My question is about P8 part b. and c. I don't just want the answers, I want to understand them. I know that the answer for d is something like RTT1++RTTn+2RTTO+RTTO = 3* RTTO+ RTT1++RTTn..

I want to actually understand what is going on though.

For B: What are parallel TCP connections and how do they effect the problem?

For C: I now that as little as one RTT is needed for all the referenced objects in persistant HTTP request, does that mean that it takes one RTT for the the TCP to get the IP address, and then another for all the reference objects?

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 are visited before your host receives the IP address from DNS, the successive visits incur an RTT of RTT Web page associated with the link contains exactly one object, consisting of a small amount of HTML text. Let RTTo 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? , RTTn. Further suppose that the P8. Referring to Problem P7, 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