Ethernet LAN

Created: 07/04/2023 

Last Updated: 07/04/2023

Introduction:

Local Area Network is a standard for connecting devices with a limited area such as home and office. They can be wired LAN or wireless, WLAN. The Ethernet Lans are the most common ones found in our home and or offices. They use Ethernet cables to connect devices into the local area network with 8-pin plug or jack.

Background

Data communication Archiecture (OSI Model)

• Physical Layer: The physical layer of LAN Ethernet is responsible for the physical transmission of data over the network. This layer uses a variety of technologies, including twisted-pair copper cables, coaxial cables, and fiber optic cables. The physical layer also defines the electrical and optical signaling used to transmit data over the network.

• Data Link Layer: The data link layer of LAN Ethernet is responsible for providing reliable delivery of data over the network. This layer uses a variety of mechanisms to ensure reliable delivery, including error detection and correction, flow control, and addressing. The data link layer also defines the frame format used to transmit data over the network.

• Network Layer: The network layer of LAN Ethernet is responsible for routing data between different nodes on the network. This layer uses a variety of routing algorithms to determine the best path for data to travel between nodes. The network layer also defines the addressing scheme used to identify nodes on the network.

• Transport Layer: The transport layer of LAN Ethernet is responsible for providing a reliable connection between two nodes on the network. This layer uses a variety of mechanisms to ensure reliable delivery, including acknowledgments, retransmissions, and flow control. The transport layer also defines the service model used to provide reliable delivery of data between nodes.

• Application Layer: The application layer of LAN Ethernet is responsible for providing services to the user. This layer includes a variety of protocols, such as HTTP, FTP, and Telnet, that are used to provide services such as web browsing, file transfer, and remote login.

Hardware Components:

• Switches: Switches are used to connect devices on a LAN and to forward data between devices.

• Routers: Routers are used to connect different LANs together and to route data between LANs.

• Servers: Servers are used to provide services to users on a LAN, such as file sharing, web hosting, and email.

Comsumer Electronics Design:

In a typical consumer device such as a laptop, tv, wifi mesh extender, the embedded processer communicates with the network swtich via a phy receiver chip, which is chip that acts in the physical layer that converts digital data from an embedded processor into eletrical signals (i.e differential signals) that can be transmitted over a long distance using Ethernet cables (to be more precisely, a physical medium).

The PHY chip is responsible for a number of tasks, including:

• Encoding and decoding data: The PHY chip encodes digital data into electrical signals that can be transmitted over the physical medium. It also decodes electrical signals back into digital data at the receiver.

• Signal conditioning: The PHY chip adjusts the electrical signals to ensure that they are received correctly by the receiver. This includes tasks such as equalization and gain control.

• Error detection and correction: The PHY chip detects and corrects errors that occur during transmission. This helps to ensure that the data is received correctly by the receiver.

• Clock synchronization: The PHY chip synchronizes the clocks of the transmitter and receiver to ensure that the data is transmitted and received at the same time.

The PHY chip is a complex piece of hardware, but it is essential for the reliable transmission of data over a network. By understanding how the PHY chip works, you can better understand how networks function and how to troubleshoot network problems.

Summary:

The design of LAN Ethernet is a critical part of any network infrastructure. For consumer eletronics, the clocking, timing delays, placement of the phy receiver with respect to the ethernet port, are important design parameteres. Recommendation is to follow design guidelines closesly and be conservative.