In the late 1970s, ISO proposed the open systems interconnection reference model. Protocol layering greatly simplifies the complexity of network protocols. In the OSI 7 layer model, the network layer functions mainly as ().
A.
transmit the original bitstream over the channel
B.
Strengthen the physical layer data transmission function of the original bitstream and conduct traffic control
C.
how to route packets from source to destination
D.
Make sure that each paragraph that reaches the other party is correct