Learn about server network cards in one minute

I have already introduced to you what a server is and what parts a server consists of. Today I will talk to you about the server's network card.

What is a network card? Simply put, a network card is a device that connects a computer to a local area network. Computers are mainly connected to the network through a network card. A network card, also known as a network adapter or a network interface card NIC (Network interface Card), is the most basic and important connection device in a computer network system.

1. Main functions of network card

In the TCP/IP model, the network card works at the physical layer and data link layer and is used to receive and send computer data.

All computers in the network must have a unique MAC address, which is provided by the network card. The main functions of the network card include:

• Data transmission (encapsulation) and reception (decapsulation): When sending data, add the header and tail; when receiving data, strip the header and tail
• Data encoding and decoding: encoding and decoding of physical layer data
• Data link management: mainly the implementation of CSMA/CD (Carrier Sense Multiple Access with Collision Detection)

2. Evolution of Network Cards

Now let's take a look at the evolution of network cards over the years.

3. Classification of Network Cards

What are the categories of network cards? Now let me show you how to do it.

Server dedicated network card VS ordinary network card

Compared with server-specific network cards, ordinary network cards refer to those used in ordinary PCs, workstations, and consumer electronic products, which do not have high requirements for reliability and security. The difference between servers and ordinary PC workstations is that servers are always in operation and require long-term stable operation, which requires server network cards to have the following characteristics:

(1) Fast data transmission speed

The server is always in the process of data calculation and exchange. The data of ordinary network 10Mbps and 100Mbps can no longer meet the needs of large data traffic network. The network card rates commonly used by current servers are 10Gbps, 25Gbps, etc.

(2) Low CPU usage

The server's CPU is constantly working, processing large amounts of data. If a server's CPU is mostly providing data responses to the network card, it will inevitably affect the processing speed of other tasks. The server network card has its own control chip that can handle some CPU tasks, thereby reducing the CPU's computing overhead.

(3) High safety performance

If the server's network card fails, the server will be unable to receive or send data, which is equivalent to a downtime, so high reliability is a must-have feature for server network cards. Server network cards basically have fault tolerance functions, such as Intel's AFT (network card error redundancy) and ALB (network card load balancing) technologies.

4. Server Network Card

Below I will introduce you to the server's network card.

• NIC: Network interface Card refers specifically to an Ethernet card that supports TCP/IP protocol and is used in Ethernet networks.
• CNA: Converged Network Adapter, essentially an Ethernet card, but supports FCoE (FC over Ethernet)
• HBA: Host Bus Adapter, specifically FC network card, supports FC protocol, connects to storage or fiber switch
• HCA: Host Channel Adapter refers specifically to Infiniband network card, or IB card. It is used in high-performance computers with high bandwidth and low latency.

5. Network card interface

There are two main types of physical interfaces for network cards: electrical ports and optical ports.

(1) Electrical port: a common RJ45 port, for example, to connect a network cable

(2) Optical port: used to connect optical modules. According to the interface packaging shape, it can be divided into SFP+, SFP28, QSFP+

• SFP+: supports GE/10GE rate
• SFP28: Supports GE/10GE/25GE rates
• QSFP+: supports 40GE/100GE rates

6. Network Card Manufacturers

What are the manufacturers of network cards?

I believe everyone should have some knowledge about server network cards now, so I will stop here today.