What are the main functions of the network card?

The main functions of the network card include: 1. Encapsulation and decapsulation of data. When sending, the data passed by the upper layer is added with a header and a tail to become an Ethernet frame; 2. Link management, through CSMA /CD protocol to achieve; 3. Data encoding and decoding, namely Manchester encoding and decoding.

First of all, let’s introduce what a network card is:

A network card is a piece of hardware designed to allow computers to perform tasks on a computer network Computer hardware for communications. Since it has a MAC address, it belongs to Layer 2 of the OSI model. It allows users to connect to each other via cable or wirelessly. Each network card has a unique 48-bit serial number called a MAC address, which is written in a ROM on the card.

Every computer on the network must have a unique MAC address. No two network cards produced have the same address. This is because the Institute of Electrical and Electronics Engineers (IEEE) is responsible for assigning unique MAC addresses to network interface controller (network card) vendors.

The main functions of the network card:

1. Data encapsulation and decapsulation

When sending, add the header and tail to the data passed from the upper layer to become Ethernet frame. When receiving, the header and tail of the Ethernet frame are stripped off, and then sent to the upper layer

2. Link management

Mainly through CSMA/CD (Carrier Sense Multiple Access with Collision Detection , Carrier Sense Multiple Access with Collision Detection) protocol to implement

3. Data encoding and decoding

is Manchester encoding and decoding. Among them, Manchester code, also known as digital bidirectional code, phase code or phase encoding (PE), is one of the commonly used binary code line encoding methods. It is used by the physical layer to encode the clock and data of a synchronous bit stream. In communications technology, a code used to represent the combination of data and timing signals in the bit stream to be sent. Commonly used in Ethernet communications, train bus control, industrial buses and other fields.

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