Commit 9359df
2025-03-07 21:17:13 R. Bishop: Ethernet Initial Commit| /dev/null .. communications/ethernet.md | |
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| + | # Ethernet Communications |
| + | |
| + | ## What is Ethernet Communication? |
| + | |
| + | Ethernet communication is a widely used **networking technology** that enables devices to transmit and receive data over a wired connection. It operates using a set of standardized protocols defined by the **IEEE 802.3** standard, allowing devices to communicate efficiently within local area networks (LANs) and beyond. Unlike **serial communication**, which transmits data one bit at a time, Ethernet can handle large amounts of data at high speeds using packet-based transmission. |
| + | |
| + | --- |
| + | |
| + | ## Why Use Ethernet Instead of Serial Communication? |
| + | |
| + | ### **Higher Data Transfer Speeds** |
| + | |
| + | Ethernet supports significantly higher data rates compared to traditional serial communication: |
| + | |
| + | - **Serial communication** typically operates at speeds ranging from **9.6 kbps to 115.2 kbps** (RS-232) or up to **10 Mbps** (RS-485). |
| + | - **Ethernet communication** supports speeds of **10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps, and even higher**, making it ideal for data-intensive applications. |
| + | |
| + | ### **Network Scalability** |
| + | |
| + | - **Serial communication** is primarily designed for **point-to-point** or small-scale multi-device networks. |
| + | - **Ethernet supports multiple devices** within a network, enabling seamless communication between computers, servers, IoT devices, and industrial equipment. |
| + | |
| + | ### **Longer Distance Capabilities** |
| + | |
| + | - Standard **copper-based Ethernet (Cat5e/Cat6)** can transmit data up to **100 meters (328 feet)** per segment. |
| + | - **Fiber-optic Ethernet** can extend communication up to **several kilometers**, far exceeding the limits of traditional serial connections. |
| + | |
| + | ### **Reliability & Error Handling** |
| + | |
| + | - Ethernet uses **error detection and correction mechanisms** like **Cyclic Redundancy Check (CRC)** to ensure data integrity. |
| + | - Serial communication has limited error detection, making it more prone to data corruption over long distances. |
| + | |
| + | --- |
| + | |
| + | ## Full-Duplex vs. Half-Duplex Ethernet |
| + | |
| + | ### **What is Duplex Communication in Ethernet?** |
| + | |
| + | Ethernet supports both **full-duplex** and **half-duplex** communication modes, depending on network requirements and hardware capabilities. |
| + | |
| + | ### **Full-Duplex Ethernet** |
| + | |
| + | - Allows **simultaneous transmission and reception** of data. |
| + | - Eliminates collisions, making communication more efficient. |
| + | - Example: **Gigabit Ethernet (1 Gbps and above) always operates in full-duplex mode.** |
| + | |
| + | ### **Half-Duplex Ethernet** |
| + | |
| + | - Data can only be transmitted in **one direction at a time**. |
| + | - Used in older Ethernet networks that rely on **CSMA/CD (Carrier Sense Multiple Access with Collision Detection)**. |
| + | - Example: **Legacy 10 Mbps or 100 Mbps Ethernet using hubs.** |
| + | |
| + | --- |
| + | |
| + | ## Common Ethernet Protocols & Technologies |
| + | |
| + | Ethernet is implemented using various protocols and technologies tailored for different applications: |
| + | |
| + | ### **Standard Ethernet Protocols** |
| + | |
| + | - **Fast Ethernet (100BASE-T)** → Supports speeds up to **100 Mbps** over twisted-pair cables. |
| + | - **Gigabit Ethernet (1000BASE-T)** → Operates at **1 Gbps**, common in modern networks. |
| + | - **10 Gigabit Ethernet (10GBASE-T)** → Designed for high-speed data centers and enterprise networks. |
| + | - **Power over Ethernet (PoE)** → Allows data and electrical power to be transmitted over the same cable, useful for IP cameras and VoIP phones. |
| + | - **Ethernet over Fiber (1000BASE-LX, 10GBASE-SR, etc.)** → Enables long-distance communication over fiber-optic cables. |
| + | |
| + | ### **Industrial & Secure Ethernet Variants** |
| + | |
| + | - **Industrial Ethernet (PROFINET, EtherNet/IP, Modbus TCP, etc.)** → Used in automation, manufacturing, and industrial environments. |
| + | - **Time-Sensitive Networking (TSN)** → Enables low-latency communication for real-time applications like autonomous vehicles. |
| + | - **VLANs (Virtual Local Area Networks)** → Segment network traffic for improved security and efficiency. |
| + | - **MACsec (Media Access Control Security)** → Provides encryption for secure Ethernet communication. |
| + | |
| + | --- |
| + | |
| + | ## Ethernet Data Transmission Format |
| + | |
| + | Ethernet communication follows a structured data transmission format, known as the **Ethernet frame**. Below is a table showing the typical format of an Ethernet frame: |
| + | |
| + | | Field | Size (Bytes) | Description | |
| + | |-------|------------|-------------| |
| + | | Preamble | 7 | Synchronization sequence for receiver alignment | |
| + | | Start Frame Delimiter (SFD) | 1 | Marks the start of a valid Ethernet frame | |
| + | | Destination MAC Address | 6 | MAC address of the recipient | |
| + | | Source MAC Address | 6 | MAC address of the sender | |
| + | | EtherType/Length | 2 | Indicates the protocol type or length of payload | |
| + | | Payload (Data) | 46-1500 | The actual transmitted data | |
| + | | Frame Check Sequence (FCS) | 4 | CRC used for error detection | |
| + | |
| + | This structured approach ensures reliable data transmission while maintaining compatibility across different network devices. |
| + | |
| + | --- |
| + | |
| + | ## Ethernet in the Fire & Security Industry |
| + | |
| + | Ethernet plays a crucial role in modern **fire and security systems**, providing fast and reliable data transmission for real-time monitoring and control. Key applications include: |
| + | |
| + | - **IP Surveillance Cameras** → High-definition video feeds over Ethernet. |
| + | - **Access Control Systems** → Securely manage door entry systems using networked controllers. |
| + | - **Fire Alarm & Building Automation Systems** → Monitor sensors and alarms over Ethernet-based protocols like BACnet/IP. |
| + | - **Intrusion Detection Systems** → Real-time alerts transmitted via secure Ethernet connections. |
| + | |
| + | --- |
| + | |
| + | Ethernet communication has become the backbone of modern networking, offering **high-speed, reliable, and scalable** connectivity. While serial communication is still used for specialized applications, Ethernet is the preferred choice for most industrial, commercial, and security systems due to its **efficiency, flexibility, and advanced features**. |