作者pop10353 (女乃 豆頁 單戈 示申)
看板Network
標題[問答] hub & switch
時間Sun Jul 28 17:21:39 2013
Suppose there are five computers connected together to form a LAN.
The maximum data transport rate that the network cable can provide is 100Mbps,
ideally.
If we use a hub to connect them,all computers in the network share the
100Mbps bandwidth. <<這句話是說所有電腦會分享總寬頻？
那麼分享的意思是共用、還是分割？
If we use a switch,then any two of the computers can communicate with
each other without disturbing the other computers.
Assume that the other four computers only communicate with each other,
and each has a constant data rate of 20Mbps.<<想問這句話確切的意思??
Now,you want to download a 10MB file from a remote server,which is located
outside your local network.
Q1:How long will it take if using a hub?
Q2:How long will it take if using a switch?
Ans:1. (10*8)/ (100-20*4)= 4sec
2. (10*8)/ 100=0.8sec
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◆ From: 124.9.193.233
1F：推 imiss0960:共用 07/28 19:00
如果是共用 那為什麼第一個問題100Mbps要扣掉80??
※ 編輯: pop10353 來自: 124.9.193.233 (07/28 20:09)
2F：推 badctc252:共用是指共同使用頻寬如果一台PC使用了20%的頻寬剩下的 07/29 20:47
3F：→ badctc252:PC只能用80% 07/29 20:48
4F：推 kimi7918:那句話的意思是，四台電腦都占用20Mbps互相傳輸 08/01 14:40
5F：→ kimi7918:使用HUB的話，剩下的那port就只剩下20M可以用 08/01 14:40
6F：→ kimi7918:但Switch不會占用頻寬，剩下那Port還是有100M可對外溝通 08/01 14:41