??ࡱ?>??  ????????~?~?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????  !"#$%&(2)*+,-./013i456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghj?klmnopqrstuvwxyz{|}~?Root Entry????????p?{?;????Q???ƴ????PowerPoint Document( ????+?Text_Content??????-Object1????5?F???z?????z??????????????????????????????????????  !"#$%&'()*????,-./0123456789:;<=>?@ABCDE????G????IJKLMNOPQRSTUVWXYZ[??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????B i? ?\ ?v&?????B i? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP  B ? ???-?- &?????A b? .  ???--???? N? ?3 ?3??? ?--  N?$?O??]?]O?Ov%9?R?R?S?S?T?T?U?U?V?V?X?X?Z?Z?^????????????????????????????S?S?U?U?V?V?W?W?X?X?Y?Y?Z?Z?ZZYZYXXXXVWVWUVUVTUTUSSSSR?R$?????????? %??????$T?T?~?~?T?$T?T?~?~?T?$_?_?t?t?_?$K?K?????K?$K?K?????K?????-?????????,`?X???8 ????>?????????????????(???"?e?g?i?k?m?o?q?s?u?w?y????$([\{????????A?B?C?D?E?F?G?H?I?J?K?R?S?T?U?X?[?f?h?j?l?n?p?r?t?v?x?z???񁌁????????????????????????@?B?D?F?H?b????????????!%),.:;?]}????????????????????*???? ???? ??=? ;? ?\ ?v&????=? ;? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP  ? = ???-?- &????<? 4? .  ???--???? N? ?3 ?3??? ?--  N?$?O??]?]O?Ov%9?R?R?S?S?T?T?U?U?V?V?X?X?Z?Z?^????????????????????????????S?S?U?U?V?V?W?W?X?X?Y?Y?Z?Z?ZZYZYXXXXVWVWUVUVTUTUSSSSR?R$?????????? %??????$T?T?~?~?T?$T?T?~?~?T?$_?_?t?t?_?$K?K?????K?$K?K?????K?????-$]?]?q?q?]?$??????????$?? ? ??$???????? %K?K?L? %????????f%1??????????????????????????????????????????????????????????????????????????????????????????????????h%2???????????????????????????????????????????????????????????????????????????????????????????????????? %?????? %???????-$??@@?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$Z?Zdd?Z?$d?dmm?d?$m?mww?m?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$w?w?w? %w????$w?w???w?$??????????$??????????$??????????$??????????$??????????$????????$?????$?????$??$?$??$$?$?.?.?$?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??'?'??$'?'?0?0?'?$0?0?:?:?0?$:?:?C?C?:?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?? ? ??$ ? ?*?*? ?$*?*?5?5?*?$5?5?????5?$????I?I???$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??)?)??$)?)?3?3?)?$3?3?=?=?3?$=?=?G?G?=?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??$?$??$$?$?-?-?$?$-?-?6?6?-?$6?6?????6?%???w????-$?????$BBNNB$??????????-$J?J?T?T?J?$T?T?]?]?T?$]?]?h?h?]?$h?h?q?q?h?-$@?@?L?L?@? %?????? %??????%????????????????%???????????????? %?????? %?????? %?????? %??K?L? %??K?L? %??J?K??--'??&????--&TNPP &?????????? ???? ?$]?]?q?q?]?$??????????$?? ? ??$???????? %K?K?L? %????????f%1??????????????????????????????????????????????????????????????????????????????????????????????????h%2???????????????????????????????????????????????????????????????????????????????????????????????????? %?????? %???????-$??@@?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$Z?Zdd?Z?$d?dmm?d?$m?mww?m?$Z?Z?d?d?Z?$d?d?m?m?d?$m?m?w?w?m?$w?w?w? %w????$w?w???w?$??????????$??????????$??????????$??????????$??????????$????????$?????$?????$??$?$??$$?$?.?.?$?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??'?'??$'?'?0?0?'?$0?0?:?:?0?$:?:?C?C?:?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?? ? ??$ ? ?*?*? ?$*?*?5?5?*?$5?5?????5?$????I?I???$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??)?)??$)?)?3?3?)?$3?3?=?=?3?$=?=?G?G?=?$??????????$??????????$??????????$??????????$??????????$????????$?? ? ??$ ? ??? ?$?????$??$?$??$$?$?-?-?$?$-?-?6?6?-?$6?6?????6?%???w????-$?????$BBNNB$??????????-$J?J?T?T?J?$T?T?]?]?T?$]?]?h?h?]?$h?h?q?q?h?-$@?@?L?L?@? %?????? %??????%????????????????%???????????????? %?????? %?????? %?????? %??K?L? %??K?L? %??J?K??--'??&????--&TNPP &?????????| ???l ??? ? ? ?8 ?&????? ? ? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP  ??  ?-?- &????? ? ? .  ???-- ???? ^^ ^^&Creator: Mgxwmf 2.0 05/27/92&$Authors: Bob Giese and Scott Vollmer&0Compatible with pscript,Apple LaserWriter II NTX??? ?-  ????%--%--Y%-YY-%Y----'??&????--&TNPP &?????????| ???l ???? ?? ?8 ?&?????? ?? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP  ? ? ?-?- &?????? ?? .  ???-- ???? ^^ ^^&Creator: Mgxwmf 2.0 05/27/92&$Authors: Bob Giese and Scott Vollmer&0Compatible with pscript,Apple LaserWriter II NTX??? ?-  ????%--%--Y%-YY-%Y----'??&????--&TNPP &?????????0???T ?4  @@``??@??????T ?4??????T ?4?? ??$?/??????T ?4;??????T ?4???)?=?Q;??????T ?4???????????????T ?4))==QQ;??????T ?4))RR{{??e??????T ?4  ""..???????T ?4???????????? ???T ?4??????llM??? ???T ?4????????q??? ???????L ?<?"Arial?????L ?<?Times New Roman?,??>3?????L ?<?Times New Roman?,??>3?????L ?<??Times New Roman?,??>3?????L ?<??Times New Roman?,??>3?????L ?<??Times New Roman Cyr??>3?????L ?<??Times New Roman Cyr??>3?????L ?<???Times New Roman Cyr??>3??????$???* ?? I,,,,,???Rw?????dd?????dd?????dd4????dd?????dd?????? I ???Rw?????dd?????dd?????dd4????dd?????dd?????? I     ???Rw?????dd?????dd?????dd4????dd?????dd????? ??? ? (?????????? 8???8???t?:???D?$Rw?????????42????dd?3???5???/?/???0?0???1?1?????h ???????????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0`????????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1?? ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ??E? ?? ? ? (?????D???????????????? 8????????00??8???a? ??????1?$??0t????i??????????????????95????????? ? ??????? ?????? ?????? ????????? ?????? ??? ????/??/ ?/08????dZ ?408????dZ???(1?1?1?????? ??*? (????? ????? ????????? 8???????8?????6??????j?$??04???V???? ?????????5?/?/?/?/?/?/?/?/?/ ?/?/?/?/?/?/???X0?H09?408????dd???(1?19?1?????? ??? ? (?????`??? ?p????? 8???????8???t?8??????D?$??0p????????<hT??????42????dZ?3 ?5???/?/???0?0???1?1????6????$???????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0????????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1??  ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ??E? ??2?  ? (?????????@???????i???????? 8????????00??8????? ??????Z?$??0L????????S???????V????????5??????????? ?????? ?????? ???/?/ ?/?/?/?/?/?/???X0?H0?408????dd???(1?1?1?????? ????  ? (????????0???* $????? 8???????8???K?8???????$??0L????????? 8???????8?????:??????k?$??0???????@??????????? 8???????8?????6????????$??0?q???t??????? ??????????>?5????? ????????? Source address????/??/?/ ??/ ? ?/ ??/ ?????0??0?408????dZ ?408????dZ?408????dZ???(1?1?1?????? ???? (????????o???????i???????? 8???????8????6????????$??04???R???????[???N?????????#5????? ????????? Destination address????/??/?/ ??/ ? ?/ ??/ ????00? 0?408????dZ ?408????dZ ?408????dZ?408????dZ???(1?1#?1?????? ???? (?????R???p???zj???????? 8???????8???d?6??????4?$??04???????????DO?????????5???? ???? ?????? Type field???/?/?/ ??/ ??/ ??/ ??/ ? ?/ ????00? 0?408????dZ?408????dZ?408????dZ ?408????dZ???(1?1?1?????? ??? (??????????t???????? 8???????8???v?6??????F?$??04???????>??????????5???? ?????? Data field????/??/?/ ??/ ??/ ? ?/ ?????0??0 ?4!      "\#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[]n^_`abcdefghijklmo?pqrstuvwxyz{|}~?????????? ? ??????? ?????? ?????? ????????? ?????? ??? ??????????? ?????? ?????? ?????? ??????? ?????? ??? - ??????? ?????? (??? ?????????) ?????????? ?????? ??????? - ????????? ??? ??????? (?????????), ???????????? ?????? ??????? ? ??? ?????? ??????? ?????? ??? ????????? ????????????????? ?????? ? ??????????? ??????????? ???????? ? ?????????? ?????? ?? ????? ?????? ?????? ??????? ??? ?????????? ??????, ????? ?? ?????????? ? ???????? ?????????? ?? ???? ???????????? ?????? ?????? ???????, ???????????? ? Ethernet, Token Ring, FDDI, ??????????? ? ?????????? ?????????? ???????????? ?????? ????? ?????? Trailers Headers Now is the time for all good ????-?????? ??????? ??????? ??????? ?????? ????? ?????? ?????? ????? ???? ?????? ?????? ?? ??????????????? ????????? ??? ??????????? ?????????? ????????? Header ????????? Trailer men to come to the aid of of their country Headers Headers Trailers Trailers Now is the time for all good men to come to the aid of their country ????? ????? Trailers Headers ????? - ??? ??????? ??????????, ??????? ???????? ???? ?? ??????? ? ???? ? ????? ??? ?????? ?????? ??????? ? ????? ???????? ??????????? ?????? ??? ??????????? ??????????. ?????? ?????? ??? ? ????????? ??????? Network packet header hierarchy Physical Data Link Network Transport Session Presentation Application Data link header Network layer header Transport layer header Session layer header Presentation and Application layer header OSI Model layers Data link trailers ???????????? ? ??????????? ????? ??????? ??? ?????? ???? ?? ?????????? ?????? ??????????? ??????? ???????? ???? ????????? ? ???? ?????? ??????????? ?????? ?????? ????????? ??????????? ? ??????????? ?????? ?? ?????? ?????? ????????? ?????? ??? (?????????? ???????? ? ?????) ??? ??????????????? ???, ????? ???? ???????????? ?? ?? ??????? ?????????? ??????? ????? ???????? ????? ????? ??????????????? ?????? ????????? ?????? ?????? ?????????? ???????? ? ?????, ??? ?????????? MAC-?????? (Media Access Control) ??? ??????????? ?????? ?????????? ?????? ??????????? IEEE ???-?????? Ethernet, Token Ring, FDDI ????? 6 ???? (48 ???) ?????? ????? ? ???? ???????? ?????????? ?????? ??????? ????????? ? ??????????? ?????? ???? ??????? ??????? ??? ???? ???-??????? Unique - ?????????? Multicast - ?????????, ?????????? ?????? ??????? Broadcast - ????????????????? ??????????? ??? ????????, ?????????? ??? ??????? ? ???? ???????????? ??????????? ????? ? ?????? ????? ????????? ????? ???? ?????? ?????????? ???????????? ???-??????? 02 60 8C 01 02 03 08 00 20 04 05 06 Data field CRC - 32 Vendor ID: 3Com Node ID: 010203 Vendor ID: SUN Node ID: 040506 ????????????? ?????????????: 24 bits (3 bytes) (Vendor ID) ????????????? ????: 24 bits (3 bytes) (Node ID) ????? ????????? Destination address ????? ????????? Source address ????????????? ????????????? - ?????? ??? ????? ??????????? ? ?????????????? IEEE ????????????? ???? - ????????? ??? ????? ??????????? ?????????????? ? ????????????? ?????? ???????????? ????? ????? ???? ?? 224 =16,777,216 ?????????? ??????? ???-????? ?????????? ????? ?????????? ??? PROM-??????? ???????? ?????????????? IEEE802.3 ? Ethernet ???????? ???????? 10 Mbps ????????????? ??????? IEEE802.3 ????? ???? ???????? ???????? ??????? SQE, ??????????? ?????????????? ????????? ???????? ??????????? IEEE802.3 ????? ??????????? ?????????? ??????????? - Jabber control Ethernet ?????????? ?????????? ?? ????????? IEEE802.3 ?????? ?????? Ethernet ? IEEE802.3 ????? ????????? ?????? ??????? ??????? ???????? ??????? Ethernet ?????????? ???????????? ??? ???????????? ? ????????????? ????? (Unacknowledged Connectionless) IEEE802.3 ????? ???????????? ????????? ? ????????????? ??? ???????????? ????? (Connection- Oriented) ??? ?????????? IEEE802.2 ?????? ?????? Ethernet ????????? MAC-?????? ????????? ??????? 3 - 7 ??? ? ?????? ????????? MAC trailer ????????? Preamble ????? ????????? Source address ????? ????????? Destination address ???? ???? ?????? Type field ???? ?????? Data field CRC-32 ????????? ????????????? ??? ????????????? ????????? ? ???????? ???????? ???????????? ?????? ?? ?????????? ?????? ???????? ??????? ? ???? Ethernet ????? ????????? Ethernet 64 ???? ???? ???? - ????????? ??? ????????? ???????? ?????? ??????????? IEEE 0800 - TCP/IP 0600 - XNS 8137 - Novel NetWare IPX ??????????? ????? (CRC-32) ??????????? ????????????? ???????? 99,999% ??????? ???????????? ? ???????? ????? ? Ethernet . . . . Byte 0 Byte 1 Byte 5 Byte 0 Byte 1 Byte 5 ?????/??/? ?/? ?/??/? ?/??/??/??/?????0??0 ?408????dZR?408????dZ6?408????dZ!?408????dZ?408????dZ4?408????dZ?408????dZ?408????dZ ?408????dZ?408????dZ?408????dZ?408????dZ*?408????dZ???(1?1r?1????????6????`????????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0?????????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1??  ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ????? ??R?  ? (?????????@???& i???????? 8????????00??8????? ??????z?$??0,4???????S??? V???????"?25??????? ???????????? ? ???????? ????? ? Ethernet ??? /?/?/?/ ?/?/?/?/?/?/?/?/?/ ?/???X0?H02?408????dd???(1?12?1?????? ???? (?????L???????????????????? 8??????????8? ??z? !???????!???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z? c???????c???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z? 8???????8???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??.? (????????a??? ???????????? 8???????8?????3??????n?$??0X4???3???{???????????????? 5. . . .???</?,/ ?/ ????X0?H0 ?408????dZ???(1?1 ?1?????? ???? (?????????????F????????? 8??????????8? ??z? ????????????????? ? 8?????????? ??z? 3???????3???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z?  ???? ????? ? 8?????????? ??z? t????t????? ? 8?????????? ??z? ??????????? ? 8?????????? ??z? ^???????^???????? ? 8?????????? ???? (?????M???w???????=????? 8??????????8? ??z? "???x???"???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z? c???x???c???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z? :???x???:???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ???? (?????????????>???????????? 8??????????8? ??z? ????????????????? ? 8?????????? ??z? +???????+???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z? ??????????????? ? 8?????????? ??z? l???????l???????? ? 8?????????? ??z? ????????????????? ? 8?????????? ??z? T???????T???????? ? 8?????????? ???? (?????????w???>???=????? 8??????????8? ??z? ????x???????<? ? 8?????????? ??z? +???x???+???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z? ???x??????<? ? 8?????????? ??z? l???x???l???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z? T???x???T???<? ? 8?????????? ???? (?????????w???F=????? 8??????????8? ??z? ????x???????<? ? 8?????????? ??z? 3???x???3???<? ? 8?????????? ??z? ????x???????<? ? 8?????????? ??z?  x??? <? ? 8?????????? ??z? tx???t<? ? 8?????????? ??z? ?x????<? ? 8?????????? ??z? ^???x???^???<? ? 8?????????? ???? ?????? ??*? (?????m???V???????????????? 8???????8?????1??????j?$??0x4???????o???u???????? ????5Byte 0???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??*? (?????????V???(???????????? 8???????8?????1??????j?$??0?4??? ???o???????????? ????5Byte 1???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??*? (????????V???N????????? 8???????8?????1??????j?$??0?4???F???o???????? ????5Byte 5???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ???? ?????? ??*? (?????U??? ???????????????? 8???????8?????1??????j?$??0?4???????%???]???{???? ????5Byte 0???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??*? (????????? ??????????????? 8???????8?????1??????j?$??0?4??????%???????{???? ????5Byte 1???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??*? (????????? ???5????????? 8???????8?????1??????j?$??0?4???-???%???{???? ????5Byte 5???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ???? (?????`??????????????????? 8???????8?????3????????$??0?4???????????v??????????s?5????? ?????????????/??/?/ ??/ ? ?/ ????X0?H0?408????dZ???(1?1?1?????? ??)? (??????????????????????? 8?? ????????? Bit 0 Bit 0 Bit 7 ?????????? ?????? Bit 7 ?????????? ?????? ????? ????????? Type field 6 bytes 6 bytes 2 bytes 46 - 1500 bytes 4 bytes Multicast bit (M-bit) LSB - ??????? MSB - ??????? M . . . . Destination address Source address Data field Frame Check Sequence ???? ? ?????? ??????????????? ??????? ?????????????????? ???????? ??????? ???????????? ? ???????? ????? ? Ethernet ?????? ??? ???? ???????? ?????????? ????????? ???????? ??? ??????? ???????? ??? ????????8?????3??????i?$??0?4???B????????????????????5Bit 0???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??)? (????? ???I????????? 8???????8?????3??????i?$??0?4???@???c??????????5Bit 0???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??)? (????????????????????????? 8???????8?????3??????i?$??0?4???'???????????????????5Bit 7???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ???? (????? ???????0???n???????? 8???????8?????3????????$??0?4???=???????????T???????u?5?????????? ??????????/??/ ?/ ??/ ??/ ????X0?H0?408????dZ???(1?1?1?????? ??)? (?????????:?????????? 8???????8?????3??????i?$??0?4???'???T??????????5Bit 7???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ???? (?????.????T???????? 8???????8?????3????????$??0?4???a????!???????u?5?????????? ??????????/??/ ?/ ??/ ??/ ????X0?H0?408????dZ???(1?1?1?????? ???? (?????C???????????Y???????? 8???????8?????3????????$??0?4???v???????n???????????s?5????? ?????????????/??/?/ ??/ ? ?/ ????X0?H0?408????dZ???(1?1?1?????? ??z? ?/???????????? ? 8????????? ??z? :9???????????? ? 8????????? ???? (?????f???W????? 8??????????8? ??z? f????????? ? 8?????????? ??z? f????????? ? 8?????????? ??z? fT???T???? ? 8?????????? ??z? f????????? ? 8?????????? ??z? f??????? ? 8?????????? ??z? fa???a???? ? 8?????????? ??z? f*???*???? ? 8?????????? ??z? h???? ????? ? 8?????????? ??z? q????????? ? 8?????????? ??z? qT???T???? ? 8?????????? ??z? q????????? ? 8?????????? ??z? q??????? ? 8?????????? ??z? qa???a???? ? 8?????????? ??z? f??????? ? 8?????????? ??z? fj???j???? ? 8?????????? ??z? f????????? ? 8?????????? ??z? f??????? ? 8?????????? ??z? fx???x???? ? 8?????????? ??z? f????????? ? 8?????????? ??z? qj???j???? ? 8?????????? ??z? q????????? ? 8?????????? ??z? q??????? ? 8?????????? ??z? qx???x???? ? 8?????????? ??z? q????????? ? 8?????????? ??z? q*???*???? ? 8?????????? ??z? fa???a???? ? 8?????????? ??z? f????????? ? 8?????????? ??z? ????q????? ? 8?????????? ??z? f??????? ? 8?????????? ??z? f??? ? 8?????????? ??z? fn???n???? ? 8?????????? ??z? f????????? ? 8?????????? ??z? f""? ? 8?????????? ??z? f{{? ? 8?????????? ??z? qn???n???? ? 8?????????? ??z? q????????? ? 8?????????? ??z? q""? ? 8?????????? ??z? q{{? ? 8?????????? ??z? fjj? ? 8?????????? ??z? f??? ? 8?????????? ??z? f? ? 8?????????? ??z? fvv? ? 8?????????? ??z? qjj? ? 8?????????? ??z? q??? ? 8?????????? ??z? q? ? 8?????????? ??z? qvv? ? 8?????????? ??z? f**? ? 8?????????? ??z? f??? ? 8?????????? ??z? f??? ? 8?????????? ??z? q**? ? 8?????????? ??z? q??? ? 8?????????? ??z? q??? ? 8?????????? ??z? fTT? ? 8?????????? ??z? ???j???? ? 8?????????? ??.? (?????2b???2????????? 8???????8?????3??????n?$??0????e|????????????? 5Type field???</?,/ ?/ ????X0?H0 ?408????dZ???(1?1 ?1?????? ??+? (??????????_7???????? 8???????8?????3??????k?$??0 ????(????,????????56 bytes???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??+? (??????????_????????? 8???????8?????3??????k?$??0 ????( ???,j????????56 bytes???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??+? (??????z???P ???????? 8???????8?????3??????k?$??04?????????????????52 bytes???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ???? ?????? ??-? (?????s????&Y????? 8???????8?????1??????m?$??0? (??????????Pd???????? 8???????8?????<??????~?$??0??????????F???????&?5Optional IEEE 802.2 fields???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??z? ??????F???? ? 8?????????? ??'? (??????????? ????????? 8???????8?????<??????g?$??0??????????? d????????5Pad???</?,/?/ ????X0?H0?408????dZ???(1?1?1?????? ??z? ??????????? ? 8?????????? ???? (????????????????????????? 8???????8???<?<?????? ?$??0?????????????y?????????????5Start of Frame Delimiter???</?,/?/ ????0??0 ?408????dZ?408????dZ ?408????dZ???(1?1?1?????? ??? (????????????????????????? 8???????8?????<????????$??0????????????????????????g?5Destination address???</?,/?/ ????0??0 ?408????dZ?408????dZ???(1?1?1?????? ??{? (?????????????????????????? 8???????8?????<????????$??0?????'???????Z???????????c?5Source address???</?,/?/ ????0??0?408????dZ?408????dZ???(1?1?1?????? ??x? (?????9?????????????? 8???????8?????<????????$??0?????u?????????????`? 5Length field???</?,/ ?/ ????0??0?408????dZ?408????dZ???(1?1 ?1?????? ??l? (??????????E? (?????????F???????????????? 8???????8????? ??????~?$??0?????????P???????????? ???&?5IEEE 802.3 with IEEE 802.2???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??z? E???????C???????? ? 8????????? ??z? B???q???????q???? ? 8????????? ??z? j?????????? ? 8????????? ??z? d???????d???d???? ? 8????????? ??z? d???????d???s???? ? 8????????? ??z? d???????d????? ? 8????????? ??z? d????d???}? ? 8????????? ??z? d???????????????? ? 8????????? ??z?  ????d????? ? 8????????? ??z? d????d????? ? 8????????? ??z? d????d????? ? 8????????? ??z? B???????????????? ? 8????????? ??z? B???????????????? ? 8????????? ??z? E???????C???????? ? 8????????? ??<? (?????????????????P???????? 8???????8????? ??????|?$??0?????????????j???F???? ???$?5Start of Frame Delimiter???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??7? (?????????????????c???????? 8???????8????? ??????w?$??0?????????????????Y???? ????5Destination address???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??2? (?????O???D???????????????? 8???????8????? ??????r?$??0?????f???N???????????? ????5Source address???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??(? (?????????????_???q????? 8???????8????? ??????h?$??0????V???????H???g? ????5DSAP???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??(? (?????C???K????????? 8???????8????? ??????h?$??0?????Z???4???x? ????5SSAP???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??+? (?????$????z???A????? 8???????8????? ??????k?$??0????;????c???7? ????5Control???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??(? (?????b????N???y????? 8???????8????? ??????h?$??0????y???7???o? ????5Data???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??'? (?????^???qN????????? 8???????8????? ??????g?$??0 ????u???{7????? ????5CRC???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??)? (?????J???H???D???????????? 8???????8????? ??????i?$??0 ????a???R???-???????? ????51byte???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??0? (????????????????????????? 8???????8????? ??????p?$??08????????????s???????? ???? 52 or 6 bytes???</?,/ ?/ ???X0?H0 ?408????dd???(1?1 ?1?????? ??0? (?????????????????^???????? 8???????8????? ??????p?$??0V@ABCDEFGHIJKLMNOPQRSTUWxXYZ[\]^_`abcdefghijklmnopqrstuvwy?z{|}~???0X????4???88????? ????54 bytes???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??'? (?????f????U???;????? 8???????8????? ??????g?$??0h????}????>???1? ????5PAD???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ???? (?????L??????{???????????? 8???????8? ??,? (?????????????x???f???????? 8???????8????? ??????l?$??0p???????????a???\???? ????5Preamble???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??+? (????????]???O???????????? 8???????8????? ??????k?$??0t????4???g???8???????? ????57 bytes???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??4? (?????P???t???????????????? 8???????8????? ??????t?$??0?????g???~???????????? ????5Length 2 bytes???</?,/?/ ???X0?H0?408????dd???(1?1?1?????? ??z? B????????????? ? 8????????? ???? (?????????? ????????? 8???????8???B?<???????$??0?????????? ???????????5???????? ??????? ???????????? ????? ???????? ????????? AppleTalk ? Novell NetWare ?????? ?????????? IEEE802.3 TCP/IP ? DECNet ?????? ?????????? Ethernet???0/? /?/??/??/??/? ?/??/??/??/??/??/? ?/? ?/??/??/??/??/? ?/??/??/??/??/??/? ?/? ?/????x0?h07?408????dZ?408????dZ7?408????dZ?408????dZ*?408????dZ???(1?1??1????????6?????$? ??????????0 p??????%? ????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D????? ? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0?????????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1??  ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ??? ??E?  ? (?????????@???\???i???????? 8????????00??8????? ??????m?$??0?????????S???7???V???????? 5Ethernet ???</?,/ ?/???X0?H0 ?408????dd???(1?1 ?1?????? ????  ? (????????0???* $????? 8???????8????8????????$??0?????`???? ?5D???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ???? (?????>????- g????? 8???????8? ??(? (?????i????????1????? 8???????8?????3??????h?$??0|?????????k????????5Data???</?,/?/ ???X0?H0?408????dZ???(1?1?1?????? ??z? ??????????? ? 8????????? ??%? (??????N???3????????? 8?????????8????? ??????e?$??0|?????X??????????? ?5C???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??z? ?????????????? ? 8????????? ??z? L???+L???????? ? 8????????? ??z? ??????}? ? 8????????? ??z? og???oP???? ? 8????????? ??z? ????e???????N???? ? 8????????? ???? (?????K???L????P???????? 8???????8??? ?3????????$??0?????~???f???]6?????????(5?????????????? ?????? ????? ???????????????D/?4/?/ ?/ ?/ ?/ ?/ ?/  ?/ ????0??0?408????dZ?408????dZ???(1?1(?1?????? ???? (?????????. ????? 8???????8??? ?3????????$??0?????#2???? ??????(5????? ????????????? ????? ?????????????????D/?4/?/ ?/  ?/ ???????? ?????? ?????????? ? ???? D ??????????? ????? ??????????????? ????? ????????? ????????????????? ????? (broadcast medium) ?????????????? ?????? ????? ???????????? ???????????? ? Ethernet A B C D ???????????? ???????? ?????? ??? A ???????? ?????? ??? C ???????? ???????? ?????? ? Ethernet transmit packet assemble packet deferring on? start transmission send jam signal increment attempts compute and wait backoff time done excessive collision errors done transmit ok ?/ ?/ ?/ ?/ ????0??0?408????dZ?408????dZ???(1?1(?1?????? ???? (?????m???????e???????????? 8???????8???+?3????????$??0????????? ???2?????????????5?????? ?????????? ? ???? D???p/?`/?/ ?/  ?/ ?/ ?/ ?/ ?/ ?/ ????0??0?408????dZ?408????dZ???(1?1?1?????? ???? (?????????-5????? 8???????8????3????????$??0?????$???G?????}?]5??????????? ????? ??????????????? ????? ????????? ????????????????? ????? (broadcast medium)???x/?h/ ?/ ?/ ?/ ?/ ?/ ?/ ?/ ?/  ?/ ?/ ?/ ?/ ?/ ?/ ???00? 0?408????dZ ?408????dZ?408????dZ?408????dZ???(1?1]?1?????? ??z? ???? ????????? ? 8????????? ???? (?????BY????]???????? 8???????8??? ?3????????$??0?????us???TC?????????(5?????????????? ?????? ????? ???????????????D/?4/?/ ?/ ?/ ?/ ?/ ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????/  ?/ ????0??0?408????dZ?408????dZ???(1?1(?1????????6????[&???????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0,????????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1??  ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ???? ????  ? (?????????@???????i???????? 8????????00??8???0? ???????$??0?????????S???????V?????????5???????????? ? Ethernet ????/??/ ?/?/?/ ?/???X0?H0?408????dd???(1?1?1?????? ???? ???v?? ??z? V????????????? ? 8????????? ??z? ?%????????? ? 8????????? ??z? L???%???L???????? ? 8????????? ???? (?????/???? ???}????? 8???????8? ???? (?????????????u??????????? 8???????8? ???? (?????<??????? 8???????8? ???? (??????????,???????? 8???????8? ??z? ???????????????? ? 8????????? ??z? ???>???????? ? 8????????? ??z? /???????? ? 8????????? ??z? -~-????? ? 8????????? ??%? (??????????T???????? 8?????????8????? ??????e?$??0??????????:???? ??? ?5A???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??%? (?????P???%???????????????? 8?????????8????? ??????e?$??0?????j???/???????????? ??? ?5B???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??%? (??????@???5????????? 8?????????8????? ??????e?$??0??????J???????? ??? ?5C???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??%? (???????Ke????? 8?????????8????? ??????e?$??0??????1[? ??? ?5D???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ???? (?????????'??????? 8???????8? ???? (?????b???????????6????? 8???????8? ???? (??????????????????????? 8???????8? ???? (??????A????????????? 8???????8? ??0? (?????????N???????? 8???????8????? ??????p?$??0?????????4????? ???? 5???????????????</?,/ ?/ ???X0?H0 ?408????da???(1?1 ?1?????? ??? (?????!?????????????? 8???????8?????1??????U?$??0????R???[i? ?????5???????? ?????? ??? A???/?/?/ ?/ ?/ ?/ ?/ ?/ ???X0?H0?408????dZ???(1?1?1?????? ??z? ????????????????? ? 8????????? ???? (???????????????????? 8???????8? ???? (?????T^???B???????? 8???????????8? ??z? g????[b???? ? 8????????? ??? (?????????? g????? 8???????8?????1??????U?$??0$?????????? N? ?????5???????? ?????? ??? C???/?/?/ ?/ ?/ ?/ ?/ ?/ ???X0?H0?408????dZ???(1?1?1?????? ??z? ??????????? ? 8???????????6?????R???????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0 ?? ? 8????????? ??z? E ?E G???? ? 8????????? ??z? > G???????G???? ? 8????????? ??z? C?Cd? ? 8????????? ???? (??????????)????????? 8???????8???8? ???????$??0????????????v? ?????5 transmission done ????</?,/?/ ????0??0?408????db?408????db?408????db???(1?1?1?????? ??z? ????w????w? ? 8????????? ??z? ???? ?????? ? 8????????? ??'? (?????????????????? 8???????8????? ??????g?$??0?????)???'?????? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (?????=????????j????? 8???????8????? ??????f?$??0?????T???????`? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (???????j????? 8???????8????? ??????g?$??0?????4?`? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??z? ????p???????p???? ? 8????????? ??z? ????f???????E???? ? 8????????? ??z? ????G???????G???? ? 8????????? ??'? (?????????????????????????? 8???????8????? ??????g?$??0????? ???????t???????? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (????? v????????????? 8???????8????? ??????f?$??0?????"????z????? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (??????v?????? 8???????8????? ??????f?$??0?????????? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (???????Q????? 8???????8????? ??????g?$??0???????: ? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??~? (???????? d?????? 8???????8????? ????????$??0?????0???M?? ???f?5collision detect????</?,/?/ ????0??0 ?408????db?408????db???(1?1?1?????? ??? (?????????~??????? 8???:?8(??8???????????Ole ????????????CompObj????2OlePres000????????(Ole10Native??????????????? ????5?FDrawDraw?????????? ????5?FDrawDraw????????"PowerPoint DocumentYuri Demchenko?!?? ? !%`5e9S@?@? k?[F4????"S? ??? ???? ?????S?????????? ????S???????? ??? ?????S????? ? ??? ?????????Object1?Windows Draw Drawing?Draw?-Windows Draw Drawing????@ ? ???????????? $*????? ???? (??????/>????? 8???????8???=? ?????? ?$??0?????4? ?????5too many attempts ????</?,/?/ ????0??0 ?408????db ?408????db?408????db???(1?1?1?????? ??? (?????i{??????? 8???:?8(??8?????????????Object2?Windows Draw Drawing?Draw?-Windows Draw Drawing????@ ? ???????????? $*Object2 5?F?n??z???n??z??Ole ????????????CompObj ????2OlePres000???? ????(Ole10Native?????????????PersistentStorage Directory8????????>Current User????????????Header????????????9?!?? ? !%`5e9S@?@? k?[F4????"S? ??? ???? ?????S?????????? ????S???????? ??? ?????S????? ? ??? ???????????? ??z? ??Z?? ? 8????????? ??z? ZwZ????? ? 8????????? ??z? W?????????? ? 8????????? ??z? u^u?? ? 8????????? ??z? z?z~? ? 8????????? ??z? w{wN? ? 8????????? ??z? c?@?? ? 8????????? ??`? ???<?? ??z? ????????L???p? ? 8?????????? ??z? L???p????? ? 8?????????? ??z? ????????p? ? 8?????????? ??z? ????p????????? ? 8?????????? ??`? ???<?? ??z? ????o???????o???? ? 8?????????? ??z? ????o???????m???? ? 8?????????? ??z? ????m????o???? ? 8?????????? ??z? ?o???????o???? ? 8????????????6?????f???????????0 p??????%?????? ???,? ????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? ??? 8?????8? ??(? ???? ? (?????????????8???????? 8?????????8???D?????? ??? ? (?????_???5???? ????? 8???????8???t?:??????D?$??0XH???????R???g? ??????42????dd?3 ?5???/?/???0?0???1?1??  ????????}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p0?? 8?????8? ??(`? ????  ? (?????????@????i???????? 8????????00??8????? ????????$??0H????????S????V???????b?"5???????? ?????? ?????? ? Ethernet ???p/?`/?/?/?/?/?/?/?/ ?/???X0?H0"?408????dd???(1?1"?1?????? ??? ?????? ??;? (??????>+?????? 8???????8????? ??????{?$??0H?????H?? ???#?5done packet_check error???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ???? (????? ??9??????? 8?????????8? ??SY? @???/Y?@? ???? (????? ?????????=???u???????? 8?????????8? ??2? (????? ??????????o???????? 8???????8????? ??????r?$??0X????!??????????e???? ????5receive packet???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??3? (?????-??? ???9???|???????? 8???????8????? ??????s?$??0X????D??????"???r???? ????5start receiving???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ???? (????????????? ???????????? 8???????8???6? ???????$??0l????????????????????? ?????5done receiving ? ???</?,/?/ ????0??0?408????db ?408????db?408????db???(1?1?1?????? ???? (?????????????????????? 8???????8???6? ???????$??0l???????????????? ? ?????5packet too small ????</?,/?/ ????0??0?408????db ?408????db?408????db???(1?1?1?????? ??~? (?????????x???H????? 8???????8????? ????????$??0x?????????????>? ???f?5recognize address????</?,/?/ ????0??0 ?408????db?408????db???(1?1?1?????? ??/? (???????Ng????? 8???????8????? ??????o?$??0??????7]? ???? 5extra bits????</?,/ ?/ ???X0?H0 ?408????da???(1?1 ?1?????? ??y? (??????????????????? 8???????8????? ????????$??0?????????I????? ???a? 5 valid CRC????</?,/ ?/ ????0??0?408????db?408????db???(1?1 ?1?????? ???? (???????????????????? 8???????8???2? ???????$??0???????????????? ?????5valid length ????</?,/?/ ????0??0?408????db?408????db?408????db???(1?1?1?????? ??6? (??????????[??? ????? 8???????8????? ??????v?$??0??????????D???? ????5disassemble packet???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ???? (????? ?W????:????????? 8?????????8? ??5? (??????????o???n????? 8???????8????? ??????u?$??0????? ???X???d? ????5done error length???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??3? (??????????"????? 8???????8????? ??????s?$??0?????????? ? ????5done receive ok???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??8? (?????c+_?????? 8???????8????? ??????x?$??0?????z5H?? ??? ?5done alignment error???</?,/?/ ???X0?H0?408????da???(1?1?1?????? ??z? @???}???@??????? ? 8????????? ??z? @???????@??? ???? ? 8????????? ??z? T??????? ? 8????????? ??z? xx? ? 8????????? ??z? ?( (? ? 8????????? ??z? )()?? ? 8????????? ??z? I????I???@? ? 8????????? ??z? I???I????? ? 8????????? ??z? ???/V???/? ? 8????????? ??z? ????%????? ? 8????????? ??z? ???N???? ? 8????????? ??z? ?N???5???N???? ? 8????????? ??z? X??????X???C???? ? 8????????? ??z? X???E???????E???? ? 8????????? ??z? ????r????r???? ? 8????????? ??'? (?????\??? ???????}???????? 8???????8????? ??????g?$??0?????s??????????s???? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (?????_???J?????????? 8???????8????? ??????f?$??0?????v???T?????? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (?????????????????^???????? 8???????8????? ??????g?$??0????? ???????t???T???? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ???? (??????????????:????? 8???????8? ??'? (?????????[L????????? 8???????8????? ??????g?$??0?????????e5????? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (?????8???h?????????? 8???????8????? ??????f?$??0?????O???r?????? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (?????b????????????? 8???????8????? ??????g?$??0H???y????????? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (?????????????????'???????? 8???????8????? ??????f?$??0H??????????j??????? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (?????????????4????? 8???????8????? ??????f?$??0H???????r???*? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (??????$w????? 8???????8????? ??????g?$??0H???? m? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??&? (??????? 9????? 8???????8????? ??????f?$??0(H??????/? ????5no???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??'? (?????h???????f????? 8???????8????? ??????g?$??00H??????????\? ????5yes???</?,/?/ ???X0?H0?408????d`???(1?1?1?????? ??`? ???<?? ??z? 8??????????)???? ? 8????????? ??z? ????(???8??????? ? 8????????? ??z? 7?????????'???? ? 8????????? ??z? ???(???7??????? ? 8????????? ??`? ???<?? ??z? J???????*? ? 8????????? ??z? ????*J???? ? 8????????? ??z? H??????)? ? 8????????? ??z? ???*H???? ? 8????????? ??`? ???<?? ??z? 7????I????? ? 8????????? ??z? I????7????? ? 8????????? ??z? 7????G????? ? 8????????? ??z? G????7????? ? 8????????? ??`? ???<?? ??z? J?????????????     ???? }!"#?%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}?????? ? 8????????? ??z? ?????J????? ? 8????????? ??z? H????????? ? 8????????? ??z? ????H????? ? 8????????? ??`? ???<?? ??z? 4???e???????q???? ? 8????????? ??z? ????p???4???b? ? 8????????? ??z? 3???b????p???? ? 8????????? ??z? ????q???3???e???? ? 8????????? ???? (????? ????????;???????????? 8?????????8? ??z? ????&???V???&???? ? 8????????? ???? (????? ???????????? 8?????????8? ???? (????? ?,?????????? 8?????????8? ???? (????? ?U???? ???????? 8?????????8? ??`? ???<?? ??z?  ?(? ? 8????????? ??z? ?(? ? 8????????? ??z? ~?'? ? 8????????? ??z? ?(~ ? ? 8????????? ??z? 5??????5???n???? ? 8????????? ??z? 4???b;????? ? 8????????? ??z? ?????????? ? 8????????? ??z? ??????????? ? 8????????? ??z? L????b????? ? 8????????? ??z? b????b???????? ? 8????????? ??z? U???????Q???????? ? 8????????? ??z? Q???????Q????? ? 8????????? ??z? ???????? ? 8????????? ??z? ???'? ? 8????????? ??z? ?(?/? ? 8????????? ??&? (?????????J?????????? 8???????8?????,??????f?$??0TH???$???`|????? ????5no???</?,/?/ ???X0?H0?408????dZ???(1?1?1????????6????q ????M???????????0 p:?8?$7??????̙33????????$7???????????3????$7???????33?3?3???f?$7???999??????MMM????$7????????f???????$7?????????f??3??$7??????3??????????? ???}????.1996-98. Yu.Demchenko???/??? 0Computer Networking Technologies???4x?$x??????̙33???????? ???? (?????????????0 p$?? 8?????????8? ??? ???? ? (?????????P????????? 8???????8?????:????????$??0????????m?????????R?5?*???h/?X/?/ ?/ ????X0?H0?408????dd???@1?01?1?????1?? ??=? ? (????????P?????? 8???????8?????:??????e?$??0????J???mV????? ?5*???</?,/?/ ????X0?H0?408????dd???(1?1?1?? ???? ? (?????0P@ ????? 8???????8?????:????????$??0?????jm ?????Y? 5Slide 2_*???h/?X/?/ ?/ ????X0?H0 ?408????dd???@1?01?1?????1?? ??e? ? (?????????@???q???`???????? 8????????00??8????? ????????$??0????????S???M???M???????5?)5 ???</?,/)?/,???X0?H0)?408????dd???(1?1)?1?????? ???? (?????k???????? ????? 8?????????8? ???? (?????????J???? ????????? 8???????8? ???? (?????????????M e???????? 8???????8? ???? (?????G???t???~ ????????? 8???????8? ???? (?????????????? k???????? 8???????8? ??G? ? (????????0???* $????? 8???????8?????6??????o?$??0?????;???K???? ?????;5Body Text Second Level Third Level Fourth Level Fifth Level????/??/ ?/  ?/ ?/ ?/ ?/???x0?h0 ?408????dd ?408????dd ?408????dd ?408????dd ?408????dd???(1?1;?1????????'??????? ???,? ?????H????.???/???0???4x?$x??????̙33???????? ???? (????????? ???,? $?? 8?????????8? ???? ??=?  ? (????????????????P???????? 8???????8????? ??????e?$??0???????????????P??????? ?5*???</?,/?/ ????X0?H0?408????dd???(1?1?1?? ??=? ? (????????,P???????? 8???????8????? ??????e?$??0?????#??? P??????? ?5*???</?,/?/ ????X0?H0?408????dd???(1?1?1?? ???? ? (?????????????n????????? 8?????????8???D??????? ??^? ? (????????h???? ????? 8???????8?????:????????$??0?????????E???(\?Ya?Ȏ w??߱??S?_?1?EQ?w??v?]???qűf????c?<?|p????|p???X>8?̇z?ǚ??"??5?'E,k?cD,k?/?X>???dG]??ǥ?c??7Q??5?ˢ$k?7DI>8??DI>8?̝'%??X3!J???f>Z??c??iQ??5??EI>8??_%??X3S??c??mQ???%??R;)8N*?5?s"??5?K"??5??"??5????k?(w?$??Z'?kE"k揋D>8?̟?|p???(??X3M$???f>^$???f??H?;?ގ`??????S??E*?????e?Ӫ}?*??p*???Ty??S?|?S????G?֩?Z?ݏ|?S叉?~ǚ?3"??5?D*k??D*k?o?T>8????|?l-?yz?? ??ǚ?Q??5?+?,k?(?ǚ??(??k]V??]=/?\?\?k?E?? ?5?Q?,?????%????f>F????nY?XQ??5??EY>8??Nj??#???uC }?"~?.?Z???5????8???CxO9)8??S&?e"~S? ?s??n[;֯Wp|?|??ߏI?-??U/???X>w??/?|p??/???=M?m?d???v?}`?R{?Q????8?lXԫ,?c"???;??8~w7??#b?}? ???:???? d?𝨻??ܯ ?????z?Ez?????!?????????F???%?>?z?a?3x?!tV?$???d??( ? ? ??????????z?a=m?Rg??9??wJu??( ? ? ??????????`!?%??9??8?Kt?????\????????]]@+@+??x?UN?J1??mKEŃ/栞?]D??P Ջ??E??h?&d#???6?^t?_?e?c???O@?A@Kn?]h ?Г????G?/ꤳ?0v??? ???cU?pv?rz>?.??A?:?ѻ_W???y?U??x{?ۅ??MYV???t cS???y?x???m?p??ӑ?2??rN{?x:囻?Д?bS ?b??Fn#F?w?? ??}?yjr? E/$???????)???zߗp???6?????՜.??+,??0p?????? ? ?? ????  ???A4 Paper (210x297 mm)????2 Time??[?(`?X?  \ ??????(Windows Draw Drawing ?Draw0?(Windows Draw Drawing???0???(Windows Draw Drawing ?Draw0?(Windows Draw Drawing?b/? 0????DTimes New Roman2=O 40==KE MB0;>==>9 <>45;8 ! ?$:9?$ )??0Z? ???4?@545;5=85 C@>2=O 40==KE ?&? ???B>@>9 C@>25=L <>45;8 ! - C@>25=L 40==KE (8;8 :0=0;L=K9) ?@545;O5B <5B>4K 4>ABC?0 - ?@>F54C@K 8;8 ?@028;0 (0;3>@8B<K), >?@545;ONI85 <5B>4K 4>ABC?0 : ! 5B>4K 4>ABC?0 A;C60B 4;O ?>;CG5=8O :><<C=8:0F8>==>3> :0=0;0 8 >15A?5G5=8O 2>7<>6=>AB8 ?>;CG0BL 8 ?5@54020BL 40==K5 ?> MB><C :0=0;C <5B>4K 4>ABC?0 ! >?@545;ONB B>;L:>, <>6=> ;8 ?5@54020BL 8 ?>;CG0BL 8=D>@<0F8N ?> A5B8 !CI5AB2CNI85 A59G0A <5B>4K 4>ABC?0, 8A?>;L7C5<K5 2 Ethernet, Token Ring, FDDI, @07@01>B0=K 2 @57C;LB0B5 4;8B5;L=KE 8AA;54>20=89?Z pZ2XpZ2?pZ2 X?  =!1?  $? ??0:5BK ?&? ? ??? ? ??f4@5A0F8O C@>2=O #! (#?@02;5=8O >ABC?>< : !@545) ?&43?6???! @07@010BK20;8AL B0:, GB>1K 1KBL =57028A8<K<8 >B  A5B52KE ?@>B>:>;>2 !B0=F88 <>3CB >1I0BLAO <564C A>1>9 =5?>A@54AB25==> B>;L:> 8A?>;L7CO 04@5A0 C@>2=O C?@02;5=8O 4>ABC?>< : A@545, B0: =07K205<K5 MAC-04@5A0 (Media Access Control) 8;8  D878G5A:85 04@5A0 D878G5A:85 04@5A0 =07=0G0NBAO IEEE !-04@5A0 Ethernet, Token Ring, FDDI 8<5NB 6 109B (48 18B) :064K9 04@5A 2 A5B8 O2;O5BAO C=8:0;L=K< :0640O AB0=F8O ?@8=8<05B 8 0=0;878@C5B 04@5A0 2A5E ?0:5B>2 <55BAO B@8 B8?0 !-04@5A>2 Unique - C=8:0;L=K9 Multicast - 3@C??>2>9, 04@5ACNI89 3@C??C AB0=F89 Broadcast - H8@>:>25I0B5;L=K9 A?5F80;L=K9 B8? ?5@540G8, 04@5ACNI89 2A5 AB0=F88 2 A5B8 >?@545;O5BAO A?5F80;L=K< 18B>< 2 ?0:5B5 04@5A 8AB>G=8:0 <>65B 1KBL B>;L:> C=8:0;L=K< ???0Z]0Z<0Zd0Z0Zc0Z??0?Z?]<dc  ???y %  22   +$6? ??2$>@<8@>20=85 !-04@5A>2 ?&?  ? ??ZA=>2=K5 E0@0:B5@8AB8:8 IEEE802.3 8 Ethernet ?&.-????!:>@>ABL ?5@540G8 10 Mbps -;5:B@8G5A:85 DC=:F88 IEEE802.3 8<55B B5AB :>=B@>;O :0G5AB20 A83=0;0 SQE, ?>72>;ONI89 :>=B@>;8@>20BL A>AB>O=85 2=5H=53> B@0=AA825@0 IEEE802.3 8<55B 2>7<>6=>ABL >B:;NG5=8O B@0=AA825@0 - Jabber control Ethernet 8A?>;L7C5B B@0=AA825@ ?> AB0=40@BC IEEE802.3 $>@<0B ?0:5B0 Ethernet 8 IEEE802.3 8<5NB @07;8G=K9 D>@<0B ?0:5B>2 $C=:F88 :>=B@>;O :0=0;>< Ethernet 8A?>;L7C5B :><<C=8:0F88 157 CAB0=>2;5=8O 8 ?>4B25@645=8O A2O78 (Unacknowledged Connectionless) IEEE802.3 <>65B 8A?>;L7>20BL ?@>B>:>;K A CAB0=>2;5=85< 157 CAB0=>2;5=8O A2O78 (Connection- Oriented) ?@8 @50;870F88 IEEE802.2??00Z?0Z0Z40Z0Z?0Z0?4?    ?? %: )# 9 )*& ???? ???d>@O4>: D>@<8@>20=8O 8 ?5@540G8 18B>2 2 Ethernet ?&32?$? ??b>@O4>: D>@<8@>20=8O 8 ?5@540G8 18B>2 2 Ethernet?&21?$ ???064K9 B8? A5B8 ?5@5405B 8=D>@<0F8N @07;8G=K< A?>A>1>< MB> A>7405B ?@>1;5<K ?@8 ?>AB@>5=88 A5B52KE <>AB>2 >@O4>: ?5@540G8 ?>109B>2>9 8=D>@<0F88 :064K9 109B ?5@5405BAO ?>18B>2> 2 >1@0B=>< (@525@A=><) ?>@O4:5 ?5@2K9 ?5@540205<K9 18B - -18B, - 845=B8D8:0B>@ 3@C??>2>9 ?5@540G8 3@C??>2>9 04@5A - G5B=K9 ?@8 ?@85<5 109BK ?>18B>2> @525@A8@CNBAO @8<5@: 5@540G0 04@5A0 02-60-8!-01-02-03 02 60 8! 01 02 03 00000010 01100000 10001100 00000001 00000010 00000011 ?>@O4>: ?5@540G8 01000000 00000110 00110001 10000000 01000000 11000000??70Z30Z(0Z?0Z?0?Z(0Z?0Z73(?(  ????  !17?A? ??? ? ??0$>@<0B ?0:5B0 IEEE802.3 ?&?  ??( 01>G0O 3@C??0 IEEE802.3 ?@8=O;0 70 >A=>2C AB0=40@B Ethernet V2.0 0;3>@8B< 4>ABC?0 CSMA/CD =51>;LH85 @07;8G8O 2 D>@<0B5 ?0:5B0  =0G0;5 ?0:5B0 8<55BAO 7-<8 109B>20O ?@50<1C;0 8 AB0@B>2K9 109B !B0@B>2K9 109B(RFD - Start-of-Frame Delimiter) A>45@68B 18B I/G, >?@545;ONI89 8=48284C0;L=K9 (I/G=0) 8;8 3@C??>2>9 04@5A 18B U/L, >?@545;ONI89 B8? D878G5A:>3> 04@5A0 - ;>:0;L=K9 (U/L=0), =07=0G05<K9 IEEE 8;8 3;>10;L=K9, =07=0G05<K9 2 40==>9 A5B8 >;5 Pad ?@54=07=0G5=> 4;O 4>?>;=5=8O ?0:5B0 4> <8=. @07<5@0 64 109B 2-109B>2>5 ?>;5 4;8=K ?>;O 40==KE Length (=5 2:;NG05B ?>;5 Pad) @87=0:8 >?@545;5=8O D>@<0B0 ?0:5B0 :>=B@>;;5@>< ?>;O Type (Ethernet) 8 Length (IEEE802.3) 8<5NB >48=0:>2>5 ?>;>65=85 <8=8<0;L=>5 7=0G5=85 ?>;O Type Ethernet - 0600 (hex) <0:A8<0;L=0O 4;8=0 ?0:5B0 Ethernet 05DC (hex)??B0Z=0ZA0Z90Z??0?Z?0Z?0ZB=A9?  ????  $   + 6%5? ??b5B0;L=>5 A@02=5=85 ?0:5B>2 IEEE802.3 8 Ethernet ?&21?? ?? Ethernet ?&  ???5B>4 4>ABC?0 >A=>20= <=>65AB25==>< 4>ABC?5 A :>=B@>;5< =5ACI59 8 >1=0@C65=85< AB>;:=>25=89 - Carier Sense Multiple Access with Collisuion Detection (CSMA/CD) 01>B0 =0G0;0AL 2 1973 (Bob Metcalfe 8 David Boggs 87 Xerox Palo Alto Research Center (PARC)) - M:A?5@8<5=B0;L=>5 2=54@5=85 Ethernet - 2 1975. Ethernet Version 1.0 A>2<5AB=> @07@01>B0=0 Digital, Intel, Xerox 21980.  1982 ?@8=OB0 25@A8O Ethernet V2.0, 8725AB=0O :0: Blue Book specification 8;8 DIX AB0=40@B. Ethernet 1K; ?@8=OB A 87<5=5=8O<8 2 :0G5AB25 AB0=40@B0 IEEE 802.3 8 ANSI 8802/3. Ethernet A>>B25BAB2C5B B>;L:> B>;L:> ?5@2K< 42C< C@>2=O< <>45;8 !. 5@540G0 8=D>@<0F88 <564C AB0=F8O<8 ?@>8AE>48B ?0:5B0<8. Ethernet ?>445@68205B B>;L:> :><<C=8:0F88 157 CAB0=>2;5=8O A2O78.??x0Z]pZ(?pZ(B0ZY]?h+ # (&   #78 8???(?@545;5=85 CSMA/CD ?&?  ??&Ethernet 8A?>;L7C5B <5B>4 4>ABC?0 - Carier Sense Multiple Access with Collisuion Detection (CSMA/CD) !5B520O AB0=F8O ?@5645, G5< ?5@54020BL 8=D>@<0F8N, :>=B@>;8@C5B A83=0; =0 H8=5, GB>1K C1548BAO, GB> =8:0:0O AB0=F8O =5 ?5@5405B 8=D>@<0F8N (CARIER SENSE) $878G5A:0O A@540 - 548=K9 :015;L, : :>B>@><C ?>4:;NG5=K 2A5 A5B52K5 AB0=F88 - 2A5 8<5NB 4>ABC?, ?5@540NB ?>->48=>G:5 (MULTIPLE ACCESS) H81:8 >?@545;ONBAO 70 AG5B B>3>, GB> ?5@540NI0O AB0=F8O ?@>A;CH8205B H8=C AB>;:=>25=8O 2>7=8:0NB, 5A;8 425 8;8 1>;LH5 AB0=F89 =0G8=0NB ?5@54020BL >4=>2@5<5==> (COLLISION DETECTION) 5A;8 ?5@540NI0O AB0=F8O >1=0@C68205B AB>;:=>25=85, >=0 ?5@5405B A83=0; 70B>@0 (jam signal) ?>2B>@=0O ?5@540G0 =0G8=05BAO G5@57 A;CG09=K9 8;8 >?@545;5==K9 (=07=0G05<K9 2 7028A8<>AB8 >B ?@8>@8B5B0) ?@><56CB>: 2@5<5=8 ?\e0Zl0ZC0ZelB?? +( !@=2 ? ???"Ethernet. K2>4K ?&? ???Ethernet >?@545;O5B <5B>4 4>ABC?0, >G5=L 1;87:89 : CSMA/CD Ethernet 4>?CA:05B <=>3>?@>B>:>;L=K5 @5H5=8O =0 1>;55 2KA>:8E C@>2=OE Ethernet >?@545;O5B 2 >A=>2=>< 0??0@0B=>5 @5H5=85, 0 =5 ?@>3@0<<=>5 Ethernet O2;O5BAO H8@>:>25I0B5;L=K< B8?>< A5B8 A5 ?0:5BK 40==KE 2 A5B8  ?@>A;CH820NBAO 2A5<8 AB0=F8O<8 > ?@8 MB>< B0:65 ACI5AB2CNB H8@>:>25I0B5;L=K5 ?0:5BK Ethernet =5 30@0=B8@C5B 4>AB02:C ?0:5B>2 Ethernet <>65B >?@545;OBL >H81:8 2 ?0:5B0E B>;L:> ?>A@54AB2>< CRC Ethernet >15A?5G8205B B>;L:> ?5@540GC 8 ?@85< 40==KE ?> :015;N 8 @50;87C5B :><<C=8:0F88 157 CAB0=>2;5=8O A2O78 0456=>ABL :><<C=8:0F89 >1KG=> >15A?5G8205BAO ?@>B>:>;0<8 1>;55 2KA>:8E C@>2=59 (C@>2=8 3-7) >=B@>;;5@ Ethernet <>65B ?@>?CA:0BL ?0:5BK, 5A;8 >= 70=OB???0Zp0Z)0Z0Z;0Z?p):?h=  8F     ???V@>1;5<K ?@0:B8G5A:>3> ?@8<5=5=8O Ethernet ?&,+?! ??.-DD5:B82=>ABL Ethernet A8;L=> 7028A8B >B @50;87C5<KE ?@8;>65=89 > =5 2A5 ?@>3@0<<=K5 ?@>4C:BK 1>;55 2KA>:8E C@>2=59 @07@010BK20;8AL 4;O @01>BK 2 A@545 Ethernet 5=LH89 @07<5@ ?0:5B>2 =5 O2;O5BAO 1>;55 MDD5:B82=K< 2 Ethernet 07<5@ :015;O =5 2;8O5B =0 A:>@>ABL ?5@540G8 2 Ethernet Ethernet ?5@5405B 8 ?@8=8<05B 40==K5 A> A:>@>ABLN 10 Mbps, => ?@8 MB>< @50;L=0O A:>@>ABL ?5@540G8 40==KE 3>@0740 <5=LH5 (?@81;87. 0.256-1Mbps) >=AB@C:F8O :015;L=>9 A8AB5<K <>65B ACI5AB25==> 2;8OBL =0 @50;L=CN ?@>872>48B5;L=>ABL A5B8 Ethernet 70 AG5B 7045@65: 8 8A:065=89 ?0:5B>2, 0 B0:65 CA8;5=85< AB>;:=>25=89 !CI5AB2CNB >3@0=8G5=8O =0 <8=8<0;L=K9 8 <0:A8<0;L=K9 @07<5@ ?0:5B>2 ?T 0ZE0ZF0Z EE??  y 5 -  =[ C???6>@<0;L=0O @01>B0 Ethernet ?&? ???0!B>;:=>25=8O 2 Ethernet ?&?  ???F;3>@8B< ?5@540G8 ?0:5B0 2 Ethernet?&$#? ???D;3>@8B< ?@85<0 ?0:5B0 2 Ethernet ?&#"? /?L????? ?!?"?#?$?% ?& ?' ?( ?) ?*?+?,?-?.?/?0??? ?  0`? ??????̙33???????`? ???????????3???`? ???????33?3?3???f`? ???999??????MMM???`? ????????f??????`? ?????????f??3?`? ??????3???????????>???" dd?????????,?|???" dd?????????? ? ? ?" ?? ?$?" ?/ ?n???" dd@?????????   @@``??P?R    @ ` ?`? p?>??> ???? ???( ? ??? ?  ?`? ???g?ֳ??g?ֳ???????? ?????? ? ?N???*?"   ??? ?  ?`?????g?ֳ??g?ֳ???????? ???@???  ? ?N??*?$   ?? ?  ?`?????g?ֳ??g?ֳ???????? ???`p?? ? ?^??Slide 2_*?$     ?? ? # ?l?? ?????7D????7D???????1? ?)?)???? ? ??? ? ?]??) ?*? *?d ? ? ?<????????1???T????^ ? ? ?6???????????/?^ ? ? ?6?????????`}??^ ?  ? ?6??????????w?Y?^ ?  ? ?6?????????g? ??# ?  ? ?T?H????N?o???N?o??????? ???5Z??? ? ????;Body Text Second Level Third Level Fourth Level Fifth Level?    ? <?< ? c ?$???? ?? ??????̙33??????? ?$Blank Presentation?~?? 0 >?6 ????( ? ??? ? ? ?T?t??jJ??jJ??????? ????0??  ? ?T??*?  ?? ?? ? ? ?T?ت??jJ??jJ??????? ????C X0?? ? ?V??*?  ?? ?p ? ? ?0?????1? ?????? ?? ??: ? ? ?T?h????g?ֳ??g?ֳ?????? ??H .*??? ? ???RClick to edit Master text styles Second level Third level Fourth level Fifth level?!    ? S?? ? ? ?Z?4???jJ??jJ???????? ??????  ? ?T??*?  ?? ?? ? ? ?Z?????jJ??jJ???????? ???C X??? ? ?V??*?  ?? ?< ? c ?$???? ?? ??????̙33????????? ??0? ?0?( ? ? ?H ? ? ?0????re?"f??? ?? ??????̙33????????x?? 0??Rw???=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z@???( ? ??  ? ? ???t??ֳ?7D?ֳ?7D????????????1???? ?)?)???Wx?~?? ? ???;?? ? ? ?T??r??D[????D[????????? ? ?? ??? ?? ? ?,???;???)?=?Q?H ? ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z`???( ? ??  ? ? ???N??ֳ?7D?ֳ?7D????????????1???? ?)?)????? ???  ? ???;?? ? ? ?T??L??D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ? ? ?0???@??޽h?? ?? ??????̙33????????,? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ?+??+??;; ?+?( ? ? ?^? ? ? ?6?A???????? =3? ?  ? ? ?????ֳ?7D?ֳ?7D????????????1???? ?)?)????????  ? ???;? ? ? ?Z?PN??o??>?o??>????????? g? ????1I89 D>@<0B?"  ? ????????????dB ? ? ?<????1???????? ?d ? ? ?<????????1???? x'h ?dB ? ? ?<????1???????? C C l ?dB ? ? ?<????1???????? ??l ?? ? ? ?Z?4R??o??>?o??>?????????? ?* \  ?d??Trailers?" ????????????? ? ? ?Z??y??o??>?o??>?????????? ?Y  ?c??Headers?"   ???????????? ? ? ?Z? d??o??>?o??>?????????? I ?L  ?x??Now is the time for all good?"   ????????????dB ? ? ?<????1???????: @ z: ?  ? ? ?Z?$O??o??>?o??>????????? ???  ???$09;-A5@25@?"  ?????????????& ? ? ?Z??,??o??>?o??>?????????? ?/?  ???. 01>G0O AB0=F8O :;85=B0?" ? ????????????d ? ? ?<????????1????x'? ?dB ? ? ?<????1????????C C ? ?dB ? ? ?<????1??????????? ? ? ? ?Z?????o??>?o??>????????? ~ ??  ???&0?@>A 1;>:0 40==KE?" ? ????????????dB ? @ ? ?<????1????????L?? ? ? ?Z?????o??>?o??>?????????!@?? ?~?? 0?@>A?& ? ???????????? ? ? ?Z?????o??>?o??>?????????? ?B ?  ?|?? B25B?& ? ???????????? ? ? ?Z?H???o??>?o??>?????????EE u ? ????>;5 40==KE?&  ? ????????????d ? ? ?<????????1???;??dB ? ? ?<????1???????7???dB ? ? ?<????1???????7???x ? ? ?Z?????o??>?o??>???????????6? ????~0==K5 87 ?>;L7>20B5;LA>9 ?@>3@0<<K 8;8 C?@02;ONI0O 8=D>@<0F8O?$@ ?? @????????????  ? ? ?Z?@???o??>?o??>???????????9? ??? 030;>2>: Header?" ? ????????????$ ? ? ?Z??`g?o??>?o??>???????????h? ???":>=G0=85 Trailer?$ ?  ????????????d ? ? ?<????????1???J x' ?dB ? ? ?<????1???????F C C ! ?dB ? ? ?<????1???????F ??! ?? ? ? ?Z?????o??>?o??>?????????? { ?  ?u??men to come to the aid of?"   ????????????dB ?! ? ?<????1????????  z? ?d ?" ? ?<????????1???x'??dB ?# ? ?<????1???????? C C ??dB ?$ ? ?<????1???????? ????? ?% ? ?Z?pM??o??>?o??>?????????<{ 2 ? ?l??of their country?"   ????????????dB ?& ? ?<????1????????  z? ?dB ?' ? ?<????1???????? ???? ?( ? ?Z??Q??o??>?o??>?????????? ?  ?c??Headers?"   ????????????? ?) ? ?Z?????o??>?o??>?????????<?? ?c??Headers?"   ????????????? ?* ? ?Z?l`??o??>?o??>?????????w ?*   ?d??Trailers?" ????????????? ?+ ? ?Z??l??o??>?o??>?????????,?* ? ?d??Trailers?" ????????????dB ?, @ ? ?<????1???????? z? ?dB ?- ? ?<????1????????C?dB ?. ? ?<????1??????????Y?dB ?/ ? ?<????1????????LLb?^ ?0 ? ?6???????1?????P?^2 ?1 ? ?6???????1???3:?^ ?2 ? ?6???????1?????.?^2 ?3 ? ?6???????1????2?, ?4 ? ?Z?8???o??>?o??>?????????? =??  ???DNow is the time for all good men to come to the aid of their country?$E cD????????????^? ?5 ? ?6?A???????B ?a? ?dB ?6 ? ?<????1???????? ?? ? ?7 ? ?Z?|???o??>?o??>?????????d ?O   ?|?? B25B?& ? ???????????? ?8 ? ?Z???i?o??>?o??>?????????3 ?[ ?  ?|?? B25B?& ? ????????????? ?9 ? ?Z?`?i?o??>?o??>???????????* ?  ?d??Trailers?" ????????????? ?: ? ?Z???i?o??>?o??>????????? ??  ?c??Headers?"   ????????????? ?; ? ?Z??o??>????????????? ?>??V0:5B - MB> 548=8F0 8=D>@<0F88, :>B>@CN ?5@5405B >4=0 87 AB0=F89 2 A5B8 : >4=>9 8;8 3@C??5 4@C38E AB0=F89 A F5;LN ?5@540G8 =5>1E>48<KE 40==KE 8;8 C?@02;ONI59 8=D>@<0F88. ?:? ??l! =????????????H ? ? ?0???@??޽h?? ?? ??????̙33?????????? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ????()(??8?( ? ?(?  ?( ? ?????ֳ?7D?ֳ?7D????????????1???? ?)?)???l??????  ? ???;?t ?( # ?l???ֳ?7D?ֳ?7D???????1??)?)?????b? ????L#@>2=8 <>45;8 ! 8 703>;>2:8 ?0:5B>2 ?.' &? ??;))==QQ? ?( ? ?Z??$??t? ??t? ???????????0 Rg ?}??Network packet header hierarchy?$  Z??e))RR{{???_?8 ???aY ?)(???aY? ?T ???J  ?(# ? ????J ?l ?( ? ?<????????1?????u?l ?( ? ?<????????1????}B?l ?( ? ?<????????1????J?l ?( ? ?<????????1??????l ? ( ? ?<????????1???????l ? ( ? ?<????????1?????y ?l ? ( ? ?<????????1????? G ?? ? ( ? ?Z?x1???g?ֳ??g?ֳ??????????? ?J  ?H??Physical?$  Z?? ? ( ? ?Z?\4???g?ֳ??g?ֳ???????????|  ?I?? Data Link?$  Z ?? ?( ? ?Z?2 4;O :064>9 A5B8 =5 87<5=O5BAO 064K9 ?>A;54CNI89 C@>25=L ?><5I05B A2>9 703>;>2>: 2 ?>;5 40==KE ?@54K4CI53> C@>2=O 064K9 703>;>2>: 4>102;O5BAO 8 8A:;NG05BAO B>;L:>  A2>53> C@>2=O ?(? 0 Z??R k<??e))RR{{???H ?( ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z??0??( ? ?0?  ?0 ? ???%??ֳ?7D?ֳ?7D????????????1???? ?)?)????i???  ? ???;?? ?0 ? ?T??ۡ?D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?0 ? ?0???@??޽h?? ?? ??????̙33?????????? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ?????8???( ? ?8?  ?8 ? ???q?ֳ?7D?ֳ?7D????????????1???? ?)?)????? ???  q ???;?d ?8 ? ?<????????1????E?u?? ?8 ? ?Z?|#q?o??>?o??>?????????B??? ?p??02 60 8C 01 02 03 ?$ a  ????????????dB ?8 ? ?<????1????????y?? ?8 ? ?Z??/q?o??>?o??>?????????/fT ? ?o??08 00 20 04 05 06?$ a  ????????????dB ?8 ? ?<????1????????  y?? ?8 ? ?Z?pq?o??>?o??>?????????B?? ?h?? Data field?$  a   ????????????dB ? 8 ? ?<????1????????y?? ? 8 ? ?Z??t??o??>?o??>?????????8?^? ?f??CRC - 32?$  a  ???????????? ? 8 ? ?Z?4??o??>?o??>?????????vl ????*Vendor ID: 3Com Node ID: 010203?$+ b*  ???????????? ? 8 ? ?Z??Dq?o??>?o??>?????????d?? Z ????,Vendor ID: SUN Node ID: 040506 ?$- b,  ????????????dB ? 8? ? ?<????1?????????{*?dB ?8? ? ?<????1????????2???dB ?8? ? ?<????1????????u? <?? ?8 ? ?Z????o??>?o??>?????????e7t= ?j???45=B8D8:0B>@ ?@>872>48B5;O: 24 bits (3 bytes) (Vendor ID) 45=B8D8:0B>@ C7;0: 24 bits (3 bytes) (Node ID) ?$q bp  ?$$????????????H ?8 ? ?Z??Qq?C<?;??C<?;??????????i?6m ???F4@5A ?@85<=8:0 Destination address?$$ Z#  ?????????????> ?8 ? ?Z? aq?C<?;??C<?;??????????X? \ ???<4@5A 8AB>G=8:0 Source address?$ Z  ?????????????dB ?8? ? ?<????1???????? ! ??dB ?8 ? ?<????1?????????X??dB ?8 ? ?<????1????????????dB ?8 ? ?<????1????????????dB ?8 ? ?<????1???????? ? ??l ?8 ? ?T?4oq?D[????D[??????????????? ????P45=B8D8:0B>@ ?@>872>48B5;O - ?5@2K5 B@8 109B0 =07=0G0NBAO 8 @538AB@8@CNBAO IEEE 45=B8D8:0B>@ C7;0 - A;54CNI85 B@8 109B0 =07=0G0NBAO ?@>872>48B5;5< 8 A>>B25BAB2CNB =><5@C 8=B5@D59A=>9 :0@BK 8<55B ?>;5 87 224 =16,777,216 C=8:0;L=KE 04@5A>2 !-04@5A =07K205BAO B0:65 0??0@0B=K< 8;8 PROM-04@5A>< ??/ 0 Z" 0 Z) 0 Zw 0 Z8 0 Z/")U  7??/7% ??;???)?=?Q?H ?8 ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z?@??( ? ?@?  ?@ ? ??Hzq?ֳ?7D?ֳ?7D????????????1???? ?)?)????????  q ???;?? ?@ ? ?T?،q?D[????D[????????? ? ??4Z??? q ?,???;???)?=?Q?H ?@ ? ?0???@??޽h?? ?? ??????̙33?????????? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ?? ?H??( ? ?H?  ?H ? ???q?ֳ?7D?ֳ?7D????????????1???? ?)?)???l??????  q ???;?P ?H # ?l?4?q?ֳ?7D?ֳ?7D???????1??)?)?????? ? ???2$>@<0B ?0:5B0 Ethernet ?. ?  ??;))==QQ??8 ????? ?H??????l ?H ? ?<????????1?????y ?< ?H ? ?Z?(?q??N?o???N?o??????????6? ? ???(03>;>2>: MAC-C@>2=O?$ Z  ? ???  ""..?l ?H ? ?<????????1???? ???^ ?H ? ?Z?@?q??N?o???N?o??????????H *?? ????J03>;>2:8 C@>2=59 3 - 7 ! 8 40==K5?$& Z%  ? ???  ""..?l ?H ? ?<????????1???????4 ? H ? ?Z???q??N?o???N?o???????????y ???*:>=G0=85 MAC trailer?$ Z  ?  ???  ""..?f ? H ? ?6???????1???????fB ? H ? ?6???1???????????fB ? H ? ?6???1???????CC??fB ? H ? ?6???1???????? ? ??fB ?H ? ?6???1???????? ? ??fB ?H ? ?6???1???????????6 ?H ? ?Z? ?q??N?o???N?o????????????? ???$@50<1C;0 Preamble?, Z ? ??  ???  ""..?P ?H ? ?Z???q??N?o???N?o??????????np ? ???<4@5A AB>G=8:0 Source address?. Z ? ?????  ""..?Z ?H ? ?Z?84??N?o???N?o??????????L??? ????F4@5A ?@85<=8:0 Destination address?.$ Z# ? ?????  ""..?L ?H ? ?Z?? 4??N?o???N?o??????????? ?? ? ???8>;5 B8?0 ?0:5B0 Type field?. Z ? ?? ???  ""..?> ?H ? ?Z?4??N?o???N?o???????????k?? ???,>;5 40==KE Data field?, Z ? ??  ???  ""..?? ?H ? ?Z?L4??N?o???N?o??????????Pk, ?l??CRC-32?, Z ? ????  ""..?> ?H ? ?T??'4?t? ??t? ??????????ME9 ????@50<1C;0 @54=07=0G5=0 4;O A8=E@>=870F88 ?@85<=8:0 A B0:B>2>9 G0AB>B>9 ?@8=8<05<>3> ?0:5B0 5 ACI5AB2C5B 548=>9 B0:B>2>9 G0AB>BK 2 A5B8 Ethernet ;8=0 ?@50<1C;K Ethernet 64 18B0 >;5 B8?0 - >?8AK205B B8? ?@>B>:>;0 A5B52>3> C@>2=O =07=0G05BAO IEEE 0800 - TCP/IP 0600 - XNS 8137 - Novel NetWare IPX >=B@>;L=0O AC<<0 (CRC-32) 30@0=B8@C5B 4>AB>25@=>ABL :>=B@>;O 99,999%?  Z?  Z5 Z  Z3  Z Z+  Z ???3???3???*????3L  47 # ??e))RR{{???H ?H ? ?0???@??޽h?? ?? ??????̙33????????RU? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies \T?TT@???P??S?( ? ?P?  ?P ? ??p.4?ֳ?7D?ֳ?7D????????????1???? ?)?)????R???  4 ???;?^ ?P ? ?6???????1????????^B ?P ? ?6???1???????<QQ??^B ?P ? ?6???1???????<????^B ?P ? ?6???1???????<((??^B ?P ? ?6???1???????<????^B ?P ? ?6???1???????<????^B ? P ? ?6???1???????<hh??^B ? P ? ?6???1???????<????? ? P ? ?Z??X4?C<?;??C<?;???????????0 P R ?p?? . . . .?,  Z  ? ?????????????^ ? P ? ?6???????1????' r ??^B ? P ? ?6???1???????<? ? ??^B ?P ? ?6???1???????<c c ??^B ?P ? ?6???1???????<? ? ??^B ?P ? ?6???1???????<9 9 ??^B ?P ? ?6???1???????<? ? ??^B ?P ? ?6???1???????<  ??^B ?P ? ?6???1???????<? ? ??^ ?P ? ?6???????1????????^B ?P ? ?6???1????????RR??^B ?P ? ?6???1????????????^B ?P ? ?6???1????????**??^B ?P ? ?6???1????????????^B ?P ? ?6???1????????????^B ?P ? ?6???1????????jj??^B ?P ? ?6???1????????????^ ?P ? ?6???????1????j ??^B ?P ? ?6???1???????<????^B ?P ? ?6???1???????<[[??^B ?P ? ?6???1???????<????^B ? P ? ?6???1???????<11??^B ?!P ? ?6???1???????<????^B ?"P ? ?6???1???????<  ??^B ?#P ? ?6???1???????<????^ ?$P ? ?6???????1????j ??^B ?%P ? ?6???1????????????^B ?&P ? ?6???1????????[[??^B ?'P ? ?6???1????????????^B ?(P ? ?6???1????????11??^B ?)P ? ?6???1????????????^B ?*P ? ?6???1????????  ??^B ?+P ? ?6???1????????????^ ?,P ? ?6???????1????' r ??^B ?-P ? ?6???1????????? ? ??^B ?.P ? ?6???1????????c c ??^B ?/P ? ?6???1????????? ? ??^B ?0P ? ?6???1????????9 9 ??^B ?1P ? ?6???1????????? ? ??^B ?2P ? ?6???1????????  ??^B ?3P ? ?6???1????????? ? ??R?8 ???~ N ?7P???~ N?? ?4P ? ?Z?z4??/????/??????????????N ?l??Byte 0?, Z ? ?????????????? ?5P ? ?Z???4??/????/????????????XN ?l??Byte 1?, Z ? ?????????????? ?6P ? ?Z?4?4??/????/???????????E ?~ N ?l??Byte 5?, Z ? ?????????????R?8 ??|e  ?;P?|?e ?? ?8P ? ?Z???4??/????/????????????|? ?l??Byte 0?, Z ? ?????????????? ?9P ? ?Z?|?4??/????/???????????|? ?l??Byte 1?, Z ? ?????????????? ?:P ? ?Z?H?4??/????/???????????, |e  ?l??Byte 5?, Z ? ?????????????$ ?G=8:0?0 Z ? ?? ????????????? ?=P ? ?Z??4?C<?;??C<?;????????????7? ?k??Bit 0?, Z ? ?????????????? ?>P ? ?Z?\?4?C<?;??C<?;???????????=5:  ?k??Bit 0?, Z ? ?????????????? ??P ? ?Z???4?C<?;??C<?;?????????? $? ?k??Bit 7?, Z ? ?????????????$ ?@P ? ?Z???4?C<?;??C<?;??????????T:`? ???"5@5405BAO ?5@2K<?, Z ? ?? ????????????? ?AP ? ?Z???4?C<?;??C<?;???????????$+  ?k??Bit 7?, Z ? ?????????????$ ?BP ? ?Z?P?4?C<?;??C<?;?????????? ^??  ???"5@5405BAO ?5@2K<?, Z ? ?? ????????????$ ?CP ? ?Z??4?C<?;??C<?;??????????-s? ? ???4@5A ?@85<=8:0?0 Z ? ?? ????????????dB ?DP@ ? ?<????1????????? ?k?dB ?EP@ ? ?<????1????????? j"?^ ?FP ? ?6???????1?????A? ?^B ?GP ? ?6???1????????7?^B ?HP ? ?6???1???????k?7k?^B ?IP ? ?6???1?????????7??^B ?JP ? ?6???1????????7?^B ?KP ? ?6???1???????w?7w?^B ?LP ? ?6???1?????????7??^B ?MP ? ?6???1?????????B??^B ?NP ? ?6???1????????9?^B ?OP ? ?6???1???????k?Bk?^B ?PP ? ?6???1?????????B??^B ?QP ? ?6???1????????B?^B ?RP ? ?6???1???????w?Bw?^B ?SP ? ?6???1?????????B??^B ?TP ? ?6???1?????????7??^B ?UP ? ?6???1?????????7??^B ?VP ? ?6???1???????4?74?^B ?WP ? ?6???1?????????7??^B ?XP ? ?6???1?????????7??^B ?YP ? ?6???1???????A?7A?^B ?ZP ? ?6???1?????????B??^B ?[P ? ?6???1???????4?B4?^B ?\P ? ?6???1?????????B??^B ?]P ? ?6???1?????????B??^B ?^P ? ?6???1???????A?BA?^B ?_P ? ?6???1?????????B??^B ?`P ? ?6???1?????????B??^B ?aP ? ?6???1???????+?7+?^B ?bP@ ? ?6???1???????+?B+?^B ?cP ? ?6???1?????????B??^B ?dP ? ?6???1???????@ ?B@ ?^B ?eP ? ?6???1?????????7??^B ?fP ? ?6???1???????7?77?^B ?gP ? ?6???1?????????7??^B ?hP ? ?6???1?????????7??^B ?iP ? ?6???1?????????B??^B ?jP ? ?6???1???????7?B7?^B ?kP ? ?6???1?????????B??^B ?lP ? ?6???1?????????B??^B ?mP ? ?6???1???????? ?7? ?^B ?nP ? ?6???1???????4 ?74 ?^B ?oP ? ?6???1???????? ?7? ?^B ?pP ? ?6???1???????? ?7? ?^B ?qP ? ?6???1???????? ?B? ?^B ?rP ? ?6???1???????4 ?B4 ?^B ?sP ? ?6???1???????? ?B? ?^B ?tP ? ?6???1???????? ?B? ?^B ?uP ? ?6???1???????? ?7? ?^B ?vP ? ?6???1???????? ?7? ?^B ?wP ? ?6???1???????M ?7M ?^B ?xP ? ?6???1???????? ?B? ?^B ?yP ? ?6???1???????? ?B? ?^B ?zP ? ?6???1???????M ?BM ?^B ?{P ? ?6???1???????? ?B? ?^B ?|P ? ?6???1????????77??? ?}P ? ?Z?(??C<?;??C<?;???????????bbn ?p?? Type field?,  Z  ? ?????????????? ?~P ? ?Z?8"??C<?;??C<?;??????????%?? ?m??6 bytes?, Z ? ?????????????? ?P ? ?Z?<#??C<?;??C<?;??????????a%?? ?m??6 bytes?, Z ? ?????????????? ??P ? ?Z??4??C<?;??C<?;????????????} ?m??2 bytes?, Z ? ?????????????P?8 ?? 8V  ??P?8? V ? ??P ? ?Z?D>???/????/???????????? 8V? ?o?? 46 - 1500?,  Z  ? ?????????????? ??P ? ?Z?I???/????/???????????? ?-  ?m?? bytes?, Z ? ?????????????? ??P ? ?Z??I??C<?;??C<?;??????????? %?2  ?m??4 bytes?, Z ? ????????????? ??P ? ?Z??T??C<?;??C<?;??????????WH ?I ?{??Multicast bit (M-bit)?, Z ? ?????????????^ ??P ? ?6???????1??? ?%? ?^B ??P ? ?6???1??????? 77? ?^B ??P ? ?6???1??????? ??? ?^B ??P ? ?6???1??????? ? ?^B ??P ? ?6???1??????? yy? ?^B ??P ? ?6???1??????? ??? ?^B ??P ? ?6???1??????? PP? ?^B ??P ? ?6???1??????? ??? ?$ ??P ? ?Z?@i??C<?;??C<?;?????????? ? ??  ???LSB - <;04H89?, Z  ? ?? ????????????$ ??P ? ?Z??r??C<?;??C<?;?????????? &??  ???MSB - AB0@H89?, Z  ? ?? ????????????dB ??P ? ?<????1?????????s??? ??P ? ?Z??s??C<?;??C<?;??????????aG?? ?_??M?$ Z  ????????????? ??P ? ?Z????C<?;??C<?;???????????& F :  ?p?? . . . .?,  Z  ? ?????????????dB ??P ? ?<????1??????????? ?? ??P ? ?Z?t???C<?;??C<?;???????????Y? ?s??Destination address?& Z  ????????????? ??P ? ?Z?x???C<?;??C<?;??????????;?G? ?n??Source address?& Z  ????????????? ??P ? ?Z?@???C<?;??C<?;?????????????  ?j?? Data field?&  Z   ????????????? ??P ? ?Z?\???C<?;??C<?;??????????P ?l?  ?t??Frame Check Sequence?& Z  ????????????Z ??P ? ?Z?????C<?;??C<?;??????????? )?? ????L8BK 2 109B0E ?5@540NBAOA;520 =0?@02>?&' Z&  ?!????????????0 ??P ? ?Z?H???C<?;??C<?;???????????sW? ???6>A;54>20B5;L=>ABL ?5@540G8?$ Z  ? ???????????? ??P ? ?T?????D[????D[???????????? ??  ???? ?80 Z 0 Z? ??;???)?=?Q?H ?P ? ?0???@??޽h?? ?? ??????̙33????????x? ?  0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z`?X??( ? ?X?  ?X ? ??l???ֳ?7D?ֳ?7D????????????1???? ?)?)???????  ? ???;?? ?X ? ?T?????D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?X ? ?0???@??޽h?? ?? ??????̙33?????????M? ?  0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ?L?L??oo`?,L?( ? ?`?  ?` ? ???%??ֳ?7D?ֳ?7D????????????1???? ?)?)???l??????  ? ???;?p ?` # ?l?h,??ֳ?7D?ֳ?7D???????1??)?)??????? ????R!@02=5=85 ?0:5B>2 Ethernet 8 IEEE802.3 ?.* )???;))==QQ?jI?8 ??2q} ?o`?2?q}?f ?` ? ?6???????1???o? ?Z ?fB ?` ? ?6???1????????? ?Y ?fB ?` ? ?6???1???????`? `Y ?fB ?` ? ?6???1???????? Y ?fB ?` ? ?6???1????????? ?Y ?fB ? ` ? ?6???1???????T? TY ?fB ? ` ? ?6???1????????? ?Y ?fB ? ` ? ?6???1???????? Y ?? ? ` ? ?Z???t? ??t? ???????????i ?  ?g??I?, Z ? ???e))RR{{???? ? ` ? ?Z?H???t? ??t? ???????????? ?e  ?h?? G?, Z ? ???e))RR{{???? ?` ? ?Z?L???t? ??t? ??????????Ni   ?g??U?, Z ? ???e))RR{{???? ?` ? ?Z?(F??t? ??t? ??????????N? e  ?h?? L?, Z ? ???e))RR{{??? ?` ? ?Z????t? ??t? ??????????@ ??  ?p?? . . . .?,  Z  ? ???e))RR{{???f ?` ? ?6???????1???_? ?Z ?fB ?` ? ?6???1????????? ?Y ?fB ?` ? ?6???1???????Q? QY ?fB ?` ? ?6???1????????? ?Y ?fB ?` ? ?6???1????????? ?Y ?fB ?` ? ?6???1???????E? EY ?fB ?` ? ?6???1????????? ?Y ?fB ?` ? ?6???1???????? Y ?? ?` ? ?Z?t\??t? ??t? ??????????f? ?n  ?l??Byte 0?, Z ? ???e))RR{{???f ?` ? ?6???????1???9? V??fB ?` ? ?6???1????????? ???fB ?` ? ?6???1???????+? +??fB ?` ? ?6???1????????? ???fB ?` ? ?6???1???????x? x??fB ?` ? ?6???1???????? ??fB ? ` ? ?6???1????????? ???fB ?!` ? ?6???1????????? ???? ?"` ? ?Z?|f??t? ??t? ??????????? ?6 ?g??U?, Z ? ???e))RR{{???? ?#` ? ?Z??i??t? ??t? ??????????? ?? ?h?? L?, Z ? ???e))RR{{???? ?$` ? ?Z?f??t? ??t? ???????????? ?m ?g??U?, Z ? ???e))RR{{???f ?%` ? ?6???????1???? = Z ?fB ?&` ? ?6???1???????^ ? ^ Y ?fB ?'` ? ?6???1??????? ?  Y ?fB ?(` ? ?6???1???????? ? ? Y ?fB ?)` ? ?6???1???????R ? R Y ?fB ?*` ? ?6???1???????? ? ? Y ?fB ?+` ? ?6???1???????? ? ? Y ?fB ?,` ? ?6???1????????? ?Y ?f ?-` ? ?6???????1?????  ??fB ?.` ? ?6???1???????' ? ' ??fB ?/` ? ?6???1???????? ? ? ??fB ?0` ? ?6???1???????t ? t ??fB ?1` ? ?6???1??????? ?  ??fB ?2` ? ?6???1???????? ? ? ??fB ?3` ? ?6???1???????h ? h ??fB ?4` ? ?6???1????????? ??? ?5` ? ?Z?????t? ??t? ?????????? mI ?n??. . . . ?,  Z ? ???e))RR{{???f ?6` ? ?6???????1???'? Q??fB ?7` ? ?6???1???????r? r??fB ?8` ? ?6???1???????? ??fB ?9` ? ?6???1????????? ???fB ?:` ? ?6???1???????f? f??fB ?;` ? ?6???1??????? ? ??fB ?<` ? ?6???1????????? ???fB ?=` ? ?6???1????????? ???? ?>` ? ?Z?h???t? ??t? ?????????? ? ? n  ?l??Byte 1?, Z ? ???e))RR{{???? ??` ? ?Z?????t? ??t? ??????????V? ?n  ?l??Byte 5?, Z ? ???e))RR{{???? ?@` ? ?Z?L???t? ??t? ??????????? ??  ?l??Byte 0?, Z ? ???e))RR{{???? ?A` ? ?Z?????t? ??t? ???????????? 3 ?  ?l??Byte 1?, Z ? ???e))RR{{???? ?B` ? ?Z?????t? ??t? ??????????? ~?  ?l??Byte 5?, Z ? ???e))RR{{???fB ?C`B ? ?6???1??????????? ?fB ?D` ? ?6???1???????z ?? ?? ?E` ? ?Z?l???t? ??t? ????????????? ?m??7 bytes?, Z ? ???e))RR{{???? ?F` ? ?Z?????t? ??t? ????????????? ?l??1 byte?, Z ? ???e))RR{{???? ?G` ? ?Z?????t? ??t? ???????????? ? ?m??6 bytes?, Z ? ???e))RR{{???? ?H` ? ?Z????t? ??t? ??????????S ?? ? ?m??6 bytes?, Z ? ???e))RR{{???? ?I` ? ?Z?????t? ??t? ??????????? ?? ?m??2 bytes?, Z ? ???e))RR{{???? ?J` ? ?Z?????t? ??t? ??????????<??? ?l??1 byte?, Z ? ???e))RR{{???? ?K` ? ?Z?$??t? ??t? ??????????g??? ?l??1 byte?, Z ? ???e))RR{{??? ?L` ? ?Z?4???t? ??t? ????????????F ?r?? 1 or 2 bytes?,  Z  ? ???e))RR{{??? ?M` ? ?Z????t? ??t? ????????????1? ?r?? < 1496 bytes?,  Z  ? ???e))RR{{???  ?N` ? ?Z????t? ??t? ???????????? ? &  ?x??Source Address?0 Z ? ???e))RR{{???? ?O` ? ?Z??(??t? ??t? ???????????A /?  ?k??Bit 0?, Z ? ???e))RR{{???? ?P` ? ?Z??1??t? ??t? ???????????~?" ?k??Bit 0?, Z ? ???e))RR{{???? ?Q` ? ?Z?:??t? ??t? ???????????A 1?  ?k??Bit 7?, Z ? ???e))RR{{??? ?R` ? ?Z?h???t? ??t? ??????????z7 8 ?  ?}??Destination Address?0 Z ? ???e))RR{{???  ?S` ? ?Z? O??t? ??t? ??????????8? cQ  ?w??Transmitted first?, Z ? ???e))RR{{???? ?T` ? ?Z?tX??t? ??t? ???????????~?" ?k??Bit 7?, Z ? ???e))RR{{???  ?U` ? ?Z??a??t? ??t? ??????????d??} ?w??Transmitted first?, Z ? ???e))RR{{???? ?V` ? ?Z??e??t? ??t? ???????????2_? ?g??*?, Z ? ???e))RR{{???f ?W` ? ?6???????1????Yq??fB ?X` ? ?6???1????????W???fB ?Y` ? ?6???1????????W???fB ?Z` ? ?6???1??????? W ??fB ?[` ? ?6???1???????q Wq ??fB ?\` ? ?6???1????????W??? ?]` ? ?Z?Hw??t? ??t? ????????????1 ?n??Preamble?,  Z ? ???e))RR{{???fB ?^` ? ?6???1???????? W? ??fB ?_` ? ?6???1???????QWQJ?fB ?`` ? ?6???1??????? W J?? ?a` ? ?Z?|???t? ??t? ???????????N ? ?j??Data?, Z ? ???e))RR{{???fB ?b` ? ?6???1????????W???? ?c` ? ?Z?????t? ??t? ???????????N!? ?i??FCS?, Z ? ???e))RR{{??? ?d` ? ?Z?????t? ??t? ???????????0?? ????Optional IEEE 802.2 fields?, Z ? ???e))RR{{???fB ?e` ? ?6???1????????W???? ?f` ? ?Z?????t? ??t? ???????????N?? ?i??Pad?, Z ? ???e))RR{{???fB ?g` ? ?6???1???????? J?J?  ?h` ? ?Z?????t? ??t? ????????????v ?x??Start of Frame Delimiter?& Z  ??e))RR{{??? ?i` ? ?Z?X???t? ??t? ???????????5M A ?s??Destination address?& Z  ??e))RR{{??? ?j` ? ?Z?$???t? ??t? ?????????? 5? A ?o??Source address?& Z  ??e))RR{{???? ?k` ? ?Z?????t? ??t? ??????????i 5A ?l?? Length field?&  Z   ??e))RR{{??? ?l` ? ?Z?????t? ??t? ??????????hu? ????(Destination Service Access Point (DSAP)?&) Z(  ??e))RR{{??? ?m` ? ?Z?L???t? ??t? ??????????uh? ????"Source Service Access Point (SSAP)?&# Z"  ??e))RR{{??? ?n` ? ?Z?????t? ??t? ???????????+ ?n??Control fields?& Z  ??e))RR{{???H ?` ? ?0???@??޽h?? ?? ??????̙33????????x? ?  0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z??h??( ? ?h?  ?h ? ??8???ֳ?7D?ֳ?7D????????????1???? ?)?)????? ???  ? ???;?? ?h ? ?T????D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?h ? ?0???@??޽h?? ?? ??????̙33????????,9? ?  0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies 68?.8??LLp??7?( ? ?p?  ?p ? ???8??ֳ?7D?ֳ?7D????????????1???? ?)?)???????  ? ???;??3?8 ???5 ?Kp???5?f ?p ? ?6?????????????l ?p ? ?<????????1???yPo?l ?p ? ?<????????1???y%o}?l ?p ? ?<????????1???y?o??l ?p ? ?<????????1???y?o< ?l ?p ? ?<????????1???yD o? ?l ? p ? ?<????????1???y? o# ?l ? p ? ?<????????1???y+ o? ?l ? p ? ?<????????1???y? o1?lB ? pB ? ?<????1????????L)L?lB ? pB ? ?<????1????????L3L?lB ?pB ? ?<????1????????/ P/ ?lB ?p ? ?<????1???????u s ?lB ?pB ? ?<????1????????5P5?? ?p ? ?Z?T@?????>????>???????????? ?e??802.3?&   ??M??????ll?? ?p ? ?Z??????>????>????????? ? ?  ?e??802.2?&   ??M??????ll?? ?p ? ?Z?tK?????>????>?????????& ?  ?e??802.3?&   ??M??????ll?l ?p ? ?<????????1??? P?l ?p ? ?<????????1??? %}?l ?p ? ?<????????1?      !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|??????????????? ???l ?p ? ?<????????1??? ?< ?l ?p ? ?<????????1??? D ? ?? ?p ? ?Z??Z?????>????>?????????? ?kZ ?d??Preamble?"   ??M??????ll? ?p ? ?Z??[?????>????>????????? M<? ?o??Destination Address?"   ??M??????ll?? ?p ? ?Z??k?????>????>?????????_ ??A ?j??Source Address?"   ??M??????ll?? ?p ? ?Z?Xu?????>????>?????????? ?? ?f?? Type Field?"    ??M??????ll?? ?p ? ?Z??~?????>????>?????????? ? ?  ?f?? Data Field?"    ??M??????ll?l ?p ? ?<????????1??? ?  ?? ?p ? ?Z????????>????>?????????8 (? ?_??CRC?"   ??M??????ll?? ? p ? ?Z?̑?????>????>????????? ];? ?c??8 bytes?"   ??M??????ll?? ?!p ? ?Z?(??????>????>????????? ?;t ?c??6 bytes?"   ??M??????ll?? ?"p ? ?Z?`??????>????>????????? 7;? ?c??6 bytes?"   ??M??????ll?? ?#p ? ?Z????????>????>????????? ?;-  ?c??2 bytes?"   ??M??????ll?? ?$p ? ?Z????????>????>?????????R ? ??  ?l??46 to 1500 bytes?"   ??M??????ll?? ?%p ? ?Z????????>????>????????? ?; ?c??4 bytes?"   ??M??????ll?? ?&p ? ?Z????????>????>?????????j ??4 ?i?? Ethernet V2.0?"    ??M??????ll? ?'p ? ?Z????????>????>???????????4 ?v??IEEE 802.3 with IEEE 802.2?"   ??M??????ll?lB ?(p ? ?<????1???????u7s7?lB ?)p ? ?<????1???????r? ??lB ?*p? ? ?<????1?????????  ' ?lB ?+p ? ?<????1????????L???lB ?,p? ? ?<????1??????????U?lB ?-p ? ?<????1????????V? ?lB ?.p? ? ?<????1????????? ?' ?lB ?/p ? ?<????1????????V)V?lB ?0pB ? ?<????1????????N PN ?lB ?1p ? ?<????1????????W ? ?lB ?2p? ? ?<????1????????? ?5?lB ?3p ? ?<????1???????rL L?lB ?4p ? ?<????1???????r! !?lB ?5p ? ?<????1???????uVsV? ?6p ? ?Z????????>????>??????????B?? ?t??Start of Frame Delimiter?"   ??M??????ll? ?7p ? ?Z????????>????>?????????U-? ?o??Destination address?"   ??M??????ll?? ?8p ? ?Z?t??????>????>???????????2 ?j??Source address?"   ??M??????ll?? ?9p ? ?Z???????>????>?????????oc?? ?`??DSAP?"   ??M??????ll?? ?:p ? ?Z????????>????>?????????st {?  ?`??SSAP?"   ??M??????ll?? ?;p ? ?Z?l?????>????>?????????T3 ??  ?c??Control?"   ??M??????ll?? ?????>??????????k ~?  ?`??Data?"   ??M??????ll?? ?=p ? ?Z??!?????>????>??????????? ~_ ?_??CRC?"   ??M??????ll?? ?>p ? ?Z?!?????>????>?????????z?t6 ?a??1byte?"   ??M??????ll?? ??p ? ?Z?:?????>????>????????????p ?h?? 2 or 6 bytes?"    ??M??????ll?? ?@p ? ?Z??????>??????????P?? ?h?? 2 or 6 bytes?"    ??M??????ll?? ?Ap ? ?Z?tK?????>????>?????????p??V  ?b??1 byte?"   ??M??????ll?? ?Bp ? ?Z?P?????>????>?????????x? ?T  ?b??1 byte?"   ??M??????ll?f ?Cp ? ?6?????????O? % ?? ?Dp ? ?Z?$X?????>????>?????????M? ?c??4 bytes?"   ??M??????ll?? ?Ep ? ?Z??i?????>????>??????????- ??  ?_??PAD?"   ??M??????ll?f ?Fp ? ?6?????????|??? ?Gp ? ?Z??r?????>????>?????????X?? ?d??Preamble?"   ??M??????ll?? ?Hp ? ?Z?v?????>????>?????????M?K ?c??7 bytes?"   ??M??????ll?? ?Ip ? ?Z?l??????>????>???????????b ?l??Length 2 bytes?"   ??M??????ll?lB ?Jp ? ?<????1???????rV @ ?? ?Lp ? ?T? ???t? ??t? ?????????$5( ???4 07;8G85 ?0:5B>2 >?@545;O5BAO B8?>< A5B52>3> ?@>B>:>;0 AppleTalk 8 Novell NetWare >1KG=> 8A?>;L7CNB IEEE802.3 TCP/IP 8 DECNet >1KG=> 8A?>;L7CNB Ethernet?Z8 Z7  Z Z+  Z????66 ??e))RR{{???H ?p ? ?0???@??޽h?? ?? ??????̙33????????x? ?  0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z??x??( ? ?x?  ?x ? ??̬??ֳ?7D?ֳ?7D????????????1???? ?)?)????????  ? ???;?? ?x ? ?T?X???D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?x ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z????( ? ???? ?? ? ?T?????D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?  ?? ? ??h???ֳ?7D?ֳ?7D????????????1???? ?)?)????@ ???  ? ???;?H ?? ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z ????( ? ???  ?? ? ?? ??ֳ?7D?ֳ?7D????????????1???? ?)?)????????  ? ???;?? ?? ? ?T?d??D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?? ? ?0???@??޽h?? ?? ??????̙33????????x? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??z@????( ? ???  ?? ? ???9??ֳ?7D?ֳ?7D????????????1???? ?)?)????=???  ? ???;?? ?? ? ?T?d7??D[????D[????????? ? ??4Z??? ? ?,???;???)?=?Q?H ?? ? ?0???@??޽h?? ?? ??????̙33?????????? ? 0???????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ???`???$?( ? ???  ?? ? ??pc??ֳ?7D?ֳ?7D????????????1???? ?)?)????a ???  ? ???;?dB ?? ? ?<????1???????s?dB ?? ? ?<????1????????u?dB ?? ? ?<????1????????jjl?p ?? ? ?H??????A????1????Q"? ?p ?? ? ?H??????A????1???T????p ?? ? ?H??????A????1??? ^/= ?p ? ? ? ?H??????A????1???o? ??dB ? ? ? ?<????1????????????dB ? ?? ? ?<????1???????99??dB ? ? ? ?<????1????????55??dB ? ?? ? ?<????1???????JJ??? ?? ? ?T??A??o??>?o??>???????? ?s?  ?_??A?$ a  ????????????? ?? ? ?T?8t??o??>?o??>?????????d?/ ?_??B?$ a  ????????????? ?? ? ?T?B??o??>?o??>????????V ??  ?_??D?$ a  ????????????^ ?? ? ?6?????????I n]? ?? ?? ? ?Z??~??C<?;??C<?;?????????? ???  ?b??Data?$ Z  ????????????dB ??? ? ?<????1??????? "" ?? ?? ? ?T?4??o??>?o??>?????????? cB ?_??C?$ a  ????????????dB ?? ? ?<????1???????S??S?dB ??? ? ?<????1???????S||??dB ?? ? ?<????1???????S????dB ??? ? ?<????1????????????dB ??? ? ?<????1??????????L ?? ? ?Z????C<?;??C<?;???????????{? ? ????P5A>>B25BAB285 04@5A0 0:5B 83=>@8@C5BAO?&) Z(  ? )????????????L ?? ? ?Z?ء??C<?;??C<?;??????????? ^? ????P4@5A A>>B25BAB2C5B 0:5B >1@010BK205BAO?&) Z(  ? )????????????J ?? ? ?Z?????C<?;??C<?;??????????b?? f ????60==K5 ?>AK;0NBAO : C7;C D?$ Z  ?$???????????? ?? ? ?Z?????C<?;??C<?;???????????! eq  ?4???5@54025<K9 ?0:5B ?@>A<0B@8205BAO 2A5<8 AB0=F8O<8 H8@>:>25I0B5;L=0O A@540 (broadcast medium)?&^ Z]  ?J????????????dB ??? ? ?<????1???????c! ! {?L ?? ? ?Z?\???C<?;??C<?;???????????r?? ????P5A>>B25BAB285 04@5A0 0:5B 83=>@8@C5BAO?&) Z(  ? )????????????H ?? ? ?0???@??޽h?? ?? ??????̙33?????????? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies ??????T?( ? ???  ?? ? ??????ֳ?7D?ֳ?7D????????????1???? ?)?)????? ???  ? ???;? ?8 ?|FO%  ???F|O% ?lB ?? ? ?<????1???????????lB ?? ? ?<????1????????g?lB ?? ? ?<????1???????|?|^?x ?? ? ?H??????A????1???c?5? ?x ?? ? ?H??????A????1????F?}?x ?? ? ?H??????A????1???p?B/ ?x ? ? ? ?H??????A????1???R a#??lB ? ? ? ?<????1????????????lB ? ?? ? ?<????1???????L?L??lB ? ? ? ?<????1???????G?G??lB ? ?? ? ?<????1???????]?]??? ?? ? ?T?????;??>?;??>???????? ??  ?_??A?$ a  ????????????? ?? ? ?T?l???;??>?;??>??????????? ?_??B?$ a  ????????????? ?? ? ?T?????;??>?;??>????????? ?e4 ?_??C?$ a  ????????????? ?? ? ?T?h??;??>?;??>?????????Q {?  ?_??D?$ a  ????????????f ?? ? ?6??????????? ?% ?x ?? ? ?H??????A????1???????x ?? ? ?H??????A????1????? ??x ?? ? ?H??????A????1???? ?? ?? ? ?Z????;??>?;??>???????????~s ????!B>;:=>25=85?$  a   ? ????????????4 ?? ? ?Z?x???/????/???????????Q X? ? ???*5@540G0 40==KE 4;O A?$ Z  ?????????????lB ??? ? ?<????1??????? U ;?x ?? ? ?H??????A????1????L?f2 ?? ? ?6???????1???? ?n??lB ??B ? ?<????1????????h???4 ?? ? ?Z?\$???/????/????????????=O? ???*5@540G0 40==KE 4;O C?$ Z  ?????????????lB ??? ? ?<????1????????U ;?H ?? ? ?0???@??޽h?? ?? ??????̙33????????K*? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies U)?M)??@@???(?( ? ???  ?? ? ???????>?????????E o& ? ?m??transmit packet?$ a  ??M??????ll?l ?? ? ?<????????1??? ?? A?? ?? ? ?Z?xL?????>????>?????????6 ?- ! ?m??assemble packet?$ a  ??M??????ll? ?? ? ?Z?,N?????>????>????????? |~ L ?p??deferring on??$ b  ??M??????ll?l ?? ? ?<????????1???? R7_?? ? ? ? ?Z?XM?????>????>?????????. Q? ? ?j?? start?$  a   ??M??????ll?? ? ? ? ?Z??a?????>????>?????????= ?? a ?j?? transmission?$  a   ??M??????ll???@ ????? ? ???????l ? ? ? ?<????????1????????? ? ? ? ?Z??q?????>????>??????????? ?m??send jam signal?$ a  ??M??????ll?l ?? ? ?<????????1????i ?W ? ?? ? ?Z?lz?????>????>??????????? R#  ?p??increment attempts?$ a  ??M??????ll?l ?? ? ?<????????1????? ???1 ?? ? ?Z???????>????>?????????J? ?? ???compute and wait backoff time?& b  ???M??????ll?r" ?? ? ?B??G? ??????1???b ? d?? ?? ? ?Z?d??????>????>?????????? ? v? ???done excessive collision errors?&  b  ??M??????ll?r" ?? ? ?B??G? ??????1????? ?? ?? ? ?Z?(??????>????>?????????]? ? ?q?? done transmit ok?& b  ??M??????ll?lB ?? ? ?<????1???????? ? ??lB ?? ? ?<????1???????? D? ??lB ?? ? ?<????1???????? ?? M?lB ?? ? ?<????1??????? c  ?lB ?? ? ?<????1????????NnN?lB ??? ? ?<????1???????u?uG?lB ??B ? ?<????1???????? ?n??lB ?? ? ?<????1???????s? s? ? ?? ? ?Z?P??????>????>??????????k Y ?  ?t?? transmission done ??& b  ??M??????ll?lB ??B ? ?<????1???????? ? ? ? ?lB ? ? ? ?<????1???????} ?? ?!? ? ?Z?l??????>????>?????????B? ??  ?a??yes?$ `  ??M??????ll?? ?"? ? ?Z????????>????>?????????m j ? ?  ?`??no?$ `  ??M??????ll?? ?#? ? ?Z????????>????>?????????M j ? ?  ?a??yes?$ `  ??M??????ll?lB ?$?B ? ?<????1???????( ?? ??lB ?%?? ? ?<????1???????! ?! ??lB ?&? ? ?<????1???????# ?? ??? ?'? ? ?Z????????>????>?????????# ?? b ?a??yes?$ `  ??M??????ll?? ?(? ? ?Z?$??????>????>?????????; ?? V ?`??no?$ `  ??M??????ll?? ?)? ? ?Z???????>????>??????????? >V  ?`??no?$ `  ??M??????ll?? ?*? ? ?Z???????>????>?????????? ??  ?a??yes?$ `  ??M??????ll? ?+? ? ?Z?T??????>????>?????????I } ? M  ?p??collision detect??$ b  ??M??????ll??? ?,? ? ?<?A ???????? ? ? ?X? $???? 0???m 0?  ?-? ? ?Z???????>????>??????????? _?  ?w??too many attempts ??$ b  ??M??????ll??? ?.? ? ?<?A ????????? ?? ?X? $???? 0???m 0?lB ?/? ? ?<????1??????? ? ?? ?lB ?0?? ? ?<????1????????)?? ?lB ?1? ? ?<????1????????&?&?lB ?2? ? ?<????1??????????f ?lB ?3? ? ?<????1????????[ ?? ?lB ?4? ? ?<????1????????? ?? ?lB ?5?B ? ?<????1???????p? ?? ??@ ?|L? r  ?:??|L? r ?fB ?6?B ? ?6???1???????|L? ?fB ?7? ? ?6???1???????|? r ?fB ?8?? ? ?6???1???????? ? r ?fB ?9?? ? ?6???1???????L? ? ??@ ?? ?? ? ????? ?? ??fB ?;?B ? ?6???1???????? ?? ??fB ??? ? ?6???1???????? ?? ??H ?? ? ?0???@??޽h?? ?? ??????̙33????????&9? ? 0????=?*1996-98. Yu.Demchenko ?@Computer Networking Technologies 08?(8??^^???7?( ? ???  ?? ? ???J??ֳ?7D?ֳ?7D????????????1???? ?)?)????!???  ? ???;???8 ????. ??????.? ?? ? ?Z??Ԕ?>???????????[ ?u??done packet_check error?$ a  ??q?????????r" ?? ? ?B??G? ??????1??????.?4?8 ??gY? ?^??g?Y??r" ?? ? ?B??G? ??????1????gi ??? ?? ? ?Z?HY?????>????>?????????:nF ? ?l??receive packet?$ a  ??M??????ll?? ?? ? ?Z??[?????>????>?????????]{i ? ?m??start receiving?$ a  ??M??????ll?? ? ? ? ?T??l?????>????>?????????< 5 ?r??done receiving ? ?& b  ??M??????ll? ? ? ? ?Z??m?????>????>??????????X* ? ?r??packet too small ??& b  ??M??????ll? ? ? ? ?Z?8y?????>????>??????????? 6 ?  ?r??recognize address??& b  ??M??????ll?? ? ? ? ?Z????????>????>?????????? f ~?  ?i?? extra bits??$  a   ??M??????ll?? ? ? ? ?Z?Ȓ?????>????>???????????   ?k?? valid CRC??$ b   ??M??????ll? ?? ? ?Z????????>????>????????? J  ?n??valid length ??& b  ??M??????ll? ?? ? ?Z?@??????>????>?????????? ?| ?p??disassemble packet?$ a  ??M??????ll?r" ?? ? ?B??G? ??????1????Z f ? ? ?? ? ?Z???????>????>?????????"m ? ?  ?o??done error length?$ a  ??M??????ll?? ?? ? ?Z?h??????>????>????????? R ? ?m??done receive ok?$ a  ??M??????ll? ?? ? ?Z????????>????>?????????? ? ?  ?r??done alignment error?$ a  ??M??????ll?lB ?? ? ?<????1???????p ?p ?lB ?? ? ?<????1???????p ?p ??lB ?? ? ?<????1???????? F ? F ?lB ?? ? ?<????1????????? ?? ?lB ?? ? ?<????1????????? P? ?lB ?? ? ?<????1???????Y? YS?lB ?? ? ?<????1???????y y? ?lB ?? ? ?<????1???????y? y?lB ?? ? ?<????1???????C? ?? ?lB ?? ? ?<????1???????NSU S?lB ??? ? ?<????1??????? ? > ?lB ??B ? ?<????1???????e ? ??lB ? ?? ? ?<????1????????????lB ?!? ? ?<????1????????????lB ?"? ? ?<????1???????. ? ??? ?#? ? ?Z?4??????>????>?????????? }$ ? ?a??yes?$ `  ??M??????ll?? ?$? ? ?Z?x??????>????>?????????? ? *  ?`??no?$ `  ??M??????ll?? ?%? ? ?Z????????>????>?????????# ^? ? ?a??yes?$ `  ??M??????ll?f ?&? ? ?6?????????? ? ?? ?'? ? ?Z????????>????>??????????? |;  ?a??yes?$ `  ??M??????ll?? ?(? ? ?Z????????>????>?????????h ? ? H  ?`??no?$ `  ??M??????ll?? ?)? ? ?Z?hH????>????>?????????? *?  ?a??yes?$ `  ??M??????ll?? ?*? ? ?Z?? H????>????>?????????+'?? ?`??no?$ `  ??M??????ll?? ?+? ? ?Z?H????>????>?????????34 ??  ?`??no?$ `  ??M??????ll?? ?,? ? ?Z?0H????>????>??????????w T?  ?a??yes?$ `  ??M??????ll?? ?-? ? ?Z??)H????>????>??????????9 =?  ?`??no?$ `  ??M??????ll?? ?.? ? ?Z?X3H????>????>??????????f 0?  ?a??yes?$ `  ??M??????ll??@ ???1 ? ?3????1 ??lB ?/?B ? ?<????1?????????h ??lB ?0? ? ?<????1?????????h ??lB ?1?? ? ?<????1???????h ?1 ??lB ?2?? ? ?<????1???????h ?1 ???@ ??? B?  ?8???? B? ?lB ?4?B ? ?<????1????????? z? ?lB ?5? ? ?<????1????????? z? ?lB ?6?? ? ?<????1???????y? B? ?lB ?7?? ? ?<????1???????y? B? ??@ ?yB w 7  ?=??yB w 7 ?lB ?9?B ? ?<????1???????yB g I ?lB ?:? ? ?<????1???????yI g 7 ?lB ?;?? ? ?<????1???????g I w 7 ?lB ??B ? ?<????1???????? z+ ?lB ??? ? ?<????1????????+ z ?lB ?@?? ? ?<????1???????y+ B ?lB ?A?? ? ?<????1???????y B+ ??@ ???+ ? ?G????+ ??lB ?C?B ? ?<????1?????????d ??lB ?D? ? ?<????1?????????d ??lB ?E?? ? ?<????1???????d ?+ ??lB ?F?? ? ?<????1???????d ?+ ??r" ?H? ? ?B??G? ??????1????tg ??lB ?I?B ? ?<????1????????????r" ?J? ? ?B??G? ??????1??? ? ? ?r" ?K? ? ?B??G? ??????1???`  ??r" ?L? ? ?B??G? ??????1???? 8???@ ?? ? ??  ?Q??? ? ?? ?lB ?M?B ? ?<????1???????? ? ?? ?lB ?N? ? ?<????1???????? ? ?? ?lB ?O?? ? ?<????1????????? ?? ?lB ?P?? ? ?<????1????????? ?? ?lB ?R? ? ?<????1???????e ?e ??lB ?S? ? ?<????1???????d ?k O ?lB ?T? ? ?<????1???????A2 ?2 ?lB ?U? ? ?<????1????????1 ?A ?lB ?V?B ? ?<????1????????O |O ?lB ?W?? ? ?<????1????????M?G ?lB ?X?B ? ?<????1????????N?N?lB ?Y? ? ?<????1????????N? ?lB ?Z? ? ?<????1????????H  H ?lB ?[?? ? ?<????1??????? ?  A ?lB ?\? ? ?<????1???????% ? ? ? ?? ?]? ? ?Z??TH???m????m??????????(? ?<  ?`??no?$ Z  ??M??????ll?H ?? ? ?0???@??޽h?? ?? ??????̙33????????8? 0 ???P????( ? ??? ? ? ?N??????1???? ???8" ??  ?? ? ? ?T??a???g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???p????( ? ??? ? ? ?N??????1???? ???8" ??  ?? ? ? ?T?????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????$???( ? ?$?? ?$ ? ?N??????1???? ???8" ??  ?? ?$ ? ?T???i??g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?$ ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????,???( ? ?,?? ?, ? ?N??????1???? ???8" ??  ?? ?, ? ?T?(á??g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?, ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????4???( ? ?4?? ?4 ? ?N??????1???? ???8" ??  q? ?4 ? ?T?\q??g?ֳ??g?ֳ?????? ?? ?? ???  q ??? ?H ?4 ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????<???( ? ?<?? ?< ? ?N??????1???? ???8" ??  q? ?< ? ?T?l~q??g?ֳ??g?ֳ?????? ?? ?? ???  q ??? ?H ?< ? ?0????re?"f??? ?? ??????̙33????????8? 0 ????D???( ? ?D?? ?D ? ?N??????1???? ???8" ??  q? ?D ? ?T?Зq??g?ֳ??g?ֳ?????? ?? ?? ???  q ??? ?H ?D ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???0?L???( ? ?L?? ?L ? ?N??????1???? ???8" ??  4? ?L ? ?T?? 4??g?ֳ??g?ֳ?????? ?? ?? ???  4 ??? ?H ?L ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???P?T???( ? ?T?? ?T ? ?N??????1???? ???8" ??  ?? ?T ? ?T??????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?T ? ?0????re?"f??? ?? ??????̙33????????8?  0 ???p?\???( ? ?\?? ?\ ? ?N??????1???? ???8" ??  ?? ?\ ? ?T????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?\ ? ?0????re?"f??? ?? ??????̙33????????8?  0 ?????d???( ? ?d?? ?d ? ?N??????1???? ???8" ??  ?? ?d ? ?T?$????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?d ? ?0????re?"f??? ?? ??????̙33????????8?  0 ?????l???( ? ?l?? ?l ? ?N??????1???? ???8" ??  ?? ?l ? ?T?p???g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?l ? ?0????re?"f??? ?? ??????̙33????????8?  0 ?????t???( ? ?t?? ?t ? ?N??????1???? ???8" ??  ?? ?t ? ?T?|????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?t ? ?0????re?"f??? ?? ??????̙33????????8?  0 ?????|???( ? ?|?? ?| ? ?N??????1???? ???8" ??  ?? ?| ? ?T??????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?| ? ?0????re?"f??? ?? ??????̙33????????8? 0 ????????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T??????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???0?????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???P?????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T?(D???g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ???p?????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T?L????g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T??.???g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????????( ? ???? ?? ? ?N??????1???? ???8" ??  ?? ?? ? ?T??=???g?ֳ??g?ֳ?????? ?? ?? ???  ? ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????8? 0 ?????????( ? ???? ?? ? ?N??????1???? ???8" ??  H? ?? ? ?T?XH??g?ֳ??g?ֳ?????? ?? ?? ???  H ??? ?H ?? ? ?0????re?"f??? ?? ??????̙33????????x???N?@??????6?D(M?*T?IJ ?`S!Ѳ,?.?@?,???Ct?-kV}?,??#?=?@?g?Ip??? Q??Ϻ???L??s?sv:?j?c?W0?2?2?T??:??u?9׿?{?%͆9웟?m?V?Uh?*?A? ????cm???;?>? nd?`??|?y??M?W??????lj2W?????N!?Y*?*;??????g|?s?LJ??ѿρ~Ly?{?|??0?5??v?"9?? ???y? ????TC??^?y?O1?L%??ѵ??zg???u|?_Z??-? ??;Ǭ?[???_ ?>?x??LJ????_?????^???M?Ը3??$ ? ? ? ? ?%~W?UR?x???N?@??????6?D(M?*T?IJ ?`S!Ѳ,?.?@?,???Ct?-kV}?,??#?=?@?g?Ip??? Q??Ϻ???L??s?sv:?j?c?W0?2?2?T??:??u?9׿?{?%͆9웟?m?V?Uh?*?A? ????cm???;?>? nd?`??|?y??M?W??????lj2W?????N!?Y*?*;??????g|?s?LJ??ѿρ~Ly?{?|??0?5??v?"9?? ???y? ????TC??^?y?O1?L%??ѵ??zg???u|?_Z??-? ??;Ǭ?[???_ ?>?x??LJ????_?????^???M?Ը3??$ ? ? ? ? ?%~W?URr?vg?m??:??[?nTr?u[? ???~????\N?Qv???*???*???*??~?>?w?z|?~????????????????????????????????5?0DocumentSummaryInformation8????????????+?Current User????????????FJSummaryInformation(?????????????LDocumentSummaryInformation8????????????H????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Oh??+'??04 px?? ,8 X d p |????BПротоколы маршрутизации Routing Protocols oYuri Demchenko?-C:\MSOffice\Templates\Blank Presentation.pot RYuri Demchenkop7riMicrosoft PowerPoint\Bl@??@f????@p?/i =?@???z??JG??????y  E 7&?????? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP   ?? ????-?-- !???-????-??-&????$m??&???????w@` ??؟?w??w ?wcf!- ????@Times New Roman؟?w??w ?wcf!-? . 2 ?.? . . 2 ?71996. . 2 ?O-. .2 ?S98. Yu.Demchenko  .&????Dmm?&????  .72 ?} Computer Networking Technologies   .&?????m??&???? ????@Times New Roman؟?w??w ?wcf!-? .2 ?YSlide 2_. . 2 ??1.?-?-g?4--?--?^?z----?O?z----?W??----?e?k-- ????@Times New Roman؟?w??w ?wcf!-? .?5?????@Times New Roman؟?w??w ?wcf!-.2 ?5 ?????????.-?. .???????@Times New Roman؟?w??w ?wcf!-. 2 ???.-?. .??????@Times New Roman؟?w??w ?wcf!-.2 ???????? .-?. .?v?????@Times New Roman؟?w??w ?wcf!-.2 ?v?????? ??????.-?. .?1?????@Times New Roman؟?w??w ?wcf!-.2 ?1????????? ??????.-?. .?N?????@Times New Roman؟?w??w ?wcf!-. 2 ?N??? .-?.?--- !?}u?---?-????-?-??&-?-?  .?.?????@Times New Roman؟?w??w ?wcf!-.2 ?. ?????????.-?. .???????@Times New Roman؟?w??w ?wcf!-. 2 ???.-?. .??????@Times New Roman؟?w??w ?wcf!-.2 ???????? .-?. .?o?????@Times New Roman؟?w??w ?wcf!-.2 ?o?????? ??????.-?. .?*?????@Times New Roman؟?w??w ?wcf!-.2 ?*????????? ??????.-?. .?G?????@Times New Roman؟?w??w ?wcf!-. 2 ?G??? .-?.--??"System!cf! !???-?&TNPP &????s New RomanTimes New Roman CyrBlank PresentationWindows Draw DrawingiСтандарты и функции уровня данных эталонной модели ВОС 2Определение уровня данных Пакеты PowerPoint Presentation^Адресация уровня УДС (Управления Доступом к Среде) 0Формирование МАС-адресов EОсновные характеристики IEEE802.3 и Ethernet PowerPoint PresentationUПорядок формирования и передачи битов в Ethernet TПорядок формирования и передачи битов в EthernetPowerPoint Presentation%Формат пакета IEEE802.3 LДетальное сравнение пакетов IEEE802.3 и Ethernet Ethernet Определение CSMA/CD Ethernet. Выводы KПроблемы практического применения Ethernet ,Нормальная работа Ethernet &Столкновения в Ethernet ;Алгоритм передачи пакета в Ethernet8Алгоритм приема пакета в Ethernet  Fonts UsedDesign TemplateEmbedded OLE Servers Slide Titles?&_?????Yuri DemchenkoYuri Demchenko????՜.??+,??0? hp???? ? ? ?? ? 2?A4 Paper (210x297 mm)Bl? Times New RomanTimes New Roman CyrBlank PresentationWindows Draw Drawing:????????? ? ??????? ?????? ?????? ????????? ?????? ??? ??????????? ?????? ?????? ?????? PowerPoint Presentation4????????? ?????? ?????????Oh??+'??0 px???   @ L X dpx?,????????? ????????????? Routing Protocols Yuri Demchenko?-C:\MSOffice\Templates\Blank Presentation.poternYuri Demchenkop8riMicrosoft PowerPoint\Bl@^A?@f????@p?/i =?@?:?z??JG??????y  E 7&?????? &????&#????TNPP ?2??OMi & TNPP? &????&TNPP   ?? ????-?-- !???-????-??-&????$m??&???????w@c ,?؟?w??w ?w?f- ????@Times New Roman؟?w??w ?w?f-? . 2 ?.? . . 2 ?71996. . 2 ?O-. .2 ?S98. Yu.Demchenko  .&????Dmm?&????  .72 ?} Computer Networking Technologies   .&?????m??&???? ????@Times New Roman؟?w??w ?w?f-? .2 ?YSlide 2_. . 2 ??1.?-?-g?4--?--?^?z----?O?z----?W??----?e?k-- ????@Times New Roman؟?w??w ?w?f-? .?5?????@Times New Roman؟?w??w ?w?f-.2 ?5 ?????????.-?. .???????@Times New Roman؟?w??w ?w?f-. 2 ???.-?. .??????@Times New Roman؟?w??w ?w?f-.2 ???????? .-?. .?v?????@Times New Roman؟?w??w ?w?f-.2 ?v?????? ??????.-?. .?1?????@Times New Roman؟?w??w ?w?f-.2 ?1????????? ??????.-?. .?N?????@Times New Roman؟?w??w ?w?f-. 2 ?N??? .-?.?--- !?}u?---?-????-?-??&-?-?  .?.?????@Times New Roman؟?w??w ?w?f-.2 ?. ?????????.-?. .???????@Times New Roman؟?w??w ?w?f-. 2 ???.-?. .??????@Times New Roman؟?w??w ?w?f-.2 ???????? .-?. .?o?????@Times New Roman؟?w??w ?w?f-.2 ?o?????? ??????.-?. .?*?????@Times New Roman؟?w??w ?w?f-.2 ?*????????? ??????.-?. .?G?????@Times New Roman؟?w??w ?w?f-. 2 ?G??? .-?.--??"System?f !???-?&TNPP &????? (?????????? ???????? ? ?????) ???????????? ???-??????? .???????? ?????????????? IEEE802.3 ? Ethernet PowerPoint Presentation3??????? ???????????? ? ???????? ????? ? Ethernet 2??????? ???????????? ? ???????? ????? ? EthernetPowerPoint Presentation?????? ?????? IEEE802.3 2????????? ????????? ??????? IEEE802.3 ? Ethernet Ethernet ??????????? CSMA/CD Ethernet. ?????? ,???????? ????????????? ?????????? Ethernet ?????????? ?????? Ethernet ???????????? ? Ethernet $???????? ???????? ?????? ? Ethernet#???????? ?????? ?????? ? Ethernet  Fonts UsedDesign TemplateEmbedded OLE Servers Slide Titles