Fundamentals of Network Communication, week (1-6) All Quiz Answers with Assignments.

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Fundamentals of Network Communication




week 5 Assignment:

PROMPT

Please give answer to each question concisely.

1. Raise two main advantages of packet switching, compared to message switching.

2. Given a 20-bit frame and bit-error-rate p in communication. What is the probability that the frame has no error? What is the probability of 1-bit errors?

3. Give two features that the data link layer and transport layer have in common, and further give two features in which they differ.

4. Which OSI layer is responsible for (a) determining the best path to route packets; (b) providing end-to-end reliable communications; (c) providing node-to-node reliable communications?

5. How does the network layer in a connection-oriented packet-switching network differ from the network layer in a connection less packet-switching network?

1. 1.Packet switching is similar to message switching using short messages .Advantages Send the data across a network Security benefit Big files can be sent as a collective Small packets can move easily because they can choose different routes through the network.

 2. For all of the bits to be correct, the probability of (1 - p) should happen for all bits: P=(1−p)20 For the probability of one bit error, we should use the binomial probability formula: P=(201)p(1−p)19 

3 .Features they have in common: Both layers can provide recovery from transmission errors. Both layers can provide flow control. Both layers can support multiplexing. Features they have in common: Both layers can provide recovery from transmission errors. Both layers can provide flow control. Both layers can support multiplexing. 

4.(a) The network layer is concerne with the selection of paths across the network. (b) The transport layer is concerned with providing reliable service on an end-to-end basis across the network. 

5. Both Connection-oriented service and Connection-less service are used for the connection establishment between two or more than two devices. These type of services are offered by network layer. Connection oriented service is related to the telephone system. It includes the connection establishment and connection termination. In connection-oriented service, Handshake method is used to establish the connection between sender and receiver.Connection-less service is related to the postal system. It does not include any connection establishment and connection termination. Connection less Service does not give the guarantee of reliability. In this, Packets do not follow same path to reach destination.



PROMPT

A bit stream 1101011011 is transmitted using the standard CRC method. The polynomial generator is x+ x + 1. What is the actual bit string transmitted? Show the major steps to your answer.

The Generated Polynomial G(x)=x+x+1=(1+1)X + 1 =2x + 1 Since 1+1 =0 mod 2, G(x)= 1 and this is encoded as 1 in binary



PROMPT

Suppose a IP header consists of four 16-bit words: (11111111 11111111, 11111111 00000000, 11110000 11110000, 11000000 11000000). Please find the Internet checksum for the code.

b0 = 11111111 11111111 = 216 – 1 = 65535 b1 = 11111111 00000000 = 65280 b2 = 11110000 11110000 = 61680 b3 = 11000000 11000000 = 49344 x = b0 + b1 + b2 + b3 modulo 65535 = 241839 modulo 65535 = 45234 b4 = −x modulo 65535 = 20301 So the Internet checksum = 01001111 01001101



PROMPT

Suppose that a group of computers is connected to an Ethernet LAN. If the computers communicate only with each other, does it make sense to use IP protocol in the computers? Should the computers run TCP directly over Ethernet? How is addressing handled?

One thing IP does is abstract the link layer from upper  levels of the stack - there was a time where it was possible you could have Ethernet or token ring, and  there are things like PPP and HDLC, and also the loop back interface. This is something you get to decide when you create  your custom protocol above. An option if you don't want  to support routing at all is just using the MAC address.  Non-IP protocols like IPX/SPX and AppleTalk had their  own address schemes and methods to obtain host  addresses.



PROMPT

(1) The figures below show the TCP/UDP communication pattern diagrams. Which diagram works for TCP? Why?

(2) Fill the missing steps (blank boxes) in both diagrams for TCP/UDP correspondingly.

1 .Diagram - ( a ) for UDP Diagram - ( b ) for TCP 2. bind(), listen(), accept (), connect()



















1 comment:

  1. Hello,
    really appreciate your work.
    I want other 4 course assignment of this specialization computer communication course.
    Please provide us.
    I did fundamental course now remaining are
    2.Peer to peer protocols and LAN
    3.packet switching networks
    4.TCP/IP and advance
    5.project assignment
    Please provide us

    ReplyDelete