Important MAC protocols in the Network

We certainly don't know the MAC protocol. This Protocol defines the network address and is the foundation of our network. Now, we will give a brief analysis and introduction on this protocol, hoping to give you a deeper understanding of this Protocol.

Meaning

Media Access Control

Meaning

Media Access Control

It defines how data packets are transmitted on the media. In a link that shares the same bandwidth, access to the connection media is "first served. Physical addressing is defined here, and the logical topology signal is also defined here through the path of the physical topology. Line Control, Error Notification not corrected), frame transmission sequence and selectable traffic control are also implemented in this sublayer.

Annotation

The Protocol is located at the data link layer in the OSI Layer-7 protocol. The data link layer is divided into upper-layer LLC Logical Link Control and lower-layer MAC Media Access Control. MAC is mainly responsible for controlling and connecting physical media on the physical layer. When sending data, the MAC protocol can determine whether data can be sent in advance. If data can be sent, it adds some control information to the data, and finally sends the data and control information to the physical layer in the specified format; when receiving data, the MAC protocol first checks the input information and determines whether a transmission error has occurred. If no error occurs, the control information is removed and sent to the LLC Logical Link control layer.

Application

MAC protocol is widely used in both traditional wired LAN and popular Wireless lan wlan. In traditional LAN, the physical layers of various transmission media correspond to the corresponding MAC layer. Currently, the commonly used network adopts the MAC layer standard of IEEE 802.3 and the CSMA/CD access control mode; in a wireless LAN, the MAC standard is IEEE 802.11, which uses DCF distribution control) and PCF center control ).

1. MAC protocol for traditional wired LAN

In network standards, the physical layers of various transmission media correspond to the relative MAC layer. For example, when the same axis is used as the transmission media, the corresponding MAC layer standard is 802.14. When each computer is connected to a ring, corresponding MAC standard is 802.5. Currently, the most popular network standard is Ethernet, which is defined as 802.3 on the MAC layer. The MAC layer of 802.3 defines the access control mode for transmission media as CSMA/CD.

2. CSMA/CD media access control protocol

Due to Ethernet, CSMA/CDCarrier Sense Multiple Access/Collision Detection has become the most widely used MAC protocol in local networks. CSMA/CD is suitable for random competitive media access control in the topology of bus LAN. A bus-type network allows only one Node at a time) to send data. Once two or more nodes send data at the same time, a data collision occurs and the data cannot be sent and received normally. CSMA/CD protocol is used to ensure that only one node on the network sends data at the same time, reducing the probability of Data "Collision.