Test 2 Review Questions

Question 1

What are the protocols used in the Physical Layer

Answer 1

802.11 abng, 4G, LTE

Question 2

What are the protocols used in the Transport Layer

Answer 2

TCP

Question 3

What are the protocols used in the Network Layer

Answer 3

IP

Question 4

Of the OSI Layers, which are reliable and why?

Answer 4

Data Link, Transport and because they have ARQ Error Correction.

Question 5

What does ARQ do from the Sender Side?

Answer 5

1. Send Msg 2. Set a timer 3. Wait for an ACK

Question 6

What does ARQ do from the Receiver Side?

Answer 6

1. Receive Msg 2. Send Ack

Question 7

What happens on the sender side if the ACK arrives first?

Answer 7

1. Stop timer 2. Send next message

Question 8

What happens on the sender side if the timer goes off 1st

Answer 8

1. Send msg 2. Set a new timer

Question 9

Nodes A & B are exchanging messages using the ARQ algorithm. State which action node B should take? Node A Node B M(3) ->

Answer 9

Next would be the following from Node B: < – Ack(5)

Question 10

True or False? Is the Network Layer reliable

Answer 10

False, it does not have error correction.

Question 11

What is difference between TCP and UDP

Answer 11

UDP does not have error correction

Question 12

_____ labels increase the maintainability of a program:

Answer 12

Symbolic

Question 13

Java is a ___ language:

Answer 13

High level

Question 14

A program written in assembly lang is called a ____ program

Answer 14

Object

Question 15

Translators for ___ are called assemblers:

Answer 15

assembly language

Question 16

An __ operation involves comparison of values and subsequent use of the outcome to go next

Answer 16

Conditional

Question 17

The conversion of symbolic op codes such as Load, Add, Substract to binary makes uses of the structure called the ____:

Answer 17

Op code Table

Question 18

If op code table is sorted alpha, the __ search algo is used to find the op code:

Answer 18

Binary

Question 19

You have 13, 34, 35, 41, 48, 51, 54 and you are looking for the number 48, how would you use Binary Search:

Answer 19

Search by the bisection by cutting in half, looking at index related to your search, then cut that search in half to get 48. (Assume they are sorted)

Question 20

How many searches would it take to find something with 1024 elements?

Answer 20

1024 = 2^10 so log 1024 = 10 searches

Question 21

If you aren’t using the binary search to find things on a table, then you are using this type of search:

Answer 21

Sequential

Question 22

4 tasks performed by assembler:

Answer 22

1st pass: build symbol table 2nd pass: 1. Replace Symbol with binary 2. Replace Opcode with binary 3. Perform pseudo op code 4. Write to object file

Question 23

What is the most important task of an OS:

Answer 23

Manage system resources (Most important)

Question 24

HDTV images have a resolution of 1,920 x 1090 and use 24 bits to store color info for each pixel. a. What is the lowest bw to transmit such an image over a computer in less than 0.1 sec

Answer 24

Question 25

HDTV images have a resolution of 1,920 x 1090 and use 24 bits to store color info for each pixel. b. Smoother video requires at least 24 frames per second. To leave a buffer margin, consider a system that is able to transmit 30 frame per second. What kind of network connection is the slowest that would provide enough bw?

Answer 25

Bw = bits/time = 1980\*1080 [pixel/img]\* 24 [bits/pixel] 30 [img/s] = 1,492,992,000 bps = 1.492992 Gbps \* We would require han 10 Gbps since it rounds up by 10's. (Gbps = Divide by a Billion)

Question 26

The us library of congress has almost 35 million books. Assume avg book has 400 kb of text About how many bytes of data storage will be needed to store this much info online?

Answer 26

Storage = 34 M [book] x 400 [kb/book] = 14000 Mk\*B = 14000 Mk\*B x 1024^2 [B/M] x 1024 [1 Kb] = 1.5 x 10^13 B = 15 x 10^12 B x [1 TB/1024^4] = 13.67 TB

Question 27

What is HTTP

Answer 27

Hypertext Transfer Protocol

Question 28

What is FTP

Answer 28

File Transfer Protocol

Question 29

What is SMTP

Answer 29

Simple Mail Transfer Protocol

Question 30

What is POP3

Answer 30

Post Office Protocol 3

Question 31

Why is the network layer not reliable?

Answer 31

1. It doesn't have an ARQ / Error Correcting Code. 2. If sender A wanted to send a message to B, it would not be able to bypass C in between. 3. I drew the diagram kindof poorly illustrating this

Question 32

Draw 5 Bit Binary Sequence 11001 onto an an analog carrier by carrier for the Amplitude:

Answer 32

1 = Higher Amplitudes, 2 peaks each value 0 = Lower Amplitude, 2 peaks each value

Question 33

Draw 5 Bit Binary Sequence 11001 onto an an analog carrier by carrier for Frequency:

Answer 33

1 = More waves/freq 0 = less waves/freq More or less draw this (it isn't perfect):