KTI Networks KGS-2404 manual IEEE802.3 CSMA/CD MAC

Data

Link

Layer

IEEE 802.2 LLC

IEEE802.3 CSMA/CD MAC

Physical

Layer

IEEE 802.3 PLS

IEEE 802.3

MAU

Coaxial/STP/UTP

CS

MII

ANSI X3T9.5 PMD

Fiber

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.

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