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The above diagram shows the Ethernet architecture in OSI model. LLC sub-
layer and MAC sub-layer will respond to the Data Link layer, and the transceivers
will respond to the Physical layer.
Logical Link Control (LLC)
Data link layer is composed of both the sub-layers of MAC and MAC-client.
Here MAC client may be logical link control or bridge relay entity.
Logical link control acts as the interface between the Ethernet MAC and
upper layers in the protocol stack, usually Network layer. Network layer has nothing
to do with the nature of the LAN, so it operates over other different LAN
technologies such as Token Ring, FDDI and so on. Likewise, as for the interface to
the MAC layer, LLC defines the services provided by the interface independent
medium access technology, which some natures of the medium itself apply.
Coaxial/STP/UTP
IEEE 802.2 LLC
IEEE802.3 CSMA/CD MAC
IEEE 802.3 PLS
ANSI X3T9.5 PMD
CS
IEEE 802.3
MAU
Physical
Layer
Data
Link
Layer
MII
Fiber