Imagine an HTTP session. In response to a GET message, the www.pitt.edu web serv
ID: 3779511 • Letter: I
Question
Imagine an HTTP session. In response to a GET message, the www.pitt.edu web server sends a to response that consists of 100 kilobytes of data to starfire1.sis.pitt.edu. Let the temporary client port number be 25000.
A. What are all of the headers (network, transport, application) associated with the packet containing the response?
B. How many bits are sent in total?
C. Suppose the local network to which starfire1.sis.pitt.edu is attached is does not allow large packets. For this part, assume that IP must break the packet into three fragments. What are the headers of each of the three packets? How many bits are received in total?
Explanation / Answer
A. The response packet contains all the 3 headers. Header of Apllication,transport and finally the header of the Internet/network layer.
B. The total bits are=all three header bits +100kilobytes(which is data)
=20bytes(IP header)+8bytes(UDP header)+200bytes(HTTP response header. it can vary from 200
bytes to 2KB)+100KB
=20+8+200+100000
=100228 bytes
=100228*8
=801824 bits will be sent in total
C.As IP breaks it into 3 parts there will be an overhead of 2 header to the data. The header for the three packets is just IP/ network header.
The total number of bits that are received in total are 801824+20*8+20*8=801824+320
=802144 bits