Signamax
™
065-7921PoE 12-Port 10/100/1000BaseT/TX Web Smart PoE Switch
25
This above diagram shows the Ethernet architecture, LLC sub-layer and MAC sub-layer,
which are responded to the Data Link layer, and transceivers, which are responded to the
Physical layer in OSI model. In this section, we are mainly describing the MAC sub-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 supports the interface between the Ethernet MAC and upper layers
in the protocol stack, usually Network layer, which is nothing to do with the nature of the LAN.
So it can operate over other different LAN technology such as Token Ring, FDDI and so on.
Likewise, for the interface to the MAC layer, LLC defines the services with the interface
independent of the medium access technology and with some of the nature of the medium
itself.
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