mac 的功能到底是什么? 欢迎讨论.........

joyclick

1 What does the MAC sublayer of the Data Link Layer do ? (choose all that apply)
a. builds frames
b. checks to see that nothing got damaged in transit by CRC
c. determines "which machine goes first on the wire"
d. provides path to the destination host
e. Gets data on and off the wire



2. The ""_____"" OSI layer provides synchronization by placing checkpoints in the data stream.