{"id":500,"date":"2008-02-15T02:23:51","date_gmt":"2008-02-15T02:23:51","guid":{"rendered":"http:\/\/pchero21.com\/?p=500"},"modified":"2008-02-15T02:23:51","modified_gmt":"2008-02-15T02:23:51","slug":"ns-tutorial-vii-ping-protocol-%ec%a0%9c%ec%9e%91%ec%8b%9c-%eb%ac%b8%ec%a0%9c%ec%a0%90","status":"publish","type":"post","link":"http:\/\/pchero21.com\/?p=500","title":{"rendered":"NS Tutorial VII – Ping protocol \uc81c\uc791\uc2dc \ubb38\uc81c\uc810"},"content":{"rendered":"

 NS Tutorial VII. A new protocol for ns \uc139\uc158\uc744 \uadf8\ub300\ub85c \ub530\ub77c\ud558\uba74 \ubb38\uc81c\uc810\uc774 \ubc1c\uc0dd\ud55c\ub2e4.<\/p>\n

 \uc544\ub9c8\ub3c4…Tutorial\uc744 \uc4f4 \uc2dc\uc810\uc774\ub791 \uc9c0\uae08\uc758 ns2 \ubc84\uc804\uc774\ub791 \ub9de\uc9c0 \uc54a\uc544\uc11c \uc0dd\uae30\ub294 \ubb38\uc81c\uc778 \uac83 \uac19\ub2e4.<\/p>\n

 ping.cc \uc640 ping.h \uc744 \ub098\ub984\ub300\ub85c \ubc14\uafd4\ubcf4\uc558\ub2e4.<\/p>\n

 \uc774\ub984\ub9cc \ubc14\uafb8\uc5c8\uace0 \ub098\uba38\uc9c0 \ubd80\ubd84\uc740 \ubaa8\ub450 ping.cc, ping.h\uc640 \ub3d9\uc77c\ud558\ub2e4.<\/p>\n

 \uc8fc\uc758\ud574\uc11c \ubcfc \ubd80\ubd80\uc740 <\/p>\n

hdr_ip* hdrip = hdr_ip::access(pkt);<\/p>\n

hdr_pong* hdr = hdr_pong::access(pkt);<\/p><\/blockquote>\n

\ubd80\ubd84\uc774\ub2e4. <\/p>\n

\npong.h<\/span> (Language : c)<\/span><\/legend>\n
    \n
  1. \n
     <\/div>\n<\/li>\n
  2. \n
    #ifndef ns_pong_h<\/span><\/div>\n<\/li>\n
  3. \n
    #define ns_pong_h<\/span><\/div>\n<\/li>\n
  4. \n
     <\/div>\n<\/li>\n
  5. \n
    #include “agent.h”<\/span><\/div>\n<\/li>\n
  6. \n
    #include “tclcl.h”<\/span><\/div>\n<\/li>\n
  7. \n
    #include “packet.h”<\/span><\/div>\n<\/li>\n
  8. \n
    #include “address.h”<\/span><\/div>\n<\/li>\n
  9. \n
    #include “ip.h”<\/span><\/div>\n<\/li>\n
  10. \n
     <\/div>\n<\/li>\n
  11. \n
    \/\/ pong header\uc758 \uad6c\uc870\ub97c \uc120\uc5b8<\/span><\/div>\n<\/li>\n
  12. \n
    \/\/ ret : \ubcf4\ub0b4\ub294 \uac83(0)\uc778\uc9c0 \ubc1b\ub294 \uac83(1)\uc778\uc9c0\ub97c \uad6c\ubd84\ud558\uae30 \uc704\ud55c \uc6a9\ub3c4\ub85c \uc0ac\uc6a9\ub428.<\/span><\/div>\n<\/li>\n
  13. \n
    \/\/ send_time : round-trip-time\uc744 \uad6c\ud558\uae30 \uc704\ud55c \uc6a9\ub3c4\ub85c \uc0ac\uc6a9\ub428.<\/span><\/div>\n<\/li>\n
  14. \n
    struct<\/span> hdr_pong {<\/span><\/div>\n<\/li>\n
  15. \n
        char<\/span> ret;<\/div>\n<\/li>\n
  16. \n
        double<\/span> send_time;<\/div>\n<\/li>\n
  17. \n
        <\/div>\n<\/li>\n
  18. \n
        \/\/ Header acces methods<\/span><\/div>\n<\/li>\n
  19. \n
        static<\/span> int<\/span> offset_; \/\/ required by PacketHeaderManager<\/span><\/div>\n<\/li>\n
  20. \n
        \/\/ inline \ud568\uc218\ub294 \ucc98\ub9ac \uc624\ubc84\ud5e4\ub4dc\ub97c \uac70\uc758 \uc5c6\uc560\ub294 \ubc29\ubc95\uc73c\ub85c \uc0ac\uc6a9\ub428.<\/span><\/div>\n<\/li>\n
  21. \n
        \/\/ compile\ub41c size\ub294 \ucee4\uc9c0\uc9c0\ub9cc \uc131\ub2a5\uc774 \ub192\uc544\uc9d0. \ub530\ub77c\uc11c \uac04\ub2e8\ud55c \ud568\uc218\ub294 inline\uc73c\ub85c \uc815\uc758\ud558\ub294 \uac83\uc774 \ud6a8\uc728\uc801\uc784<\/span><\/div>\n<\/li>\n
  22. \n
        inline<\/span> static<\/span> int& offset(<\/span>)<\/span> {<\/span> return<\/span> offset_; }<\/span><\/div>\n<\/li>\n
  23. \n
        inline<\/span> static<\/span> hdr_pong* access(<\/span>const<\/span> Packet* p)<\/span> {<\/span><\/div>\n<\/li>\n
  24. \n
            return<\/span> (<\/span>hdr_pong*)<\/span>p->access(<\/span>offset_)<\/span>;<\/div>\n<\/li>\n
  25. \n
        }<\/span><\/div>\n<\/li>\n
  26. \n
    }<\/span>;<\/div>\n<\/li>\n
  27. \n
     <\/div>\n<\/li>\n
  28. \n
    \/\/ Agent\ub97c \uc0c1\uc18d\ubc1b\uc544 PongAgent \uc0dd\uc131\uc790\uc640 \uc0ac\uc6a9\ub420 \uba54\uc18c\ub4dc\ub97c \uc120\uc5b8<\/span><\/div>\n<\/li>\n
  29. \n
    \/\/ PongAgnet() : \uc0dd\uc131\uc790<\/span><\/div>\n<\/li>\n
  30. \n
    \/\/ command() : sned\uc77c \ub54c \uc0ac\uc6a9\ub418\ub294 \uba54\uc18c\ub4dc<\/span><\/div>\n<\/li>\n
  31. \n
    \/\/ recv() : receive\uc77c \ub54c \uc0ac\uc6a9\ub418\ub294 \uba54\uc18c\ub4dc, \uc774\uac83\uc740 \uc790\ub3d9\uc73c\ub85c \ud638\ucd9c\ub428<\/span><\/div>\n<\/li>\n
  32. \n
    \/\/ off_pong_ : pong header\uc758 offset\uc744 \ub098\ud0c0\ub0b4\uae30 \uc704\ud574 \uc0ac\uc6a9\ub428.<\/span><\/div>\n<\/li>\n
  33. \n
    class PongAgent : public Agent {<\/span><\/div>\n<\/li>\n
  34. \n
    public:<\/div>\n<\/li>\n
  35. \n
        PongAgent(<\/span>)<\/span>;<\/div>\n<\/li>\n
  36. \n
        int<\/span> command(<\/span>int<\/span> argc, const<\/span> char<\/span>*const<\/span>* argv)<\/span>;<\/div>\n<\/li>\n
  37. \n
        void<\/span> recv(<\/span>Packet*, Handler*)<\/span>;<\/div>\n<\/li>\n
  38. \n
    }<\/span>;<\/div>\n<\/li>\n
  39. \n
     <\/div>\n<\/li>\n
  40. \n
    #endif<\/span><\/div>\n<\/li>\n<\/ol>\n<\/fieldset>\n

    <\/p>\n

    \npong.cc<\/span> (Language : c)<\/span><\/legend>\n
      \n
    1. \n
       <\/div>\n<\/li>\n
    2. \n
      #include “pong.h”<\/span><\/div>\n<\/li>\n
    3. \n
       <\/div>\n<\/li>\n
    4. \n
      int<\/span> hdr_pong::offset_<\/span>;<\/div>\n<\/li>\n
    5. \n
       <\/div>\n<\/li>\n
    6. \n
      \/\/ PacketHeaderClass\ub97c \uc0c1\uc18d\ubc1b\uc544 PongHeaderClass\ub97c \uc120\uc5b8<\/span><\/div>\n<\/li>\n
    7. \n
      \/\/ \uc774\ubbf8 \ub9ce\uc740 protocol header\ub4e4\uc774 PacketHeaderClass\ub97c \uc0c1\uc18d\ubc1b\uc544 \uc815\uc758\ub418\uc5b4 \uc788\ub2e4.<\/span><\/div>\n<\/li>\n
    8. \n
      \/\/ \ub3d9\uc77c\ud55c \ubc29\ubc95\uc73c\ub85c PacketHeader \uc544\ub798\uc5d0 Pong header\ub97c \ub454\ub2e4.<\/span><\/div>\n<\/li>\n
    9. \n
      \/\/ pong.h \uc5d0\uc11c \uc815\uc758\ud55c hdr_pong\uc758 offset\ub97c \uc5f0\uacb0\ud55c\ub2e4.<\/span><\/div>\n<\/li>\n
    10. \n
      static<\/span> class PongHeaderClass : public PacketHeaderClass {<\/span><\/div>\n<\/li>\n
    11. \n
      public:<\/div>\n<\/li>\n
    12. \n
          PongHeaderClass(<\/span>)<\/span> : PacketHeaderClass(<\/span>“PacketHeader\/Pong”<\/span>, sizeof<\/span>(<\/span>hdr_pong)<\/span>)<\/span> {<\/span><\/div>\n<\/li>\n
    13. \n
              bind_offset(<\/span>&hdr_pong::offset_<\/span>)<\/span>;<\/div>\n<\/li>\n
    14. \n
          }<\/span><\/div>\n<\/li>\n
    15. \n
      }<\/span> class_ponghdr;<\/div>\n<\/li>\n
    16. \n
       <\/div>\n<\/li>\n
    17. \n
      \/\/ TclClass\ub97c \uc0c1\uc18d\ubc1b\uc544 PongClass\ub97c \uc120\uc5b8<\/span><\/div>\n<\/li>\n
    18. \n
      \/\/ Agent \ud558\uc704\uc5d0 Pong\uc744 \ub450\uae30 \uc704\ud574 “Agent\/Pong”\uc744 \uc9c0\uc815<\/span><\/div>\n<\/li>\n
    19. \n
      \/\/ \uc774 \ubd80\ubd84\uc740 tcl \ud30c\uc77c\uc744 \uc791\uc131\ud560 \ub54c “set p0 [new Agent\/Pong]”\uc640 \uac19\uc774 \uc0ac\uc6a9\ub428<\/span><\/div>\n<\/li>\n
    20. \n
      \/\/ PongAgent\ub97c TclObject\ub85c \uc0dd\uc131\ud558\uc5ec \ubc18\ud658<\/span><\/div>\n<\/li>\n
    21. \n
      static<\/span> class PongClass : public TclClass {<\/span><\/div>\n<\/li>\n
    22. \n
      public:<\/div>\n<\/li>\n
    23. \n
          PongClass(<\/span>)<\/span> : TclClass(<\/span>“Agent\/Pong”<\/span>)<\/span> {<\/span> }<\/span><\/div>\n<\/li>\n
    24. \n
          TclObject* create(<\/span>int<\/span>, const<\/span> char<\/span>*const<\/span>*)<\/span> {<\/span><\/div>\n<\/li>\n
    25. \n
              return<\/span> (<\/span>new PongAgent)<\/span>;<\/div>\n<\/li>\n
    26. \n
          }<\/span><\/div>\n<\/li>\n
    27. \n
      }<\/span> class_pong;<\/div>\n<\/li>\n
    28. \n
       <\/div>\n<\/li>\n
    29. \n
      \/\/ PongAgent\uc758 \uc0dd\uc131\uc790\ub97c \uad6c\uccb4\uc801\uc73c\ub85c \uc815\uc758\ud558\ub294 \ubd80\ubd84<\/span><\/div>\n<\/li>\n
    30. \n
      \/\/ \uc0dd\uc131\uc790\uc5d0\uc11c\ub294 C++\uacfc Tcl\uc744 \ubc14\uc778\ub4dc\ud558\ub3c4\ub85d \ud568.<\/span><\/div>\n<\/li>\n
    31. \n
      PongAgent::PongAgent<\/span>(<\/span>)<\/span> : Agent(<\/span>PT_PONG)<\/span> {<\/span><\/div>\n<\/li>\n
    32. \n
          bind(<\/span>“packetSize_”<\/span>, &size_)<\/span>;<\/div>\n<\/li>\n
    33. \n
      }<\/span><\/div>\n<\/li>\n
    34. \n
       <\/div>\n<\/li>\n
    35. \n
      \/\/ PongAgent\uc758 command \uba54\uc18c\ub4dc\ub97c \uc815\uc758<\/span><\/div>\n<\/li>\n
    36. \n
      \/\/ \uad81\uadf9\uc801\uc73c\ub85c \uc774 \ubd80\ubd84\uc740 pong packet\uc744 send\ud558\ub294 \ubd80\ubd84\uc774\ub2e4.<\/span><\/div>\n<\/li>\n
    37. \n
      \/\/ Packet\uc744 \uc0dd\uc131\ud558\uace0, pong header\uc758 \uc2dc\uc791\uc9c0\uc810\uc73c\ub85c \uc774\ub3d9\ud558\uc5ec,<\/span><\/div>\n<\/li>\n
    38. \n
      \/\/ ret\ub97c 0\uc73c\ub85c \uc124\uc815\ud558\uace0, \uc2dc\uac04\uc744 \uc124\uc815\ud55c \ub2e4\uc74c, Packet\uc744 \uc804\uc1a1\ud55c\ub2e4.<\/span><\/div>\n<\/li>\n
    39. \n
      int<\/span> PongAgent::command<\/span>(<\/span>int<\/span> argc, const<\/span> char<\/span>*const<\/span>* argv)<\/span> {<\/span><\/div>\n<\/li>\n
    40. \n
          if<\/span>(<\/span>argc == 2<\/span>)<\/span> {<\/span><\/div>\n<\/li>\n
    41. \n
              if<\/span>(<\/span>strcmp(<\/span>argv[<\/span>1<\/span>]<\/span>, “send”<\/span>)<\/span> == 0<\/span>)<\/span> {<\/span><\/div>\n<\/li>\n
    42. \n
              <\/div>\n<\/li>\n
    43. \n
                  \/\/ \uc0c8\ub85c\uc6b4 packet\uc744 \uc900\ube44<\/span><\/div>\n<\/li>\n
    44. \n
                  \/\/ Creaqte a new packet<\/span><\/div>\n<\/li>\n
    45. \n
                  Packet* pkt = allocpkt(<\/span>)<\/span>;<\/div>\n<\/li>\n
    46. \n
                  <\/div>\n<\/li>\n
    47. \n
                  \/\/ packet\uc758 pong header \uc2dc\uc791 \uc9c0\uc810\uc73c\ub85c \uc774\ub3d9<\/span><\/div>\n<\/li>\n
    48. \n
                  \/\/ Access the Pong header for the new packet<\/span><\/div>\n<\/li>\n
    49. \n
                  hdr_pong* hdr = hdr_pong::access<\/span>(<\/span>pkt)<\/span>;<\/div>\n<\/li>\n
    50. \n
       <\/div>\n<\/li>\n
    51. \n
                  \/\/ pong header\uc758 ret\ub97c 0\uc73c\ub85c \uc124\uc815<\/span><\/div>\n<\/li>\n
    52. \n
                  \/\/ Set the ‘ret’ field to 0, so the receiving node<\/span><\/div>\n<\/li>\n
    53. \n
                  \/\/ knows that it to generate an echo packet<\/span><\/div>\n<\/li>\n
    54. \n
                  hdr->ret = 0<\/span>;<\/div>\n<\/li>\n
    55. \n
                  <\/div>\n<\/li>\n
    56. \n
                  \/\/ pong header\uc758 send time\uc744 \ud604\uc7ac\uc758 \uc2dc\uac04\uc73c\ub85c \uc124\uc815<\/span><\/div>\n<\/li>\n
    57. \n
                  \/\/ Store the current time in the ‘send_time’ field<\/span><\/div>\n<\/li>\n
    58. \n
                  hdr->send_time = Scheduler::instance<\/span>(<\/span>)<\/span>.clock<\/span>(<\/span>)<\/span>;<\/div>\n<\/li>\n
    59. \n
                  <\/div>\n<\/li>\n
    60. \n
                  \/\/ \ub9cc\ub4e4\uc5b4\uc9c4 packet\uc744 \uc804\uc1a1<\/span><\/div>\n<\/li>\n
    61. \n
                  \/\/ Send the packet<\/span><\/div>\n<\/li>\n
    62. \n
                  send(<\/span>pkt, 0<\/span>)<\/span>;<\/div>\n<\/li>\n
    63. \n
                  <\/div>\n<\/li>\n
    64. \n
                  \/\/ Return TCL_OK, so the calling function knows that<\/span><\/div>\n<\/li>\n
    65. \n
                  \/\/ the command has been procoessed<\/span><\/div>\n<\/li>\n
    66. \n
                  return<\/span> (<\/span>TCL_OK)<\/span>;<\/div>\n<\/li>\n
    67. \n
              }<\/span><\/div>\n<\/li>\n
    68. \n
          }<\/span><\/div>\n<\/li>\n
    69. \n
          <\/div>\n<\/li>\n
    70. \n
          \/\/ If the command hasn’t been proceesed by PongAgent()::command,<\/span><\/div>\n<\/li>\n
    71. \n
          \/\/ call the command() function for the base class<\/span><\/div>\n<\/li>\n
    72. \n
          return<\/span> (<\/span>Agent::command<\/span>(<\/span>argc, argv)<\/span>)<\/span>;<\/div>\n<\/li>\n
    73. \n
      }<\/span><\/div>\n<\/li>\n
    74. \n
       <\/div>\n<\/li>\n
    75. \n
      \/\/ PongAgent\uc758 recv() \uba54\uc18c\ub4dc\ub97c \uc815\uc758<\/span><\/div>\n<\/li>\n
    76. \n
      \/\/ Pong Packet\uc744 \uc218\uc2e0\ud558\uc600\uc744 \ub54c \uc218\ud589\ud558\ub294 \ubd80\ubd84\uc744 \uc815\uc758<\/span><\/div>\n<\/li>\n
    77. \n
      void<\/span> PongAgent::recv<\/span>(<\/span>Packet* pkt, Handler*)<\/span> {<\/span><\/div>\n<\/li>\n
    78. \n
          \/\/ ip header\uc758 \uc2dc\uc791 \uc9c0\uc810\uc73c\ub85c \uc774\ub3d9<\/span><\/div>\n<\/li>\n
    79. \n
          \/\/ Access the IP header for the received packet<\/span><\/div>\n<\/li>\n
    80. \n
          hdr_ip* hdrip = hdr_ip::access<\/span>(<\/span>pkt)<\/span>;<\/div>\n<\/li>\n
    81. \n
          <\/div>\n<\/li>\n
    82. \n
          \/\/ pong header\uc758 \uc2dc\uc791 \uc9c0\uc810\uc73c\ub85c \uc774\ub3d9<\/span><\/div>\n<\/li>\n
    83. \n
          \/\/ Access the pong header for the received packet<\/span><\/div>\n<\/li>\n
    84. \n
          hdr_pong* hdr = hdr_pong::access<\/span>(<\/span>pkt)<\/span>;<\/div>\n<\/li>\n
    85. \n
          <\/div>\n<\/li>\n
    86. \n
          \/\/ ret = 0 \uc774\uba74, \uc989 \ucc98\uc74c \uc218\uc2e0\ud55c packet\uc77c \ub54c \ucc98\ub9ac\ud558\ub294 \ubd80\ubd84<\/span><\/div>\n<\/li>\n
    87. \n
          if<\/span>(<\/span>hdr->ret == 0<\/span>)<\/span> {<\/span><\/div>\n<\/li>\n
    88. \n
              \/\/ packet\uc5d0 \uc788\ub294 \uc2dc\uac04\uc744 stime\uc5d0 \ud560\ub2f9<\/span><\/div>\n<\/li>\n
    89. \n
              double<\/span> stime = hdr->send_time;<\/div>\n<\/li>\n
    90. \n
              <\/div>\n<\/li>\n
    91. \n
              \/\/ packet\uc744 \ud3d0\uae30<\/span><\/div>\n<\/li>\n
    92. \n
              Packet::free<\/span>(<\/span>pkt)<\/span>;<\/div>\n<\/li>\n
    93. \n
              <\/div>\n<\/li>\n
    94. \n
              \/\/ \uc751\ub2f5\uc744 \uc704\ud55c packet\uc744 \uc0dd\uc131<\/span><\/div>\n<\/li>\n
    95. \n
              Packet* pktret = allocpkt(<\/span>)<\/span>;<\/div>\n<\/li>\n
    96. \n
              <\/div>\n<\/li>\n
    97. \n
              \/\/ packet\uc758 pong header \uc2dc\uc791\uc9c0\uc810\uc73c\ub85c \uc774\ub3d9<\/span><\/div>\n<\/li>\n
    98. \n
              hdr_pong* hdrret = hdr_pong::access<\/span>(<\/span>pktret)<\/span>;<\/div>\n<\/li>\n
    99. \n
              <\/div>\n<\/li>\n
    100. \n
              \/\/ packet\uc758 ret\ub97c 1\ub85c \uc124\uc815<\/span><\/div>\n<\/li>\n
    101. \n
              hdrret->ret = 1<\/span>;<\/div>\n<\/li>\n
    102. \n
              <\/div>\n<\/li>\n
    103. \n
              \/\/ packet\uc758 send_time\uc5d0 packet\uc744 \uc218\uc2e0\ud55c \uc2dc\uac04\uc744 \uc124\uc815<\/span><\/div>\n<\/li>\n
    104. \n
              hdrret->send_time = stime;<\/div>\n<\/li>\n
    105. \n
              <\/div>\n<\/li>\n
    106. \n
              \/\/ packet\uc744 \uc804\uc1a1<\/span><\/div>\n<\/li>\n
    107. \n
              send(<\/span>pktret, 0<\/span>)<\/span>;<\/div>\n<\/li>\n
    108. \n
          }<\/span> else<\/span> {<\/span>        \/\/ ret = 1 \uc774\uba74, \uc989 \ubcf4\ub0b8 packet\uc774 \ub2e4\uc2dc \ub418\ub3cc\uc544\uc654\uc744 \ub54c \ucc98\ub9ac\ud558\ub294 \ubd80\ubd84<\/span><\/div>\n<\/li>\n
    109. \n
              \/\/ \ucd9c\ub825\uc744 \uc704\ud55c \ubcc0\uc218 out\uc744 \uc120\uc5b8<\/span><\/div>\n<\/li>\n
    110. \n
              char<\/span> out[<\/span>100<\/span>]<\/span>;<\/div>\n<\/li>\n
    111. \n
              <\/div>\n<\/li>\n
    112. \n
              \/\/ out \ubcc0\uc218\uc5d0 \ub0b4\uc6a9\uc744 \uae30\ub85d<\/span><\/div>\n<\/li>\n
    113. \n
              \/\/ “\uc774\ub984(Agent\/Pong) recv from(Source address) rtt(round-trip-time)”\uc758 \ud615\ud0dc\ub97c \uac16\ucd94\uc5b4 \uae30\ub85d<\/span><\/div>\n<\/li>\n
    114. \n
              sprintf(<\/span>out, “%s recv %d %3.1f”<\/span>,<\/div>\n<\/li>\n
    115. \n
              <\/div>\n<\/li>\n
    116. \n
              \/\/ %s\uc5d0 \ud574\ub2f9\ud558\ub294 \ubd80\ubd84(\ub178\ub4dc \uc774\ub984)<\/span><\/div>\n<\/li>\n
    117. \n
              name(<\/span>)<\/span>,<\/div>\n<\/li>\n
    118. \n
              <\/div>\n<\/li>\n
    119. \n
              \/\/ %d\uc5d0 \ud574\ub2f9\ud558\ub294 \ubd80\ubd84(\ub178\ub4dc \uc8fc\uc18c)<\/span><\/div>\n<\/li>\n
    120. \n
              hdrip->src_.addr_<\/span> >> Address::instance<\/span>(<\/span>)<\/span>.NodeShift_<\/span>[<\/span>1<\/span>]<\/span>,<\/div>\n<\/li>\n
    121. \n
              <\/div>\n<\/li>\n
    122. \n
              \/\/ %3.1f\uc5d0 \ud574\ub2f9\ud558\ub294 \ubd80\ubd84(\uc751\ub2f5\uc2dc\uac04)<\/span><\/div>\n<\/li>\n
    123. \n
              \/\/ (\ud604\uc7ac\uc2dc\uac04 – send_time * 1000) –> round-trip-time<\/span><\/div>\n<\/li>\n
    124. \n
              (<\/span>Scheduler::instance<\/span>(<\/span>)<\/span>.clock<\/span>(<\/span>)<\/span> – hdr->send_time)<\/span> * 1000<\/span>)<\/span>;<\/div>\n<\/li>\n
    125. \n
              <\/div>\n<\/li>\n
    126. \n
              \/\/ tcl instance\ub97c \uc0dd\uc131<\/span><\/div>\n<\/li>\n
    127. \n
              Tcl& tcl =Tcl::instance<\/span>(<\/span>)<\/span>;<\/div>\n<\/li>\n
    128. \n
              <\/div>\n<\/li>\n
    129. \n
              \/\/ tcl instance\ub85c out\uc744 \ubc18\ud658<\/span><\/div>\n<\/li>\n
    130. \n
              tcl.eval<\/span>(<\/span>out)<\/span>;<\/div>\n<\/li>\n
    131. \n
              <\/div>\n<\/li>\n
    132. \n
              \/\/ packet\uc744 \ud3d0\uae30<\/span><\/div>\n<\/li>\n
    133. \n
              Packet::free<\/span>(<\/span>pkt)<\/span>;<\/div>\n<\/li>\n
    134. \n
          }<\/span><\/div>\n<\/li>\n
    135. \n
      }<\/span><\/div>\n<\/li>\n<\/ol>\n<\/fieldset>\n

       \uadf8\ub9ac\uace0 VII.3 Necessary changes \uc758<\/p>\n

      { SRMEXT off_srm_ext_ }
      { Ping off_ping_ }} {
      set cl PacketHeader\/[lindex $pair 9]<\/p><\/blockquote>\n

       \ubd80\ubd84\uc740 \uc548\ud574\uc918\ub3c4 \ub41c\ub2e4.<\/p>\n

       \ud574\ub2f9 \uc18c\uc2a4\ub97c \ucc3e\uc544\ubcf4\uba74 ‘tcl\/lib\/ns-packet.tcl’ \ud30c\uc77c\uc744 \ucc3e\uc544\ubcf4\uba74<\/p>\n

      # XXX Old code. Do NOT delete for now. – Aug 30, 2000<\/span><\/p><\/blockquote>\n

      \ub77c\uace0 \uc801\ud600\uc788\ub294 \uac83\uc744 \ubcfc \uc218 \uc788\ub2e4.<\/p>\n

       \uc989, \uac74\ub4dc\ub9ac\uc9c0 \uc54a\ub294 \uac83\uc774 \uc88b\ub2e4. : )<\/p>\n","protected":false},"excerpt":{"rendered":"

       NS Tutorial VII. A new protocol for ns \uc139\uc158\uc744 \uadf8\ub300\ub85c \ub530\ub77c\ud558\uba74 \ubb38\uc81c\uc810\uc774 \ubc1c\uc0dd\ud55c\ub2e4.  \uc544\ub9c8\ub3c4…Tutorial\uc744 \uc4f4 \uc2dc\uc810\uc774\ub791 \uc9c0\uae08\uc758 ns2 \ubc84\uc804\uc774\ub791 \ub9de\uc9c0 \uc54a\uc544\uc11c \uc0dd\uae30\ub294 \ubb38\uc81c\uc778 \uac83 \uac19\ub2e4.  ping.cc \uc640 ping.h \uc744 \ub098\ub984\ub300\ub85c \ubc14\uafd4\ubcf4\uc558\ub2e4.  \uc774\ub984\ub9cc \ubc14\uafb8\uc5c8\uace0 \ub098\uba38\uc9c0 \ubd80\ubd84\uc740 \ubaa8\ub450 ping.cc, ping.h\uc640 \ub3d9\uc77c\ud558\ub2e4.  \uc8fc\uc758\ud574\uc11c … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[30],"tags":[285,286,294],"_links":{"self":[{"href":"http:\/\/pchero21.com\/index.php?rest_route=\/wp\/v2\/posts\/500"}],"collection":[{"href":"http:\/\/pchero21.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pchero21.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pchero21.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pchero21.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=500"}],"version-history":[{"count":0,"href":"http:\/\/pchero21.com\/index.php?rest_route=\/wp\/v2\/posts\/500\/revisions"}],"wp:attachment":[{"href":"http:\/\/pchero21.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=500"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pchero21.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=500"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pchero21.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=500"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}