What is a network adapter, where is it located and how does it work? Here are the main issues that will be addressed in this article.
Why is it necessary?
An adapter is equipment that providesnetwork operation at the channel and physical levels. It belongs to the peripheral devices. It directly interacts with the data transmission medium.
Адаптер успешно решает задачу надёжного обмета binary data on external communication lines. Since it is a computer controller, it performs its work under the control of the driver installed in the operating system. Mounted the same network adapter in the socket of the motherboard. It converts parallel codes that are used in the computer into a stream of powerful signals that transmit data over the network. Therefore, they are required to be compatible with the network operating system and the information bus of the PC itself. How to install a network adapter in the motherboard?
Customize
We have sorted out what the network adapter is, nowYou can consider his preparation for work. If it meets the PnP standard, then the setting is automatic. In another case, you need to manually work with the interrupt request line and the I / O address.
Functions
We considered what a network adapter is and how it is configured, and now let's talk about the tasks that are solved when sending or receiving messages. A total of nine:
- Conduct a galvanic isolation with twisted pair or coaxial cable. Pulsed transformers are mainly used for this purpose, although it is possible to use optocouplers.
- Transmission (reception) of data. They come from RAM to the adapter or from it into the computer’s memory through input / output channels and direct access.
- BufferingIt is used to match the speed at which data is sent from or to the adapter as it is transmitted over the network. Also during the processing of information it is stored in a buffer. It allows the adapter to work with the entire information package. Also, thanks to the adapter, the data processing speeds of the various components of the LAN are coordinated with each other.
- Formation package.Network adapter data must be divided into separate blocks in the transfer mode (or they are collected at the reception), then to arrange them as a frame of a certain format. It will be composed of several service fields, where the address of the recipient’s computer is indicated, as well as the checksum of the frame, by which the device accepts whether the delivered information is correct.
- Access to the communication channel.Also in its "jurisdiction" a set of rules with which you can get the opportunity to work with the transmission medium. In addition, the adapter detects conflicts and monitors the status of the network.
- Identification of your address in the package that is accepted. It can be determined by setting the switches, stitched into the EPROM or stored in a special register.
- Convert parallel code tosequential during the transfer of data, and he carries out their reverse conversion when they are received. There is a small exception to this. When the data transfer mode is active, the information is transmitted in a serial code via a communication channel.
- Encoding / decoding data.At this stage, electrical signals are generated that are used to represent information. In most cases, Manchester coding is used. This method does not require a synchronization signal to be used to recognize ones and zeros. In this case, a polarity change is used.
- Receive or transmit data pulses.
Also, network adapters when working with the necessary software can recognize and handle an error that occurs due to poor equipment operation, collisions, or electrical interference.
Base address
It is also called physical. Some network adapters can use the computer’s RAM as a buffer to store outgoing and incoming data packets.
The base address in this case is a hexadecimal number that indicates where the information is located.
Classification by protocol access and environment access methods
The network technology uses three basic adapter types:
- Ethernet.
- FDDI.
- Token ring
Usually, a certain model works only on its own network technology. But at the same time they can support, as a rule, several different data transmission media.
For example, Ethernet works with:
- Fiber optic cable.
- Unshielded twisted pair.
- Coaxial cable.
When a device must work with an environment for which it was not originally intended, then converters and transceivers are used. Also, network adapters are distinguished by the internal data bus:
- PCI.
- EISA.
- Isa.
- MCA.
By what parameters can network adapters be classified?
In addition to the above, can also be used such:
- Type of tire.
- Buffer size for the package.
- Transmission speed.
- Compatible with different microprocessors.
- Speed tires.
- By the presence / absence of the use of direct memory access.
- Connector design
- Addressing I / O ports and interrupt requests.
Physical implementation
Let's take the network as an example.Adapter for Windows 7. For the most part, they can be placed on the motherboard. But the TP-Link network adapter is derived beyond the boundaries of the system unit.
This is not least related to hisfunctionality (the ability to connect multiple computers and create a Wi-Fi network, that is, it also performs the function of a router and router). The latter feature allows the adapter to create even a small local area network that connects all devices with the necessary interface within reach. You can also find a USB network adapter. It is usually offered to people by mobile network operators. Network USB-adapter in this case looks like a USB flash drive, and it connects in the same way. For data transmission, however, 2G or 3G Internet is used. These are the ways in which we can see the network adapter for Windows 7. By the way, how is this device implemented in laptops? If we talk about the network adapter Asus, then it must be present in the devices. The same applies to other laptops. The fact is that they are designed for use in various conditions, including mobile ones, when you have to work with everything in a row.
Conclusion
So, we found out what a network adapter is, what types they are and how they are implemented in practice.
We also looked at an example of creating a localnetwork with their help. In conclusion, it should be said that they can be found not only on home computers or laptops, but also on the servers of providers that provide Internet access to their users. Only here they are used as a transitional gateway.
