I. Mac sublayer Basics
1. the MAC Sub-layer has two main functions: addressing (MAC address), that is, addressing the target node; second, it is used to prevent multiple users from competing to share physical media or channels.
2. Two Channel types: point-to-point channel, which requires no intermediate device between two nodes and encapsulates point-to-point data link layer protocol; and broadcast channel, it is a situation where a channel is shared by multiple links (shared channels and physical media). Data sent by one node can be received by multiple nodes at the same time, the corresponding link is a "broadcast link". It also requires encapsulation of broadcast-type data link layer protocols, such as Ethernet and WLAN (unlimited LAN) protocols.
3. There is no MAC Sub-layer in the TCP/IP architecture.
4. the intranet of a LAN in the same network segment does not need to be addressed through layer-3 IP addresses, but by layer-2 MAC addresses.
5. The conflicted domain is the range of nodes where media access conflicts may occur. Its size is the number of nodes that may share the same media.
6,
Deep understanding of Computer Network note 6. Media Access Control Sub-Layer