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proc1 length proc2 putinterval newproc cvx } bind def /ngrayt 256 array def /nredt 256 array def /nbluet 256 array def /ngreent 256 array def /gryt FMLOCAL /blut FMLOCAL /grnt FMLOCAL /redt FMLOCAL /indx FMLOCAL /cynu FMLOCAL /magu FMLOCAL /yelu FMLOCAL /k FMLOCAL /u FMLOCAL /colorsetup { currentcolortransfer /gryt exch def /blut exch def /grnt exch def /redt exch def 0 1 255 { /indx exch def /cynu 1 red indx get 255 div sub def /magu 1 green indx get 255 div sub def /yelu 1 blue indx get 255 div sub def /k cynu magu min yelu min def /u k currentundercolorremoval exec def nredt indx 1 0 cynu u sub max sub redt exec put ngreent indx 1 0 magu u sub max sub grnt exec put nbluet indx 1 0 yelu u sub max sub blut exec put ngrayt indx 1 k currentblackgeneration exec sub gryt exec put } for {255 mul cvi nredt exch get} {255 mul cvi ngreent exch get} {255 mul cvi nbluet exch get} {255 mul cvi ngrayt exch get} setcolortransfer {pop 0} setundercolorremoval {} setblackgeneration } bind def /tran FMLOCAL /fakecolorsetup { /tran 256 string def 0 1 255 {/indx exch def tran indx red indx get 77 mul green indx get 151 mul blue indx get 28 mul add add 256 idiv put} for currenttransfer {255 mul cvi tran exch get 255.0 div} exch Fmcc settransfer } bind def /BITMAPCOLOR { /d 8 def gsave translate rotate scale /h exch def /w exch def /bitmapsave save def colorsetup /is w d wbytes string def /cf currentfile def w h d [w 0 0 h neg 0 h] {cf is readhexstring pop} {is} {is} true 3 colorimage bitmapsave restore grestore } bind def /BITMAPCOLORc { /d 8 def gsave translate rotate scale /h exch def /w exch def /lb w d wbytes def sl lb lt {lb ms} if /bitmapsave save def colorsetup /is im 0 lb getinterval def ws 0 lb getinterval is copy pop /cf currentfile def w h d [w 0 0 h neg 0 h] {ip} {is} {is} true 3 colorimage bitmapsave restore grestore } bind def /BITMAPTRUECOLORc { gsave translate rotate scale /h exch def /w exch def /bitmapsave save def /is w string def ws 0 w getinterval is copy pop /cf currentfile def w h 8 [w 0 0 h neg 0 h] {ip} {gip} {bip} true 3 colorimage bitmapsave restore grestore } bind def /BITMAPTRUECOLOR { gsave translate rotate scale /h exch def /w exch def /bitmapsave save def /is w string def /gis w string def /bis w string def /cf currentfile def w h 8 [w 0 0 h neg 0 h] { cf is readhexstring pop } { cf gis readhexstring pop } { cf bis readhexstring pop } true 3 colorimage bitmapsave restore grestore } bind def /BITMAPTRUEGRAYc { gsave translate rotate scale /h exch def /w exch def /bitmapsave save def /is w string def ws 0 w getinterval is copy pop /cf currentfile def w h 8 [w 0 0 h neg 0 h] {ip gip bip w gray} image bitmapsave restore grestore } bind def /ww FMLOCAL /r FMLOCAL /g FMLOCAL /b FMLOCAL /i FMLOCAL /gray { /ww exch def /b exch def /g exch def /r exch def 0 1 ww 1 sub { /i exch def r i get .299 mul g i get .587 mul b i get .114 mul add add r i 3 -1 roll floor cvi put } for r } bind def /BITMAPTRUEGRAY { gsave translate rotate scale /h exch def /w exch def /bitmapsave save def /is w string def /gis w string def /bis w string def /cf currentfile def w h 8 [w 0 0 h neg 0 h] { cf is readhexstring pop cf gis readhexstring pop cf bis readhexstring pop w gray} image bitmapsave restore grestore } bind def /BITMAPGRAY { 8 {fakecolorsetup} COMMONBITMAP } bind def /BITMAPGRAYc { 8 {fakecolorsetup} COMMONBITMAPc } bind def /ENDBITMAP { } bind def end /ALDsave FMLOCAL /ALDmatrix matrix def ALDmatrix currentmatrix pop /StartALD { /ALDsave save def savematrix ALDmatrix setmatrix } bind def /InALD { restorematrix } bind def /DoneALD { ALDsave restore } bind def %%EndProlog %%BeginSetup (3.0) FMVERSION 1 1 612 792 0 1 14 FMDOCUMENT 0 0 /Helvetica-Bold FMFONTDEFINE 1 0 /Times-Roman FMFONTDEFINE 2 0 /Times-Bold FMFONTDEFINE 3 0 /Times-Italic FMFONTDEFINE 4 0 /Helvetica FMFONTDEFINE 5 0 /Courier-Bold FMFONTDEFINE 32 FMFILLS 0 0 FMFILL 1 .1 FMFILL 2 .3 FMFILL 3 .5 FMFILL 4 .7 FMFILL 5 .9 FMFILL 6 .97 FMFILL 7 1 FMFILL 8 <0f1e3c78f0e1c387> FMFILL 9 <0f87c3e1f0783c1e> FMFILL 10 FMFILL 11 FMFILL 12 <8142241818244281> FMFILL 13 <03060c183060c081> FMFILL 14 <8040201008040201> FMFILL 16 1 FMFILL 17 .9 FMFILL 18 .7 FMFILL 19 .5 FMFILL 20 .3 FMFILL 21 .1 FMFILL 22 0.03 FMFILL 23 0 FMFILL 24 FMFILL 25 FMFILL 26 <3333333333333333> FMFILL 27 <0000ffff0000ffff> FMFILL 28 <7ebddbe7e7dbbd7e> FMFILL 29 FMFILL 30 <7fbfdfeff7fbfdfe> FMFILL %%EndSetup %%Page: "1" 1 %%BeginPaperSize: Letter %%EndPaperSize 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (January 24, 1994) 72 737.98 T 72 444.68 558 444.68 2 L 2 Z N 72 75.33 558 75.33 2 L 0.25 H N 0 10 Q (1) 527.85 60.96 T 0 9 Q ( of) 533.41 60.96 T 0 10 Q (18) 546.89 60.96 T 207 659 558 669 C 207 660 459 660 2 L 0.25 H 0 Z 0 X 0 K N 0 0 612 792 C 1 24 Q 0 X 0 K -0.17 (Guide to Ethernet) 207 677 S 2 12 Q (Charles Spurgeon) 207 609 T 0 9 Q (Networking Services) 207 549 T (University of T) 207 537 T (exas at Austin) 268.76 537 T 1 10 Q (Document version 2.5) 207 425.33 T 3 9 Q (Copyright 1994 by Charles Spur) 207 402 T (geon \050c.spur) 324.01 402 T (geon@utexas.edu\051. This document may be fr) 368.6 402 T (eely) 528.55 402 T (r) 207 391 T (edistributed in its entir) 210.16 391 T (ety pr) 291.98 391 T (ovided that this copyright notice is not r) 312.36 391 T (emoved. It may not be sold) 456.08 391 T (for pr) 207 380 T (o\336t or incorporated in commer) 227.39 380 T (cial documents without the written permission of the copy-) 338.4 380 T (right holder) 207 369 T (.) 249.2 369 T 72 326 558 329 C 207 328.15 558 328.15 2 L 0.25 H 2 Z 0 X 0 K N 72 328.15 198 328.15 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (1.0) 181.33 333 T (Introduction) 207 333 T 1 10 Q -0.15 (This is a brief guide to the Ethernet system and the variety of media systems that can be) 207 305.33 P (used to build an Ethernet. The whole subject of designing, building, and operating a) 207 293.33 T -0.37 (local area network \050LAN\051 is a lar) 207 281.33 P -0.37 (ge one, and this guide makes no attempt to deal with all) 337.27 281.33 P (of the issues. Instead, this guide provides you with an brief introduction to the Ethernet) 207 269.33 T (system, media types, and con\336guration guidelines.) 207 257.33 T 72 214 558 217 C 207 216.16 558 216.16 2 L 0.25 H 2 Z 0 X 0 K N 72 216.16 198 216.16 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (2.0) 181.33 221 T (The Ethernet System) 207 221 T 1 10 Q (Ethernet is a LAN technology that transmits information between computers at 10 mil-) 207 193.33 T -0.38 (lion bits per second \05010Mbps\051. New Ethernet standards are currently under development) 207 181.33 P (that will provide for data rates of 100Mbps.) 207 169.33 T -0.35 (There are several LAN technologies in use today) 207 145.33 P -0.35 (, but Ethernet is by far the most popular) 399.58 145.33 P (technology for departmental networks. The vast majority of computer vendors provide) 207 133.33 T (equipment with Ethernet attachments, making it possible to link all manner of comput-) 207 121.33 T (ers with an Ethernet LAN. Because of this widespread use there is a lar) 207 109.33 T (ge market for) 491.59 109.33 T (Ethernet equipment, which helps keep the technology competitively priced. The ability) 207 97.33 T FMENDPAGE %%EndPage: "1" 2 %%Page: "2" 2 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (The Ethernet System) 189 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (2) 54 60.96 T 0 9 Q ( of) 59.56 60.96 T 0 10 Q ( 18) 70.54 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 1 10 Q (to link a wide range of computers using a vendor) 189 680.66 T (-neutral network technology is essen-) 384.49 680.66 T (tial in a university environment. For these and other reasons the UT Networking Ser-) 189 668.66 T (vices group recommends Ethernet technology for use on UTnet.) 189 656.66 T (From the time of the \336rst Ethernet standard,) 189 632.66 T (the speci\336cations and rights to Ethernet) 366.94 632.66 T (technology have been easily available to anyone who wished to build Ethernet equip-) 189 620.66 T -0.29 (ment. This openness resulted in a lar) 189 608.66 P -0.29 (ge Ethernet market, and is one reason Ethernet is so) 333.36 608.66 P (widely implemented in the computer industry today) 189 596.66 T (. The speci\336cations for Ethernet) 395.45 596.66 T (were \336rst published in 1980 by a multi-vendor consortium that created the DEC-Intel-) 189 584.66 T (Xerox \050DIX\051 standard. Ethernet technology was then adopted by the 802 committee of) 189 572.66 T (the Institute of Electrical and Electronics Engineers \050IEEE\051.) 189 560.66 T (The IEEE standard was published in 1985, and its formal title is \322IEEE 802.3 Carrier) 189 536.66 T -0.16 (Sense Multiple Access with Collision Detection \050CSMA/CD\051 Access Method and Phys-) 189 524.66 P (ical Layer Speci\336cations.\323 This standard provides an \322Ethernet like\323 system based on) 189 512.66 T (the original DIX Ethernet technology) 189 500.66 T (. All Ethernet equipment since 1985 is built) 337.69 500.66 T (according to the IEEE 802.3 standard, which is pronounced \322eight oh two dot three.\323) 189 488.66 T -0.39 (Ethernets can be linked together to form extended networks using devices called bridges) 189 464.66 P (and routers. Bridges can be used to link multiple Ethernets within a department to sup-) 189 452.66 T (port more computers. Routers are used on UTnet to provide a campus-wide backbone) 189 440.66 T (network that spans multiple buildings. While individual Ethernets in a campus LAN) 189 428.66 T (system may only support dozens of computers, the total system of UTnet Ethernets) 189 416.66 T (linked with bridges or routers supports thousands of machines.) 189 404.66 T 0 F (2.1) 166.11 374.66 T (Operation of Ethernet) 189 374.66 T 1 F (Each Ethernet-equipped computer) 189 350.66 T (, also known as a station, operates independently of) 325.15 350.66 T -0.05 (all other stations on the network, and there is no central controller) 189 338.66 P -0.05 (. All attached stations) 451.08 338.66 P -0.32 (are connected to a shared media system. Signals are broadcast over the medium to every) 189 326.66 P -0.23 (attached station. In order to send an Ethernet packet a station \336rst listens to the medium,) 189 314.66 P (and when the medium is idle the station transmits its data.) 189 302.66 T (Access to the shared medium is determined by the medium access control \050MAC\051) 189 278.66 T -0.15 (mechanism embedded in each station interface. The media access control mechanism is) 189 266.66 P -0.19 (based on CSMA/CD, and functions somewhat like a dinner party in a dark room. Every-) 189 254.66 P (one around the table must listen for a period of quiet before speaking \050Carrier Sense\051.) 189 242.66 T -0.09 (Once a space occurs everyone has an equal chance to say something \050Multiple Access\051.) 189 230.66 P (If two people start talking at the same instant they detect that fact, and quit speaking) 189 218.66 T -0.04 (\050Collision Detection.\051 The CSMA/CD mechanism is invoked for every transmission on) 189 206.66 P -0.14 (the network. The mechanism is designed to enforce fair access to the shared medium so) 189 194.66 P (that all stations get a chance to use the network.) 189 182.66 T (If two stations happen to transmit at the same instant their signals collide, the stations) 189 158.66 T (are noti\336ed of the collision, and they reschedule their transmission. T) 189 146.66 T (o avoid another) 465.34 146.66 T (collision, the stations involved each choose a random time interval to schedule the) 189 134.66 T (retransmission of the collided fame.) 189 122.66 T FMENDPAGE %%EndPage: "2" 3 %%Page: "3" 3 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (The Ethernet System) 207 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (3 of 18) 529.53 60.96 T 1 10 Q (If repeated collisions occur for a given transmission attempt, then the stations begin) 207 680.66 T (backing of) 207 668.66 T (f by expanding the interval from which the random retransmission time is) 249.29 668.66 T (chosen. Repeated collisions indicate a busy network. The backof) 207 656.66 T (f process, formally) 465.52 656.66 T -0.22 (known as \322truncated binary exponential backof) 207 644.66 P -0.22 (f,\323 provides an automatic method for sta-) 394.73 644.66 P (tions to adjust to traf) 207 632.66 T (\336c conditions on the network.) 289.55 632.66 T 0 F (2.2) 184.11 602.66 T (Elements of the Ethernet System) 207 602.66 T 1 F (The Ethernet system consists of three basic elements: 1. the physical media used to) 207 578.66 T -0.01 (carry Ethernet signals between computers, 2. a set of media access control rules embed-) 207 566.66 P (ded in each Ethernet interface that allow multiple computers to access the shared Ether-) 207 554.66 T (net channel, and 3. an Ethernet packet, or frame, that consists of a standardized set of) 207 542.66 T (\336elds used to carry data over the system.) 207 530.66 T -0.27 (Computers attached to an Ethernet send application data to one another using high-level) 207 506.66 P (protocol packets, which are carried in the data \336eld of Ethernet frames. The system of) 207 494.66 T (high-level protocols and the Ethernet system are independent entities that cooperate to) 207 482.66 T (deliver application data between computers. A given Ethernet system can carry several) 207 470.66 T -0.35 (dif) 207 458.66 P -0.35 (ferent kinds of high-level protocol data. The Ethernet is simply a trucking system that) 217.92 458.66 P -0.01 (carries packages of data between computers; it doesn\325) 207 446.66 P -0.01 (t care what is inside the packages.) 422.36 446.66 P -0.38 (Each computer on the LAN is equipped with an Ethernet interface which is connected to) 207 422.66 P (the media system. For the Ethernet media access control system to work properly) 207 410.66 T (, all) 531.4 410.66 T -0.17 (computers must be able to respond to one another's signals within a speci\336ed amount of) 207 398.66 P (time. T) 207 386.66 T (o ensure that every computer can hear the network signals within the speci\336ed) 235.18 386.66 T -0.4 (time, the maximum round trip travel time of signals on the shared Ethernet channel must) 207 374.66 P (be limited.) 207 362.66 T -0.08 (The longer a segment, the more time it takes for a signal to propagate over it. T) 207 338.66 P -0.08 (o ensure) 522.07 338.66 P (that the round trip propagation timing limits are met, each media variety has maximum) 207 326.66 T (segment lengths de\336ned in the standard. The con\336guration guidelines for Ethernet pro-) 207 314.66 T (vide rules for combining these segments so that the correct signal timing is maintained) 207 302.66 T (for the entire network system.) 207 290.66 T (If the speci\336cations for media segment lengths and the con\336guration rules for combin-) 207 266.66 T -0.05 (ing segments are not followed, then computers attached to the Ethernet system may not) 207 254.66 P (hear one another's signals within the required time limit, and could end up interfering) 207 242.66 T (with one another) 207 230.66 T (.) 273.62 230.66 T (Therefore, the correct operation of an Ethernet depends upon a media system that is) 207 206.66 T (built according to the rules for each media type. More complex systems with multiple) 207 194.66 T (segment types must be built according to the multi-segment con\336guration guidelines) 207 182.66 T (provided by the IEEE for combining segments. This guide describes the basic rules for) 207 170.66 T (each media type, and also contains the multi-segment con\336guration rules from the stan-) 207 158.66 T (dard.) 207 146.66 T (Now that we\325ve taken a quick look at how Ethernet works, let\325) 207 122.66 T (s see what the Ethernet) 457.37 122.66 T (media varieties look like. But \336rst, we need to learn some jar) 207 110.66 T (gon.) 450.27 110.66 T FMENDPAGE %%EndPage: "3" 4 %%Page: "4" 4 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (IEEE Acronyms) 189 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (4) 54 60.96 T 0 9 Q ( of) 59.56 60.96 T 0 10 Q ( 18) 70.54 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 672.33 540 675.33 C 189 674.48 540 674.48 2 L 0.25 H 2 Z 0 X 0 K N 54 674.48 180 674.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (3.0) 163.33 679.33 T (IEEE Acronyms) 189 679.33 T 1 10 Q (The computer world is full of acronyms and jar) 189 651.66 T (gon, and Ethernet is no exception.) 378.13 651.66 T (Before making a survey of Ethernet media types, let\325) 189 639.66 T (s look at how the IEEE 802.3 stan-) 400.23 639.66 T (dard de\336nes the components used to connect a computer to a media system. This will) 189 627.66 T (also serve to introduce the set of acronyms and other jar) 189 615.66 T (gon used in the standard.) 412.54 615.66 T 54 399.9 540 422.9 C 189 407.9 540 407.9 2 L 0.25 H 2 Z 0 X 0 K N 54 407.9 180 407.9 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 1.) 54 393.9 T 4 F (Block diagram of a network connection.) 189 393.9 T 1 10 Q (The \336gure shows the set of entities de\336ned in the IEEE standard to describe an attach-) 189 372.23 T (ment to the Ethernet system. While this set of entities and their three-letter identi\336ers) 189 360.23 T (might seem like alphabet soup of interest to network engineers only) 189 348.23 T (, these identi\336ers) 459.28 348.23 T (describe real-world devices that you need to know about.) 189 336.23 T (Starting at the right hand side of the \336gure we \336nd the physical medium, which is used) 189 312.23 T -0.01 (to carry Ethernet signals between computers. This could be any one of several Ethernet) 189 300.23 P (media types, including thick or thin coaxial cable, twisted-pair cable and \336ber optic) 189 288.23 T (cable. Connected to the medium is the medium dependent interface, or MDI. This part) 189 276.23 T (of the standard describes the piece of hardware used for making a direct physical and) 189 264.23 T (electrical connection to the medium.) 189 252.23 T (In the case of thick Ethernet, the most commonly used MDI is a type of clamp that is) 189 228.23 T -0.03 (installed directly onto the coaxial cable. For twisted-pair Ethernet, the MDI is an RJ-45) 189 216.23 P (telephone-style jack that provides a connection to the four twisted-pair wires used to) 189 204.23 T (carry network signals in the twisted-pair media system.) 189 192.23 T (The next device is called the medium attachment unit, or MAU. This device is called a) 189 168.23 T (transceiver in the original DIX Ethernet standard, since it both TRANSmits and) 189 156.23 T -0.23 (reCEIVEs signals on the medium. The medium dependent interface is part of the MAU,) 189 144.23 P (providing the MAU with a direct physical and electrical connection to the medium.) 189 132.23 T -0.1 (Following the MAU is the attachment unit interface or AUI. This is called a transceiver) 189 108.23 P (cable in the DIX standard. The AUI provides a path for signals and power carried) 189 96.23 T 54 89.3 540 687.33 C 165.53 436.9 540 612.33 C 165.53 436.9 540 612.33 R 7 X 0 K V 183.53 470.47 255.53 560.47 R V 0.5 H 2 Z 0 X N 255.53 497.76 264.53 533.76 R 7 X V 0 X N 264.53 497.76 273.53 533.76 R 4 X V 0 X N 273.53 506.47 345.53 524.47 R 4 X V 0 X N 345.53 497.47 354.53 533.47 R 4 X V 0 X N 354.53 497.47 363.53 533.47 R 6 X V 0 X N 363.53 479.47 417.53 551.47 R 6 X V 0 X N 417.53 488.47 471.39 542.47 R 6 X V 0 X N 471.39 471.18 525.39 561.18 R 7 X V 0 X N 1 10 Q (Ethernet) 201.77 523.15 T (Interface) 201.77 513.15 T (\050MAC\051) 201.77 503.15 T (Attachment Unit) 276.39 538.33 T (Interface \050AUI\051) 278.53 528.08 T (Medium) 422.81 528.15 T (Dependent) 422.81 518.15 T (Interface) 422.81 508.15 T (\050MDI\051) 422.81 498.15 T (Physical) 480.2 518.86 T (Medium) 480.2 508.86 T 183.12 572.76 264.12 572.76 2 L N 264.12 572.76 264.12 563.76 2 L N 228.12 572.76 228.12 581.76 2 L N (DTE W) 183.12 583.92 T (ith External MAU) 214.08 583.92 T 182.81 458.9 470.81 458.9 2 L N 470.81 458.9 470.81 467.9 2 L N 326.81 458.9 326.81 449.9 2 L N (DTE W) 245.81 440.9 T (ith Internal MAU, AUI Not Exposed) 276.78 440.9 T (Medium) 367.21 528.15 T (Attachment) 367.21 518.15 T (Unit) 367.21 508.15 T (\050MAU\051) 367.21 498.15 T 54 89.3 540 687.33 C 0 0 612 792 C FMENDPAGE %%EndPage: "4" 5 %%Page: "5" 5 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Thick Ethernet \320 T) 207 739.85 T (ype 10BASE5) 284.25 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (5 of 18) 529.53 60.96 T 1 10 Q (between the Ethernet interface and the MAU. The AUI may be connected to the Ether-) 207 680.66 T (net interface in the computer with a 15-pin connector) 207 668.66 T (. The computer itself is de\336ned as) 419.06 668.66 T (data terminal equipment \050DTE\051 in the IEEE standard. Each DTE is equipped with an) 207 656.66 T (Ethernet interface that performs the medium access control \050MAC\051 functions.) 207 644.66 T -0.16 (And there we have it: the DTE contains an Ethernet interface which forms up and sends) 207 620.66 P (Ethernet frames that carry the data between computers attached to the network. The) 207 608.66 T -0.23 (Ethernet interface is attached to the media system using a set of equipment that includes) 207 596.66 P (an AUI and a MAU with its associated MDI.) 207 584.66 T (The MAU and MDI are speci\336cally designed for each media type used in Ethernet.) 207 560.66 T (Coaxial MAUs dif) 207 548.66 T (fer from twisted-pair MAUs, for example, both in the technology) 281.22 548.66 T (used for the actual connection to the media \050MDI\051, as well as the method used for send-) 207 536.66 T (ing Ethernet signals over the media and for detecting collisions.) 207 524.66 T -0 (Notice that in the \336gure above there are two kinds of DTE con\336gurations shown) 207 500.66 P 1 14 Q -0.01 ( \320) 528.09 500.66 P 1 10 Q -0 ( one) 538.58 500.66 P (with an external MAU and one with an internal MAU. W) 207 488.66 T (ith an external con\336guration) 436.15 488.66 T (the DTE contains only an Ethernet interface, and the AUI and MAU are both located) 207 476.66 T (outside the DTE. This is how a DTE looks when connected to a thick coaxial system) 207 464.66 T (using an external AUI cable and MAU.) 207 452.66 T (However) 207 428.66 T (, it\325) 243.23 428.66 T (s also possible for the MAU and AUI to be part of the network interface) 256.56 428.66 T (inside the DTE, with the only exposed device being the MDI that connects directly to) 207 416.66 T -0.32 (the network media. This is the type of connection made in the thin coax and twisted-pair) 207 404.66 P -0.15 (media systems. In this case, the AUI is nothing more than a set of wires on the interface) 207 392.66 P (board that link the Ethernet chips together) 207 380.66 T (.) 374.67 380.66 T (T) 207 356.66 T (o help make more sense of this alphabet soup let's look next at the Ethernet media) 212.41 356.66 T (types. W) 207 344.66 T (e will also show a computer connected to segments of each media type. It) 241.73 344.66 T -0.04 (should be emphasized that this is just a brief survey) 207 332.66 P -0.04 (, and the descriptions of each media) 412.27 332.66 P -0.09 (type do not contain all the information you need to correctly build lar) 207 320.66 P -0.09 (ge media systems.) 482.76 320.66 P 72 277.33 558 280.33 C 207 279.48 558 279.48 2 L 0.25 H 2 Z 0 X 0 K N 72 279.48 198 279.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (4.0) 181.33 284.33 T (Thick Ethernet) 207 284.33 T 0 14 Q (\320) 293.64 284.33 T 0 12 Q ( T) 301.42 284.33 T (ype 10BASE5) 311.2 284.33 T 1 10 Q (The identi\336er \32210BASE5\323 is one of a set of media identi\336ers that have been de\336ned by) 207 256.66 T -0.11 (the IEEE. As new media systems are developed, the IEEE creates a shorthand identi\336er) 207 244.66 P (for each system. The \32210\323 refers to the speed of the system, which is 10 megabits per) 207 232.66 T -0.19 (second. \322BASE\323 refers to the signalling method known as baseband. This is the method) 207 220.66 P (used for the majority of Ethernet media types, and simply means that the Ethernet sig-) 207 208.66 T (nals are the only signals being carried by that particular medium. The \3225\323 refers to the) 207 196.66 T (maximum segment length allowed when multiplied by 100. In the case of thick Ether-) 207 184.66 T (net, each segment may be up to 500 meters in length.) 207 172.66 T FMENDPAGE %%EndPage: "5" 6 %%Page: "6" 6 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Thick Ethernet \320 T) 189 739.85 T (ype 10BASE5) 266.25 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (6) 54 60.96 T 0 9 Q ( of) 59.56 60.96 T 0 10 Q ( 18) 70.54 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 434.72 540 457.72 C 189 442.72 540 442.72 2 L 0.25 H 2 Z 0 X 0 K N 54 442.72 180 442.72 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 2.) 54 428.72 T 4 F (Connecting a computer to thick Ethernet.) 189 428.72 T 0 10 Q (4.1) 166.11 401.05 T (Thick Ethernet Components) 189 401.05 T 0 9 Q (1.) 189 385.05 T 2 10 Q (Network medium) 202.74 385.05 T 1 F (. The thick Ethernet system uses a thick \050approx 0.4 inch diame-) 277.41 385.05 T (ter\051 and relatively in\337exible coaxial cable. The cable may have plain PVC \050yellow) 202.74 373.05 T (color\051 or T) 202.74 361.05 T (e\337on) 245.34 361.05 T 1 14 Q (\252) 265.33 361.05 T 1 10 Q ( \050orange-brown color\051 outer insulating jacket. T) 279.04 361.05 T (e\337on is used for) 469.03 361.05 T (\322plenum rated\323 cable, which is often required for installation in air handling spaces) 202.74 349.05 T (\050also called plenums\051 to meet \336re regulations. Thick Ethernet cable must be rated at) 202.74 337.05 T (50 ohms characteristic impedance, and have a solid center conductor) 202.74 325.05 T (. Thick coaxial) 476.97 325.05 T (segments are equipped with male type \322N\323 coaxial connectors at each end. T) 202.74 313.05 T (ypical) 509.3 313.05 T (cable types are Belden 9880 \050PVC\051 and 89880 \050plenum rated\051.) 202.74 301.05 T 0 9 Q (2.) 189 286.05 T 2 10 Q (T) 202.74 286.05 T (erminator) 208.49 286.05 T 1 F (. There must be a type-N 50 ohm terminator installed at each end of a) 251.24 286.05 T (thick coaxial cable segment.) 202.74 274.05 T 0 9 Q (3.) 189 259.05 T 2 10 Q (MAU \050transceiver\051.) 202.74 259.05 T 1 F ( An Ethernet interface is attached to a thick Ethernet segment) 286 259.05 T (with an outboard MAU. There may be a maximum of 100 MAUs attached to a seg-) 202.74 247.05 T (ment. The speci\336cations state that each MAU connection to the thick coax must be) 202.74 235.05 T (separated by 2.5 meters of coaxial cable between it and the next MAU connection,) 202.74 223.05 T (and there are black bands printed on the thick coaxial cable to help maintain this) 202.74 211.05 T (spacing. The MAU spacing and the restriction on the number of MAUs are both) 202.74 199.05 T (designed to limit the amount of signal attenuation and distortion that can occur on a) 202.74 187.05 T (given cable segment.) 202.74 175.05 T (The most popular attachment mechanism \050MDI\051 for a 10BASE-5 MAU is sold by) 202.74 160.05 T (AMP Corporation, and consists of a metal and plastic clamp that makes a direct) 202.74 148.05 T (physical and electrical connection to the coaxial cable. This clamp is also called a) 202.74 136.05 T -0 (transceiver tap, since to install the clamp you must drill a hole into the thick coaxial) 202.74 124.05 P (cable in a process known as tapping the cable. Since this clamp may be installed) 202.74 112.05 T (while the network is active, it is also called a \322non-intrusive\323 tap.) 202.74 100.05 T 54 89.3 540 687.33 C 165.53 471.72 540 677.33 C 165.53 471.72 540 677.33 R 7 X 0 K V 484.5 503.25 484.5 667.75 2 L 4 H 2 Z 0 X N 181.03 503.58 343.03 561.58 R 7 X V 0.5 H 0 X N 270.53 513.08 342.53 549.08 R 6 X V 0 X N 279.53 504.08 297.53 513.08 R 6 X V 0 X N 306.53 504.08 333.53 513.08 R 6 X V 0 X N 476.24 601.08 489.96 625.22 R V 4 H N 459.1 585.08 M 469.1 564.59 463.01 528.04 436.22 535.24 D 417.62 540.24 396.56 537.26 375.7 531.6 D 367.15 529.29 358.79 531.83 350.28 531.61 D 3 H N 452.53 580.08 466.03 595.08 R 4 X V 0.5 H 0 X N 345.53 524.08 361.53 537.58 R 4 X V 0 X N 1 10 Q (Ethernet) 287.03 536.58 T (Interface) 286.53 528.08 T (15-pin) 341.03 580.58 T (AUI Connector) 341.03 570.58 T (AUI Cable) 391.03 552.08 T (\05050 meter max\051) 391.03 542.08 T (AMP) 495.03 620.08 T (Thick) 495.03 610.08 T (Coaxial) 495.03 600.08 T (T) 495.03 590.08 T (ap) 500.43 590.08 T (\050MDI\051) 495.03 580.08 T 265.78 577.58 265.78 631.58 2 L V N 265.53 631.58 193.53 649.08 2 L V N 193.53 648.83 193.53 571.75 2 L V N 193.28 572 265.53 577.58 2 L V N 217.03 573.75 204.53 561.58 2 L N 241.03 575.08 251.03 561.58 2 L N 201.28 647.08 201.28 572.5 2 L N 354.49 551.85 347.52 542.08 348.25 554.06 351.37 552.96 4 Y V 357.03 569.08 351.38 552.95 2 L N 342.53 522.08 348.03 540.08 R 7 X V 0 X N (Thick Coax Segment) 389.53 658.08 T (\050500 meter maximum\051) 389.53 648.08 T 465.99 644.88 477.53 641.58 465.99 638.27 465.99 641.58 4 Y V 427.53 641.58 465.99 641.58 2 L N 480.78 495.33 488.28 504.83 R 3 X V 0 X N 481.53 489.83 487.53 495.33 R 3 X V 0 X N 483.28 485.58 485.78 489.83 R 3 X V 0 X N (Male \322N\323 Connector) 367.78 499.33 T 466.49 505.13 478.03 501.83 466.49 498.52 466.49 501.83 4 Y V 452.78 501.83 466.49 501.83 2 L N (50 Ohm T) 362.53 485.33 T (erminator) 402.92 485.33 T 466.21 491.8 477.77 488.58 466.26 485.19 466.23 488.5 4 Y V 444.28 488.33 466.24 488.49 2 L N 449.99 591.04 467.99 596.54 R 7 X V 0 X N 440.53 595.08 476.53 631.08 R 7 X V 0 X N (MAU) 447.39 611.08 T 1 9 Q (DTE) 194.29 531.96 T 54 89.3 540 687.33 C 0 0 612 792 C FMENDPAGE %%EndPage: "6" 7 %%Page: "7" 7 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Thick Ethernet \320 T) 207 739.85 T (ype 10BASE5) 284.25 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (7 of 18) 529.53 60.96 T 1 10 Q -0.04 (Another) 220.74 680.66 P -0.04 (, much less popular) 253.1 680.66 P -0.04 (, form of thick Ethernet MDI consists of a tap composed) 330.3 680.66 P (of two type-N coaxial cable connectors. Installing this tap requires cutting the thick) 220.74 668.66 T (coaxial cable, installing N connectors on each cable end, and then installing the tap) 220.74 656.66 T (as a sort of \322barrel\323 connector in-line with the coaxial cable. Cutting the cable halts) 220.74 644.66 T (the operation of the network, earning this approach the label of \322intrusive tap.\323) 220.74 632.66 T (Thick Ethernet MAUs are equipped with a male 15-pin connector to provide an) 220.74 617.66 T (attachment for the AUI cable. This connector has two locking posts, providing an) 220.74 605.66 T (attachment point for a sliding latch connector) 220.74 593.66 T (.) 401.73 593.66 T 0 9 Q (4.) 207 578.66 T 2 10 Q (AUI cable) 220.74 578.66 T 1 F ( \050transceiver cable\051. An AUI cable is used to provide power to the MAU,) 263.77 578.66 T -0.35 (and to carry signals between the MAU and the Ethernet interface. The AUI cable has) 220.74 566.66 P -0.26 (a female 15-pin connector on one end that is equipped with a sliding latch; this is the) 220.74 554.66 P (end that is attached to the MAU. The other end of the AUI cable has a male 15-pin) 220.74 542.66 T -0.04 (connector that is usually equipped with locking posts; this is the end that is attached) 220.74 530.66 P (to the Ethernet interface. Some 15-pin connectors on Ethernet interfaces are) 220.74 518.66 T (equipped with screw posts instead of the sliding latch fastener) 220.74 506.66 T (, requiring a specially) 468.23 506.66 T (equipped AUI cable.) 220.74 494.66 T -0.03 (The standard AUI cable is a relatively thick wire \0500.4 inch diameter\051 that may be up) 220.74 479.66 P (to 50 meters \050164 feet\051 long. \322Of) 220.74 467.66 T (\336ce grade\323 AUI cables are thinner \050approximately) 351.85 467.66 T (1/4 inch\051 and more \337exible. Of) 220.74 455.66 T (\336ce grade AUI cables also have higher signal loss) 344.37 455.66 T -0.28 (than standard AUI cables and consequently must be limited in length. One vendor of) 220.74 443.66 P (of) 220.74 431.66 T (\336ce grade cables rates them as having four times the amount of signal attenuation) 228.89 431.66 T (as standard cables, and only sells them in two and \336ve meter lengths.) 220.74 419.66 T 0 9 Q (5.) 207 404.66 T 2 10 Q -0.35 (Ethernet interface) 220.74 404.66 P 1 F -0.35 (. An Ethernet interface is a board that is installed in the DTE or is) 298.39 404.66 P -0.23 (built into the DTE at the factory) 220.74 392.66 P -0.23 (. Thick Ethernet interfaces have a female 15-pin con-) 346.97 392.66 P (nector equipped with a sliding latch for the AUI cable attachment.) 220.74 380.66 T -0.02 (These \336ve components are suf) 207 356.66 P -0.02 (\336cient to build a single thick Ethernet cable segment that) 328.32 356.66 P -0.24 (can support up to 100 MAU attachments, and can be as much as 500 meters \0501,640 feet\051) 207 344.66 P (long.) 207 332.66 T (The IEEE standard requires that individual segments be connected together with Ether-) 207 308.66 T (net repeaters. The repeater is a signal ampli\336cation device that keeps the system operat-) 207 296.66 T -0.19 (ing correctly by cleaning up and amplifying the signals that it repeats from one segment) 207 284.66 P (to the other) 207 272.66 T (. The repeater also has circuits that ensure that collisions that occur on any) 251.98 272.66 T (segment are propagated onto all other segments to which the repeater is attached. By) 207 260.66 T (doing this the repeater makes all segments function as though they were a single big) 207 248.66 T -0.03 (segment, or what is known as a single Ethernet \322collision domain.\323 This makes it possi-) 207 236.66 P -0.19 (ble for computers attached to any segment in a system of Ethernet segments linked with) 207 224.66 P (repeaters to hear the same signals and to operate as a single LAN.) 207 212.66 T (A thick coaxial segment is known as a \322mixing segment\323 in the multi-segment con\336gu-) 207 188.66 T (ration guidelines. A mixing segment is formally de\336ned as one which may have more) 207 176.66 T (than two MDI connections.) 207 164.66 T FMENDPAGE %%EndPage: "7" 8 %%Page: "8" 8 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Thin Ethernet \320 T) 189 739.85 T (ype 10BASE2) 261.74 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (8) 54 60.96 T 0 9 Q ( of) 59.56 60.96 T 0 10 Q ( 18) 70.54 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 672.33 540 675.33 C 189 674.48 540 674.48 2 L 0.25 H 2 Z 0 X 0 K N 54 674.48 180 674.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (5.0) 163.33 679.33 T (Thin Ethernet) 189 679.33 T 0 14 Q (\320) 269.63 679.33 T 0 12 Q ( T) 277.41 679.33 T (ype 10BASE2) 287.19 679.33 T 1 10 Q (The thin Ethernet system uses a much more \337exible cable that makes it possible to con-) 189 651.66 T (nect the coaxial cable directly to the Ethernet interface in the computer) 189 639.66 T (. In this connec-) 471.83 639.66 T -0.15 (tion scheme the AUI, MAU, and MDI are part of the network interface in the computer) 189 627.66 P -0.15 (.) 535.15 627.66 P (This reduces the number of outboard components you need to purchase and install to) 189 615.66 T (connect a computer to the medium, thereby lowering the cost of an attachment to the) 189 603.66 T (network.) 189 591.66 T 54 363.04 540 386.04 C 189 371.04 540 371.04 2 L 0.25 H 2 Z 0 X 0 K N 54 371.04 180 371.04 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 3.) 54 357.04 T 4 F (Connecting a computer to thin Ethernet.) 189 357.04 T 0 10 Q (5.1) 166.11 329.38 T (Thin Ethernet Components) 189 329.38 T 0 9 Q (1.) 189 313.38 T 2 10 Q (Network Medium) 202.74 313.38 T 1 F (. The thin Ethernet system is based on thinner \050approx. 3/16th of) 278.52 313.38 T (an inch\051 coaxial cable that is more \337exible and easier to deal with than the thick) 202.74 301.38 T -0.01 (Ethernet variety) 202.74 289.38 P -0.01 (. The cable must have a 50 ohm characteristic impedance rating and) 266.2 289.38 P (a stranded center conductor) 202.74 277.38 T (. These speci\336cations may be met by cable types RG 58) 312.37 277.38 T -0.35 (A/U or RG 58 C/U, but cable vendors sometimes use these cable numbers to identify) 202.74 265.38 P (cables with dif) 202.74 253.38 T (ferent impedance ratings. It\325) 261.41 253.38 T (s up to you to make sure that the cable) 374.1 253.38 T (you purchase meets the speci\336cations.) 202.74 241.38 T (Thin Ethernet cable sections must be equipped with male BNC connectors at each) 202.74 226.38 T (end. Segments may be a maximum of 185 meters in length, and not 200 meters as) 202.74 214.38 T (the rounded-up \3222\323 in the shorthand identi\336er might lead you to believe. The stan-) 202.74 202.38 T (dard requires that multiple segments be linked with repeaters.) 202.74 190.38 T 0 9 Q (2.) 189 175.38 T 2 10 Q -0.04 (T) 202.74 175.38 P -0.04 (erminators) 208.49 175.38 P 1 F -0.04 (. Each end of a complete thin Ethernet segment must be equipped with) 255.68 175.38 P (a 50 ohm terminating resistance. Multiport repeaters used for linking thin Ethernet) 202.74 163.38 T -0.32 (segments often have internal 50 ohm termination provided on each port, which eases) 202.74 151.38 P (the task of terminating the end of the thin coax segment attached to the repeater) 202.74 139.38 T (.) 520.29 139.38 T -0.16 (Some thin Ethernet repeaters have switchable termination that you can enable or dis-) 202.74 127.38 P (able, depending on your requirements. It is essential that no more than two 50 ohm) 202.74 115.38 T 54 89.3 540 687.33 C 165.53 400.04 540 588.33 C 165.53 400.04 540 588.33 R 7 X 0 K V 198.53 431.54 360.53 489.54 R V 0.5 H 2 Z 0 X N 297.03 432.04 315.03 441.04 R 6 X V 0 X N 283.28 505.54 283.28 559.54 2 L V N 283.03 559.54 211.03 577.04 2 L V N 211.03 576.29 210.78 499.71 2 L V N 211.03 500.04 283.03 505.54 2 L V N 235.53 502.04 222.03 489.54 2 L N 258.53 503.04 268.53 489.54 2 L N 218.78 575.04 218.53 500.71 2 L N 367.53 467.96 367.53 461.71 2 L N 360.28 462.71 370.03 467.21 R 7 X V 0 X N 386.39 433.75 391.39 446.25 R 7 X V 0 X N 384.39 444 393.14 449.75 R 7 X V 0 X N 387.42 491.39 M 379.39 533.7 424.77 551.84 439.92 584.14 D 3 H N 385.67 486.39 389.67 493.39 R 7 X V 0.5 H 0 X N 1 10 Q (BNC T) 396.46 461.75 T (ee) 424.91 461.75 T 383.17 481.14 391.92 486.89 R 7 X V 0 X N (Male BNC Connector) 397.92 490.39 T (Male BNC 50 Ohm) 396.89 443.5 T (T) 396.89 433.5 T (erminator) 402.29 433.5 T (Thin Ethernet Coax) 422.42 546.64 T (\050185 meter maximum) 422.42 536.64 T (Ethernet Interface) 204.03 462.46 T (W) 204.03 452.46 T (ith Internal MAU) 213.06 452.46 T (Female BNC MDI) 326.03 414.96 T 362.47 445.68 365.78 457.21 369.09 445.68 365.78 445.68 4 Y V 365.78 423.46 365.78 445.68 2 L N 406.96 482.59 395.42 485.89 406.96 489.2 406.96 485.89 4 Y V 431.92 485.89 406.96 485.89 2 L N 378.36 462.21 387.61 467.46 R N 374.39 460.46 380.14 469.21 R 7 X V 0 X N 383.89 455.21 392.64 455.21 2 L N 383.64 475.21 392.39 475.21 2 L N 384.89 453.21 391.64 476.71 R 7 X V 0 X N 324.03 432.04 351.03 441.04 R 6 X V 0 X N 288.28 440.79 360.28 476.79 R 6 X V 0 X N (Interface) 290.28 450.79 T (Ethernet) 290.03 459.04 T (AUI) 0 -270 339.28 450.46 TF (MAU) 0 -270 353.28 449.96 TF ( 0.5 meter minimum\051) 422.42 526.64 T 54 89.3 540 687.33 C 0 0 612 792 C FMENDPAGE %%EndPage: "8" 9 %%Page: "9" 9 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Thin Ethernet \320 T) 207 739.85 T (ype 10BASE2) 279.74 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (9 of 18) 529.53 60.96 T 1 10 Q -0.11 (terminators be installed on a given segment, or the collision detection mechanism in) 220.74 680.66 P (the MAUs attached to the segment will not function correctly) 220.74 668.66 T (.) 465.76 668.66 T 0 9 Q (3.) 207 653.66 T 2 10 Q -0.09 (Interface and MAU.) 220.74 653.66 P 1 F -0.09 ( In the thin Ethernet system the MAU is built into the Ethernet) 306.88 653.66 P (interface, and therefore an external AUI cable is not required. The thin coax is \337exi-) 220.74 641.66 T (ble enough to be connected directly to the MDI on the interface. The thin Ethernet) 220.74 629.66 T -0.01 (MDI is a female BNC connector) 220.74 617.66 P -0.01 (. T) 350.33 617.66 P -0.01 (o make an attachment to a thin Ethernet segment) 360.72 617.66 P (this connector is attached to one end of a BNC T) 220.74 605.66 T (ee connector) 414.91 605.66 T (, so called because it) 465.29 605.66 T (looks like the letter \322T) 220.74 593.66 T (.\323 The other two ends of the BNC T) 309.95 593.66 T (ee make the physical and) 452.76 593.66 T (electrical connection to the thin Ethernet segment.) 220.74 581.66 T -0.03 (T) 207 557.66 P -0.03 (o help make the individual pieces clearer) 212.41 557.66 P -0.03 (, the BNC connectors in the \336gure are shown) 375.6 557.66 P (unattached to one another) 207 545.66 T (. The thin Ethernet segment in the \336gure is drawn as terminat-) 309.42 545.66 T -0.24 (ing at this computer to show you how a thin Ethernet terminator is connected. However) 207 533.66 P -0.24 (,) 553.24 533.66 P -0.31 (a given thin Ethernet segment may also be connected to several computers in a topology) 207 521.66 P (known as \322daisy chaining.\323 In the daisy chain topology another piece of thin coax is) 207 509.66 T (connected to the BNC T) 207 497.66 T (ee, instead of a terminator) 303.46 497.66 T (, and this piece of coax is attached to) 407.14 497.66 T -0.09 (the BNC T) 207 485.66 P -0.09 (ee on the next computer in line. The BNC T) 249.98 485.66 P -0.09 (ee at the very end of the segment) 424.42 485.66 P (is the only one that requires a terminator) 207 473.66 T (.) 368.28 473.66 T (The thin Ethernet coaxial segment is de\336ned as a mixing segment, since it can support) 207 449.66 T -0.05 (more than two MDI connections. Y) 207 437.66 P -0.05 (ou may have up to 30 MAUs connected to each thin) 347.87 437.66 P (Ethernet segment. Each repeater connection requires a MAU, and must be counted) 207 425.66 T (toward the total of 30 MAU connections per segment. Since thin coaxial cable has) 207 413.66 T (higher signal attenuation than thick coax, the limit of 185 meters of cable helps ensure) 207 401.66 T (that signal losses are held to acceptable limits. The standard also recommends using) 207 389.66 T (high quality BNC connectors with low resistance gold plated center conductors.) 207 377.66 T -0.12 (The limit on the number of connections, and the recommendation of low resistance con-) 207 353.66 P (nectors is intended to help reduce the DC resistance caused by the coaxial connectors) 207 341.66 T -0.12 (used in a thin Ethernet system. This, in turn, helps ensure that the total DC resistance of) 207 329.66 P (the segment is kept low enough so that the essential collision detect mechanism contin-) 207 317.66 T (ues to work properly) 207 305.66 T (.) 289.35 305.66 T -0.4 (There are no special MAU spacing rules in the thin Ethernet media system. However the) 207 281.66 P -0.23 (speci\336cations state that the pieces of coaxial cable used to build a thin Ethernet segment) 207 269.66 P (may be no shorter than 0.5 meters \0501.64 feet\051 in length. This ef) 207 257.66 T (fectively limits the mini-) 457.47 257.66 T (mum spacing between MAU connections to 0.5 meters.) 207 245.66 T (Notice that the BNC T) 207 221.66 T (ee is connected directly to the BNC MDI on the interface. The) 296.8 221.66 T (standard notes that the length of the \322stub\323 from the BNC MDI on the interface to the) 207 209.66 T (coaxial cable should be no longer than four centimeters, to prevent the occurrence of) 207 197.66 T (signal re\337ections which can cause frame errors.) 207 185.66 T FMENDPAGE %%EndPage: "9" 10 %%Page: "10" 10 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (T) 189 739.85 T (wisted-pair Ethernet \320 T) 193.83 739.85 T (ype 10BASE-T) 295.04 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (10) 54 60.96 T 0 9 Q ( of) 65.11 60.96 T 0 10 Q ( 18) 76.1 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 51.86 670.18 537.86 673.18 C 186.86 672.34 537.86 672.34 2 L 0.25 H 2 Z 0 X 0 K N 51.86 672.34 177.86 672.34 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (6.0) 161.19 677.18 T (T) 186.86 677.18 T (wisted-pair Ethernet) 193.3 677.18 T 0 14 Q (\320) 311.92 677.18 T 0 12 Q ( T) 319.7 677.18 T (ype 10BASE-T) 329.48 677.18 T 1 10 Q (The twisted-pair Ethernet system operates over two pairs of wires, one pair used for) 186.86 649.52 T (receive data signals and the other pair used for transmit data signals. The two wires in) 186.86 637.52 T (each pair must be twisted together for the entire length of the segment, which is a stan-) 186.86 625.52 T (dard technique used to improve the signal carrying characteristics of a wire pair) 186.86 613.52 T (.) 504.94 613.52 T 51.86 337.33 537.86 360.33 C 186.86 345.33 537.86 345.33 2 L 0.25 H 2 Z 0 X 0 K N 51.86 345.33 177.86 345.33 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 4.) 51.86 331.33 T 4 F (Connecting a computer to twisted-pair Ethernet.) 186.86 331.33 T 0 10 Q (6.1) 163.96 303.66 T (T) 186.86 303.66 T (wisted-pair Components) 192.22 303.66 T 0 9 Q (1.) 186.86 287.66 T 2 10 Q (Network Medium.) 200.6 287.66 T 1 F ( The twisted-pair Ethernet system was designed to allow seg-) 278.88 287.66 T (ments of up to 100 meters in length when using modern \322voice grade\323 twisted-pair) 200.6 275.66 T (telephone wiring that meets the EIA/TIA Category Three wire speci\336cations and) 200.6 263.66 T (follows the correct wiring scheme. The maximum segment length at your site may) 200.6 251.66 T -0 (be shorter or longer than this depending on the quality of the twisted-pair cabling in) 200.6 239.66 P (your system.) 200.6 227.66 T (There are twisted-pair Ethernet cable testers available that allow you to check the) 200.6 212.66 T (electrical characteristics of the cable you use, to see if it meets the important electri-) 200.6 200.66 T -0.15 (cal speci\336cations. These speci\336cations include signal crosstalk, which is the amount) 200.6 188.66 P (of signal that crosses over between the receive and transmit pairs, and signal attenu-) 200.6 176.66 T (ation, which is the amount of signal loss encountered on the segment.) 200.6 164.66 T (The transmit and receive data signals on a twisted-pair segment are polarized, with) 200.6 149.66 T (one wire of each signal pair carrying the positive \050+\051 signal, and the other carrying) 200.6 137.66 T (the negative \050-\051 signal. When connecting a twisted-pair interface to a repeater hub) 200.6 125.66 T (this polarity must be preserved, so that the positive terminal on one end of the seg-) 200.6 113.66 T (ment is connected to the positive terminal on the other end.) 200.6 101.66 T 51.86 87.15 537.86 685.18 C 163.38 374.33 537.86 586.18 C 163.38 374.33 537.86 586.18 R 7 X 0 K V 450.11 507.96 454.61 507.96 2 L 0.5 H 2 Z 0 X N 403.57 502.21 M 395.82 484.71 418.65 451.2 389.55 445.97 D 381.89 444.6 373.92 445.76 366.11 444.21 D 3 H N 196.38 411.54 358.39 469.54 R 7 X V 0.5 H 0 X N 294.89 412.04 312.89 421.04 R 6 X V 0 X N 281.14 485.54 281.14 539.54 2 L V N 280.89 539.54 208.88 557.04 2 L V N 208.88 556.29 208.63 479.71 2 L V N 208.88 480.04 280.89 485.54 2 L V N 233.38 482.04 219.88 469.54 2 L N 256.39 483.04 266.39 469.54 2 L N 216.63 555.04 216.38 480.71 2 L N 1 10 Q (Ethernet Interface) 201.88 442.46 T (W) 201.88 432.46 T (ith Internal MAU) 210.92 432.46 T 321.89 412.04 348.89 421.04 R 6 X V 0 X N 286.14 420.79 358.14 456.79 R 6 X V 0 X N (Interface) 288.14 430.79 T (Ethernet) 287.89 439.04 T (AUI) 0 -270 337.14 430.46 TF (MAU) 0 -270 351.14 429.96 TF 393.54 512 478.54 571.64 R 7 X V 0 X N 412.07 506.36 419.93 512.07 R 3 X V 0 X N 424.36 506.21 432.22 511.93 R 3 X V 0 X N 458.14 508.43 471.72 512 R 7 X V 0 X N 435.57 506.36 443.43 512.07 R 3 X V 0 X N 450.86 506.71 454.11 511.96 R 7 X V 0 X N 401.61 501.96 406.11 507.71 R 7 X V 0 X N 400.07 506.36 407.93 512.07 R 3 X V 0 X N 361.73 442.09 367.48 446.59 R 7 X V 0 X N 357.14 440.57 362.86 448.43 R 3 X V 0 X N (Five Port Repeater \050Hub\051) 398.86 576.71 T (MAU) 0 -270 407.14 521.71 TF (MAU) 0 -270 418.89 521.96 TF (MAU) 0 -270 430.39 521.71 TF (MAU) 0 -270 442.89 522.46 TF (MAU) 0 -270 454.89 512.96 TF (RJ-45 Jack) 363.86 412.71 T 362.09 426.78 360.85 438.72 368.23 429.25 365.16 428.02 4 Y V 367.86 421.21 365.17 428.01 2 L N (RJ-45 Plugs) 319.36 483.71 T 386.56 497.98 398.35 500.22 389.54 492.07 388.05 495.02 4 Y V 371.36 486.71 388.06 495.02 2 L N (T) 409.57 469.86 T (wisted-pair cable) 414.98 469.86 T (\050100 meters maximum) 410.29 460.86 T ( for typical voice grade) 409.57 450.43 T ( twisted-pair cable\051) 409.57 440 T 4 9 Q (X) 401.36 513.21 T (X) 412.36 513.21 T (X) 436.86 513.71 T (X) 424.86 513.46 T 90 450 6.88 7 435.23 560.71 A 1 10 Q (R) 432.61 557.71 T 428.61 559.46 406.11 545.21 2 L N 429.86 556.46 416.61 545.46 2 L N 432.36 554.21 427.86 545.46 2 L N 437.11 553.71 438.86 545.71 2 L N 440.61 555.46 460.11 542.21 2 L N 459.61 541.21 453.11 536.21 2 L N 460.11 542.21 465.11 513.96 2 L N (15-pin AUI) 473.21 503.36 T (BNC) 464.93 482.61 T 457.22 493.13 454.1 504.72 462.89 496.55 460.05 494.84 4 Y V 463.57 488.86 460.06 494.84 2 L N 370.17 461.39 366.86 449.86 363.55 461.39 366.86 461.39 4 Y V 366.86 479.36 366.86 461.39 2 L N (Connector) 473.57 494.57 T (MDI) 488.57 482.43 T (\050MDI\051) 364.29 403.86 T (Pin 1 = T) 411.81 413.58 T (ransmit Data \050+\051) 449.03 413.58 T (Pin 2 = T) 411.81 402.44 T (ransmit Data \050-\051) 449.03 402.44 T (Pin 3 = Receive Data \050+\051) 411.81 390.58 T (Pin 6 = Receive Data \050-\051) 411.81 380.15 T 51.86 87.15 537.86 685.18 C 0 0 612 792 C FMENDPAGE %%EndPage: "10" 11 %%Page: "11" 11 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (T) 207 739.85 T (wisted-pair Ethernet \320 T) 211.83 739.85 T (ype 10BASE-T) 313.04 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (1) 525.03 60.96 T (1 of 18) 529.53 60.96 T (2.) 207 680.66 T 2 10 Q (MAU.) 220.74 680.66 T 1 F (When connecting two twisted-pair MAUs together over a segment, the trans-) 249.61 680.66 T (mit data pins of one MDI must be wired to the receive data pins of the other MDI,) 220.74 668.66 T -0.13 (and vice versa. For a single segment connecting only two computers you can do this) 220.74 656.66 P (by building a special \322crossover\323 cable, with the transmit pins on the RJ-45 plug at) 220.74 644.66 T -0.2 (one end of the cable wired to the receive data pins on the RJ-45 plug at the other end) 220.74 632.66 P (of the crossover cable.) 220.74 620.66 T (However) 220.74 605.66 T (, when you are wiring multiple segments in a building it\325) 256.98 605.66 T (s much easier to) 483.79 605.66 T (wire the cable connectors \322straight through\323 and not worry about whether the wires) 220.74 593.66 T -0.38 (in the jumper cables or other twisted-pair cables in your building have been correctly) 220.74 581.66 P (crossed over) 220.74 569.66 T (. The way to accomplish this is to do the crossover wiring inside the) 270.43 569.66 T (multiport repeater hub. The twisted-pair Ethernet standard recommends this) 220.74 557.66 T (approach, and states that each port of the hub that is crossed over internally should) 220.74 545.66 T (be marked with an \322X.\323) 220.74 533.66 T (T) 220.74 518.66 T (wisted-pair MAUs send a special link pulse to one another over the twisted-pair) 226.15 518.66 T -0.17 (segment when the segment is idle. V) 220.74 506.66 P -0.17 (endors can provide a link light on the MAU and) 365.43 506.66 P (if the link lights on both MAUs are lit when you connect a segment, then you have) 220.74 494.66 T (an indication that the segment is working correctly) 220.74 482.66 T (.) 423.01 482.66 T (T) 207 458.66 T (wisted-pair Ethernet segments are de\336ned as link segments in the Ethernet speci\336ca-) 212.41 458.66 T (tions. A link segment is formally de\336ned as a point-to-point full duplex medium that) 207 446.66 T (connects two and only two MDIs. The phrase \322full duplex\323 means that there are sepa-) 207 434.66 T (rate signal paths for sending and receiving data. The smallest network built with a link) 207 422.66 T (segment would consist of two computers, one at each end of the link segment.) 207 410.66 T (The more typical installation uses multiport repeaters, also called \322hubs\323 or \322concentra-) 207 386.66 T (tors,\323 to provide a repeater connection between a lar) 207 374.66 T (ger number of link segments. Y) 415.8 374.66 T (ou) 541.39 374.66 T (connect the MAU in the Ethernet interface in your computer to one end of the link seg-) 207 362.66 T (ment, and the other end of the link segment is connected to the MAU in the repeater) 207 350.66 T -0.14 (hub. That way you can attach as many link segments with their associated computers as) 207 338.66 P (you have hub ports, and the computers all communicate via the repeater hub.) 207 326.66 T (In any twisted-pair Ethernet system with more than two computers, you need a multi-) 207 302.66 T (port repeater hub to connect the individual segments together) 207 290.66 T (, and a \336ve-port hub is) 451.43 290.66 T -0.25 (shown in the \336gure. Four of the ports are equipped with twisted-pair MAUs and twisted-) 207 278.66 P (pair RJ-45 jacks as MDIs. The \336fth port may be connected either to a thin Ethernet seg-) 207 266.66 T (ment, or to an outboard MAU using the 15-pin AUI connector) 207 254.66 T (.) 455.44 254.66 T (A common error when connecting a computer to a twisted-pair segment is to use the) 207 230.66 T (widely available \322silver satin\323 patch cable typically used to connect telephones to the) 207 218.66 T (telephone jack on the of) 207 206.66 T (\336ce wall. The problem is that the silver satin patch cable for) 302.86 206.66 T (telephones does not have twisted wire pairs in it, and the lack of twisted pairs results in) 207 194.66 T (excessive signal crosstalk and \322phantom collisions.\323 This occurs because collisions are) 207 182.66 T -0.13 (detected in twisted-pair Ethernet by the simultaneous occurrence of signals on the trans-) 207 170.66 P (mit and receive wire pairs, and excessive crosstalk can trigger the collision detect cir-) 207 158.66 T (cuit. This problem can be avoided by using only twisted-pair patch cables rated for use) 207 146.66 T (in twisted-pair Ethernet systems to make a connection between the MAU in the com-) 207 134.66 T (puter or the hub and the rest of segment.) 207 122.66 T FMENDPAGE %%EndPage: "11" 12 %%Page: "12" 12 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Fiber Optic Ethernet \320 T) 189 739.85 T (ypes FOIRL and 10BASE-F) 290.22 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (12) 54 60.96 T 0 9 Q ( of) 65.11 60.96 T 0 10 Q ( 18) 76.1 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 672.33 540 675.33 C 189 674.48 540 674.48 2 L 0.25 H 2 Z 0 X 0 K N 54 674.48 180 674.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (7.0) 163.33 679.33 T (Fiber Optic Ethernet) 189 679.33 T 1 14 Q (\320) 307.63 679.33 T 0 12 Q ( T) 314.62 679.33 T (ypes FOIRL and 10BASE-F) 324.4 679.33 T 1 10 Q (The \336ber optic media system use pulses of light instead of electrical currents to send) 189 651.66 T -0.34 (signals, which provides electrical isolation for equipment at each end of a \336ber link. The) 189 639.66 P -0.01 (electrical isolation provides immunity from the ef) 189 627.66 P -0.01 (fect of lightning strikes and the dif) 387.55 627.66 P -0.01 (fer-) 525.58 627.66 P (ent ground currents found in separate buildings. This is essential when segments must) 189 615.66 T (travel outside a building to link separate buildings.) 189 603.66 T 54 313.61 540 336.61 C 189 321.61 540 321.61 2 L 0.25 H 2 Z 0 X 0 K N 54 321.61 180 321.61 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 5.) 54 307.61 T 4 F (Connecting a computer to a 10BASE-FL segment.) 189 307.61 T 1 10 Q (The most commonly used \336ber optic medium type is the link segment. There are two) 189 285.95 T (\336ber optic link segments in use today) 189 273.95 T (, the original Fiber Optic Inter) 337.71 273.95 T (-Repeater Link) 457.98 273.95 T (\050FOIRL\051 segment, and the newer 10BASE-FL segment. The original FOIRL speci\336ca-) 189 261.95 T (tion provided a link segment of up to 1000 meters between two repeaters only) 189 249.95 T (. As the) 500.08 249.95 T (cost of repeaters dropped and more and more multiport repeater hubs were used, it) 189 237.95 T (became cost-ef) 189 225.95 T (fective to link individual computers to a \336ber optic port on a repeater) 249.04 225.95 T -0.16 (hub. V) 189 213.95 P -0.16 (endors created outboard FOIRL MAUs to allow this, although a repeater) 214.94 213.95 P -0.16 (-to-DTE) 503.8 213.95 P (\336ber connection was not speci\336cally described in the FOIRL standard.) 189 201.95 T -0.19 (T) 189 177.95 P -0.19 (o deal with this and other aspects of \336ber optic Ethernet, a new set of \336ber optic media) 194.41 177.95 P -0.18 (standards, called 10BASE-F) 189 165.95 P -0.18 (, was developed. This new set of standards includes revised) 301.39 165.95 P (speci\336cations for a \336ber optic link segment that allow direct attachments to computers.) 189 153.95 T (The 10BASE-F speci\336cations include the following three segment types.) 189 141.95 T 5 11 Q (\245) 189 113.95 T 2 10 Q -0.38 (10BASE-FL) 204.86 113.95 P 1 F -0.38 (The new Fiber Link speci\336cations. The 10BASE-FL standard replaces) 259.18 113.95 P -0.23 (the older FOIRL speci\336cations, and is designed to interoperate with existing FOIRL-) 202.75 101.95 P 54 89.3 540 687.33 C 165.53 350.61 540 600.33 C 165.53 350.61 540 600.33 R 7 X 0 K V 389.21 467 M 363.88 477.69 309.53 443.77 312.64 518.62 D 1 H 2 Z 0 X N 388.39 452.77 M 376.53 454.05 370.71 478.03 357.04 480.32 D 343.64 482.57 312.89 477.2 323.23 515.68 D N 381.53 518.79 M 384.23 511.4 382.48 502.47 387.03 495.93 D N 371.64 517.43 M 373.73 498.37 393.48 490.94 406.07 492.32 D 453 497.47 500.81 500.89 548.72 500.17 D N 348.1 381.52 M 389.87 387 431.04 350.21 472.05 369.16 D 495.29 379.91 508.29 410.37 512.38 440.02 D 516.28 468.26 488.69 464.05 475.35 460.46 D 3 H N 302.95 523.32 392.06 586.85 R 7 X V 0.5 H 0 X N 310.02 513.79 314.52 519.54 R 7 X V 0 X N 308.48 518.18 316.34 523.89 R 3 X V 0 X N 1 10 Q (FO Repeater Hub) 231.31 557.29 T 90 450 7.12 7 347.67 579.2 A 4 9 Q (R) 344.85 575.81 T 172.15 353.59 334.15 411.59 R 7 X V 0 X N 261.65 363.09 333.65 399.09 R 6 X V 0 X N 270.65 354.09 288.65 363.09 R 6 X V 0 X N 297.65 354.09 324.65 363.09 R 6 X V 0 X N 336.65 374.09 352.65 387.59 R 7 X V 0 X N 1 10 Q (Ethernet) 278.15 386.59 T (Interface) 277.65 378.09 T 256.9 427.59 256.9 481.59 2 L V N 256.65 481.59 184.65 499.09 2 L V N 184.65 498.84 184.65 421.76 2 L V N 184.4 422.01 256.65 427.59 2 L V N 208.15 423.76 195.65 411.59 2 L N 232.15 425.09 242.15 411.59 2 L N 192.4 497.09 192.4 422.51 2 L N 333.65 372.09 339.15 390.09 R 7 X V 0 X N 394.66 441.9 464.66 480.65 R 7 X V 0 X N 385.99 451.43 391.74 455.93 R 7 X V 0 X N 390.62 449.59 396.33 457.45 R 3 X V 0 X N 386.12 465.06 391.87 469.56 R 7 X V 0 X N 390.74 463.22 396.46 471.08 R 3 X V 0 X N 467.46 455.4 483.46 468.9 R 7 X V 0 X N 464.46 453.4 469.96 471.4 R 7 X V 0 X N 4 9 Q (TX) 0 -270 406.6 445.72 TF (RX) 0 -270 406.6 465.09 TF (FOMAU) 0 -270 351.89 534.29 TF (TX) 304.89 525.79 T (RX) 318.14 525.54 T 321.02 513.79 325.52 519.54 R 7 X V 0 X N 319.48 518.18 327.34 523.89 R 3 X V 0 X N 1 10 Q (FOMAU) 421.11 458.77 T (AUI Cable) 423.18 372.5 T 340.38 513.79 344.47 519.54 R 7 X V 0 X N 338.98 518.18 346.13 523.89 R 3 X V 0 X N 350.52 513.79 355.02 519.54 R 7 X V 0 X N 348.98 518.18 356.84 523.89 R 3 X V 0 X N 4 9 Q (TX) 336.89 525.29 T (RX) 348.64 525.54 T (FOMAU) 0 -270 320.39 534.29 TF (FOMAU) 0 -270 381 534.62 TF 369.63 514.12 374.13 519.87 R 7 X V 0 X N 368.1 518.51 375.95 524.22 R 3 X V 0 X N 379.63 514.12 384.13 519.87 R 7 X V 0 X N 378.1 518.51 385.95 524.22 R 3 X V 0 X N (TX) 366 525.62 T (RX) 377.75 525.87 T 1 10 Q (10BASE-FL Segment) 277.7 458.85 T (\0502000 meter maximum\051) 277.7 448.85 T (FO link to another FO hub) 406.11 501.55 T 317.7 568.06 340.5 581.5 2 L N 376.89 568.04 355.5 581 2 L N 347 568 347 572 2 L N (10BASE-FL) 231.1 567.21 T (10BASE-FL) 411.24 467.07 T (15-pin AUI) 335.72 401.71 T (Connector) 335.72 392.43 T 54 89.3 540 687.33 C 0 0 612 792 C FMENDPAGE %%EndPage: "12" 13 %%Page: "13" 13 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Universal 15-pin Connector) 207 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (13 of 18) 524.53 60.96 T 1 10 Q (based equipment. 10BASE-FL provides for a full duplex \336ber optic link segment) 220.75 680.66 T (that may be up to 2000 meters long providing that only 10BASE-FL equipment is) 220.75 668.66 T (used in the segment. If 10BASE-FL equipment is mixed with FOIRL equipment,) 220.75 656.66 T (then the maximum segment length may be 1000 meters. A 10BASE-FL segment) 220.75 644.66 T (may be attached between two computers, or two repeaters, or between a computer) 220.75 632.66 T -0.04 (and a repeater port. Because of the widespread use of \336ber links, 10BASE-FL is the) 220.75 620.66 P (most widely used portion of the new 10BASE-F \336ber optic speci\336cations.) 220.75 608.66 T 5 11 Q (\245) 207 580.66 T 2 10 Q (10BASE-FB) 220.74 580.66 T 1 F (The Fiber Backbone link segment system. The 10BASE-FB speci\336ca-) 275.45 580.66 T (tions describe a special synchronous signaling backbone approach that allows the) 220.75 568.66 T (limit on the number of repeaters that may be used in a given Ethernet system to be) 220.75 556.66 T (exceeded. 10BASE-FB links do not attach to computers or end nodes, and are only) 220.75 544.66 T -0.28 (used to link special 10BASE-FB repeater hubs together in a lar) 220.75 532.66 P -0.28 (ge repeated backbone) 469.77 532.66 P (system. 10BASE-FB links may be up to 2000 meters in length.) 220.75 520.66 T 5 11 Q (\245) 207 492.66 T 2 10 Q (10BASE-FP) 220.74 492.66 T 1 F (The Fiber Passive system. This provides a set of speci\336cations for a) 274.89 492.66 T (\336ber optic mixing segment that links multiple computers on a \336ber optic media sys-) 220.75 480.66 T (tem without using repeaters. 10BASE-FP segments may be up to 500 meters long,) 220.75 468.66 T -0.2 (and a 10BASE-FP \336ber optic passive star coupler typically links up to 33 computers.) 220.75 456.66 P -0.04 (In the \336gure we show a computer linked to a repeater hub with a 10BASE-FL segment.) 207 432.66 P (The computer is equipped with an Ethernet interface that has a 15-pin AUI connector) 207 420.66 T (.) 547.57 420.66 T (This connector allows us to make a connection to an outboard \336ber optic MAU) 207 408.66 T (\050FOMAU\051, using a standard AUI cable. The FOMAU, in turn, is connected to the) 207 396.66 T -0.22 (repeater hub with two strands of \336ber optic cable. Another port on the repeater is shown) 207 384.66 P (connecting to another FO repeater hub, which could be located some distance away) 207 372.66 T (. A) 540.26 372.66 T (major advantage of the \336ber optic link segment is the long distances that it can cover) 207 360.66 T (.) 545.38 360.66 T 72 317.33 558 320.33 C 207 319.48 558 319.48 2 L 0.25 H 2 Z 0 X 0 K N 72 319.48 198 319.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (8.0) 181.33 324.33 T (Universal 15-pin Connector) 207 324.33 T 1 10 Q (Note that the 15-pin AUI connector on an interface is a \322universal\323 connector that) 207 296.66 T (makes it possible to connect the interface to any Ethernet segment type, for the small) 207 284.66 T -0.08 (additional cost of an outboard MAU. In the last \336gure we saw a 15-pin AUI connection) 207 272.66 P (to an outboard 10BASE-FL MAU. Y) 207 260.66 T (ou can make the same sort of connection to a thin) 354.8 260.66 T (or twisted-pair segment.) 207 248.66 T (Y) 207 224.66 T (ou can attach a 15-pin AUI connector to a thin Ethernet segment, for example, by) 213.22 224.66 T (using an external MAU equipped with a thin Ethernet BNC MDI. The MAU with its) 207 212.66 T (BNC MDI is attached directly to a BNC T) 207 200.66 T (ee on the thin Ethernet coax, and the 15-pin) 375.64 200.66 T (AUI connector on the MAU is connected to the 15-pin AUI connector on the Ethernet) 207 188.66 T -0.36 (interface with an AUI cable. W) 207 176.66 P -0.36 (ith a small enough MAU you can even eliminate the AUI) 330.22 176.66 P -0.21 (cable, and connect the 15-pin connector of the MAU directly to the 15-pin connector on) 207 164.66 P (the Ethernet interface of the computer) 207 152.66 T (.) 358.27 152.66 T (Now that we've seen what the Ethernet media varieties look like, let\325) 207 128.66 T (s look at the guide-) 481.38 128.66 T (lines used for building a multi-segment Ethernet system with these varieties. The next) 207 116.66 T (part of this guide describes one of the models provided by the IEEE for multi-segment) 207 104.66 T (con\336guration.) 207 92.66 T FMENDPAGE %%EndPage: "13" 14 %%Page: "14" 14 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Con\336guration Rules: T) 189 739.85 T (ransmission System Model 1) 285.37 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (14) 54 60.96 T 0 9 Q ( of) 65.11 60.96 T 0 10 Q ( 18) 76.1 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 672.33 540 675.33 C 189 674.48 540 674.48 2 L 0.25 H 2 Z 0 X 0 K N 54 674.48 180 674.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (9.0) 163.33 679.33 T (Con\336guration Rules: T) 189 679.33 T (ransmission System Model 1) 317.61 679.33 T 0 10 Q (1) 481.69 684.13 T 1 F (Section 13 of the IEEE 802.3 standard provides two models for verifying the con\336gura-) 189 651.66 T -0.13 (tion of multi-segment Ethernets. The version of section 13 shown in this guide was pub-) 189 639.66 P (lished in November) 189 627.66 T (, 1993, along with the 10BASE-F speci\336cations. The con\336guration) 267.44 627.66 T (model shown here is called T) 189 615.66 T (ransmission System Model 1. It consists of a set of basic) 306.07 615.66 T (con\336guration rules that can be applied to most Ethernets. The second model provides a) 189 603.66 T (set of calculations that you can use to verify more complex Ethernet topologies, and is) 189 591.66 T (described in the) 189 579.66 T 2 F ( Ethernet Con\336guration Guide.) 252.29 579.66 T 1 F -0.01 (In the rule-based con\336guration model shown here, a set of multi-segment con\336guration) 189 555.66 P -0.01 (rules are provided for combining Ethernet segments based on conservative calculations) 189 543.66 P -0.27 (for the components involved. Y) 189 531.66 P -0.27 (ou shouldn't let the fact that these con\336guration rules are) 313.8 531.66 P (based on conservative calculations lead you to believe that you can bend the rules and) 189 519.66 T (always get away with it. There isn't a lot of engineering mar) 189 507.66 T (gin left in maximum-sized) 428.78 507.66 T (Ethernets, despite the allowances made in the standards for manufacturing tolerances) 189 495.66 T (and equipment variances. If you want guaranteed performance and reliability) 189 483.66 T (, then you) 496.43 483.66 T (need to stick to the published guidelines.) 189 471.66 T (The multi-segment con\336guration rules are as follows:) 189 447.66 T 0 9 Q (1.) 189 429.66 T 2 10 Q (Repeater sets ar) 202.74 429.66 T (e r) 271.39 429.66 T (equir) 282.58 429.66 T (ed for all segment inter) 305.17 429.66 T (connection.) 403.8 429.66 T 1 F ( The repeaters used) 452.39 429.66 T (must comply with all IEEE speci\336cations in section 9 of the 802.3 standard, and do) 202.74 417.66 T (signal retiming and reshaping, preamble regeneration, etc. If you do not use true) 202.74 405.66 T (IEEE 802.3 repeaters for all segment interconnections, then your Ethernet system) 202.74 393.66 T (cannot be veri\336ed using either con\336guration model.) 202.74 381.66 T 0 9 Q (2.) 189 366.66 T 2 10 Q (MAUs that ar) 202.74 366.66 T (e part of r) 261.96 366.66 T (epeater sets count toward the maximum number of) 304.8 366.66 T (MAUs on a segment.) 202.74 354.66 T 1 F ( Thick Ethernet repeaters typically use an outboard MAU to) 291.02 354.66 T (connect to the thick Ethernet coax. Thin coax and twisted-pair repeater hubs use) 202.74 342.66 T (internal MAUs located on each repeater port.) 202.74 330.66 T 0 9 Q (3.) 189 315.66 T 2 10 Q (The transmission path permitted between any two DTEs may consist of up to) 202.74 315.66 T -0.22 (\336ve segments, four r) 202.74 303.66 P -0.22 (epeater sets \050including optional AUIs\051, two MAUs, and two) 288.51 303.66 P (AUIs) 202.74 291.66 T 1 F (. The repeater sets are assumed to have their own MAUs, which are not) 224.95 291.66 T (counted in this rule.) 202.74 279.66 T 0 9 Q (4.) 189 264.66 T 2 10 Q (AUI cables for 10BASE-FP and 10BASE-FL shall not exceed 25 m.) 202.74 264.66 T (\050Since two) 490.37 264.66 T (MAUs per segment ar) 202.74 252.66 T (e r) 296.65 252.66 T (equir) 307.85 252.66 T (ed, 25 m per MAU r) 330.43 252.66 T (esults in a total AUI cable) 416.3 252.66 T (length of 50 m per segment\051.) 202.74 240.66 T 0 9 Q (5.) 189 225.66 T 2 10 Q (When a transmission path consists of four r) 202.74 225.66 T (epeaters and \336ve segments, up to) 388.3 225.66 T -0.1 (thr) 202.74 213.66 P -0.1 (ee of the segments may be mixing and the r) 215.89 213.66 P -0.1 (emainder must be link segments.) 398.34 213.66 P (When \336ve segments ar) 202.74 201.66 T (e pr) 298.89 201.66 T (esent, each \336ber optic link segment \050FOIRL,) 315.64 201.66 T 54 167.29 540 183.29 C 189 175.29 333 175.29 2 L 0.25 H 2 Z 0 X 0 K N 0 0 612 792 C 1 9 Q 0 X 0 K -0.33 (1. Portions of the information contained herein are copyrighted information of the IEEE extracted) 189 161.29 P (from IEEE Std 802.3j-1993, IEEE Standard for Local and Metropolitan Area Networks) 189 150.29 T (\320) 505.5 150.29 T ( Fiber) 509.99 150.29 T (Optic Active and Passive Star) 189 139.29 T (-Based Elements, T) 296.16 139.29 T (ype 10BASE-F) 366.17 139.29 T (, copyright) 420.62 139.29 T (\251) 461.81 139.29 T ( 1993 by the Insti-) 468.64 139.29 T (tute of Electrical and Electronics Engineers, Inc. The IEEE takes no responsibility for damages) 189 128.29 T -0.19 (resulting from the reader) 189 117.29 P -0.19 (\325) 277.85 117.29 P -0.19 (s misinterpretation of said information resulting from the placement and) 280.35 117.29 P (context in this publication. Information is reproduced with the permission of the IEEE.) 189 106.29 T FMENDPAGE %%EndPage: "14" 15 %%Page: "15" 15 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Con\336guration Rules: T) 207 739.85 T (ransmission System Model 1) 303.37 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (15 of 18) 524.53 60.96 T 2 10 Q (10BASE-FB, 10BASE-FL\051 shall not exceed 500 m, and each 10BASE-FP seg-) 220.74 680.66 T (ment shall not exceed 300 m.) 220.74 668.66 T 0 9 Q (6.) 207 653.66 T 2 10 Q -0.25 (When a transmission path consists of thr) 220.74 653.66 P -0.25 (ee r) 392.86 653.66 P -0.25 (epeater sets and four segments, the) 408.24 653.66 P (following r) 220.74 641.66 T (estrictions apply) 266.93 641.66 T 1 F (:) 337.17 641.66 T 2 F (a. The maximum allowable length of any inter) 220.74 626.66 T (-r) 416.94 626.66 T (epeater \336ber) 424.52 626.66 T (segment shall not) 481.14 626.66 T (exceed 1000 m for FOIRL, 10BASE-FB,) 220.74 614.66 T (and 10BASE-FL segments and shall) 393.97 614.66 T (not exceed 700 m) 220.74 602.66 T (for 10BASE-FP segments.) 296.24 602.66 T (b. The maximum allowable length of any r) 220.74 587.66 T (epeater to DTE \336ber segment shall) 401.58 587.66 T (not exceed 400 m for 10BASE-FL) 220.74 575.66 T (segments and shall not exceed 300 m for) 366.2 575.66 T (10BASE-FP) 220.74 563.66 T (segments and 400 m for segments terminated in a 10BASE-FL) 274.89 563.66 T (MAU.) 220.74 551.66 T -0.24 (c. Ther) 220.74 536.66 P -0.24 (e is no r) 250.86 536.66 P -0.24 (estriction on the number of mixing segments in this case.) 283.55 536.66 P 1 F -0.24 ( In other) 522.36 536.66 P (words, when using three repeater) 220.74 524.66 T (sets and four segments, all segments may be mix-) 355.63 524.66 T (ing) 220.74 512.66 T (segments if desired.) 236.02 512.66 T 72 249.04 558 272.04 C 207 257.04 558 257.04 2 L 0.25 H 2 Z 0 X 0 K N 72 257.04 198 257.04 2 L 0 Z N 0 0 612 792 C 0 9 Q 0 X 0 K (FIGURE 6.) 72 243.04 T 4 F (One possible maximum con\336guration.) 207 243.04 T 1 10 Q -0.29 (The \336gure shows an example of a maximum Ethernet con\336guration that meets the rules.) 207 221.38 P (The maximum packet transmission path in this system is between DTE1 and DTE3,) 207 209.38 T (since there are four repeaters and \336ve segments in that path. T) 207 197.38 T (wo of the segments are) 454.43 197.38 T (mixing segments, and the other three are link segments.) 207 185.38 T (While the con\336guration guidelines emphasize the maximum limits of the system, you) 207 161.38 T (should beware of stretching things as far as they can go. Ethernets, like many other sys-) 207 149.38 T (tems, work best when they are not being pushed to their limits.) 207 137.38 T 72 89.3 558 687.33 C 183.53 286.04 558 494.33 C 183.53 286.04 558 494.33 R 7 X 0 K V 435.72 455.57 M 419.45 459.64 408.23 440.2 392.14 447 D 0.5 H 2 Z 0 X N 493.23 439.71 M 499.88 439.22 525.75 446.38 512.77 431.59 D 507.39 425.45 478.55 419.86 489.73 405.74 D 493.86 400.53 503.19 401.23 510.55 403.52 D N 330.29 295.32 341.29 300.32 R 7 X V 0 X N 247.88 318.57 M 249.37 300.68 232.65 315.99 226.07 307.31 D 222.78 302.99 228.03 298.33 231.19 298.23 D 256.02 297.43 280.57 298.38 305.25 298 D 3 H N 246.11 316.41 250.61 326.16 R 7 X V 0.5 H 0 X N 282.5 414.92 M 266.04 414.49 245 412.92 251.91 426.07 D 1 H N 217.18 398.13 M 209.69 401.41 195.97 396.12 203.15 390.35 D 216.52 379.59 232.4 388.23 245.76 382.39 D 250.03 380.53 246.27 374.8 248.94 369.82 D N 215 396.07 219.5 400.82 R 7 X V 0.5 H 0 X N 1 10 Q (R) 368.7 362.42 T (Repeater Set) 226.18 473.14 T 274.18 446.71 349.5 446.71 2 L N (10BASE-FL) 282.11 459.57 T (500 meters) 280.86 436.71 T 195.86 406.71 307.29 406.71 2 L 3 H N 219.68 403.1 233.96 409.53 R V 0.5 H N 218.43 391.68 235.14 403.68 R 7 X V 0 X N 281.5 412.14 286 416.89 R 7 X V 0 X N 286.18 403.43 300.46 409.86 R V N 284.93 409.28 301.64 421.28 R 7 X V 0 X N (10BASE-5) 239.43 396.63 T (500 meters) 189.11 414.01 T (Mixing) 245.14 387.43 T (Link) 283 450.28 T 372.25 423.5 372.25 388.71 2 L N (10BASE-FL) 319.5 410 T (Link) 320.57 401.75 T (500) 375.86 409.93 T (meters) 375.86 402.79 T 244.25 314.82 252.25 319.07 R 7 X V 0 X N 299.25 311.32 328.25 340.32 R N 0 8 Q (DTE 1) 304.17 322.66 T 311.54 297.97 316.79 307.22 R N 309.79 305.45 318.54 311.2 R 7 X V 0 X N 304.54 301.7 304.54 292.95 2 L N 324.54 301.95 324.54 293.2 2 L N 302.54 293.95 326.04 300.7 R 7 X V 0 X N 300.29 292.07 306.57 303.57 R 7 X V 0 X N 323.29 292.07 330.29 303.57 R 7 X V 0 X N 1 10 Q (10BASE-2) 345.04 303.25 T (Mixing) 345.64 294.29 T 505.45 399.06 508.95 405.81 R 7 X V 0 X N 434.54 453.07 439.04 457.82 R 7 X V 0 X N 439.21 444.36 453.5 450.79 R V N 437.96 450.21 454.68 462.21 R 7 X V 0 X N (10BASE-5) 423.35 431.64 T (500 meters) 467.29 456.23 T (Mixing) 424.57 423.43 T (185 meters) 251.43 303.86 T 372 323.38 486 323.38 2 L N (10BASE-T) 401.18 335.63 T (Link) 401.93 325.88 T (100 meters) 401.29 312.52 T 486.5 307.88 516 336.88 R N 0 8 Q (DTE 3) 489.92 319.46 T 421 447 510.5 447 2 L 3 H N 372 343 372 324 2 L 0.5 H N 490.18 437.25 494.68 442 R 7 X V 0 X N 475.71 444.29 490 450.71 R V N 474.54 432.86 491.25 444.86 R 7 X V 0 X N 508.75 387.31 538.25 416.31 R 7 X V 0 X N (DTE 2) 512.17 398.89 T 349.53 343.33 394.53 388.33 R N 363.03 379.33 381.03 388.33 R N 363.03 343.33 381.03 352.33 R N 385.53 356.83 394.53 374.83 R N 90 450 9 9 372.03 365.83 A 381 365.75 385.25 365.75 2 L N 372 356.75 372 352.5 2 L N 372.25 374.75 372.25 379.25 2 L N 1 10 Q (R) 0 -90 368.62 449.66 TF 349.53 423.83 394.53 468.83 R 7 X V 0 X N 385.53 437.33 394.53 455.33 R 7 X V 0 X N 349.53 437.33 358.53 455.33 R 7 X V 0 X N 363.03 423.83 381.03 432.83 R 7 X V 0 X N 7 X 90 450 9 9 372.03 446.33 G 0 X 90 450 9 9 372.03 446.33 A 371.95 437.36 371.95 433.11 2 L 7 X V 0 X N 362.95 446.36 358.7 446.36 2 L 7 X V 0 X N 380.95 446.11 385.45 446.11 2 L 7 X V 0 X N (R) 368.7 442.92 T (R) 0 -90 247.87 450.16 TF 228.78 424.33 273.78 469.33 R 7 X V 0 X N 264.78 437.83 273.78 455.83 R 7 X V 0 X N 228.78 437.83 237.78 455.83 R 7 X V 0 X N 242.28 424.33 260.28 433.33 R 7 X V 0 X N 7 X 90 450 9 9 251.28 446.83 G 0 X 90 450 9 9 251.28 446.83 A 251.2 437.86 251.2 433.61 2 L 7 X V 0 X N 242.2 446.86 237.95 446.86 2 L 7 X V 0 X N 260.2 446.61 264.7 446.61 2 L 7 X V 0 X N (R) 247.95 443.42 T (R) 244.92 344.09 T 225.75 325 270.75 370 R 7 X V 0 X N 239.25 361 257.25 370 R 7 X V 0 X N 239.25 325 257.25 334 R 7 X V 0 X N 261.75 338.5 270.75 356.5 R 7 X V 0 X N 7 X 90 450 9 9 248.25 347.5 G 0 X 90 450 9 9 248.25 347.5 A 257.22 347.42 261.47 347.42 2 L 7 X V 0 X N 248.22 338.42 248.22 334.17 2 L 7 X V 0 X N 248.47 356.42 248.47 360.92 2 L 7 X V 0 X N (R) 244.92 344.09 T 394.45 442.31 397.95 449.06 R 7 X V 0 X N 247.62 420.75 254.38 424.25 R 7 X V 0 X N 244.88 370 251.62 373.5 R 7 X V 0 X N 72 89.3 558 687.33 C 0 0 612 792 C FMENDPAGE %%EndPage: "15" 16 %%Page: "16" 16 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Non-standard Ethernet Equipment) 189 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (16) 54 60.96 T 0 9 Q ( of) 65.11 60.96 T 0 10 Q ( 18) 76.1 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 54 672.33 540 675.33 C 189 674.48 540 674.48 2 L 0.25 H 2 Z 0 X 0 K N 54 674.48 180 674.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (10.0) 156.66 679.33 T (Non-standard Ethernet Equipment) 189 679.33 T 1 10 Q -0.19 (The Ethernet standard describes the minimum set of devices needed to make the system) 189 651.66 P (work. There's a small set of basic components whose rules of operation and electrical) 189 639.66 T (characteristics are completely speci\336ed in the standard. The components include the) 189 627.66 T (Ethernet interface, AUI cable, MAU, repeater) 189 615.66 T (, and the physical medium.) 371.76 615.66 T (By building and selling standard Ethernet equipment, vendors can be assured that their) 189 591.66 T (devices will operate correctly when attached to any properly con\336gured Ethernet sys-) 189 579.66 T -0.29 (tem. As long as your Ethernet system is built using devices and media systems that fully) 189 567.66 P (comply with the standards you can use the con\336guration models to verify that your) 189 555.66 T (Ethernet system will operate correctly) 189 543.66 T (.) 340.46 543.66 T (However) 189 519.66 T (, there are some non-standard devices designed by vendors to be used in the) 225.23 519.66 T -0.21 (packet transmission path of an Ethernet media system. By being part of the packet trans-) 189 507.66 P (mission path these devices end up being part of the signal timing that is essential for) 189 495.66 T (correct Ethernet operation.) 189 483.66 T (Since these devices are not in the standard and are not covered by any con\336guration) 189 459.66 T -0.1 (guidelines developed by the IEEE, it's dif) 189 447.66 P -0.1 (\336cult to state exactly what the impact of using) 354.08 447.66 P (such a device will be on your network. It may work, or it may not, depending on the) 189 435.66 T (total size of your network, the number of computers attached to each network segment,) 189 423.66 T (etc. The performance of non-standard devices varies, and each vendor typically has) 189 411.66 T (their own special rules for the operation of their non-standard device. The most com-) 189 399.66 T (monly used non-standard devices are the multiport transceiver and the media converter) 189 387.66 T (.) 536.24 387.66 T 0 F (10.1) 160.55 357.66 T (Multiport T) 189 357.66 T (ransceivers) 240.08 357.66 T 1 F (Multiport transceivers were developed when thick Ethernet was the only media type) 189 333.66 T (available, and network designers needed a way to concentrate a set of machines in a) 189 321.66 T -0.37 (small space. That\325) 189 309.66 P -0.37 (s why you will sometimes see these devices referred to as \322transceiver) 260.72 309.66 P (concentrators.\323) 189 297.66 T (The problem arises because the thick Ethernet standard requires that each MAU attach-) 189 273.66 T (ment be separated by 2.5 meters of cable from the next MAU attachment. This meant) 189 261.66 T -0.17 (that when you needed to connect a number of machines located in the same space to the) 189 249.66 P (network, you had to coil up enough thick Ethernet coax in a wiring closet or under a) 189 237.66 T (machine room \337oor to provide cable to meet the 2.5 meter MAU spacing requirement.) 189 225.66 T (By providing several \050usually eight\051 15-pin AUI connectors in a single multiport trans-) 189 213.66 T (ceiver) 189 201.66 T (, vendors made it easier to connect groups of computers to thick Ethernet.) 213.02 201.66 T -0.09 (However) 189 177.66 P -0.09 (, each multiport transceiver adds a certain amount of delay and other ef) 225.23 177.66 P -0.09 (fects to) 508.53 177.66 P (the signals that pass through it, and these ef) 189 165.66 T (fects may vary depending upon which ven-) 362.87 165.66 T (dor built the multiport transceiver) 189 153.66 T (. Since the multiport transceiver is not de\336ned in the) 323.37 153.66 T (IEEE 802.3 standard the extra bit times of delay and other ef) 189 141.66 T (fects it may cause are not) 431.42 141.66 T (included in the con\336guration guidelines, and your system cannot be veri\336ed using the) 189 129.66 T (IEEE guidelines. If you use multiport transceivers you should read the vendor) 189 117.66 T (\325) 500.82 117.66 T (s con\336g-) 503.6 117.66 T (uration guidelines and follow them carefully) 189 105.66 T (. Even then you may \336nd that multiport) 366.28 105.66 T FMENDPAGE %%EndPage: "16" 17 %%Page: "17" 17 612 792 0 FMBEGINPAGE 72 750.68 558 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Network Design Guidelines) 207 739.85 T 72 726.98 558 726.98 2 L 0.25 H N 72 75.33 558 75.33 2 L 2 Z N (Guide to Ethernet) 207 60.96 T (17 of 18) 524.53 60.96 T 1 10 Q (transceivers may not perform well in lar) 207 680.66 T (ge networks, or when attached to stations with) 367.25 680.66 T (maximum-length AUI cables.) 207 668.66 T 0 F (10.2) 178.55 638.66 T (Media Converters) 207 638.66 T 1 F -0.32 (The IEEE standard states that repeaters must be used to link all segment types. It used to) 207 614.66 P (be the case that buying repeaters could add a signi\336cant cost to a network design, and) 207 602.66 T -0.12 (some vendors attempted to deal with this by of) 207 590.66 P -0.12 (fering a lower cost device called a media) 392.98 590.66 P (converter) 207 578.66 T (. These devices are also called media adapters and media translators, depend-) 244.19 578.66 T (ing on the vendor) 207 566.66 T (.) 276.68 566.66 T (Media converters are designed to link segments together inexpensively without using a) 207 542.66 T (repeater) 207 530.66 T (. While they provide some of the signal ampli\336cation functions of a repeater) 238.63 530.66 T (,) 543.29 530.66 T (they do not contain the more expensive circuits used by a repeater to retime signals,) 207 518.66 T (rebuild the preamble on the Ethernet packet, partition \050isolate\051 the segment in case of) 207 506.66 T (errors, and so on.) 207 494.66 T (The lack of these more expensive circuits explains why media converters were a lower) 207 470.66 T (-) 553.46 470.66 T (cost approach to linking segments than repeaters. However) 207 458.66 T (, the cost dif) 442.53 458.66 T (ferential) 491.76 458.66 T (between media converters and true 802.3 repeaters has been dropping ever since low-) 207 446.66 T (cost repeater chips became more widely available due to the popularity of the twisted-) 207 434.66 T (pair Ethernet system.) 207 422.66 T (Therefore, there is little economic reason to use a media converter to link segments.) 207 398.66 T (This is especially true when you consider that any Ethernet system that includes media) 207 386.66 T (converters cannot be evaluated using either con\336guration model, since the media con-) 207 374.66 T (verter is not part of the standard set of equipment de\336ned in the Ethernet speci\336cations) 207 362.66 T (and included in the con\336guration rules.) 207 350.66 T -0.05 (T) 207 326.66 P -0.05 (o make sure that your network meets the speci\336cations in the standards and to make it) 212.41 326.66 P -0.21 (possible to evaluate your network using the con\336guration rules, you must use true IEEE) 207 314.66 P (802.3 repeaters for all segment interconnections. If in doubt when buying a device that) 207 302.66 T (links segments together) 207 290.66 T (, ask the vendor to verify that what they are selling is a true) 300.99 290.66 T (IEEE 802.3 repeater) 207 278.66 T (, and that it meets all of the speci\336cations in section 9 of the 802.3) 287.92 278.66 T (standard.) 207 266.66 T 72 223.33 558 226.33 C 207 225.48 558 225.48 2 L 0.25 H 2 Z 0 X 0 K N 72 225.48 198 225.48 2 L 0 Z N 0 0 612 792 C 0 12 Q 0 X 0 K (1) 175.32 230.33 T (1.0) 181.33 230.33 T (Network Design Guidelines) 207 230.33 T 1 10 Q -0.16 (This document is written to provide a quick guide to the baseband Ethernet media types) 207 202.66 P -0.16 (and a description of the rule-based con\336guration model provided by the IEEE. Network) 207 190.66 P (design and implementation issues are not covered in any detail.) 207 178.66 T -0.16 (The media descriptions shown in this guide can provide a useful overview) 207 154.66 P -0.16 (, but they can-) 501.31 154.66 P (not provide the detailed information required for lar) 207 142.66 T (ger networks. Installing a small) 414.17 142.66 T -0.21 (Ethernet can be as simple as buying a twisted-pair hub and some patch cables, for exam-) 207 130.66 P -0.24 (ple, and connecting all of your computers to the hub. But in lar) 207 118.66 P -0.24 (ger systems, the issues of) 455.4 118.66 P (structured cabling systems, what kind of media to use, and which media system will) 207 106.66 T (best provide for future growth, can be much more complex.) 207 94.66 T FMENDPAGE %%EndPage: "17" 18 %%Page: "18" 18 612 792 0 FMBEGINPAGE 54 750.68 540 750.68 2 L 2 H 0 Z 0 X 0 K N 0 9 Q (Network Design Guidelines) 189 739.85 T 54 726.98 540 726.98 2 L 0.25 H N 54 75.33 540 75.33 2 L 2 Z N 0 10 Q (18) 54 60.96 T 0 9 Q ( of) 65.11 60.96 T 0 10 Q ( 18) 76.1 60.96 T 0 9 Q (Guide to Ethernet) 189 60.96 T 1 10 Q (W) 189 680.66 T (ith regard to the con\336guration guidelines shown in this guide, note that while the) 198.04 680.66 T -0.22 (guidelines describe how far you can stretch things, this should not be taken to mean that) 189 668.66 P (a good network design should push things to their limits. The design of a multi-lane) 189 656.66 T -0.13 (highway can be a useful analogy) 189 644.66 P -0.13 (, since a highway is somewhat like a LAN in that it is a) 318.41 644.66 P (multiple access system with a \322shared channel\323 whose traf) 189 632.66 T (\336c increases and decreases) 423.08 632.66 T (over a 24 hour period.) 189 620.66 T -0.03 (When highway engineers design a multi-lane limited access highway they calculate the) 189 596.66 P -0.23 (maximum number of vehicles that can be accommodated given the number of lanes and) 189 584.66 P (entrance and exit ramps, topology of the roadway) 189 572.66 T (, and so on. Like a LAN, a highway) 386.53 572.66 T -0.29 (system has a theoretical maximum performance, but you do not want to push the system) 189 560.66 P (to its limits. After all, a highway loaded with bumper) 189 548.66 T (-to-bumper traf) 401.17 548.66 T (\336c during the) 462.33 548.66 T (homeward-bound commute is still operating within design limits, but no one is very) 189 536.66 T (happy with it.) 189 524.66 T (In much the same way a LAN stretched to its limits with a lar) 189 500.66 T (ge number of computers) 435.05 500.66 T (on maximum-length segments can end up loaded to its capacity and still be within the) 189 488.66 T -0.12 (speci\336cations and working properly) 189 476.66 P -0.12 (, but no one will be happy with it. When you design) 331.51 476.66 P -0.14 (a LAN system, you should not focus on what you can get away with or how far you can) 189 464.66 P -0.25 (push the system. Instead, you should consider how many machines you need to support,) 189 452.66 P (how much traf) 189 440.66 T (\336c they will generate, and then build a system that will be able to accom-) 247.11 440.66 T (modate the load without serious congestion.) 189 428.66 T (Each network design is a special case, since every group has a dif) 189 404.66 T (ferent mix of comput-) 451.11 404.66 T (ing equipment, and dif) 189 392.66 T (ferent computing requirements. In general, the UTnet Network-) 279.32 392.66 T (ing Services group recommends that conservative design practices be used to help deal) 189 380.66 T (with network management issues and network traf) 189 368.66 T (\336c growth. Y) 390.34 368.66 T (our network designs) 442.36 368.66 T (should emphasize modular cabling systems and network topologies that can be easily) 189 356.66 T (recon\336gured and upgraded when traf) 189 344.66 T (\336c growth demands more bandwidth.) 336.47 344.66 T (W) 189 320.66 T (e typically recommend that campus groups use twisted-pair Ethernet for new installa-) 197.63 320.66 T (tions, based on twisted-pair hubs centralized in one or more wiring closets. Locating) 189 308.66 T -0.19 (equipment in a wiring closet reduces the number of places you must visit when tracking) 189 296.66 P (down a problem. Also, as new network equipment becomes available, you can upgrade) 189 284.66 T -0.05 (your centralized hub equipment as required to improve the capabilities of your network) 189 272.66 P (system. Installing high quality twisted-pair wiring to each desktop is another way to) 189 260.66 T (provide a network system that is reliable and easily managed, and that can be upgraded) 189 248.66 T (to higher speeds in the future.) 189 236.66 T (W) 189 212.66 T (e further recommend that campus groups use only standard IEEE 802.3 media types) 197.63 212.66 T (and equipment when building Ethernets, to make sure that their networks meet the con-) 189 200.66 T (\336guration guidelines and to provide interoperability) 189 188.66 T (. W) 395.17 188.66 T (ith respect to standards you) 409.2 188.66 T (should beware of vendor claims. Ethernet has become a commodity market, and there) 189 176.66 T (are a number of vendors selling their own inventions which are not described in any) 189 164.66 T (IEEE speci\336cation. This issue is often further obscured by vendor claims that their pro-) 189 152.66 T (prietary technologies are \322compatible\323 with IEEE equipment. When in doubt, ask the) 189 140.66 T (vendor to provide the exact IEEE standards and speci\336cations that apply to the equip-) 189 128.66 T (ment they are selling.) 189 116.66 T FMENDPAGE %%EndPage: "18" 19 %%Trailer %%BoundingBox: 0 0 612 792 %%Pages: 18 1 %%DocumentFonts: Helvetica-Bold %%+ Times-Roman %%+ Times-Bold %%+ Times-Italic %%+ Helvetica %%+ Courier-Bold .