Podstrony

• Index
• Microsoft Press Microsoft Encyclopedia of Security
• Wen Chu Chen, Grace J. Yoo Encyclopedia of Asian American Issues Today (2 volumes) (2009)
• QoS in Integrated 3G Networks Robert Lloyd Evans (2)
• Cisco CCIE Fundamentals Network Design
• Zajdel Janusz A Paradyzja
• Yeffeth Glenn Wybierz Czerwona Pigulke
• Eden Cole BreakingClay
• Tom Clancy Suma wszystkich strachow t.2 (3
• Fundusze unijne i europejskie (dotacje) (2)
• Brian Herbert & Kevin J. Anderson Dune House Harkonnen
• zanotowane.pl
• doc.pisz.pl
• pdf.pisz.pl
• kerada123.opx.pl

[ Pobierz całość w formacie PDF ]
.This is in contrast to strandeda TCP/IP stack.Most of these programs usewire, whose conductor wire consists ofsome version of Winsock.dozens, perhaps hundreds, of thin copperstrands wrapped tightly around each other.Wireless ComponentsWireless networks use the same functionalWire, Strandedcomponents as networks that use a physicalElectrical wire whose central, conductingmedium.Specifically, wireless nodes needelement consists of many thin strands oftransmitters and receivers, just like wired(usually) copper or some other conductivenodes.material.These strands are rolled tightlyHowever, wireless components may takearound each other.This is in contrast tosomewhat different forms and may turn upsolid wire, whose conductor wire consists ofin unusual locations in wireless networks.a single, (relatively) large diameter copperFor example, a network may use antennas(or other conductive) wire.located at strategic points to broadcast andcapture signals across the network.In wire-less communications, each node may haveWiring Centerits own antenna, or a single antenna mayWiring center is a general term for any ofserve a limited area.Antennas will generallyseveral components that serve as commonbe placed in open, unobstructed areas intermination points for one or more nodesorder to avoid objects that can block incom-and/or other wiring centers.The wiring cen-ing or outgoing signals.ter will connect to a higher-level wiring col-BROADER CATEGORY lector, to either an intermediate distributionframe (IDF) or a main distribution frameHardware(MDF).SEE ALSONetwork, WirelessWiring Center 1087Functions of Wiring Centers Types of Wiring CentersaThe main functions of a wiring center Hubs, concentrators, and MAUs (multista-bare electrical.The wiring center collects lines tion access units) have all been referred to asin a common location in order to continue wiring centers.In part, terminology is tied tocthe connection more easily from there.Any network architecture.dnetwork-specific features or benefits (such as MAU is the term for a common termi-signal routing flexibility) are likely to be the nation point in a Token Ring network.eresult of special intelligence or capabilities Individual nodes (or lobes, in Token Ringbuilt into the wiring center.terminology) can connect to the MAU in fCollecting multiple cables at a common whatever sequence is most convenient.Inter-glocation makes the following tasks easier: nally, the MAU orders the connected lobesto produce a ring structure, as required byhInstalling cablingthe network architecture.iTracking down faults MAUs have two additional ports, calledRI (ring in) and RO (ring out), throughjCleaning and boosting signalswhich they can be connected to other(if appropriate)MAUs.These ports make it possible to kControlling (limiting) the transmission maintain the ring structure over the larger,lof packets and the dissemination of multi-MAU network.information Hub is the term for a component thatmserves as a termination point for multipleDealing with any necessary electricalnnodes that all use the same network archi-conversions involving particular nodestecture (for example, Ethernet or ARCnet).oOver time, various capabilities and ser- Hubs differ in the amount of intelligencevices have migrated from the server to wir- they have and in whether they can boost ping centers.This helps decrease the server s a signal.qworkload.It also makes certain security A concentrator is a  superhub, whichmeasures easier to implement.For example, can connect lines from different architec-ran intelligent hub can send a packet to its tures and with different cabling.For exam-sdestination and can broadcast a nonsense ple, a concentrator may be used as thepacket to nondestination nodes.In networks termination point for the nodes on multipletsuch as Ethernet and ARCnet, all packets networks, and these networks may use dif-are broadcast to all nodes.Nodes are sup- ferent architectures.uposed to ignore packets not intended for the The boundaries between the two arevnodes, but there is no way to prevent an fuzzy, but the main differences between hubseavesdropping node from reading everything and concentrators are in the number ofwthat comes through.nodes the component can handle, the num-ber of network architectures it can handle, xand the component s price.yz1088 Wiring ClosetHubs, concentrators, and MAUs repre-Wiring Sequencesent the basic wiring centers.There are allsorts of exotic variants of these types, withIn twisted-pair cabling, the wiring sequencespecialized capabilities and properties addedis the order in which the wire pairs areby vendors.attached to pins in the connector.(In a pairof wires, one wire is known as the tip andBROADER CATEGORIESthe other as the ring [ Pobierz całość w formacie PDF ]