3-07
锛?/p>
瑕佸彂閫佺殑鏁版嵁涓?/p>
1101011011
銆?/p>
閲囩敤
CRC
鐨勭敓鎴愬椤瑰紡鏄?/p>
P
锛?/p>
X
锛?/p>
=X^4+X+1
銆傝瘯姹傚簲娣诲姞鍦ㄦ暟鎹悗闈㈢殑浣欐暟銆?/p>
鏁版嵁鍦ㄤ紶杈撹繃绋嬩腑鏈�鍚庝竴涓?/p>
1
鍙樻垚浜?/p>
0
锛岄棶鎺ユ敹绔兘鍚﹀彂鐜帮紵
鑻ユ暟鎹湪浼犺緭杩囩▼涓渶鍚庝袱涓?/p>
1
閮藉彉鎴愪簡
0
锛岄棶鎺ユ敹绔兘鍚﹀彂鐜帮紵
閲囩敤
CRC
妫�楠屽悗锛屾暟鎹摼璺眰鐨勪紶杈撴槸鍚﹀氨鍙樻垚浜嗗彲闈犵殑浼犺緭锛?/p>
绛旓細
鐢熸垚澶氶」寮忥細
P
锛?/p>
X
锛?/p>
=X^4+X+1
锛岄櫎鏁?/p>
P
锛?/p>
10011
銆備綔浜?/p>
杩涘埗闄ゆ硶锛?/p>
1101011011
0000
闄や互
10011
寰?/p>
浣欐暟
1110
銆?/p>
涓ょ閿欒鍧囧彲鍙戠幇銆?/p>
CRC
宸敊妫�娴嬫妧鏈彧鑳藉仛鍒版棤宸敊鎺ュ彈锛岀己閲嶄紶鏈哄埗锛屾暟鎹?/p>
閾捐矾灞傜殑浼犺緭杩樹笉鏄彲闈犵殑浼犺緭銆?/p>
3-20
鍋囧畾
1km
闀跨殑
CSMA/CD
缃戠粶鐨勬暟鎹巼涓?/p>
1Gb/s
銆?/p>
璁句俊鍙峰湪缃戠粶
涓婄殑浼犳挱閫熺巼涓?/p>
200000km/s
銆傛眰鑳藉浣跨敤姝ゅ崗璁殑鏈�鐭抚闀裤�?/p>
绛旓細瀵逛簬
1km
鐢电紗锛屽崟绋嬩紶鎾椂寤朵负
1km / 200000km/s = 5
寰锛屽線杩斿洖寤朵负
10
寰銆?/p>
鎸夌収
CSMA/CD
宸ヤ綔鍘熺悊锛?/p>
鏈�鐭抚鐨勫彂閫佹椂闂翠笉鑳藉皬浜?/p>
10
寰銆?/p>
浠?/p>
1Gb/s
閫熺巼宸ヤ綔锛?/p>
10
寰鍙互鍙戦�佺殑姣旂壒鏁?/p>
=10
寰
*
鏁版嵁
鐜?/p>
=10*10
-6
s * 10
9
b/s = 10000b,
鍥犳锛屾渶鐭抚鏄?/p>
10000
浣嶃�?/p>
3-32
鍥?/p>
3-35
琛ㄧず鏈変簲涓珯鐐瑰垎鍒繛鎺ュ湪涓変釜灞�鍩熺綉涓婏紝骞朵笖鐢ㄧ綉
妗?/p>
B1
鍜?/p>
B2
杩炴帴璧锋潵銆?/p>
姣忎竴涓綉妗ラ兘鏈変袱涓帴鍙?/p>
锛?/p>
1
鍜?/p>
2
锛?/p>
銆?/p>
鍦ㄤ竴寮�濮嬶紝
涓や釜缃戞ˉ涓殑杞彂琛ㄩ兘鏄┖鐨勩�?/p>
浠ュ悗鏈変互涓嬪悇绔欏悜鍏朵粬鐨勭珯鍙戦�佷簡鏁?/p>
鎹抚锛?/p>
A
鍙戦�佺粰
E
锛?/p>
C
鍙戦�佺粰
B
锛?/p>
D
鍙戦�佺粰
C
锛?/p>
B
鍙戦�佺粰
A
銆傝瘯鎶婃湁鍏虫暟