Thus to support n simultaneous connections the server would need n1 sockets f 5

Thus to support n simultaneous connections the server

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(f)(5 pt.) How does SMTP mark the end of a message body? How about HTTP? Can HTTP use the same method as SMTP to mark the end of a message body? Explain.
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2 2.(20 points) Web/Http (a)(4 pt.) Suppose within your Web browser you click on a link to obtain a Webpage. 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 are visited before your host receives the IP address from DNS; the successive visits incur an round-trip-time of RTT1, RTT2, RTT3, …, RTTn. Further suppose that the Web page associated with the link contains exactly one object, consisting of a small amount of HTML text. Let denote the RTT0between 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 receivers the object? The total amount of time to get the IP address is . (b)(12 pt.) Referring to (a), suppose the HTML file references eight very small objects on the same server. Neglecting transmission times, how much time elapses with Non-persistent HTTP with no parallel TCP connections? Non-persistent HTTP with the browser configured for 5 parallel connections? (c)(4 pt.) A web page that contains 13 embedded objects is downloaded via HTTP 1.1. Assume that the size of the main page and each embedded object is one TCP segment. Suppose that a TCP connection starts out with congestion window of 1and congestion threshold of 4, how many round trips will it take to download the whole page and display it? (Ignore the time to transmit a TCP segment).
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