CSMA/CD

Carrier Sense(CS) 蝗ｳ縺ｫ遉ｺ縺吶ｈ縺�↑縲√さ繝ｳ繝斐Η繝ｼ繧ｿ�｡縲�ｼ｢縲�ｼ｣縲�ｼ､縺ｮ�泌床縺梧磁邯壹＆繧後※縺�ｋ邁｡蜊倥↑繝阪ャ繝医Ρ繝ｼ繧ｯ讒区�繧定��∴縺ｾ縺吶�ゑｼ郁ｪｬ譏弱�驛ｽ蜷井ｸ翫�√ヰ繧ｹ蝙九�繝医�繝ｭ繧ｸ縺ｧ縺吶′繧ｹ繧ｿ繝ｼ蝙九�繝医�繝ｭ繧ｸ縺ｧ繧ょ酔縺倥％縺ｨ縺ｧ縺呻ｼ� 縺薙�縺ｨ縺阪�√さ繝ｳ繝斐Η繝ｼ繧ｿ�｡縺九ｉ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ�､縺ｫ蟇ｾ縺励※繝��繧ｿ繧帝�∽ｿ｡縺励◆縺�→縺励∪縺吶�ゅ∪縺壹さ繝ｳ繝斐Η繝ｼ繧ｿ�｡�域ｭ｣遒ｺ縺ｫ縺ｯ縲√さ繝ｳ繝斐Η繝ｼ繧ｿ�｡縺ｫ蜿悶ｊ莉倥¢繧峨ｌ縺ｦ縺�ｋNIC�峨�縲√こ繝ｼ繝悶Ν荳翫↓縺吶〒縺ｫ繝��繧ｿ縺梧ｵ√ｌ縺ｦ縺�ｋ縺九←縺�°繧偵メ繧ｧ繝�け縺励∪縺吶�ゅ％繧後′ CS (Carrier Sense) 縺ｧ縺吶�ゅメ繧ｧ繝�け繧偵＠縺ｦ縲√こ繝ｼ繝悶Ν荳翫↓繝��繧ｿ縺梧ｵ√ｌ縺ｦ縺�↑縺代ｌ縺ｰ繝��繧ｿ繧帝�∽ｿ｡縺吶ｋ縺薙→縺後〒縺阪∪縺吶�ゅｂ縺励☆縺ｧ縺ｫ繝��繧ｿ縺梧ｵ√ｌ縺ｦ縺�ｌ縺ｰ縺昴�繝��繧ｿ縺後こ繝ｼ繝悶Ν荳翫°繧峨↑縺上↑繧九∪縺ｧ繝��繧ｿ騾∽ｿ｡繧貞ｾ�■縺ｾ縺吶�� 繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ�｡縺九ｉ騾∽ｿ｡縺輔ｌ縺溘ョ繝ｼ繧ｿ縺ｯ縲∝酔縺廊AN荳翫�縺吶∋縺ｦ縺ｮ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺ｫ螻翫￥縺ｨ縺�≧縺ｮ縺ｯ縲∝燕蝗槭ｂ縺願ｩｱ縺励∪縺励◆縲ょ推繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺ｧ縺ｯ縲�繝��繧ｿ縺ｮ縺ゅ※蜈医い繝峨Ξ繧ｹ��MAC繧｢繝峨Ξ繧ｹ�峨ｒ隕九※閾ｪ蛻�≠縺ｦ縺ｧ縺ゅｌ縺ｰ縺昴�繝��繧ｿ繧偵＆繧峨↓荳贋ｽ阪�繝励Ο繝医さ繝ｫ縺ｫ貂｡縺励※縲∝�逅�☆繧九ｏ縺代〒縺吶�縲り�蛻�≠縺ｦ縺ｧ縺ｪ縺代ｌ縺ｰ縺昴�繝��繧ｿ縺ｮ蜃ｦ逅�ｒ縺昴ｌ莉･荳願｡後＞縺ｾ縺帙ｓ縲ゅ▽縺ｾ繧翫�√さ繝ｳ繝斐Η繝ｼ繧ｿ�､縺ｯ螻翫＞縺溘ョ繝ｼ繧ｿ縺ｮ蜃ｦ逅�ｒ邯壹¢縺ｦ縲√さ繝ｳ繝斐Η繝ｼ繧ｿ�｢縲�ｼ｣縺ｧ縺ｯ繝��繧ｿ縺ｮ蜃ｦ逅�ｒ縺昴ｌ莉･荳願｡後＞縺ｾ縺帙ｓ縲�

Collision Detection(CD) 縺ゅ→谿九ｊ縺ｯ縲，D縺ｧ縺吶�縲� 縺薙ｌ縺ｯ繧､繝ｬ繧ｮ繝･繝ｩ繝ｼ縺ｪ繝代ち繝ｼ繝ｳ縺ｧ縺吶�ゅｂ縺苓､�焚縺ｮ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺� Carrier Sense繧定｡後▲縺ｦ縲√こ繝ｼ繝悶Ν縺ｫ繝��繧ｿ縺梧ｵ√ｌ縺ｦ縺�↑縺�ｼ√→蛻､譁ｭ縺励◆繧峨←縺�↑繧九°縺ｨ縺�≧隧ｱ縺ｫ縺ｪ繧翫∪縺吶�ゅ◎縺ｮ蝣ｴ蜷医�隍�焚縺ｮ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺後ョ繝ｼ繧ｿ繧帝�∽ｿ｡縺励※縺励∪縺�％縺ｨ縺ｫ縺ｪ繧翫∪縺吶�� 縺溘→縺医�縲√＆縺｣縺阪�蝗ｳ縺ｧ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ�｡縺九ｉ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ�､縺ｸ縺ｮ繝��繧ｿ騾∽ｿ｡縺ｨ縲√さ繝ｳ繝斐Η繝ｼ繧ｿ�｢縺九ｉ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ�｣縺ｸ縺ｮ繝��繧ｿ騾∽ｿ｡縺悟酔譎ゅ↓襍ｷ縺薙▲縺溘→縺�▲縺溽憾豕√ｒ閠�∴縺ｾ縺吶�� �｡縲�ｼ｢縺ｯ CS 繧定｡後＞繧ｱ繝ｼ繝悶Ν荳翫↓繝��繧ｿ縺梧ｵ√ｌ縺ｦ縺�↑縺�◆繧√ョ繝ｼ繧ｿ縺ｮ騾∽ｿ｡繧偵�縺倥ａ縺ｾ縺吶�ゅ☆繧九→縲∽ｸ｡譁ｹ縺ｮ繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺九ｉ騾∽ｿ｡縺輔ｌ縺溘ョ繝ｼ繧ｿ縺ｯ騾比ｸｭ縺ｧ陦晉ｪ√ｒ襍ｷ縺薙＠縺ｦ縺励∪縺�∪縺吶�り｡晉ｪ√′襍ｷ縺薙ｋ縺ｨ繝��繧ｿ縺悟｣翫ｌ縺ｦ縺励∪縺��∵ｭ｣蟶ｸ縺ｪ繝��繧ｿ繧帝�√ｋ縺薙→縺後〒縺阪∪縺帙ｓ縲ゅ％縺ｮ陦晉ｪ√′襍ｷ縺薙▲縺溘→縺�≧縺薙→繧呈､懷�縺吶ｋ縺ｮ縺� CD (Collision Detection)縺ｧ縺吶�よ､懷�縺ｯ縲¨IC縺ｧ陦後ｏ繧後※縺�∪縺吶�り｡晉ｪ√′襍ｷ縺薙ｋ縺ｨ縲��壼ｸｸ縺ｮ遽�峇螟悶�髮ｻ蝨ｧ縺ｨ縺ｪ縺｣縺ｦ縺励∪縺��縺ｧ讀懷�縺吶ｋ縺薙→縺後〒縺阪∪縺吶�� 陦晉ｪ√ｒ讀懷�縺励◆繧蛾�∽ｿ｡蜈��繧ｳ繝ｳ繝斐Η繝ｼ繧ｿ縺ｯ繝��繧ｿ騾∽ｿ｡繧剃ｸｭ譁ｭ縺励※縲√◎繧後◇繧後Λ繝ｳ繝�繝�縺ｪ譎る俣蠕�■縺ｾ縺吶�ゅ◎縺ｮ蠕後�√∪縺� Carrier Sense 繧定｡後＞繝ｻ繝ｻ繝ｻ縺ｨ縺�≧蜈ｷ蜷医↓繝��繧ｿ縺ｮ蜀埼�√ｒ陦後▲縺ｦ縺�″縺ｾ縺吶�� 縺ｾ縺ｨ繧√→縺励※縲，SMA/CD縺ｮ蜍輔″繧偵ヵ繝ｭ繝ｼ繝√Ε繝ｼ繝医↓縺励∪縺吶��

(C) Copyright 2000 Gene All Right Reserved