Internet and Wi-Fi glossary
Internet faults are easier to diagnose when the measurements are not confused with one another. This glossary explains the terms used by LumaProbe and how each one affects troubleshooting.
Speed and capacity
Bandwidth is the amount of data a connection can carry over time. Internet packages and speed tests commonly express it in megabits per second, written Mbps. Eight bits make one byte, so an 80 Mbps connection does not download a file at 80 megabytes per second. Protocol overhead and real network conditions reduce the usable file-transfer rate.
Download speed describes data moving towards the user, such as a video stream or software update. Upload speed describes data moving away, such as a cloud backup or video-call camera feed. Throughput is the rate actually achieved during a transfer. It can be lower than the connection’s theoretical or advertised capacity.
Responsiveness and consistency
Latency is the delay for a request to travel to a destination and a response to return. It is measured in milliseconds. Distance, routing, queueing and the access technology all contribute. A fast download does not guarantee low latency. Interactive uses such as calls, remote desktops and games often notice delay before they exhaust bandwidth.
Jitter describes variation between latency samples. A connection averaging 25 ms can still feel unstable if individual responses jump widely. Packet loss means network packets fail to reach their destination. A browser can observe failed web requests, but that is not identical to a controlled ICMP or UDP packet-loss test.
Addresses and name resolution
An IP address identifies an interface on an IP network. IPv4 addresses use a shorter dotted format, while IPv6 provides a much larger address space. A public IP is the address visible to services on the internet. Devices inside a home usually have private addresses and share the public address through network address translation, or NAT.
The Domain Name System, or DNS, translates names such as lumaprobe.com into IP addresses. An A record returns an IPv4 address and an AAAA record returns an IPv6 address. A resolver performs lookups on behalf of a device. Changing resolver can help diagnose a DNS problem, but it also changes which organisation processes those queries.
Local networking
Ethernet is a family of wired local-network technologies. A gigabit Ethernet link can carry up to one gigabit per second at the physical link layer, although usable throughput is lower. A network switch adds wired ports within the same local network. It does not by itself make the broadband line faster.
Wi-Fi is the local wireless connection between a device and an access point or router. Signal strength, interference, walls, channel use, device capability and distance affect it. The 2.4 GHz band usually reaches farther but has less capacity and more congestion; 5 GHz can provide higher rates over shorter practical distances. 6 GHz support depends on compatible equipment and regional rules.
Routers, access points and mesh
A router moves traffic between networks and commonly performs NAT, firewall and DHCP functions in a home. A modem or optical network terminal connects to the provider’s access technology. Providers often combine routing and Wi-Fi in one hub, but the functions are conceptually separate.
An access point provides Wi-Fi access to a wired network. A mesh system coordinates multiple nodes under one managed wireless system. Mesh can improve coverage, but each node still needs a good path back to the main router. Wired backhaul uses Ethernet for that path; wireless backhaul shares radio capacity and depends on node placement.
Web and security terms
HTTP is the application protocol used to request web resources. HTTPS adds authenticated encryption using TLS. An HTTP status code summarises the response: codes in the 200 range generally indicate success, 300-range codes redirects, 400-range codes a client-side or access issue, and 500-range codes a server-side problem. One response does not prove the entire service is healthy.
A VPN creates an encrypted tunnel to another network endpoint. It can improve privacy on an untrusted network, but it changes the route and may reduce speed or increase latency. A firewall controls allowed traffic. Port forwarding deliberately exposes a service through the router and should be configured only when the user understands the security implications.
Testing terms
A control test changes one part of the setup while keeping the rest as similar as possible. Ethernet is a useful control for Wi-Fi because it removes the wireless hop. A sample is one observation; several samples help reveal variation. An average can hide spikes, so latency and jitter should be considered together.
A browser-based test measures the experience available to that browser. A line test performed by a provider may measure a different boundary, such as the connection to the router. Both can be valid while reporting different numbers. The important question is which part of the path each method includes.
Questions or corrections
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