{"id":866,"date":"2019-10-19T17:22:54","date_gmt":"2019-10-19T09:22:54","guid":{"rendered":"http:\/\/149.129.74.185\/?p=866"},"modified":"2019-10-19T17:22:54","modified_gmt":"2019-10-19T09:22:54","slug":"%e8%ae%a1%e7%ae%97%e6%9c%ba%e7%bd%91%e7%bb%9c%e7%ac%ac%e5%9b%9b%e7%ab%a0%e4%bd%9c%e4%b8%9a","status":"publish","type":"post","link":"http:\/\/www.magicmipamipa.com\/?p=866","title":{"rendered":"\u8ba1\u7b97\u673a\u7f51\u7edc\u7b2c\u56db\u7ae0\u4f5c\u4e1a"},"content":{"rendered":"

ch4-2. A group of N stations share a 56-kbps pure ALOHA channel. Each station outputs a 1000-bit frame on an average of once every 100 sec, even if the previous one has not yet been sent (e.g., the stations can buffer outgoing frames). What is the maximum value of N?<\/span><\/p>\n

<\/p>\n

\n

Q.<\/b>\u00a0What is the baud rate of the standard 10-Mbps Ethernet?<\/span>
\nA.<\/b>\u00a0<\/span>\u00a0Mbaud<\/span><\/p>\n

<\/p>\n

\n

Q.\u00a0<\/span><\/b>Consider building a CSMA\/CD network running at 10 Mbps over a 1-km cable with no repeaters. The signal speed in the cable is 200,000 km\/sec. What is the minimum frame size?<\/span>
\nA.\u00a0<\/span><\/b><\/span>\u00a0bits<\/span><\/p>\n

<\/p>\n

\n
The reason for binary exponential backoff in the classical Ethernet is that________<\/div>\n
\n
    \n
  • this algorithm is simple<\/li>\n
  • this algorithm is fast<\/li>\n
  • this algorithm is adaptive to network load<\/li>\n
  • this algorithm is scalable to network size<\/li>\n<\/ul>\n

    maybe c<\/p>\n

    \n
    When binary exponential backoff is used, a random number between 0 and ________ is chosen and that number of slots is skipped<\/div>\n
    \n
      \n
    • 511<\/li>\n
    • 1023<\/li>\n
    • 2047<\/li>\n
    • 4095<\/li>\n<\/ul>\n<\/div>\n
      \n

      Box 1: Select the best answer<\/p>\n

      maybe 1023<\/p>\n

      \n
      \u7f51\u7edc\u63a5\u53e3\u5361\u4e3b\u8981\u5728________\u5c42\u5de5\u4f5c<\/span><\/div>\n
      \n
        \n
      • \u7269\u7406\u548c\u6570\u636e\u94fe\u63a5<\/span><\/li>\n
      • \u6570\u636e\u94fe\u63a5\u548c\u7f51\u7edc<\/span><\/li>\n
      • \u7269\u7406\u548c\u7f51\u7edc<\/span><\/li>\n
      • \u6570\u636e\u94fe\u63a5\u548c\u4f20\u8f93<\/span><\/li>\n<\/ul>\n<\/div>\n
        \n

        \u65b9\u68461\uff1a\u9009\u62e9\u6700\u4f73\u7b54\u6848<\/span><\/p>\n

        A<\/p>\n

         <\/p>\n

        \n
        \u6865\u63a5\u5668\u63d0\u4f9b\u7684\u91cd\u8981\u529f\u80fd\u4e4b\u4e00\u4e0d\u662f\uff1f<\/span><\/div>\n
        \n
          \n
        • \u51cf\u5c11\u78b0\u649e\u57df<\/span><\/li>\n
        • \u589e\u52a0\u6570\u636e\u901f\u7387<\/span><\/li>\n
        • \u589e\u52a0\u57df\u7684\u957f\u5ea6<\/span><\/li>\n
        • \u51cf\u5c11\u5e7f\u64ad\u57df<\/span><\/li>\n<\/ul>\n<\/div>\n
          \n

          \u65b9\u68461\uff1a\u9009\u62e9\u6700\u4f73\u7b54\u6848<\/span><\/p>\n

          B<\/p>\n

          \n
          There is a 10 Mbps Ethernet switch with 10 ports each of which is connected to a single computer. Then every computer\u2019s data rate is ________Mbps.<\/div>\n
          \n
            \n
          • 1<\/li>\n
          • 2<\/li>\n
          • 10<\/li>\n
          • 100<\/li>\n<\/ul>\n<\/div>\n
            \n

            Box 1: Select the best answer<\/p>\n

            10<\/p>\n

            \n
            ________ work at the physical layer while ________ work at the data link layer.<\/div>\n
            \n
              \n
            • Hubs, routers<\/li>\n
            • Hubs, switches<\/li>\n
            • Bridges, routers<\/li>\n
            • Repeaters, hubs<\/li>\n<\/ul>\n<\/div>\n
              \n

              Box 1: Select the best answer<\/p>\n

              ________\u5728\u7269\u7406\u5c42\u5de5\u4f5c\uff0c\u800c________\u5728\u6570\u636e\u94fe\u8def\u5c42\u5de5\u4f5c\u3002<\/span><\/div>\n
              \n
                \n
              • \u96c6\u7ebf\u5668\uff0c\u8def\u7531\u5668<\/span><\/li>\n
              • \u96c6\u7ebf\u5668\uff0c\u4ea4\u6362\u673a<\/span><\/li>\n
              • \u6865\u63a5\u5668\uff0c\u8def\u7531\u5668<\/span><\/li>\n
              • \u4e2d\u7ee7\u5668\uff0c\u96c6\u7ebf\u5668<\/span><\/li>\n<\/ul>\n<\/div>\n
                \n

                \u65b9\u68461\uff1a\u9009\u62e9\u6700\u4f73\u7b54\u6848<\/span><\/p>\n

                A<\/p>\n

                \n
                What kind of media used by 1000Base-F network?<\/div>\n
                \n
                  \n
                • Coaxial Cable<\/li>\n
                • Twisted Pairs<\/li>\n
                • Fiber Optics<\/li>\n
                • Power Lines<\/li>\n<\/ul>\n<\/div>\n
                  \n

                  Box 1: Select the best answer<\/p>\n

                  C<\/p>\n

                  \n

                   <\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

                  ch4-2. A group of N stations share a 56-kbps pure […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[19,16],"tags":[],"_links":{"self":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/866"}],"collection":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=866"}],"version-history":[{"count":1,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/866\/revisions"}],"predecessor-version":[{"id":869,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/866\/revisions\/869"}],"wp:attachment":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=866"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=866"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}