field-level equipment to Ethernet-based IT and management systems.

Standards such as 10BASE-T1L are designed for relatively low-speed, long-reach industrial and building applications. SPE is not a direct replacement for Cat6 or Cat6A office cabling, but it is an important emerging technology as IT networks, smart buildings and industrial systems become more closely integrated.