Question

2. Suppose within your Web browser you click on a link to obtain a Web page, and the Web page is consisting of one HTML text with eight referenced objects. Let RTT0 denote the RTT between the local host and the server containing the object, the link transmission bandwidth is R, and the HTML text file size is L0 and the reference objects have a size of L1, L2, L3, …, L8, respectively. How much time elapses from when the client clicks on the link until the client receives the object in the following scenarios?

a. Non-persistent HTTP with no parallel TCP connections?

b. Non-persistent HTTP with the browser configured for 9 parallel connections?

c. Persistent HTTP with no parallel TCP connection?

d. Persistent HTTP with the browser configured for 9 parallel connections?

Answer 1

Elapsed time = 2RTT + transmit time

DNS lookup to get the II address is : RTT1 + RTT2 + RTT3 + .... RTTN. IP address leads to a hit (Yes) there are 2 RTTs as one RTT to setup TCP handshake 3 way connection and other RTT to request and receive the small or reference objects . Total response time is 2RTT0 + RTT1 + RTT2 + ... + RTTN

(a) RTT1+…+RTTn+2RTTO+8*2RTTO = 18* RTTO+ RTT1+…+RTTn.

(b) RTT1+…+RTTn+2RTTO+4*2RTTO = 10* RTTO+ RTT1+…+RTTn.

(c) RTT1+…+RTTn+2RTTO+RTTO = 3* RTTO+ RTT1+…+RTTn..

(d) RTT1+…+RTTn+2RTTO+4*RTTO = 6* RTTO+ RTT1+…+RTTn..

Hope this helps.