)UTZKTZY 6XKLGIK^\OO 1 /TZXUJ[IZOUTZUIUSS[TOIGZOUTY 1.1 Data communications 1 1.2 Transmitters, receivers and communication channels 2 /TZKXLGIKYZGTJGXJY )UJOTM 6XUZUIURY 9USKIUSSUTR_[YKJIUSS[TOIGZOUTYVXUZUIURY 1.3 Types of communication channels 4 'TGRUMIUSS[TOIGZOUTINGTTKRY 1.4 Communications channel properties 4 9OMTGRGZZKT[GZOUT )NGTTKRHGTJ]OJZN 4UOYK 1.5 Data transmission modes 8 *OXKIZOUTULYOMTGRLRU] 9_TINXUTO`GZOUTULJOMOZGRJGZGYOMTGRY 'Y_TINXUTU[YZXGTYSOYYOUT 9_TINXUTU[YZXGTYSOYYOUT 1.6 Encoding methods 12 3GTINKYZKX *OLLKXKTZOGR3GTINKYZKX 8@XKZ[XTZU`KXU 48@TUTXKZ[XTZU`KXU 32: (( 1.7 Error detection 14 )_IROIXKJ[TJGTI_INKIQ)8) 2 4KZ]UXQOTML[TJGSKTZGRY 2.1 Overview 15 2.2 Network communication 16 )OXI[OZY]OZINOTM 6GIQKZY]OZINOTM *GZGMXGSYGTJ\OXZ[GRIOXI[OZY 2.3 Types of networks 18 2UIGRGXKGTKZ]UXQY2'4Y =OJKGXKGTKZ]UXQY='4Y 3KZXUVUROZGTGXKGTKZ]UXQY3'4Y vi Contents )U[VROTMXGZOU <OXZ[GRVXO\GZKTKZ]UXQY<64Y 2.4 The open systems interconnection model 20 5VKTGTJIRUYKJY_YZKSY :NKUVKTY_YZKSYOTZKXIUTTKIZOUTXKLKXKTIKSUJKR59/SUJKR 59/RG_KXYKX\OIKY 'VVROIGZOUTRG_KX 6XKYKTZGZOUTRG_KX 9KYYOUTRG_KX :XGTYVUXZRG_KX 4KZ]UXQRG_KX *GZGROTQRG_KX 6N_YOIGRRG_KX 2.5 Interoperability and internetworking 28 2.6 Protocols and protocol standards 30 2.7 IEEE/ISO standards 31 2.8 Network topologies 33 (XUGJIGYZGTJVUOTZZUVUOTZZUVURUMOKY 2UMOIGRGTJVN_YOIGRZUVURUMOKY 2.9 Bus topology 35 2.10 Star topology 36 2.11 Ring topology 36 2.12 Other types of topology 38 9ZGX]OXKJXOTMZUVURUM_ *OYZXOH[ZKJYZGXZUVURUM_ 3KYNZUVURUM_ :XKKZUVURUM_ 2.13 Media access methods 40 )UTZKTZOUTY_YZKSY :UQKTVGYYOTM 6URROTM 3 +ZNKXTKZTKZ]UXQY 3.1 IEEE 802.3 CSMA/CD (‘Ethernet’) 43 3.2 Physical layer 44 (GYKY_YZKSY (GYKY_YZKSY (GYK: (GYK, (XUGJ (GYK 3.3 Signaling methods 50 3.4 Medium access control 50 Contents vii 3.5 Frame transmission 51 3.6 Frame reception 51 3.7 Collisions 52 3.8 MAC frame format 53 3.9 Difference between 802.3 and Ethernet 55 3.10 Reducing collisions 55 3.11 Ethernet design rules 55 2KTMZNULZNKIGHRKYKMSKTZ 3G^OS[SZXGTYIKO\KXIGHRKRKTMZN 4UJKVRGIKSKTZX[RKY 3G^OS[SZXGTYSOYYOUTVGZN 3G^OS[STKZ]UXQYO`K 8KVKGZKXX[RKY )GHRKY_YZKSMXU[TJOTM 4 ,GYZGTJMOMGHOZ+ZNKXTKZY_YZKSY 4.1 Achieving higher speed 59 )GHROTMROSOZGZOUTY 4.2 100Base-T (100Base-TX, -T4, -FX, -T2) 60 /+++[(GYK:YZGTJGXJYGXXGTMKSKTZ 6N_YOIGRSKJO[SOTJKVKTJKTZ6.?Y[HRG_KX (GYK:>GTJ,>VN_YOIGRSKJOGJKVKTJKTZ63*Y[HRG_KX (GYK:VN_YOIGRSKJOGJKVKTJKTZ63*Y[HRG_KX (GYK: (GYK:N[HY (GYK:GJGVZKXY 4.3 Fast Ethernet design considerations 65 ;:6IGHROTMJOYZGTIKY(GYK:>: ,OHKXUVZOIIGHRKJOYZGTIKY(GYK,> (GYK:XKVKGZKXX[RKY 9GSVRKIGRI[RGZOUT 4.4 Gigabit Ethernet 1000Base-T 67 -OMGHOZ+ZNKXTKZY[SSGX_ -OMGHOZ+ZNKXTKZ3')RG_KX 6N_YOIGRSKJO[SOTJKVKTJKTZ6.?Y[HRG_KX (GYK9>LUXNUXO`UTZGRLOHKX (GYK2>LUX\KXZOIGRHGIQHUTKIGHROTM (GYK)>LUXIUVVKXIGHROTM (GYK:LUXIGZKMUX_;:6 -OMGHOZ+ZNKXTKZL[RRJ[VRK^XKVKGZKXY 4.5 Gigabit Ethernet design considerations 71 ,OHKXUVZOIIGHRKJOYZGTIKY -OMGHOZXKVKGZKXX[RKY viii Contents 5 /TZXUJ[IZOUTZU:)6/6 5.1 The origins of TCP/IP 74 5.2 The ARPA model vs the OSI model 75 5.3 The TCP/IP protocol suite vs the ARPA model 75 6 /TZKXTKZRG_KXVXUZUIURY 6.1 Overview 78 6.2 Internet protocol version 4 (IPv4) 79 9U[XIKUL/6GJJXKYYKY :NKV[XVUYKULZNK/6GJJXKYY /6\GJJXKYYTUZGZOUT 4KZ]UXQ/*GTJNUYZ/* 'JJXKYYIRGYYKY *KZKXSOTOTMZNKGJJXKYYIRGYYH_OTYVKIZOUT 4[SHKXULTKZ]UXQYGTJNUYZYVKXGJJXKYYIRGYY 9[HTKZSGYQY 9[HTKZZOTM 6XO\GZK\Y/TZKXTKZ[TOW[K/6GJJXKYYKY )RGYYRKYYGJJXKYYOTM )RGYYRKYYOTZKXJUSGOTXU[ZOTM)/*8 /6\NKGJKXYZX[IZ[XK 6GIQKZLXGMSKTZGZOUT 6.3 Internet protocol version 6 (IPv6/IPng) 94 /TZXUJ[IZOUT /6\U\KX\OK] /6\NKGJKXLUXSGZ /6\K^ZKTYOUTY /6\GJJXKYYKY ,RU]RGHKRY 6.4 Address resolution protocol (ARP) 103 'JJXKYYXKYUR[ZOUTIGINK '86NKGJKX 6XU^_'86 -XGZ[OZU[Y'86 6.5 Reverse address resolution protocol (RARP) 106 6.6 Internet control message protocol (ICMP) 107 /)36SKYYGMKYZX[IZ[XK /)36GVVROIGZOUTY 9U[XIKW[KTIN 8KJOXKIZOUTSKYYGMKY :OSKK^IKKJKJSKYYGMKY 6GXGSKZKXVXUHRKSSKYYGMKY ;TXKGINGHRKJKYZOTGZOUT Contents ix /)36W[KX_SKYYGMKY 6.7 Routing protocols 114 8U[ZOTMHGYOIY *OXKIZ\YOTJOXKIZJKRO\KX_ 9ZGZOI\KXY[YJ_TGSOIXU[ZOTM '[ZUTUSU[YY_YZKSY /TZKXOUXK^ZKXOUXGTJMGZK]G_ZUMGZK]G_VXUZUIURY 6.8 Interior gateway protocols 117 6.9 Exterior gateway protocols (EGP’s) 120 (-6 7 .UYZZUNUYZZXGTYVUXZRG_KXVXUZUIURY 7.1 TCP (transmission control protocol) 123 (GYOIL[TIZOUTY 6UXZY 9UIQKZY 9KW[KTIKT[SHKXY 'IQTU]RKJMSKTZT[SHKXY 9ROJOTM]OTJU]Y +YZGHROYNOTMGIUTTKIZOUT )RUYOTMGIUTTKIZOUT :NKV[YNUVKXGZOUT 3G^OS[SYKMSKTZYO`K :NK:)6LXGSK 7.2 UDP (user datagram protocol) 131 (GYOIL[TIZOUTY :NK;*6LXGSK 8 'VVROIGZOUTRG_KXVXUZUIURY 8.1 Introduction 133 8.2 File transfer protocol (FTP) 134 /TZKXTGR,:6IUSSGTJY ,:6[YKXIUSSGTJY 'TUT_SU[Y,:6 8.3 Trivial file transfer protocol (TFTP) 137 /TZXUJ[IZOUT ,XGSKZ_VKY 8.4 TELNET (telecommunications network) 140 8.5 RLOGIN (remote login) 143 8.6 NFS (network file system) 143 8.7 DNS (domain name system) 144 4GSKXKYUR[ZOUT[YOTMNUYZYLORKY . *GZGROTQRG_KX 6N_YOIGRRG_KX 2.5 Interoperability and internetworking 28 2.6 Protocols and protocol standards 30 2.7 IEEE/ISO standards 31 2.8 Network topologies 33 (XUGJIGYZGTJVUOTZZUVUOTZZUVURUMOKY. 3.7 Collisions 52 3.8 MAC frame format 53 3.9 Difference between 802.3 and Ethernet 55 3.10 Reducing collisions 55 3.11 Ethernet design rules 55 2KTMZNULZNKIGHRKYKMSKTZ . Gigabit Ethernet design considerations 71 ,OHKXUVZOIIGHRKJOYZGTIKY -OMGHOZXKVKGZKXX[RKY viii Contents 5 /TZXUJ[IZOUTZU:)6/6 5.1 The origins of TCP/IP 74