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........

Next Part: Part-4

For Part-2: Click Here