Question

Q3. Assume you request a webpage consisting of one document and seven images. The document size is 1 kbyte, all images have the same size of 50 kbytes, the download rate is 1 Mbps, and the RTT is 100 ms. How long does it take to obtain the whole webpage under the following conditions? (Assume no DNS name query is needed and the impact of the request line and the headers in the HTTP messages is negligible) Q4.Non-Persistent HTTP with serial connections

Answer 1

It takes 3.075 seconds to download the entire webpage.

How to solve

Document size = 1KB = 1024B

Image size = 50KB = 51200B

Number of images = 7

Download rate = 1Mbps = 125000B/s

RTT = 100ms = 0.1s

Time to download document = Document size / Download rate = 1024B / 125000B/s = 0.008192s

Time to download each image = Image size / Download rate = 51200B / 125000B/s = 0.4096s

Total time to download images = Time to download each image * Number of images = 0.4096s * 7 = 2.8672s

Total download time = Time to download document + Total time to download images = 0.008192s + 2.8672s = 2.875392s

Total time with RTT = Total download time + 2 * RTT = 2.875392s + 2 * 0.1s = 3.075392s

Therefore, it takes 3.075 seconds to download the entire webpage.