Q3. Consider the following HTTP messages. Note that [File Data] in the second message represents 18070 bytes of data.

GET /download.html HTTP/1.1

Host: www.ethereal.com

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113

Accept: text/xml,application/xml,text/html;q=0.9,image/jpeg,image/gif;q=0.2,*/*;q=0.1

Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate

Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7

Keep-Alive: 300 Connection: keep-alive

HTTP/1.1 200 OK Date: Thu, 13 May 2004 10:17:12 GMT Server: Apache Last-Modified: Tue, 20 Apr 2004 13:17:00 GMT Accept-Ranges: bytes Content-Length: 18070 Keep-Alive: timeout=15, max=100 Connection: Keep-Alive Content-Type: text/html; charset=ISO-8859-1

[File Data]

Q3-1. For Keep-Alive: timeout=15, max=100, timeout is the number of seconds to wait for the next request from the client on this connection, and max is the maximum number of requests to allow during this persistent connection. In this case, at most how many seconds does this persistent HTTP connection keep alive?

Q3-2. Show the response message if the following request is sent to the server.

HEAD /download.html HTTP/1.1 Host: www.ethereal.com User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113 Accept: text/xml,application/xml,text/html;q=0.9,image/jpeg,image/gif;q=0.2,*/*;q=0.1 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 300 Connection: keep-alive

Q3-3. Show the response message if the following request is sent to the server.

GET /download.html HTTP/1.1 Host: www.ethereal.com If-Modified-Since: Tue, 20 Apr 2004 13:17:00 GMT User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113 Accept: text/xml,application/xml,text/html;q=0.9,image/jpeg,image/gif;q=0.2,*/*;q=0.1 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 300 Connection: keep-alive