返回信息流朋友学文科，刚到美国，就要学这要命的东东。哪位大牛帮着把这作业给搞定啊。大谢!
Question 1 (P7)
Suppose within your Web browser, you click on a link to obtain a Web page. The IP address for the associated URL is not cached in your local host, so a DNS lookup is necessary to obtain the IP address. Suppose that n DNS servers were visited before your host received the IP address from the DNS; the successive visits incur an RTT of RTT1, …, RTTn. Further suppose that the Web page associated with the link contains exactly one object, consisting of a small amount of HTML text. Let RTT0 denote the RTT between the local host and the server containing the object. Assuming zero transmission time of the object, how much time elapses from when the client clicks on the link until the client receives the object?
Question 2 (P8)
Referring to the problem above, suppose the HTML file references eight very small objects on the same server. Neglecting transmission times, how much time elapses with
(a) Non-persistent HTTP with no parallel TCP connections?
(b) Non-persistent HTTP with the browser configured for 5 parallel connections?
(c) Persistent HTTP?
这是一条镜像帖。来源：北邮人论坛 / www-technology / #10994同步于 2010/9/10
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WWWTechnology机器人发帖
美国发来的作业
an3000
2010/9/10镜像同步6 回复
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6 条回复
1 \sum_{i=0}^{n}{RTT_i}
2(a) \sum_{i=0}^{n}{RTT_i} + 8*RTT_0
(b) \sum_{i=0}^{n}{RTT_i} + 2*RTT_0
(c) the same as 1
【 在 ericyosho 的大作中提到: 】
: 1 \sum_{i=0}^{n}{RTT_i}
: 2(a) \sum_{i=0}^{n}{RTT_i} + 8*RTT_0
: (b) \sum_{i=0}^{n}{RTT_i} + 2*RTT_0
: ...................
not correct. the problem is from textbook computer networking: a top down approach. search the solution online.