Applied Test Series

Question

Assume that we are retrieving a HTML base file with  10 embedded objects. Consider X Round trip time(RTT’s) are required to retrieve the base file and

 

the objects under non persistent HTTP with no parallel connection, and Y Round trip time(RTT’s) are required to retrieve the base file and

 

the objects under non persistent HTTP with 6 parallel connections.Compute X+ Y ? [Ignore the processing delays, closing TCP connection or any other delays].

 

 

Answer 1

The HTML base file contains 10 embedded objects.

X: No. of Round trip time(RTT’s) that are required to retrieve the base file when the objects under non persistent HTTP with no parallel connection

Y: No. of Round trip time(RTT’s) that are required to retrieve the base file when the objects under non persistent HTTP with 6 parallel connections

Initially, we need 1 RTT for TCP connection establishment and 1 RTT to get the HTML base file i.e. 2 RTTs are needed for both the cases.

Retrieving 10 objects without parallel connection requires 20 RTTs. ( 1 RTT for TCP connection and 1 RTT for object retrieval i.e. 2 RTTs per object). Therefore, X = 2 + 20 = 22.

Retrieving 10 objects with 6 parallel connection requires 1 (TCP connection) + 1 (6 parallel connections for retrieval of 6 objects) + 4 (4 TCP connections) + 4 (Retrieval of 4 objects that are left) = 10 RTTs. Therefore, Y = 2 + 10 = 12.

So, X+Y = 22+12 = 34 (Answer).

 

 

Comments

why Retrieval of object is there answer should 22+6 =28. right?

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Why we are not using the parallel connection for the remaining 4 objects?

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What would be the answer considering both the case  if it's mentioned that persistent HTTP is used.

Further why we haven't consider 1 RTT for connection termination?