Milan Technology MIL-S501SC-70 A-2. Fast Switching Technology, Media Access Control MAC Layer

*100BaseT4 for four-pair voice and data grade Category 3,4 or 5

UTP

*100BaseFX for 2-strand multimode fiber

￿

Media Access Control (MAC) Layer

The MAC layer is based on the same CSMA/CD protocol as 10Mbps Ethernet. The only difference is that it runs 10times faster.

Media Independent Interface (MII) Layer

The MII is a new specification that defines a standard interface between the MAC layer and any of the three physical layers (100BaseTX, 100BaseT4 or 100BaseFX). It is capable of supporting both 10Mbos and 100Mbps data rates.

100BaseTX Physical Layer

This physical layer defines the specification for 100BaseT Ethernet over two pairs of Category 5 UTP or Type 1 STP twisted pair wire. With one pair for transmit and the other for receive, the wiring scheme is identical to that used for 10BaseT Ethernet. The UTP connector, a RJ-45, is also identical to the one used for 10BaseT Ethernet. However, the punch-down blocks in the wiring closet must be category 5 certified

A-2. Fast Switching Technology

There are two big LAN killers: increased demands that new technology, such as multimedia and videoconferencing, places on available bandwidth; and the distributed computing architecture trend being driven by mature implementations of the client/server model of corporate computing. With a high-speed switch backplane, it is possible to have all ports communicating at wire speed with minimal latency and low packet loss.

18