Question

on calculations can i see how did the expect come to the solution ,all the workout should be included

QUESTION 1

1. A file of size F = 8 Gbits needs to be distributed to10 peers. Suppose the server has an upload rate of u = 68 Mbps, and that the 10 peers have upload rates of: u1 = 20 Mbps, u2 = 22 Mbps, u3 = 12 Mbps, u4 = 19 Mbps, u5 = 25 Mbps, u6 = 24 Mbps, u7 = 18 Mbps, u8 = 11 Mbps, u9 = 14 Mbps, u10 = 30 Mbps, and download rates of: d1 = 28 Mbps, d2 = 30 Mbps, d3 = 12 Mbps, d4 = 20 Mbps, d5 = 18 Mbps, d6 = 15 Mbps, d7 = 14 Mbps, d8 = 34 Mbps, d9 = 20 Mbps, d10 = 34 Mbps. What is the minimum time needed to distribute this file from the central server to the 10 peers using the client-server model (round to the nearest second)?

QUESTION 2

1. 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 four DNS servers are visited before your host receives the IP address from DNS. The first DNS server visited is the local DNS cache, with an RTT delay of RTT0 = 2 msecs. The second, third and fourth DNS servers contacted have RTTs of RTT1 = 19, RTT2 = 17, and RTT3 = 26 msecs, respectively. Assume that the Web page associated with the link contains exactly one object, consisting of a small amount of HTML text. Suppose the RTT between the local host and the Web server containing the object is RTTHTTP = 37 msecs. If the HTML object references 2 very small objects on the same web server. Neglecting transmission times, how much time elapses (in seconds) from when the client clicks on the link until the base object and all 2 additional objects are received from web server at the client, assuming a persistent HTTP connection?

Question 3

Suppose Amy, sends an email using her browser to her friend Jack. Jack uses a user agent on his mobile device to access his email from his mail server using a pull protocol. Which application layer protocols are being used in this scenario?

		SMTP and POP3
		SMTP and IMAP
		HTTP and POP3
		HTTP and SMTP
		HTTP, SMTP and IMAP

QUESTION 4

"This protocol uses UDP and can be thought of as the ""Internets Directory Service"""

		DNS
		TCP
		UDP
		All of the above
		None of the above

QUESTION 5

1. 1.     Consider the following excerpt from a simple server side UDP program:

Server.py

from socket import *

sName=’127.0.0.1’

sSocket=socket(AF_INET,SOCK_DGRAM)

sSocket.bind((sName, 12005))

while True:

msg, cAddr =sSocket.recv(2048)

newMsg = msg.decode().lower()

  sSocket.sendto(newMsg.encode(), cAddr)

In which line does a coding error exist?

		sSocket=socket(AF_INET,SOCK_DGRAM)
		sSocket.bind((sName, 12005))
		msg, cAddr =sSocket.recv(2048)
		newMsg = msg.decode().lower()
		sSocket.sendto(newMsg.encode(), cAddr)

QUESTION 6

1. Which of the following is NOT an application layer protocol?

		HTTP
		FTP
		BitTorrent
		SMTP
		None of the above

QUESTION 7

1. Which mail protocol keeps state information across sessions?

		SMTP
		POP3
		IMAP
		All of the above
		None of the above
QUESTION 8

A new startup company Networks unlimited needs to register it s mail server in the DNS system. The domain name is: networksunltd.net at IP address 202.194.54.3. Which of the following is true regarding resource record entries that will need to be made by the DNS registrar?

		Into the .com TLD server insert (networksunltd.net, mail.networksunltd.net, NS) and (mail.networksunltd.net, 202.194.54.3, A)
		Into the .com TLD server insert (networksunltd.net, 202.194.54.3, A)
		Into the .net TLD server insert (networksunltd.net, mail.networksunltd.net, MX) and (mail.networksunltd.net, 202.194.54.3, A)
		Into the .com TLD server insert (mail.networksunltd.net, 202.194.54.3, A)
		None of the above

1. points   

QUESTION 9

     Consider the following excerpt from a simple server side UDP program:

Server.py

from socket import *

sName=’127.0.0.1’

sSocket=socket(AF_INET,SOCK_DGRAM)

sSocket.bind((*******************))

while True:

msg, cAddr =sSocket.recvfrom(2048)

newMsg = msg.decode().lower()

  sSocket.sendto(newMsg.encode(), cAddr)

What code could replace the ***********’’s in line 4?

		sName, sPort
		sName, 12005
		sPort, SName
		12005. ‘xyz’
		None of the above

Answer 1

Question#1

6.32 SECONDS

Question#2

7.5 SECONDS

Question#3

HTTP and POP3

Question#4

TCP

Question#5

msg, cAddr =sSocket.recv(2048)

Question#6

BitTorrent

Question#7

IMAP

Question#8

Into the .net TLD server insert (networksunltd.net, mail.networksunltd.net, MX) and (mail.networksunltd.net, 202.194.54.3, A)

Question#9

sName, 12005

PLEASE GIVE A THUMBS UP!!!!!!!!!