Network Primer; Physical Layer Wiring Schemes Supported By The Meter - Fluke 8845A Programmer's Manual

8845A/8846A
Programmers Manual
Your Network Administrator may also need to know the Ethernet (MAC) addresses of
each Meter that you will attach to the network. You may obtain the address of the Meter
by using the front panel controls.
Read "Network Primer" for more information on IP addressing and the other information
needed to operate the Meter on a local area network (LAN).

Network Primer

In the early days of computer networking, vendors used many proprietary communication
schemes. These forced users to purchase equipment and software from one or a few
companies. As networking became more popular, users placed pressure on vendors to
establish standards to allow interoperation of various types of computers, operating
system software, and interface hardware.
One of these standardization efforts was started by the DARPA agency of the U.S.
Defense department. Another was headed up by the DEC and Xerox companies. This
effort resulted in the Ethernet wiring and low-level protocol scheme. The DARPA effort
resulted in the TCP/IP high-level protocols. Ethernet became an international standard by
the efforts of the IEEE-802.3 committee. TCP/IP is the protocol used on the international
Internet network, and is supported by consensus of the users of that network (many
thousands of hosts).
The sockets API was developed at UC Berkeley and was widely adopted by the UNIX
community to support direct host-to-host communication within a TCP/IP network.
WINSOCK is an MS Windows Dynamic Link Library (DLL) version of the original
UNIX Sockets library, and has been standardized by a large number of PC Software and
Hardware Vendors. WINSOCK has been included with Windows since the introduction
of Windows 95 and Windows NT 4.0.
To reduce the complexity of network schemes and to encourage interoperation between
varieties of networks, the protocols are built up of several layers that are isolated from
each other by well-described interfaces. Usually, the lowest layers of the protocol are
implemented in hardware logic on the interface circuits used by the computers and other
devices attached to the network wiring. The Ethernet standard consists of a set of low-
level addressing and data transmission protocols that run on several different wiring
schemes.
Computers on a network are commonly referred to as a host. The Meter is a host in this
context. Devices that facilitate communication between different sections of a network
are called by names that indicate their function, for example, routers, bridges, and
repeaters.

Physical Layer Wiring Schemes Supported by the Meter

The Meter supports the most common wiring scheme used in Ethernet networks:
10/100BaseT Unshielded Twisted Pair (or UTP).
The 10/100BaseT wiring method uses two or four pairs of twisted wires. This wiring
method supports only two connections to any one run of wire. To support more than two
physical connections, an active instrument called a hub must be used.
A hub is an active device that supports multiple 10/100BaseT connections. The network
host attached to each connection of the hub may communicate with every other host
attached to the hub. Hubs also may allow other types of cable connections, such as
10Base2 and 10Base5 (fat coax). This is done to allow a hub to communicate with other
network hosts, such as other hubs, routers, and bridges. A hub is sometimes referred to as
a network switch.
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