Functional Description
MEN Mikro Elektronik GmbH
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20A014-00 E2 – 2007-08-16
2.8.2
General
Ethernet is a local-area network (LAN) protocol that uses a bus or star topology and
supports data transfer rates of 100Mbps and more. The Ethernet specification served
as the basis for the IEEE 802.3 standard, which specifies the physical and lower
software layers. Ethernet uses the CSMA/CD access method to handle simultaneous
demands. It is one of the most widely implemented LAN standards.
Ethernet networks provide high-speed data exchange in areas that require
economical connection to a local communication medium carrying bursty traffic at
high-peak data rates.
A classic Ethernet system consists of a backbone cable and connecting hardware
(e.g. transceivers), which links the controllers of the individual stations via
transceiver (transmitter-receiver) cables to this backbone cable and thus permits
communication between the stations.
2.8.3
10Base-T
10Base-T is one of several adaptations of the Ethernet (IEEE 802.3) standard for
Local Area Networks (LANs). The 10Base-T standard (also called Twisted Pair
Ethernet) uses a twisted-pair cable with maximum lengths of 100 meters. The cable
is thinner and more flexible than the coaxial cable used for the 10Base-2 or
10Base-5 standards. Since it is also cheaper, it is the preferable solution for cost-
sensitive applications.
Cables in the 10Base-T system connect with RJ45 connectors. A star topology is
common with 12 or more computers connected directly to a hub or concentrator.
The 10Base-T system operates at 10Mbps and uses baseband transmission methods.
2.8.4
100Base-T
The 100Base-T networking standard supports data transfer rates up to 100Mbps.
100Base-T is actually based on the older Ethernet standard. Because it is 10 times
faster than Ethernet, it is often referred to as Fast Ethernet. Officially, the 100Base-T
standard is IEEE 802.3u.
Like Ethernet, 100Base-T is based on the CSMA/CD LAN access method. There
are several different cabling schemes that can be used with 100Base-T, e.g.
100Base-TX, with two pairs of high-quality twisted-pair wires.
2.8.5
1000Base-T
1000Base-T is a specification for Gigabit Ethernet over copper wire (IEEE Std.
802.3ab). The standard defines 1Gbps data transfer over distances of up to 100
meters using four pairs of CAT-5 balanced copper cabling and a 5-level coding
scheme.
Because many companies already use CAT-5 cabling, 1000Base-T can be easily
implemented.
Other 1000Base-T benefits include compatibility with existing network protocols
(i.e. IP, IPX, AppleTalk), existing applications, Network Operating Systems,
network management platforms and applications.