Glossary of network cabling terms
10Base2 - 10Mbit/s BASEband 200(185)m/segment
Ethernet topology based on coaxial wiring with a transfer rate of 10Mbit/s.
10Base5 - 10Mbit/s BASEband 500m/segment
10Base5 is the original Ethernet specification. In this case, the wiring consists of coaxial bus cables with an impedance of 50 Ohm and a max. permitted length of 500m (yellow cable). Due to the coaxial technology with two conductors (core and shield), both 10Base5 and 10Base2 allow only for half-duplex operation. The network stations are connected by means of external transceivers that receive the signal through vampire connectors directly from the bus cable without interrupting the cable by plug adapters or similar devices. The data is made available by the receiver through a 15-pin D-SUB adapter in a separate packets of send, receive and collision information. The terminal device is connected by means of an 8-wire TP cable of max. 50m in length. Maximum four repeaters are permitted between any two stations. This rule however only applies to repeaters in series. In the case of tree-type networks, an unlimited number of repeaters can thus be integrated.
10BaseT - 10Mbit/s BASEband twisted pair
With the definition of 10BaseT, the physical and the logical topology were separated. The cabling originates from a hub that provides the central active component. A category 3 cable of 100 Ohm with at least two pairs of wires is required, in which data is sent on separated send and receive wires. The connectors are 8-pin RJ45-type adapters in which the pairs are assigned to pins 1/2 and 3/6. The maximum length of a segment (= connection from the hub to the terminal device) is limited to 100m. 10BaseT technology was first introduced in the US, as it permitted the use of standard telephone wires for networking purposes. For Germany, this advantage was irrelevant, as the national telephone system was based on star-shape 4-conductor cables that did not conform to the requirements of category 3.
100BaseT4 - 100Mbit/s BASEband twisted 4 pairs
100BaseT4 is specified as an Ethernet transmission with 100Mbit/s. Similar to 10BaseT, the system is based on a star structure with a central hub . Also here, category 3 cables with impedance of 100 Ohm and RJ45 adapters are used in a system of max. 100m length. The ten times greater data transfer rate of 100mbit/s combined with the category 3 bandwidth of 25 MHz is mainly achieved by the use of all four available conductors. With 100BaseT4, three pairs are always used simultaneously in each data direction.
100BaseTX - 100Mbit/s BASEband twisted 2 pairs
100BaseTX describes a 100Mbit/s data transfer with 2 wire pairs over a network with category 5 components. Cable, RJ45 wall sockets, patch panels, etc. must be dimensioned for a transmission frequency of at least 100MHz.
For coaxial network topologies such as 10Base5 or 10Base2, each network segment must be equipped with terminal resistors (terminators) at both ends. The resistance of the terminator must corresponds to the cable impedance. For 10Base5 and 10Base2, the resistance must thus be 50 Ohm.
Person with unlimited access to all features of a local network; responsible for the administration and maintenance of the network, The administrator assigns IP addresses and must ensure that they are unique.
AUI - Attachment Unit Interface
Interface for the connection of an external Ethernet transceiver.
BNC -Bayonet Neill Concelmann
Bridges connect subnetworks and determine, based on the Ethernet address, which packets are to pass the bridge and which are to be refused. The respective information is retrieved from the bridge tables. Depending on the bridge type, this data must be manually entered by the administrator or is generated dynamically by the bridge.
In a bus system, several terminal devices share a common data line (bus line). Since only one terminal device may use the line at any one time, bus systems require a protocol that controls the access rights to the line. Traditional bus systems are the Ethernet topologies 10Base2 and 10Base5.
Ethernet is the currently most commonly used technology for local networks. There are three different Ethernet topologies: 10Base2, 10Base5 and 10BaseT ; the transfer rate of Ethernets is 10 Mbit/s.
A fast Ethernet is basically an upgrade of a 10BaseT topology from 10Mbit/s to 100Mbit/s.
GPIO = General Purpose Input Output
A hub, also referred to as a star coupler, allows for the connection of multiple network stations in a star configuration. Data packets received at a port are forwarded to all other ports.
ISDN - Integrated Services Digital Network
ISDN is the new standard of the telecommunications technology and has replaced the analog telephone network in Germany and other countries. ISDN integrates a number of services such as telephone, fax but also video conferencing and data transfer into one system. Therefore, ISDN is suitable for the transfer of voice, text, graphics and other digital data from one terminal device to an other.
LAN - Local Area Network
Local network within a defined area, using a fast transmission medium such as Ethernet.
In local networks, repeaters are used to connect two Ethernet segments in order to expand the network across several sections. Repeaters forward data packets from one network segment to the next, by "boosting" the electrical signals according to the standards, whereby the content of the packets remains unchanged. When a repeater detects a physical error in one of the segments, the respective segment is disconnected ("partitioned"). The partitioning is automatically removed as soon as the error has been eliminated.
STP - Shielded Twisted Pair
Shielded data cable containing twisted pair wires.
Similar to a hub, a switch allows for the connection of several workstations in a star configuration. Switches combine the functions of a Hub with those of a Bridge.: A switch is able to "memorize" the Ethernet address of a network station connected to a port and thus only forwards data packets destined for this address to the respective station. This does not apply to broadcast messages that are forwarded to all ports. (Switches and bridges differ in this regard, as bridges generally don't forward broadcast messages).
The term transceiver is a combination of transmitter and receiver. A transceiver implements the physical network access of a station to the Ethernet. In the modern 10Base2 and 10BaseT Ethernet topologies, it is integrated in the network card. Only in 10Base5 ((see also AUI connection) Ethernets is the transceiver connected directly to the network cable as an external component.
Data cable containing twisted pair wires. The twisting of pairs of wires greatly reduces crosstalk between the wire pairs in the cable. Twisted pair cables are available as unshielded UTP cables (unshielded twisted pair) and shielded STP cables (shielded twisted pair).
UTP - Unshielded Twisted Pair
Not shielded cable containing twisted pair wires.
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