89 Essential Computer Network Concepts Every Engineer Should Know

Computer networking concepts are extensive and often difficult to grasp; this article compiles 89 common concepts to help readers understand the fundamentals of computer networks.

主机 : Any device that can connect to a network, also called an 端系统 , such as phones, tablets, TVs, game consoles, cars, etc.

通信链路 : A physical path formed by connecting physical links (coaxial cable, twisted pair, fiber, etc.).

传输速率 : Measured in bit/s or bps, indicating the data transmission speed between end systems.

分组 : Data is fragmented into packets with headers when sent from one end system to another.

路由器 : A switching device, similar to a link‑layer switch, primarily used for forwarding data.

路径 : The sequence of links and packet switches a packet traverses through the network.

因特网服务商 : Also called ISP, referring to network operators such as mobile carriers, telecom, and Unicom.

网络协议 : Rules, standards, or conventions established for data exchange in computer networks.

IP : Internet Protocol, defining the format of packets exchanged between routers and end systems.

TCP/IP 协议簇 : A suite centered on TCP and IP, including ICMP, ARP, UDP, DNS, SMTP, etc.

分布式应用程序 : Applications where multiple end systems exchange data with each other.

套接字接口 : The socket interface that defines how end systems exchange data over the Internet.

协议 : Standards governing the format and order of messages exchanged between two or more communication entities.

客户端 : The request side in a client‑server architecture, typically PCs, smartphones, etc.

服务器 : The service side in a client‑server architecture, usually large server clusters.

转发表 : A table inside a router that maps packet destinations to outgoing interfaces.

时延 : The time a packet takes to travel from one end of the network to the other, composed of transmission, propagation, processing, and queuing delays.

丢包 : The phenomenon where packets are lost during transmission.

吞吐量 : The amount of data successfully transmitted per unit of time.

报文 : Typically refers to application‑layer packets.

报文段 : Transport‑layer packets, often called segments.

数据报 : Network‑layer packets, commonly called datagrams.

帧 : Link‑layer packets, known as frames.

客户‑服务体系 : A client‑server architecture where clients request services from a server that processes and returns results.

CIDR : Classless Inter‑Domain Routing, using variable‑length subnet masks to divide IP address space.

P2P 体系 : Peer‑to‑peer architecture where each node acts as both client and server.

IP 地址 : The unique identifier for a host on the Internet, divided into private and public IPs.

端口号 : Identifies different application processes on the same host.

URI : Uniform Resource Identifier, uniquely marks resources on the Internet.

URL : Uniform Resource Locator, a subset of URI.

HTML : HyperText Markup Language, a descriptive language consisting of tags that structure web documents.

Web 页面 : Also called a Web Page, composed of objects such as HTML files, images, or Java applets, accessible via a URI.

Web 服务器 : Provides documents to browsers and hosts website files; common implementations include Apache, Nginx, and IIS.

CDN : Content Delivery Network, uses caching and proxy techniques to deliver content from edge servers close to users.

WAF : Web Application Firewall, an application‑level firewall that enforces security policies on HTTP/HTTPS traffic.

WebService : A cross‑platform remote invocation technology for web applications.

HTTP : A protocol in the TCP/IP suite for transferring hypertext data between two points.

Session : Server‑side storage of client state to compensate for HTTP’s stateless nature.

Cookie : Small data pieces sent by the server to the browser to maintain state across requests.

SMTP 协议 : Simple Mail Transfer Protocol, used for sending email between systems.

DNS 协议 : Translates human‑readable domain names into IP addresses.

TELNET 协议 : Remote login protocol allowing a client to communicate with a remote device.

SSH 协议 : Secure Shell, an encrypted protocol for remote login, replacing Telnet.

FTP 协议 : File Transfer Protocol, used for transferring files between client and server.

MIME 类型 : Internet media types such as text/html, image/png, video/x‑msvideo, etc.

多路分解 : The process of demultiplexing incoming packets to the correct socket based on port numbers.

多路复用 : The process of multiplexing data from multiple sockets into packets for transmission.

周知端口号 : Well‑known ports (0‑1023) reserved for privileged services.

单向数据传输 : Unidirectional data flow from sender to receiver.

双向数据传输 : Bidirectional (full‑duplex) communication where both ends can send and receive.

面向连接的 : Connection‑oriented communication requiring a handshake before data transfer.

三次握手 : The three‑step handshake process to establish a TCP connection.

最大报文段长度 : MSS, the maximum amount of data that can be placed in a TCP segment.

最大传输单元 : MTU, the largest payload size that can be transmitted over a link.

冗余 ACK : Duplicate acknowledgments indicating possible packet loss.

快速重传 : Retransmission of a lost segment before its timer expires.

选择确认 : Selective acknowledgment allowing the receiver to acknowledge out‑of‑order segments.

拥塞控制 : Mechanisms to reduce sending rate when network congestion is detected.

四次挥手 : The four‑step termination process for a TCP connection.

路由选择算法 : Algorithms used by the network layer to determine packet forwarding paths.

转发 : The action of moving a packet from an input link to the appropriate output link.

分组调度 : Scheduling methods for transmitting packets, such as FIFO, priority queuing, and weighted fair queuing.

IPv4 : The widely used version of the Internet Protocol with 32‑bit addresses.

IPv6 : The next‑generation Internet Protocol with 128‑bit addresses, addressing IPv4 exhaustion.

接口 : The boundary between a host and a physical link.

ARP 协议 : Address Resolution Protocol, resolves IP addresses to MAC addresses on IPv4 networks.

RARP : Reverse ARP, maps MAC addresses back to IP addresses.

代理 ARP : Proxy ARP, forwards ARP requests across subnets.

ICMP 协议 : Internet Control Message Protocol, used for error messages and operational information.

DHCP 协议 : Dynamic Host Configuration Protocol, automates IP address assignment.

NAT 协议 : Network Address Translation, translates private IP addresses to public ones for Internet access.

IP 隧道 : Encapsulates IP packets within another protocol to traverse networks.

单播 : One‑to‑one communication.

广播 : One‑to‑all communication, sending to all nodes on a network.

多播 : One‑to‑many communication limited to a specific group of receivers.

任播 : Anycast, selects the best receiver among multiple candidates.

IGP : Interior Gateway Protocol, used within an autonomous system.

EGP : Exterior Gateway Protocol, used between autonomous systems.

RIP : Routing Information Protocol, a distance‑vector routing protocol for LANs.

OSPF : Open Shortest Path First, a link‑state routing protocol.

MPLS : Multiprotocol Label Switching, a technique that forwards packets based on labels.

节点 : Devices at the link layer.

链路 : The communication channel connecting adjacent nodes.

MAC 协议 : Media Access Control protocol, governing frame transmission on a link.

奇偶校验位 : Parity bits used for error detection in data communication.

向前纠错 : Forward error correction, allowing the receiver to detect and correct errors.

以太网 : Ethernet, the most common LAN technology defining physical and MAC layer specifications.

VLAN : Virtual LAN, a logical grouping of devices regardless of physical location.

基站 : Base station, the infrastructure for wireless networks.