Ethernet is a widely used communication technology standard for local area networks (LANs), which defines the rules for data transmission between devices such as computers, servers, and switches through wired connections. It is one of the fundamental technologies of modern networks, supporting high-speed data transmission from home networks to data centers.
1、 The core characteristics of Ethernet
Wired transmission
Connect equipment through twisted pair cables (such as Cat5e, Cat6), fiber optics, or coaxial cables to provide stable, low latency communication.
Standardization Protocol
Following the IEEE 802.3 standard, the data format, transmission rate, and physical interface are unified.
High scalability
Supports network topologies such as star and bus, and can flexibly expand the number of devices.
Speed classification
Continuously upgrading bandwidth from early 10 Mbps (traditional Ethernet) to today's 400 Gbps (ultra high speed Ethernet).
2、 The working principle of Ethernet
Data encapsulation
Data is transmitted in frames, with each frame containing the destination address, source address, data type, and checksum information.
Frame structure example:
|Preamble | destination MAC address | source MAC address | type/length | data | checksum|
MAC Address Addressing
Each network device has a unique MAC address (such as 00:1A: 2B: 3C: 4D: 5E) used to identify the device's identity.
CSMA/CD (Carrier Sense Multiple Access/Collision Detection)
Traditional Ethernet: The device listens to whether the channel is idle before sending data, and waits for retransmission if there is a conflict (now obsolete, only used for historical understanding).
Modern Switched Ethernet: Establish point-to-point connections directly through switches to avoid conflicts.
3、 Common types of Ethernet
|Type | Speed | Medium | Application Scenario|
|Traditional Ethernet | 10 Mbps | Coaxial Cable | Early LAN (obsolete)|
|Fast Ethernet | 100 Mbps | Twisted Pair (Cat5) | Home and Small Office Networks|
|Gigabit Ethernet | 1 Gbps | Twisted Pair (Cat6), Fiber Optic | Enterprise Networks, Data Centers|
|10 Gigabit Ethernet | 10 Gbps | Fiber Optic, Cat6a/7 | High Performance Computing, Cloud Server Interconnection|
|40/100/400 G Ethernet | 40~400 Gbps | multimode fiber | ultra large scale data center, 5G backbone network|
4、 Typical Applications of Ethernet
Local Area Network (LAN)
Computers in the office are interconnected with printers and file servers.
Internet access
Home broadband connects the optical modem and router through Ethernet cables.
Industrial automation
The factory equipment communicates in real-time through industrial Ethernet (such as Profinet, EtherNet/IP).
Data Center
Servers and storage devices are built into low latency networks through high-speed Ethernet (such as 25G/100G).
5、 The difference between Ethernet and WiFi
|Features | Ethernet (wired) | WiFi (wireless)|
|Transmission medium | Ethernet cable (physical connection) | Radio waves|
|Speed and latency | Higher bandwidth (such as 10Gbps), more stable | Due to signal interference, latency fluctuates greatly|
|Security | More difficult to be intercepted by external parties (requiring physical access) | Requires encryption protocols (such as WPA3) to prevent cracking|
|Applicable scenarios | Fixed devices, high demand transmission (such as NAS) | Mobile devices, flexible deployment|
6、 Expansion Technology of Ethernet
PoE (Power over Ethernet)
Simultaneously transmitting data and power through Ethernet cables, used for devices such as IP cameras and wireless APs (such as PoE++with a maximum power supply of 90W).
VLAN (Virtual Local Area Network)
Divide logical subnets in physical networks to enhance security and management efficiency.
Fiber optic Ethernet
Replace copper cables with single-mode/multi-mode optical fibers, supporting long-distance (such as over 10km) and electromagnetic interference resistance.
7、 Future Development Trends
Higher speed
The 800 Gbps and 1.6 Tbps Ethernet standards are currently under development to meet the data needs of AI training and the metaverse.
Deterministic Ethernet
Realize precise timing control in industrial automation through time sensitive networks (TSN).
Green and energy-saving
Optimize energy efficiency (such as EEE energy-saving standards) and reduce data center power consumption.
If you need to know how to configure home Ethernet or enterprise level switch selection, you can further explore!