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efa 3

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1. ?? p??t?????? ALOHA. ?p?te?e? ??a s?st? a as?? at?? et?d?s?? pa??t??. ... St? t? ALOHA e s??s ?? ? ???st?? ??? ?? d???e?s?? p?? p??e? ?a ep?te???e? ... – PowerPoint PPT presentation

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Title: efa 3


1
?ef??a?? 3?
  • ?? ?p?st??µa p??sp??as?? st? µ?s? µet?d?s??

2
?e??e??µe?a
  • ?? e??a? t? ?p?st??µa p??sp??as?? st? µ?s?
    µet?d?s??.
  • ?? p??ß??µa t?? e?????s?? t?? d?a????
  • ???t?pa t?p???? d??t???
  • ALOHA
  • IEEE 802.3 ?a? Ethernet
  • Token bus
  • Token ring
  • FDDI
  • ????f????? d??t?a

3
??sa????
  • ?p?? ??e? a?afe??e? se p??????µe?? ?ef??a?? ??
    ?p?????st?? d?as??d???ta? se d??t?? e?te µe
    s??d?se?? s?µe??? p??? s?µe?? (s?????? WAN) e?te
    µe s??d?se?? ???? µa?? st? ?d?? ?a????
    s??µat????ta? d??t?a e?p?µp?? (broadcast). Sta
    d??t?a e?p?µp?? p????? ??µß?? µ???????ta? ??a
    ????? d?a??? ep????????a? (s?????? LAN).
  • St? ?ef??a?? a?t? ?a as???????µe µe t??? d?a?????
    e?p?µp?? (? a????? d?a???? p???ap??? p??sp??as??
    ? d?a???? t??a?a? p??sp??as??) ?a? t?? t??p? p??
    ?? p???ap??? ??µß?? p?? s??d???ta? st? µ?s?
    µet?d?s?? ap??t??? p??sßas? se a?t? ?ste ?a
    µetad?s??? ded?µ??a.
  • ?? ?p?st??µa e?????? p??sp??as?? st? µ?s?
    µet?d?s?? (MACMedium access control) e??a?
    ?pe????? ?a ?a????se? p???? ??e? se??? ?a
    µetad?se? ded?µ??a se ??a d?a??? p???ap???
    p??sp??as??. ??t? ep?t?????eta? µ?s? t??
    a?t?st????? p??t??????? t?? ?p?st??µat?? MAC.

4
  • St? p??t?p? OSI t? ?p?st??µa e??????
    p??sp??as?? st? µ?s? µet?d?s?? a???e? st? ??t?
    tµ?µa t?? ep?p?d?? ?e???? ded?µ????, a???ß?? p???
    ap? t? f?s??? ep?ped?. ?? a???ß?? a??te?? t??
    tµ?µa µ?sa st? ep?ped? ?e???? ded?µ????
    ???µ??eta? ep?ped? e?????? ??????? ?e????
    (LLCLogical Link Control) ?a? ?a t? e?et?s??µe
    st? ep?µe?? ?ef??a??.

5

6
???t???a ep?d?se?? st? ?p?-st??µa MAC
  • ??ape?at?t?ta (throughput) ???a? ? µ???st??
    ???µ?? µet?d?s?? bit ?ta? t? LAN e??a?
    ßa??f??t?µ??? µe p?????? ??µß???. ? d?ape?at?t?ta
    e??a? ??a p?s?st? t?? ta??t?ta? t?? p?µp??. ??t?
    t? p?s?st? ???µ??eta? ap?d?s? t?? p??t??????? MAC
    (?p?d?s? p??t??????? MAC e??a? t? µ???st? p?s?st?
    t?? ?????? p?? µp????? ?? ??µß?? ?a µetad?s???
    ep?t????, ?ta? ???s?µ?p????? t? p??t?????? ?a?
    ?ta? t? d??t?? e??a? p??? f??t?µ??? ?a? ??e?
    p?????? ??µß???)
  • ?ts? ??ape?at?t?ta ?p?d?s? ?a??t?ta
    p?µp??
  • ?.?. ??a d??t?? p?? ???s?µ?p??e? ??a
    p??t?????? MAC µe ap?d?s? 75 ?a? p?µp??? 1Mbps
    ??e? d?ape?at?t?ta ?s? µe 0.751Mbps 75 Mbps.
  • ?a??st???s? ?p?? ??e? ???ste? se p??????µe??
    ?ef??a?? e??a? ? µ?s?? ?????? ??a ?a µetad??e?
    ??a pa??t?.

7
?? p??ß??µa t?? e?????s?? t?? d?a????
  • ?p?? p??a?af?????e ? ????? t?? ?p?st??µat?? MAC
    e??a? ?a desµe?e? t? ????t???t?ta t?? d?a???? (?
    a????? ?a e????e? t?? d?a???) s?st? µeta?? t??
    s??de?µe??? ??µß??.
  • ??a? t??p?? e?????s?? d?a???? e??a? ?? te??????
    p???p?e??a FDM, TDM p?? e?daµe st? p??????µe??
    ?ef??a??. ?? te?????? a?t?? e??a? stat???? ?a?
    e??a? ???s?µe? µ??? ??a µ???? ?a? sta?e?? a???µ?
    ???st?? (d??. ??µß??) ?a? µe???? ?????f???a??
    f??t?.
  • ??t??eta, ?ta? ? a???µ?? t?? ???st?? e??a?
    µe????? ?a? d?a???? µetaßa???µe??? ? ? ?????f???a
    ??e? µ??f? ?ata???sµ?? ??e?????ta? d??aµ????
    te?????? e?????s?? d?a????. ??t??e? e??a? ??
    te?????? p?? p??sf????? ta p??t?????a t??
    ?p?st??µat?? MAC.

8
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9
?? p??ß??µa t?? e?????s?? t?? d?a???? µe
pa?ade??µata
  • Te??e?ste t??ef????? d??s?e?? ?p??
  • ?ta? ??a? µ???e?, ???? ?? ????? µp????? ?a a????e
  • a? µ????? pe??ss?te??? ta?t?????a, ??e? ??
    ?µ???e? ?atast??f??ta?
  • ??? ?a s??t???s??? t?? e????e??? t??? ??
  • s?µµet????te?, ?ste
  • ?a µe??st?p??e?ta? ? a???µ?? t?? a?ta??ass?µe???
    µ???µ?t?? a?? sec
  • ?a e?a??st?p??e?ta? ? ?????? a?aµ???? ??a ?a
    µp??e? ??p???? ?a µ???se?

10
?e????? ap??? ??se?? ??a p???ap?? p??sßas? st?
µ?s?
  • ? s?ed?as? ?a??? s??µ?t?? p??sßas?? e??a?
    p??? d?s????. ??p??e? ??se?? e??a?
  • ???s? s??t???st? (?e?t???? ??s?)
  • ??a? sta?µ?? e??a? e?????? (master) ?a? ?? ?????
    e??a? e?e???µe??? (slaves).
  • ? ???e ?µ???t?? ?a p??pe? ?a pe??µ??e? ?a t??
    ?a??se? ? s??t???st??, a??µ? ?a? a? de? pe??µ??e?
    ?a?e?? ????? ?a µ???se?.
  • ?? ???eta? ?ta? ??pe? ? s??des? t?? s??t???st?
  • ?? f?se?? ?at?????a se µe????? pe??pt?se?? (p.?.
    wireless LAN, ?p?? ? sta?µ?? ß?s?? e??a? ? µ????
    sta?µ?? p?? t??? ß??pe? ????? ? sta ???e??t?
    s?st?µata, ?p?? ? sta?µ?? ß?s?? e??a? ? µ???? p??
    µp??e? ?a µetad?se? µe???? ?s??).
  • ?ata?eµ?µ??? ??s?
  • ????e? ??p???? ?ta? de? µ???e? ?a?e?? ?????.
  • ????, e?? d?? ?µ???t?? pe??µ????? ??p???? t??t?
    ?a te?e??se?, ?a ???e? s??????s?.
  • ?e??ss?te?? a???p?sta.
  • ????? µ????te?e? ?a??ste??se?? µ???µ?t??.
  • S???? ep?t??p??? ?????te?? ???s?µ?p???s? d??t???.
  • ???a? p?? p???p???a.

11
?a?ad???? (1)
  • ?? d??aµ???? te?????? p???ap??? p??sßas??
    st? µ?s? p?? p??sf????? ta p??t?????a t??
    ?p?st??µat?? MAC ?a? ????? ?? st??? t??
    ??a??p???s? t?? ???t????? ep?d?s?? (d??. t?
    µe??st?p???s? t?? d???e?s?? µ???µ?t?? ?a? t??
    e?a??st?p???s? t?? µ?s?? ?????? a?aµ????) ?????
    ßas?ste? st?? e??? pa?ad????
  • ?? s?st?µa ap?te?e?ta? ap? ??a p????? n
    a?e???t?t?? ??µß?? ep????????a?, ?a???a? ap? t???
    ?p????? d?µ?????e? pa??ta ??a µet?d?s?. ?a pa??ta
    d?µ????????ta? µe sta?e?? ???µ? ? se ????? t. ?
    ??µß?? p?? ??e? d?µ??????se? ??a pa??t? e??a?
    desµe?µ????, d??ad? µ???? ?a ap?sta?e? t? pa??t?
    as???e?ta? µ??? µe a?t? ?a? de µp??e? ?a ???e?
    ?aµ?a ???? e??as?a.
  • ? µ??ad???? t??p?? ep????????a? t?? ??µß?? e??a?
    µ?sa ap? t?? ????? d?a???.
  • ?? d?? ? pe??ss?te??? ??µß?? µetad?s???
    ta?t?????a pa??ta a?t? ep??a??pt??ta? ?a?
    ?atast??f??ta?. ??t? ???µ??eta? s??????s?. ?a
    s???????µe?a pa??ta µp????? ?a µetad????? ?a??
    ??p??a ???? ??????? st??µ?.

12
?a?ad???? (2)
  • ?s?? af??? t? ????? st?? ?p??? µp??e? ?a
    ?e????se? ? µet?d?s? e??? pa??t?? ap? ??p????
    ??µß? d?a??????µe d?? pe??pt?se??
  • ?a ???e? ?p??ad?p?te ??????? st??µ?
  • ? ????a? t?? ?????? ?????eta? se ?a????sµ??a
    ??????? d?ast?µata p?? ???µ????ta? ?????????de?.
    ? ??a??? t?? µet?d?s?? e??? pa??t?? ep?t??peta?
    µ??? st?? a??? ??p??a? ?????????da?.
  • ?? ??µß?? µp??e? (a) ?a e??a? se ??s? ?a
    a????e???? a? ? d?a???? e??a? desµe?µ???? ap?
    ??p???? ???? ??µß?, ?p?te ?a µ?? p???????? ?a?
    e?e???? se µet?d?s?, ?e????? p?? ?a p???a???se
    s??????s?, ?a? ?a pe??µ????? ?a ade??se? ?
    d?a???? p??? ep??e???s??? t? µet?d?s? ? (ß) ?a
    µ?? e??a? se ??s? ?a a????e???? e? t?? p??t????
    a? t? ?a???? e??a? apas????µ???, ?p?te ? ep?t???a
    ? ? ap?t???a t?? µet?d?s?? ?a ???eta? a?t???pt?
    a???te?a.

13
???t?????a p???ap??? p??sßas??
  • St? s????e?a ?a e?et?s??µe ???sµ??a
    p??t?????a p???ap??? p??sßas??. O? p??t??????
    p???ap??? p??sßas?? ??????µe t?? ?ata?eµ?µ???
    a??????µ? p?? ?a?????e? p?? ?a µ???????ta? ??
    sta?µ?? t?? d?a???, d??. p?te µp??e? ?a µetad?se?
    ???e sta?µ??. ? ep????????a ??a t? ???s? t??
    µ?s?? ???s?µ?p??e? t? ?d?? t? µ?s?.
  • ???s??? ?a???a p??t?????? t?? ?p?st??µat??
    MAC de? e????ta? a???p?st? pa??d?s?, a??µa ?a?
    ap??s?a s??????se??.
  • ?p?????? t?e?? µe???e? ?at?????e?
    p??t??????? p???ap??? p??sßas??
  • ?p?µe????µe??? µ?s??
  • ?? µ?s? d?a??e?ta? se µ????te?a µ???
    (?????s??sµ??, s????t?te?).
  • ?????e?ta? ??a µ???? se ???e ??µß? ??a
    ap???e?st??? ???s?.
  • ????????? ap?te?esµat??? t?? d?a??? se ?????
    f??t??.
  • ???a? a?ap?te?esµat??? se ?aµ??? f??t??
    ?a??st???s? st?? p??sßas?, e????e?ta? t? 1/N t??
    e????? ????? a??µ? ?a? a? e??a? ??a? ??µß??
    e?e????
  • ???a?a? p??sßas??
  • ?p?t??pe? s??????se??.
  • ?p???e? t??p?? ep???s?? t?? s??????se??.
  • ?a?? ap?d?s? se ?aµ??? f??t?? ??a? ??µß?? µp??e?
    ?a ???s?µ?p??e? p????? t?? d?a???.
  • ????? f??t?? p?e??asµ?? ???? s??????se??.
  • ??????s?? se????
  • S??t?????µe?? ????? p??sßas? ??a ap?f???
    s??????se??.
  • ?p?d?????? ta ?a??te?a ap? t?? d?? ???e?
    ?at?????e?.

14
1. ?? p??t?????? ALOHA
  • ?p?te?e? ??a s?st?µa as??µat?? µet?d?s?? pa??t??.
    ?? ap???ste?? a??? ?a? pa?a??te??.
    ???s?µ?p??e?ta? ?a? se d???f????? d??t?a.
  • ?ta? ??a? sta?µ?? ??e? pa??t?, t? µetad?de?.
  • ? sta?µ?? a???e? (??a µ???st? ????? µet?ßas?? ?a?
    ep?st??f?? ? ?p???? ???µ??eta? round-trip, ?s?
    d??ad? ?a ??a?e t? pa??t? ?a ft?se? st??
    p?????sµ? ?a? ?a ep?st???e? ap? t?? p?????sµ? ?
    ep?ßeßa??s? ?????).
  • ?? ???e? ep?ßeßa??s? ????? (Acknowledgement ACK),
    e?t??e?. ?? ???, epa?aµetad?de? t? pa??t? ??at?
    ?ata?aßa??e? ?t? ?p???e p??ß??µa. (d??.
    ?ata?aßa??e? e? t?? ?st???? ?t? ?p???e p??ß??µa)
  • ?? t? p?a?s?? e??a? s?st? ?a? ta?????e? ?
    d?e????s? t?? µe t?? d??t?, st???eta? ACK.
  • ?? de? sta?e? ACK µet? ap? p?????
    epa?aµetad?se??, e??ata?e?pe?.
  • ?? p?a?s?? µp??e? ?a ?atast?afe? ap? ????ß? ? ap?
    ???? sta?µ? p?? e?p?µpe? t?? ?d?a st??µ?
    (s??????s?).
  • ?p??ad?p?te ep??a??pt?µe?a p?a?s?a p???a????
    s??????s?.

15
  • ? µ???st?? ???µ?? d???e?s?? p?? µp??e? ?a
    ep?te???e? µe t? p??t?????? ALOHA e??a? 18 t??
    s??????? p??sfe??µe??? ?????f???a?. ??a ße?t??s?
    p?? d?µ?????????e e??a? t? ALOHA µe s??sµ??.

16
ALOHA µe s??sµ??
  • ? ?????? d?a??e?ta? se ?µ??e? ?????s??sµ??, ?se?
    µe t? ????? µet?d?s?? p?a?s???.
  • ? a????? ?pa???? ?e?t????? ???????? (? ?????
    µ??a??sµ?? s???????sµ??) ap?te?e? µe?????t?µa.
  • ? ??µß?? p?? ??e? pa??t? ?a ste??e?, t? st???e?
    st?? a??? t?? ep?µe??? ?????s??sµ??.
  • ?? ???e? s??????s? epa?aµetad?de? t? pa??t? µe
    p??a??t?ta p, µ???? ?a t? pet??e?.
  • St? t? ALOHA µe s??sµ?? ? µ???st?? ???µ??
    d???e?s?? p?? µp??e? ?a ep?te???e? e??a? s?ed??
    d?p??s??? ap? ?t? st? as???????st? ALOHA, d??ad?
    pe??p?? 37 t?? ep??e????µe??? µetad?se??.

17
2. ?? p??t?????? Carrier Sense Multiple Access
(CSMA)
  • Teµe???d?? a??? ??e??e ?at? p?s? t? µ?s?
    µet?d?s?? e??a? apas????µ??? p??? ste??e?? pa??t?
    (p.?. a????e???ta? t? f????).
  • Ste??e ??a pa??t? µ???? ape?e??e???e? t? µ?s?.
  • ?? ?at? t?? a????e?s?, t? µ?s? ß?e?e?
    ?ate???µµ???, pe??µe?e ?a e?e??e???e? ?a?
    ste??e-gt persistent.
  • ?? ?at? t?? a????e?s?, t? µ?s? ß?e?e?
    ?ate???µµ???, ß??e ?????µet?? ?a? d???µase
    a???te?a -gt non-persistent.
  • ???ß??µa µe t? persistent d?? sta?µ?? p??
    pe??µ????? ?a s??????s????.

18
CSMA (s????e?a)
  • ? ?????? d??d?s?? e??a? p??? µ????te??? ap? t??
    ????? µet?d?s??.
  • ???? ?? sta?µ?? ?????? s?ed?? aµ?s?? ?t? ????se
    ??p??a µet?d?s?.
  • ???ta a???? ??a e?e??e?? µ?s? (a????e?s?
    f????t??).
  • ?? t? µ?s? e??a? e?e??e??, µetad?d???.
  • ?? d?? sta?µ?? a??????? t?? ?d?a st??µ?,
    s????????ta?.
  • ?e??µ????? e????? d??st?µa (round trip s??
    a?ta????sµ? ??a µet?d?s? ACKep?ßeßa??s?).
  • ?? de? ?p???e? ACK, t?te a?aµetad?d???.
  • ? µ???st? ap?d?s? e?a?t?ta? ap? t?? ?????
    d??d?s?? (µ???? µ?s??) ?a? t? µ???? p?a?s???
  • ?a???te?? p?a?s?? ?a? ß?a??te??? ?????? d??d?s??
    d????? ?a??te?? ap?d?s?

19
CSMA t??a?a? p??sßas??
20
CSMA/CD
  • ?p?te?e? t? p??t?p? IEEE 802.3.
  • ?e t? CSMA, ? s??????s? ?ata?aµß??e? t? µ?s??
    ?at? t? d????e?a t?? µet?d?s??.
  • ?? CSMA/CD (Carrier Sense Multiple Access/
    Collision Detection) e??a? ße?t??s? t?? CSMA.
  • ? ße?t??s? a?t? ep?t?????eta? ?? e??? ?? sta?µ??
    a????/a????e???? t? µ?s? e?? µetad?d???. ?ta?
    a????e?s??? s??????s? staµat??? aµ?s?? t?
    µet?d?s?. ?e t?? t??p? a?t? e???????µe?ta? ??????
    ?a? e???? ?????.
  • ?? t? µ?s? e??a? e?e??e?? µetad?d???.
  • ??? ???, pe??µ????? ??a e?e??e?? ?a? ?ste?a
    µetad?d???.
  • ?? d?ap?st??e? s??????s?, t?te staµat??? t?
    µet?d?s? ?a? st?????? s?µa s???st?sµ?? (jam
    signal 32-48 bit).
  • ?et? t? s??????s?, pe??µ????? t??a?? ???????
    d??st?µa ?a? ?a?a???????.

21
CSMA/CD - S??µat???
22
??d???p???s? Manchester
  • ?aµ?a ap? t?? pa?a??a??? t?? p??t?p?? ???? 802.3
    de? ???s?µ?p??e? ?µes? d?ad??? ??d???p???s? ?p??
    t? 0 µetad?deta? ?? s?µa 0 Volt ?a? t? 1 ?? s?µa
    5 Volt ?a? a?t? ??at? ?a ?d????µasta? se as?fe?e?
    (p.?. s??????s? d?? µ?de????? d??. d?? s?µ?t?? 0
    Volt de ?a µp????se ?a ???e? a?t???pt?).
  • ??t? p?? ???s?µ?p??e?ta? s?????? e??a? ?
    ??d???p???s? Manchester. Se a?t? ? d????e?a ???e
    bit ?????eta? se d?? ?sa d?ast?µata. ?? d?ad???
    bit 1 st???eta? µe t? ?a te?e? ? t?s? se ?????
    st??µ? st? p??t? d??st?µa ?a? se ?aµ??? st??µ?
    st? de?te?? d??st?µa. ?? a?t??et? s?µßa??e? ??a
    ?a sta?e? t? d?ad??? bit 0 (st? p??t? d??st?µa
    ?aµ??? st??µ? ?a? st? de?te?? d??st?µa ?????
    st??µ?).

23
??µ? p?a?s??? t?? p??t??????? 802.3 ??a t?
?p?st??µa MAC
24
????????s?
  • ?a??? ta ?a?a?? ded?µ??a (p?? pe??????? t?? p???
    µet?d?s? p????f???a) p???????? ap? t? ep?ped?
    efa?µ???? p??? t? f?s??? ep?ped?, ???? t???
    p??st??e?ta? ep?p???? ded?µ??a (p?? af?????
    e?d???? p????f???e? ???s?µe? se ???e ep?ped?). ?
    d?ad??as?a a?t? ???µ??eta? e???????s? ?a? e??a?
    apa?a?t?t? ?ste ?a ???p??????? ?? ?p??es?e? t??
    ???e ep?p?d??. ? e???????s? fa??eta? ?a? st??
    p??????µe?? d?af??e?a ?p?? sta ded?µ??a p?? ?????
    ft?se? ap? t? ep?ped? efa?µ???? (st? s??µa
    s?µß??????ta? ?? LLC frame) ????? p??ste?e?
    ep?p???? byte ap? t? ?p?-ep?ped? MAC.

25
3. Ethernet
  • ?? Ethernet ap?te?e? µ?a ?µ?da s???e???µ????
    ???p???se?? t?? p??t?p?? IEE? 802.3 (CSMA/CD) µe
    s???e???µ????? t?p??? ?a??d??? ?a? ep?d?se??.
    ???a? d??ad? ??a s???e???µ??? p????? p?? ???p??e?
    t? p??t?p? IEE? 802.3.
  • St?? ep?µe?? p??a?a fa????ta? ?? d??f??e?
    pe??pt?se?? Ethernet. St? s?µß???sµ? xBase/Broad
    y ta s?µß??a ?p?d??????? ta e???
  • x? ta??t?ta µet?d?s?? t?? ded?µ???? se Mbps.
  • Base/Broad? t?p?? t?? s?µat?d?s?a? p??
    ???s?µ?p??e?ta?
  • yt? µ???st? µ???? t?? tµ?µat?? (se e?at??t?de?
    m).
  • ?.?. t? 10Base5 s?µa??e? ?t? ?e?t????e? sta
    10Mbps, ???s?µ?p??e? s?µat?d?t?s? ßas???? ?????
    ?a? µp??e? ?a ?p?st????e? tµ?µata µ????? µ????
    ?a? 500m.

26
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27
Ethernet 10Base T
  • ?a p??ß??µata p?? s?et????ta? µe t?? e?t?p?sµ?
    t?? d?a??p?? t?? ?a??d??? Ethernet, ?d???sa? se
    d?af??et??? s?ed?as? t?? ?a??d??s??. ?ts?
    p??????e t? Ethernet 10Base T.
  • ???? ?? sta?µ?? s??d???ta? µe ?a??d?? (s??????
    t??ef?????) st?? a?t????? epa?a??pt? ?
    p??µ??(hub).
  • ? s?ed?as? a?t? ???µ??eta? 10BaseT (t? ? s?µa??e?
    twisted pair).
  • ? ap?stas? t?? ??µß?? ap? t? hub de? ?pe?ßa??e?
    ta 100m.

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?a?? Ethernet(100Mbps)
  • ???t?p? ???? 802.3u.
  • ?e? e??a? ??? p??t?p? a??? p??s???? st? ?p?????
    p??t?p? 802.3.
  • ???? t? ap??a???? ta?? Ethernet.
  • ?as??? ?d?a
  • ??at???s? t?? µ??f?? t?? pa??t??
  • ??at???s? t?? CSMA/CD
  • ?e??s? t?? d????e?a? t?? bit ap? 100 nsec se 10
    nsec
  • ???s?µ?p??e?ta? ?a??d??s? 10Base-? (de?
    ???s?µ?p?????ta? 10Base5 ?10Base2)
  • ?e????????ta? ta µ??? ap ???? s ????
    (ep????te?a s??????se??) ??a ?a d?at??e?ta? ?
    ?a??????p???µ??? ?a??st???s? d??d?s?? µ????.
  • 100BaseT4
  • 4 d?p?a????? cat 3.
  • ??a? d?p?a?????p??? t? hub, ??a? ap? a?t? ?a? ??
    ????? d?? ????? t? d??at?t?ta ?a µeta????? p???
    t?? t?????sa ?ate????s? µet?d?s??.
  • 100BaseTX
  • 2 d?p?a????? STP ? 2 d?p?a?????UTP Cat 5.
  • ??a? d?p?a????? p??? t? hub ?a? ??a? ap? a?t?.
  • ?????? aµf?d??µ? s?st?µa.
  • ?p?stas? µeta?? sta?µ?? ?a? hub100 m.
  • 100BaseFX

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Gigabit Ethernet
  • ???t?p? IEEE 802.3z.
  • ???s?µ?p??e? µ?a ße?t??µ??? e?d??? t?? CSMA/CD.
  • ???a p??? ?a?? ep?d?s?, ???s?µ?p??e? aµf?d??µe?
    s??d?se?? ?a? µeta????a Ethernet.
  • ?p????te?a s??????se?? ?d?a µe t?? Fast Ethernet.
  • ??at??e? t? µ??f? p?a?s??? Ethernet.
  • ?p?t??pe? ?e??e?? s?µe??? p??? s?µe?? ?a?
    d?a????? e?p?µp??.
  • St?? pe??pt?s? ?????? d?a????, ???s?µ?p??e?ta?
    CSMA/CD. ?? ap?st?se?? µeta?? t?? ??µß?? e??a?
    µ????? ??a ?a ??e? ?a?? ep?d?s?.
  • ???s?µ?p??e? hub.
  • ?µf?d??µ? st? 1 Gbps ??a ?e??e?? s?µe??? p???
    s?µe??.
  • ?p???e? t??a ?a? Ethernet 10Gbps.

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Gigabit Ethernet F?s??? st??µa
  • 1000Base-SX
  • ????? µ???? ??µat??, p???t??p? ??a
  • 1000Base-LX
  • ?e???? µ???? ??µat??, p???t??p? ? µ???t??p? ??a
  • 1000Base-CX
  • ??????e? s??d?se??lt25m, ???a??sµ???? d?p?a?????
  • 1000Base-T
  • 4 ?e???, ?at?????a? 5 UTP

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4. Token bus (??t???a µe ???p???)
  • ? a????? p??t?p? IEEE 802.4.
  • ??a µ???? p?a?s?? (s??t???) ?????f??e? ?ta? de?
    µetad?de? ?a?e??.
  • ? sta?µ?? p?? ??e? ded?µ??a ?a µetad?se?
    pe??µ??e? t? s??t???. ???? ? sta?µ?? p??
    ?ata?aµß??e? t? s??t??? ??e? d??a??µa ?a
    p??????se? se µet?d?s?.
  • S??????se?? de s?µßa????? ?a??? ???e f???
    µetad?de? µ??? ? sta?µ?? p?? ??e? t? s??t???.
  • ?? sta?µ?? ß??s???ta? s??dedeµ???? se t?p?????a
    f?s???? a?t???a?, ?ste ??p??? p??ß??µa st?
    ?a??d?? ?a µ?? a???ste?e? ??? t?? t?p?????a.
  • ?µ??, ? µet?d?s? t?? s??t???? (? a????? ???p???
    d???e?s??) ?a? t?? ded?µ???? ???eta? se ???t?
    da?t????. ???ad?, se ???e ??µß? a?t?st?????eta?
    ??a? a???µ??/d?e????s?. ? ??µß?? µe t?? ?????te??
    a???µ?s? ?ata?aµß??e? p??t?? t? s??t???. St?
    s????e?a ? s??t??? ?a p?e? µe t? se??? st??
    a???ß?? ep?µe?? ??µß? d??. st?? ??µß? µe t??
    ep?µe?? d?e????s? ??p.

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Token bus(s????e?a)
  • ? ???e ??µß?? µp??e? ?a ??at?se? t? s??t??? ?a?
    s??ep?? ?a µetad?se? ded?µ??a ??a ??a µ???st?
    ??????? d??st?µa.
  • ?ta? ??p???? ??µß?? de? ??e? ded?µ??a ?a
    µetad?se? ? µetad?se? ??a t?? ta ded?µ??a e?t??
    t?? ep?t?ep?µe??? ?????? ? ???e? ? µ???st??
    ?????? µ?sa st?? ?p??? µp??e? ?a µetad?se?, t?te
    d??e? t? ???p??? st?? ep?µe?? ??µß? st? ???t?
    da?t????.
  • ? µet?d?s? t?? ded?µ???? e??? ??µß?? ???eta? µe
    ß?s? t?? es?te???? p??te?a??t?ta st?? ?d?? t??
    ??µß?.

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3. Token ring (?a?t????? µe ???p???)
  • ? a????? p??t?p? IEEE 802.5.
  • Sta p??t?pa µe s??t??? de? pa?a??????e?ta?
    d?a???? t? µ?s? ?a??? de s?µßa????? s??????se??.
  • ??a µ???? p?a?s?? (s??t???) ?????f??e? ?ta? de?
    µetad?de? ?a?e??.
  • ? sta?µ?? p?? ??e? ded?µ??a ?a µetad?se?
    pe??µ??e? t? s??t???. ???? ? sta?µ?? p??
    ?ata?aµß??e? t? s??t??? ??e? d??a??µa ?a
    p??????se? se µet?d?s?. G?a ?a ?ata??ße? t??
    s??t??? t?? a????e? ??a bit.
  • ?ta? ??a? sta?µ?? ap??t?se? t?? s??t??? t??
    ap?µa????e? ap? t? da?t???? ?a? p??sa?t? ta p???
    µet?d?s? ded?µ??a t??. ?e? ?p???e? pe?????sµ??
    ??a t? µ??e??? t?? ded?µ???? p?? ap?st?????ta?
    ??te ?a? st? ?????.
  • ?? p?a?s?? ???e? t?? ????? t?? da?t????? ?a? ?
    ?at??????? p?????sµ??, d?aß????ta? t? d?e????s?
    t??, ?aµß??e? ta ded?µ??a. ? s??t??? µe ta
    e?s?µat?µ??a ded?µ??a s??e???e? t?? ????? ?a?
    ?ta? ep?st???e? st?? sta?µ? p?? µet?d?se
    ap?s??eta? ap? a?t??.
  • St? s????e?a ? sta?µ?? e?s??e? ??a s??t??? ?????
    ded?µ??a ?ste ?a µetad?se? ??p???? ????? sta?µ??.
  • ?p?d?s? p??t??????? token ring
  • ?e µ???? f??t??, µ???? ap?d?s?
  • ?e ßa?? f??t??, ??????? a???es?

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Token ring - ?e?t?????a
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5.FDDI (Fiber Distributed Data Interface)
  • ????e? sta LAN ?????? ta??t?t?? ???a? ??a ??????
    ep?d?s?? t?p??? d??t?? da?t????? µe s??t??? p??
    ?e?t????e? sta 100Mbps se ap?st?se?? µ???? 200km
    ?a? ????ta? µ???? 1000 sta?µ??? s??dedeµ?????.
    ???s?µ?p??e? p???t??pe? ?pt???? ??e? ?? µ?s?
    µet?d?s??.
  • ?e?t????e? ?p?? ?a? t? 802.5 µe t?? e??? d?af???
    ?et? t?? ?at????? t?? s??t????, ??a ? pe??ss?te?a
    p?a?s?a ded?µ???? ap?st?????ta?. ?e ??e???eta?,
    ?µ??, ?a pe??µ??e? ? ??µß?? ?a ep?st???e? t?
    p?a?s?? ??a ?a a?aµetad?se? t? s??t??? a???
    µp??e? ?a d?µ??????se? µ?a ??a s??t??? aµ?s??
    µ???? ste??e? ta ded?µ??a t??. ?ts?, se µe??????
    da?t?????? µp????? ?a ?????f????? ta?t?????a
    p???? pa??ta.
  • ?fa?µ??e? p??te?a??t?ta ded?µ????, ?p?? t? 802.4.
  • ?p?te?e?ta? ap? d?? ?pt????? da?t?????? ? ??a?
    µetad?de? µe t? f??? t?? de??t?? t?? ???????? ?a?
    ? ????? a?t?st??fa.

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FDDI ?e?t?????a
41
????f????? ???t?a
  • ??a e?d?? WAN ???s?µ?p??e? ????? µ?s? µet?d?s??
    ?a? ??? s?µe?? p??? s?µe?? ?e??? ta ????f?????
    ???t?a.
  • ?? ep??e??? sta?µ?? p??pe? ?a µ???ast??? t??
    d?a??? a??d?? ?ste ?a ste????? ded?µ??a se
    ??p???? ap? t??? a?aµetad?te? t?? d???f????.
  • ???t?????a µe a????e?s? f????t?? de µp????? ?a
    efa?µ?st??? sta ????f????? ???t?a ?a??? ???? t??
    ?a??st???s?? d??d?s?? t?? 270msec a?t? p?? a???e?
    ??p???? sta?µ?? e??a? a?t? p?? s???ßa??e p??? ap?
    270msec.
  • ???te ?at?????e? p??t??????? ???s?µ?p?????ta? sta
    ????f????? ???t?a
  • ????d?s??p?s?
  • ALOHA
  • FDM
  • TDM
  • CDMA
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