Networking interview question Part-5

61. What is Fixed Size Framing?

In fixed-size framing, there is no need for defining the boundaries of the frames. The size itself can be used as a delimiter.

62. Define Character Stuffing?

 In byte stuffing (or character stuffing), a special byte is added to the data section of the frame when there is a character with the same pattern as the flag. The data section is stuffed with an extra byte. This byte is usually called the escape character (ESC), which has a predefined bit pattern. Whenever the receiver encounters the ESC character, it removes it from the data section and treats the next character as data, not a delimiting flag.

 63. What is Bit Stuffing?

Bit stuffing is the process of adding one extra 0 whenever five consecutive Is follow a 0 in the data, so that the receiver does not mistake the pattern 0111110 for a flag.

64. What is Flow Control?

 Flow control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment.

65. What is Error Control ?

Error control is both error detection and error correction. It allows the receiver to inform the sender of any frames lost or damaged in transmission and coordinates the retransmission of those frames by the sender. In the data link layer, the term error control refers primarily to methods of error detection and retransmission.

66. What Automatic Repeat Request (ARQ)?

 Error control is both error detection and error correction. It allows the receiver to inform the sender of any frames lost or damaged in transmission and coordinates the retransmission of those frames by the sender. In the data link layer, the term error control refers primarily to methods of error detection and retransmission. Error control in the data link layer is often implemented simply: Any time an error is detected in an exchange, specified frames are retransmitted. This process is called automatic repeat request (ARQ).

67. What is Stop-and-Wait Protocol?

 In Stop and wait protocol, sender sends one frame, waits until it receives confirmation from the receiver (okay to go ahead), and then sends the next frame.

68. What is Stop-and-Wait Automatic Repeat Request?

 Error correction in Stop-and-Wait ARQ is done by keeping a copy of the sent frame and retransmitting of the frame when the timer expires.

69. What is usage of Sequence Number in Relaible Transmission?

The protocol specifies that frames need to be numbered. This is done by using sequence numbers. A field is added to the data frame to hold the sequence number of that frame. Since we want to minimize the frame size, the smallest range that provides unambiguous communication. The sequence numbers can wrap around.

70. What is Pipelining ?

In networking and in other areas, a task is often begun before the previous task has ended. This is known as pipelining.

 71. What is Sliding Window?

 The sliding window is an abstract concept that defines the range of sequence numbers that is the concern of the sender and receiver. In other words, he sender and receiver need to deal with only part of the possible sequence numbers.

 72. What is Piggy Backing?

A technique called piggybacking is used to improve the efficiency of the bidirectional protocols. When a frame is carrying data from A to B, it can also carry control information about arrived (or lost) frames from B; when a frame is carrying data from B to A, it can also carry control information about the arrived (or lost) frames from A.

 73. What are the two types of transmission technology available?

(i) Broadcast and

(ii) point-to-point

74. What is subnet?

 A generic term for section of a large networks usually separated by a bridge or router.

75. Difference between the communication and transmission.

Transmission is a physical movement of information and concern issues like bit polarity, synchronisation, clock etc. Communication means the meaning full exchange of information between two communication media. 

Thank You........

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Networking interview question Part-4

46. What is LRC?

In LRC, a block of bits is divided into rows and a redundant row of bits is added to the whole block. It can detect burst errors. If two bits in one data unit are damaged and bits in exactly the same positions in another data unit are also damaged, the LRC checker will not detect an error. In LRC a redundant data unit follows n data units.

47. What is CRC?

CRC, is the most powerful of the redundancy checking techniques, is based on binary division.

48. What is Checksum?

Checksum is used by the higher layer protocols (TCP/IP) for error detection

49. List the steps involved in creating the checksum.

a. Divide the data into sections

b. Add the sections together using 1's complement arithmetic

c. Take the complement of the final sum, this is the checksum.

50. What are the Data link protocols?

Data link protocols are sets of specifications used to implement the data link layer. The categories of Data Link protocols are 1. Asynchronous Protocols 2. Synchronous Protocols

a. Character Oriented Protocols

b. Bit Oriented protocols

51. Compare Error Detection and Error Correction:

The correction of errors is more difficult than the detection. In error detection, checks only any error has occurred. In error correction, the exact number of bits that are corrupted and location in the message are known. The number of the errors and the size of the message are important factors.

52. What is Forward Error Correction?

Forward error correction is the process in which the receiver tries to guess the message by using redundant bits.

53. Define Retransmission?

Retransmission is a technique in which the receiver detects the occurrence of an error and asks the sender to resend the message. Resending is repeated until a message arrives that the receiver believes is error-freed.

 54. What are Data Words?

In block coding, we divide our message into blocks, each of k bits, called datawords. The block coding process is one-to-one. The same dataword is always encoded as the same codeword.

55. What are Code Words?

 "r" redundant bits are added to each block to make the length n = k + r. The resulting n-bit blocks are called codewords. 2n - 2k codewords that are not used. These codewords are invalid or illegal.

56. What is a Linear Block Code?

A linear block code is a code in which the exclusive OR (addition modulo-2) of two valid codewords creates another valid codeword.

57. What are Cyclic Codes?

Cyclic codes are special linear block codes with one extra property. In a cyclic code, if a codeword is cyclically shifted (rotated), the result is another codeword.

58. Define Encoder?

A device or program that uses predefined algorithms to encode, or compress audio or video data for storage or transmission use. A circuit that is used to convert between digital video and analog video.

59. Define Decoder?

 A device or program that translates encoded data into its original format (e.g. it decodes the data). The term is often used in reference to MPEG-2 video and sound data, which must be decoded before it is output.

60. What is Framing?

 Framing in the data link layer separates a message from one source to a destination, or from other messages to other destinations, by adding a sender address and a destination address. The destination address defines where the packet has to go and the sender address helps the recipient acknowledge the receipt.

Thank You----

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Networking interview question Part-3

31. Which layer links the network support layers and user support layers?

The Transport layer links the network support layers and user support layers.

32. What are the concerns of the Physical Layer?

Physical layer coordinates the functions required to transmit a bit stream over a physical medium.

a. Physical characteristics of interfaces and media

b. Representation of bits

c. Data rate

d. Synchronization of bits

e. Line configuration

f. Physical topology

g. Transmission mode

33. What are the responsibilities of Data Link Layer?

The Data Link Layer transforms the physical layer, a raw transmission facility, to a reliable link and is responsible for node-node delivery.

a. Framing

b. Physical Addressing

c. Flow Control

d. Error Control

e. Access Control

34. What are the responsibilities of Network Layer?

The Network Layer is responsible for the source-to-destination delivery of packet possibly across multiple networks (links).

 a. Logical Addressing

 b. Routing

35. What are the responsibilities of Transport Layer?

The Transport Layer is responsible for source-to-destination delivery of the entire message.

 a. Service-point Addressing

b. Segmentation and reassembly

c. Connection Control

d. Flow Control e. Error Control

36. What are the responsibilities of Session Layer?

The Session layer is the network dialog Controller. It establishes, maintains and synchronizes the interaction between the communicating systems.

a. Dialog control

b. Synchronization

37. What are the responsibilities of Presentation Layer?

 The Presentation layer is concerned with the syntax and semantics of the information exchanged between two systems.

a. Translation

b. Encryption

c. Compression

38. What are the responsibilities of Application Layer?

The Application Layer enables the user, whether human or software, to access the network. It provides user interfaces and support for services such as e-mail, shared database management and other types of distributed information services.

a. Network virtual Terminal

b. File transfer, access and Management (FTAM)

c. Mail services

d. Directory Services

39. What are the two classes of hardware building blocks?

Nodes and Links.

40. What are the different link types used to build a computer network?

 a. Cables

b. Leased Lines

c. Last-Mile Links

d. Wireless Links

41. What are the categories of Transmission media?

a. Guided Media

i. Twisted - Pair cable 1. Shielded TP,  2. Unshielded TP

ii. Coaxial Cable

iii. Fiber-optic cable

b. Unguided Media

i. Terrestrial microwave

ii. Satellite Communication

42. What are the types of errors?

a. Single-Bit error In a single-bit error, only one bit in the data unit has changed

b. Burst Error A Burst error means that two or more bits in the data have changed.

43. What is Error Detection? What are its methods?

Data can be corrupted during transmission. For reliable communication errors must be deducted and Corrected. Error Detection uses the concept of redundancy, which means adding extra bits for detecting errors at the destination. The common Error Detection methods are

a. Vertical Redundancy Check (VRC)

b. Longitudinal Redundancy Check (VRC)

c. Cyclic Redundancy Check (VRC)    

d. Checksum

 44. What is Redundancy?

The concept of including extra information in the transmission solely for the purpose of comparison. This technique is called redundancy.

45. What is VRC?

It is the most common and least expensive mechanism for Error Detection. In VRC, a parity bit is added to every data unit so that the total number of 1s becomes even for even parity. It can detect all single-bit errors. It can detect burst errors only if the total number of errors in each data unit is odd.

Thank You........

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Networking interview question Part-2

16. Define Routing?

The process of determining systematically hoe to forward messages toward the destination nodes based on its address is called routing.

17. What is a peer-peer process?

The processes on each machine that communicate at a given layer are called peer-peer process.

18. When a switch is said to be congested?

It is possible that a switch receives packets faster than the shared link can accommodate and stores in its memory, for an extended period of time, then the switch will eventually run out of buffer space, and some packets will have to be dropped and in this state is said to congested state.

19. What is semantic gap?

Defining a useful channel involves both understanding the applications requirements and recognizing the limitations of the underlying technology. The gap between what applications expects and what the underlying technology can provide is called semantic gap.

20. What is Round Trip Time?

The duration of time it takes to send a message from one end of a network to the other and back, is called RTT.

 21. Define the terms Unicasting, Multicasting and Broadcasting?

 If the message is sent from a source to a single destination node, it is called Unicasting. If the message is sent to some subset of other nodes, it is called Multicasting. If the message is sent to all the m nodes in the network it is called Broadcasting.

22. What is Multiplexing?

Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link.

23. Name the categories of Multiplexing?

a. Frequency Division Multiplexing (FDM)

 b. Time Division Multiplexing (TDM)

i. Synchronous TDM

ii. ASynchronous TDM Or Statistical TDM.

c. Wave Division Multiplexing (WDM)

24. What is FDM?

FDM is an analog technique that can be applied when the bandwidth of a link is greater than the combined bandwidths of the signals to be transmitted.

25. What is WDM?

WDM is conceptually the same as FDM, except that the multiplexing and DE multiplexing involve light signals transmitted through fiber optics channel.

26. What is TDM?

TDM is a digital process that can be applied when the data rate capacity of the transmission medium is greater than the data rate required by the sending and receiving devices.

 27. What is Synchronous TDM?

In STDM, the multiplexer allocates exactly the same time slot to each device at all times, whether or not a device has anything to transmit.

 28. List the layers of OSI ?

a. Physical Layer

b. Data Link Layer

c. Network Layer

d. Transport Layer

e. Session Layer

f. Presentation Layer

g. Application Layer

29. Which layers are network support layers?

a. Physical Layer b. Data link Layer and

c. Network Layers

30. Which layers are user support layers?

a. Session Layer 

b. Presentation Layer and

            c. Application Layer 

Thank You.........

Next Part: Part-3

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Starting Publisher 2007

Note:  You should be competent in a word processing program before you attempt this Tutorial.

Microsoft Publisher 2007 is a really neat program that allows you to create professional quality newsletters, brochures, flyers, postcards, calendars, award certificates, calling cards, paper airplanes, origami – and a whole lot more great “things.”

This tutorial will proceed from what we think is the easiest publication to the most complex.  First we’ll create a flyer using Microsoft Publisher 2007.  Then, we’ll create a brochure, and finally a newsletter.  Each skill we learn in the flyer will be of use in the brochure. The flyer and brochure techniques will also be used in the newsletter.  Your abilities will grow from publication to publication.  You may save your publications on a formatted 3 ½ inch diskette, a USB key, or on your hard drive.

To load the Microsoft Publisher 2007 program, Double click on the Publisher 2007 icon on the main Windows screen, or click-on Start in the lower left corner of the screen, then click-on Programs, and then click on Microsoft Publisher 2007.

You should now be in the Microsoft Publisher 2007 main screen. 

On the center of your screen you should see the view below.

On the left side of the screen you will see the Microsoft Publisher Task Pane (like the image on the right).  We’ll use the Publications from Print area to initially begin each publication. 

For “old” Publisher users, the Task Pane is something new in Publisher XP/2002-2007.  It replaces the Microsoft Publisher Catalog that was a part of the initial Publisher 2000 screen. 

In the Microsoft Publisher Task Pane, you’ll see all of the different Publications you can create.

On the right side of the screen you will see the Recent Publications Task Pane (like the image below).  This is really handy if you want to return to a publication and make some changes.  All you have to do is click the publication and it will open.

In this tutorial, whenever we indicate that you need to click a mouse button, it will mean to click the left mouse button – unless we indicate that you should click the right mouse button.  So, always move the cursor over the “place” we indicate and “click left” unless we tell you otherwise.

Next Post : http://itnews365.blogspot.com/2014/04/using-microsoft-publisher-task-pane.html

Using the Microsoft Publisher Task Pane

 

Click-on Flyers in Microsoft Publisher Task Pane (on the left side of your screen).  On the right side of the screen you will now see Flyer template design styles for a number of different Flyers (Accent Box, Arcs, etc.).

 

Use the “elevator bar” on the right side of the Flyers area to move up and down to see the various Flyer design templates.  Also notice that as you come to a new style that it will be highlighted in orange.  Notice, as you view the various types of Flyers, that you can have those “little tear off things” with your phone number on the bottom. We’ll show you how to do this.

 

Next, click-on Brochures in the Microsoft Publisher Task Pane.  Notice, when you click, a number of different types of brochures appear below the brochure selection (Informational, Price List, Event, etc).  Use the elevator bar on the right of the Brochures area, which now appears, to view the various types of brochures.  While you are doing this, notice the differences between the various types of brochures.

When you have viewed brochures, to your satisfaction, click-on Newsletters in the Microsoft Publisher Task Pane (as you did for Brochures and Flyers).  Notice again, there are several different types of Newsletters.  Use the elevator bar on the right of Newsletters to move down the various Newsletter styles. 

Now, proceed down the Publication Types list and click-on any of the publications in which you are interested – Postcards, Business Cards, Calendars, Award Certificates, Paper Airplanes – whatever you want to look at.

Microsoft Office Button

The Microsoft Office Button

We’ll use Microsoft Word 2007  for our initial illustrations of Ribbon, Tab and Group examples.

The first thing you’ll notice, when you open a 2007 Office application is that there is no longer a File choice in the Menu Bar.  The arrow above points to the Microsoft Office Button – which replaces File.

As you move your cursor over the Microsoft Office Button a preview image (image on right) will appear.

Click the Microsoft Office button.

When you click the Microsoft Office button, it will turn orange and a “File like” menu will appear (similar to the image on the right).

You’ll notice that you now have little images for choices and that some of them have little arrows pointing to the right.  These arrows indicate that there are additional choices for a selection.

We’ll show you one of these on the next page.

On the right side of the Microsoft Office Button menu screen you will see your most recently used files – Recent Documents (see arrow above on right).

Each Microsoft Office Button menu is tailored to its Office application (Word, Excel, PowerPoint, etc).

Move your cursor over the arrow to the right of the Print button ( 1. ), a menu of  print choices will appear on the right – under Preview and print the document ( 2. ) (image on right)

Click Print ( 3.) at the top of the Menu.

A standard Print Menu screen will appear.

It is suggested that you spend a few minutes clicking the various choices in the Microsoft Office Button menu screen to familiarize yourself with what they do.

If you look at the bottom of the Microsoft Office Button menu screen you will see two buttons.  Since we’re using Word, the buttons indicate Word Options and Exit Word.

The buttons change with each application (e.g. PowerPoint will indicate PowerPoint Options).  

When you click the Word Options button the image below will appear.  Notice, on the left side of the menu screen there are a number of choices (e.g. Personalize, Display, Proofing, etc.).  when you click a choice on the left side of the screen, the options for that choice appear on the right.  Take a few minutes and move through these choices to familiarize yourself with this menu screen.  You will see that Microsoft has placed a lot of resources that were under File-Tools-Options, in previous versions of Office, in this menu.

The last choice – Resources – furnishes a lot of online resources for the application which you are using. We clicked the Microsoft Word Resources text link and the image below appeared.

Notice all of the useful online resources available to you.