作者pop10353 (女乃 豆页 单戈 示申)
看板Network
标题[问答] hub & switch
时间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. <<这句话是说所有电脑会分享总宽频？
那麽分享的意思是共用、还是分割？
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.<<想问这句话确切的意思??
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 那为什麽第一个问题100Mbps要扣掉80??
※ 编辑: pop10353 来自: 124.9.193.233 (07/28 20:09)
2F：推 badctc252:共用是指共同使用频宽如果一台PC使用了20%的频宽剩下的 07/29 20:47
3F：→ badctc252:PC只能用80% 07/29 20:48
4F：推 kimi7918:那句话的意思是，四台电脑都占用20Mbps互相传输 08/01 14:40
5F：→ kimi7918:使用HUB的话，剩下的那port就只剩下20M可以用 08/01 14:40
6F：→ kimi7918:但Switch不会占用频宽，剩下那Port还是有100M可对外沟通 08/01 14:41