Simply put, in order to achieve communication between processes across the Internet, Host A process P1, and host B P2 , layer by layer we put this task to the TCP / IP protocol stack.
Transport Layer:"If someone can help me to move data from one network to another network machine A machine B, I can handle this job, because I know that different processes on which data should be handed over to the machine. "
Network layer:"If someone can help me put a machine connected to the data directly from the LAN to move to another machine, I can move the data from one network to another, because I know how to get the route, which nodes to go through. "
Link Layer:" How do I know to move in the LAN data , but also with the CSMA / CD protocol coordination, but also with the data sent and received CRC32 checksum is consistent, blabla ... But, I'm just saying, I do not do hard labor live."
Physical layer:" Upstairs gentlemen spoke up, the brothers. "
Haha very image,
accompanied by in situ links
https://www.zhihu.com/answer/46248356
not have a computer, can not be labeled reproduced, and so will have to change
