Network Glossary: Every Term You Need to Know

Networking jargon can feel like its own language. You just want to know why your game is lagging or your Zoom keeps freezing, and every answer is packed with acronyms that assume you already understand the acronyms.

This glossary cuts through that. Every term is explained in plain language with context for why it matters to you, whether you're a gamer trying to fix rubber-banding, a remote worker dealing with choppy calls, or someone trying to understand what their ISP is actually telling them.

Connection Quality Metrics

Packet Loss - The percentage of data packets that are sent but never arrive at their destination. If you send 100 packets and 2 go missing, that's 2% packet loss. Even 1% causes noticeable problems in gaming and video calls. Speed tests don't measure this. PacketProbe does.

Latency (Ping) - The time it takes for a packet to travel from your device to a server and back, measured in milliseconds (ms). When gamers say "my ping is 30," they mean their round-trip latency is 30ms. Lower is better. Under 50ms is good for gaming; under 150ms is fine for video calls.

Jitter - How much your latency varies from one packet to the next. If your ping bounces between 20ms and 80ms, you have high jitter. Jitter matters because real-time applications expect packets at regular intervals. High jitter causes stuttering audio, frozen video frames, and unpredictable game responsiveness. Under 15ms is ideal.

Round-Trip Time (RTT) - Same as latency/ping. The total time for a packet to make the complete journey to the server and back.

Throughput - The actual amount of data transferred per second, measured in Mbps or Gbps. This is what speed tests measure. It tells you how much data your pipe can carry, but not how reliably or consistently it carries it.

Bandwidth - The maximum theoretical capacity of your connection. Your ISP advertises bandwidth (e.g., "500 Mbps"). Throughput is what you actually get, which is always somewhat less than the advertised bandwidth.

Protocols

TCP (Transmission Control Protocol) - The protocol that powers web browsing, email, file downloads, and most internet traffic. TCP guarantees delivery: if a packet is lost, it's automatically resent. This reliability comes at the cost of speed, since the sender has to wait for acknowledgment. Great for data accuracy, bad for real-time applications because retransmitting a lost game input 200ms later is pointless.

UDP (User Datagram Protocol) - A faster, simpler protocol that sends packets without guaranteeing delivery. If a packet is lost, it's gone. There's no retransmission and no waiting. This makes UDP ideal for gaming, video calls, voice chat, and live streaming, where speed matters more than perfection. When you test packet loss with PacketProbe, we use a UDP-like channel for this exact reason.

WebRTC (Web Real-Time Communication) - A browser technology that enables real-time audio, video, and data communication without plugins. Zoom, Google Meet, Discord (in-browser), and many other apps use WebRTC. PacketProbe uses WebRTC's unreliable data channels to test packet loss in a way that mirrors what your real applications experience.

ICMP (Internet Control Message Protocol) - The protocol behind the ping and traceroute commands. ICMP is useful for basic connectivity checks, but some routers deprioritize ICMP traffic, which can give misleadingly high ping results.

HTTP/HTTPS - The protocol that delivers web pages. HTTPS is the encrypted version (the padlock in your browser). Both run on top of TCP.

DNS (Domain Name System) - Translates human-readable domain names (like packetprobe.com) into IP addresses (like 104.21.33.1) that computers use to find each other. When DNS is slow, every website feels slow to load because your device has to wait for the name lookup before it can connect.

Network Hardware

Router - The device that directs traffic between your home network and the internet. It assigns local IP addresses, manages connections, and (ideally) prioritizes traffic. Most home routers also include a built-in Wi-Fi access point and a small Ethernet switch.

Modem - Converts the signal from your ISP's network (cable, DSL, or fiber) into something your router can use. Some ISPs combine the modem and router into a single device (often called a gateway). Separating them gives you more control.

Switch - A device that connects multiple Ethernet devices on the same network. If you need more wired ports than your router provides, you add a switch. Unlike a router, a switch doesn't manage internet traffic or assign IP addresses.

Access Point (AP) - A device that creates a Wi-Fi network. Your router has one built in. Standalone access points are used in larger homes or offices where a single router's Wi-Fi doesn't reach everywhere.

Mesh Wi-Fi System - A set of multiple access points (nodes) that work together to blanket your home in Wi-Fi coverage. Brands like Eero, Google Wifi, and Orbi are popular examples. The nodes communicate with each other either wirelessly (wireless backhaul) or via Ethernet (wired backhaul). Wired backhaul is significantly better for latency and jitter.

MoCA Adapter - A device that carries Ethernet data over existing coaxial cable (the cable TV wiring in your walls). It's an alternative to running new Ethernet cables, and it performs close to a direct Ethernet connection.

Powerline Adapter - Carries network data over your home's electrical wiring. More convenient than running cables, but performance depends heavily on the quality and age of your wiring. Not recommended for latency-sensitive applications.

IP Addresses & Networking

IP Address - A numerical label assigned to every device on a network. Your public IP address identifies your home on the internet. Your private/local IP address (like 192.168.1.x) identifies your device within your home network.

IPv4 - The original IP address format, written as four numbers separated by dots (e.g., 192.168.1.1). There are about 4.3 billion possible IPv4 addresses, which ran out years ago.

IPv6 - The newer IP address format with a much larger address space, written in hexadecimal groups (e.g., 2001:0db8:85a3::8a2e:0370:7334). Adoption is growing but not yet universal.

NAT (Network Address Translation) - The technology that lets multiple devices in your home share a single public IP address. Your router translates between your local IP addresses and your public IP when traffic goes to and from the internet. NAT is why you can have dozens of devices but only one ISP-assigned IP.

DHCP (Dynamic Host Configuration Protocol) - The system that automatically assigns IP addresses to devices when they join your network. When your phone connects to Wi-Fi and gets a 192.168.x.x address, that's DHCP at work.

Port - A number (1-65535) that identifies a specific service or application on a device. Web traffic uses port 80 (HTTP) or 443 (HTTPS). Game servers use specific ports for online play. When you set up port forwarding, you're telling your router to send traffic arriving on a specific port to a specific device.

Port Forwarding - A router configuration that directs incoming traffic on a specific port to a specific device on your network. Necessary for hosting game servers, running a Minecraft server, or using certain peer-to-peer applications from behind NAT. You can check if a port is open with our port checker tool.

Wi-Fi Terms

2.4GHz Band - The original Wi-Fi frequency band. Longer range but slower speeds and more interference from Bluetooth, microwaves, and neighboring networks. Supports channels 1-11 (in the US). Only channels 1, 6, and 11 don't overlap with each other.

5GHz Band - A higher-frequency Wi-Fi band with faster speeds, more available channels, and less interference than 2.4GHz. The tradeoff is shorter range and worse wall penetration.

6GHz Band (Wi-Fi 6E / Wi-Fi 7) - The newest Wi-Fi frequency band, available on Wi-Fi 6E and Wi-Fi 7 devices. Much less congestion than 2.4 or 5GHz because only new devices support it. The best option for low-jitter wireless connections if your hardware supports it.

SSID - The name of a Wi-Fi network. The text you see when you scan for available networks.

Wi-Fi Channel - A specific frequency slice within a Wi-Fi band. If you and your neighbor are on the same channel, your networks interfere with each other. Switching to a less-crowded channel can improve performance.

Dual-Band / Tri-Band - A dual-band router broadcasts on both 2.4GHz and 5GHz simultaneously. A tri-band router adds a second 5GHz radio (or a 6GHz radio on newer models), which helps in busy households by giving more devices dedicated airtime.

Router Settings & Configuration

QoS (Quality of Service) - Router settings that prioritize certain types of traffic over others. With QoS enabled, you can tell your router to process gaming or video call packets before file downloads, reducing latency and jitter for the traffic that matters most.

SQM (Smart Queue Management) - An advanced form of traffic management that actively controls packet buffer sizes to prevent bloat. Available on routers running OpenWrt firmware and some consumer routers. SQM with the fq_codel algorithm is currently the gold standard for minimizing latency under load.

Buffer Bloat - A condition where oversized packet buffers in your router or modem cause excessive queuing delays. When buffers are too large, packets wait in line for too long, driving latency and jitter through the roof even when bandwidth isn't saturated. SQM is the standard fix.

MTU (Maximum Transmission Unit) - The largest packet size (in bytes) that a network link will carry without breaking it into smaller pieces. The default is usually 1500 bytes. If your MTU is set too high for your connection (common with VPNs or PPPoE connections), packets get fragmented, which adds latency and can cause packet loss.

UPnP (Universal Plug and Play) - A protocol that lets devices on your network automatically configure port forwarding on your router. Game consoles use it to open ports for online play. Convenient, but a security concern since any device can open ports without your knowledge.

Firmware - The software that runs on your router. Manufacturers release updates to fix bugs, improve performance, and patch security vulnerabilities. Many people never update their router firmware, and it's a common source of unexplained network issues.

ISP & Connection Types

ISP (Internet Service Provider) - The company that provides your internet connection (Comcast, AT&T, Verizon, etc.).

Fiber (FTTH) - Internet delivered via fiber optic cable directly to your home. The fastest and lowest-latency consumer internet technology. Typical latency: 2-10ms to the first hop.

Cable (DOCSIS) - Internet delivered over coaxial cable (the same cable that carries TV signals). Fast download speeds, but upload speeds are often much lower. Shared bandwidth with your neighbors means peak-hour congestion is common.

DSL - Internet delivered over telephone lines. Slower than cable or fiber, but a dedicated line so you don't share bandwidth with neighbors. Latency depends on distance from the ISP's equipment.

Peering Point - A location where different ISPs and networks connect and exchange traffic. Congested peering points are a common cause of latency spikes and packet loss between specific ISPs, especially during peak hours.

Traceroute - A diagnostic tool that shows the path packets take from your device to a destination, listing every router (hop) along the way. Useful for identifying where in the network path latency or loss is occurring.

Hop - Each router a packet passes through on its journey. A typical internet connection involves 10-20 hops between your device and a destination server. Each hop adds a small amount of latency.

Gaming-Specific Terms

Rubber-Banding - When your character snaps back to a previous position in a game. Caused by packet loss: your client sends movement data, the server never receives it, and the server corrects your position based on the last data it did receive.

Desync - When what you see on your screen doesn't match what the server sees. You think you're behind cover, but the server says you're still exposed. Caused by a combination of high latency and packet loss.

Hit Registration - Whether a game server registers that your shot hit a target. Poor hit registration (shots that should hit but don't count) is often caused by packet loss or high latency between you and the game server.

Tick Rate - How many times per second a game server updates the game state. A 64-tick server processes 64 updates per second. Higher tick rates require more consistent network performance; packet loss or jitter at high tick rates causes more noticeable gameplay issues.

Netcode - The umbrella term for how a game handles networking: client-side prediction, server reconciliation, lag compensation, interpolation. Good netcode can mask minor network issues; bad netcode amplifies them.

Lag Compensation - A game server technique that rewinds time to account for each player's latency when determining if a shot hit. It's why you sometimes get killed behind cover: on the shooter's screen (rewound by their latency), you were still visible.

NAT Type - A classification (Open, Moderate, Strict) that describes how restrictive your router's NAT is. Strict NAT can prevent you from connecting to some game lobbies or using voice chat. Most consoles show your NAT type in network settings.