Exercise 5 - Part 1

A user wants to reserve a flight on the website http://www.vuel.os. Suppose that the user's PC obtains from its local DNS server the IP address of the HTTP server, which we will denote by IPweb. We know that the index.html file in this server occupies 2736 octets and contains two image tags <img src="link"> to two images also stored on the server, called caribe.png (occupies 4196 octetos) and maldivas.png (occupies 5656 octetos) which will be downloaded in that order. One can assume that all HTTP GET requests occupy 1460 octetos, and in all server responses the HTTP header (that is, the sum of the status line, headers, and blank line) occupies a total of 184 octetos in total. The HTTP server implements version HTTP/1.1 without pipelining. With regard to the functioning of the TCP protocol suppose that:

• The maximum segment size TCP (MSS) is 1460 octets in the client of the user and 1580 octets in the HTTP server.
• Each segment transmission occurs at the start of a 'tick' of clock.
• The transmission time of a frame is negligible.
• Each segment takes half a 'tick' to arrive at the opposite entity.
• Segment reception confirmation is done according to the policy seen in class
• In case the retransmission timer expires, only the oldest pending confirmation segment is retransmitted.
• No segments received out of sequence are discarded.
• The value of the threshold variable is 4 MSS.
• The user's PC begins with a SN=199 and the HTTP server with a SN=2999.

Reflect in a temporal diagram the TCP segment exchange that occurs between the student's PC and the HTTP server until the index.html file is obtained (including connection establishment if necessary, where data can be sent in the third segment). Assume that processing times are negligible.