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Correct OPTION is (a) stream control transmission protocol

Explanation: The Stream Control Transmission Protocol (SCTP) is a transport LAYER protocol used in networking system where streams of data are to be continuously transmitted between TWO connected network nodes. Some of the other transport layer protocols are RDP, RUDP, TCP, DCCP, UDP ETC.

Right answer is (b) process to process communication

Easy explanation: Transport layer is 4th layer in TCP/IP MODEL and OSI reference model. It DEALS with LOGICAL communication between process. It is responsible for DELIVERING a message between NETWORK host.

Correct answer is (a) port

Easy EXPLANATION: Just as the IP ADDRESS identifies the COMPUTER, the network port identifies the application or service running on the computer. A port number is 16 bits. The COMBINATION of IP address preceded with the port number is called the socket address.

Right choice is (a) datagram CONGESTION CONTROL protocol

Easy explanation: The datagram congestion control is a transport layer protocol which deals with reliable connection setup, teardown, congestion control, explicit congestion notification, and feature negotiation. It is used in MODERN DAY systems where there are really HIGH chances of congestion. The protocol was last updated in the year 2008.

Right option is (B) winsock

For EXPLANATION: Winsock is a PROGRAMMING interface which deals with input output requests for internet applications in windows OS. It defines how windows network software should ACCESS network services.

Right answer is (a) socket

Explanation: Socket is ONE END point in a two way communication link in the network. TCP layer can IDENTIFY the application that DATA is DESTINED to be sent by using the port number that is bound to socket.

The CORRECT answer is (d) all of the mentioned

To explain: TCP provides RELIABLE and ordered delivery of a stream of BYTES between hosts communicating via an IP network. Major internet applications like WWW, email, file transfer etc rely on TCP. TCP is connection ORIENTED and it is optimized for accurate delivery rather than timely delivery.

The correct option is (a) network layer

The best I can explain: The flow of data in the OSI model flows in following manner APPLICATION -> Presentation -> Session -> TRANSPORT -> Network -> Data Link -> Physical. Each and every layer has its own set of functions and protocols to ENSURE efficient network performance.

Right choice is (a) error and diagnostic functions

To explain: ICMP abbreviation for Internet CONTROL MESSAGE Protocol is used by networking devices to send error MESSAGES and operational information indicating a host or router cannot be reached. ICMP OPERATES over the IP packet to provide error reporting functionality as IP by itself cannot report errors.

Right option is (b) internet protocol

Easy EXPLANATION: There are several protocols USED in Network LAYER. Some of them are IP, ICMP, CLNP, ARP, IPX, HRSP ETC. Hypertext TRANSFER protocol is for application layer and ethernet protocol is for data link layer.

Right ANSWER is (d) routing information protocol

The best I can explain: The Routing Information Protocol (RIP) is used by the network layer for the function of dynamic routing. Congestion control focuses on the flow of the traffic in the network and uses ALGORITHMS LIKE traffic AWARE routing, ADMISSION control and load shedding to deal with congestion.

Right option is (a) spanning tree

Best explanation: Spanning tree protocol (STP) is a network protocol that creates a LOOP free logical topology for ethernet networks. It is a LAYER 2 protocol that runs on bridges and switches. The MAIN purpose of STP is to ENSURE that you do not create loops when you have redundant PATHS in your network.

Right option is (d) all of the mentioned

For explanation I would SAY: The routing algorithm is what decides where a packet should GO next. There are SEVERAL routing techniques like shortest path algorithm, static and dynamic routing, decentralized routing, distance vector routing, LINK state routing, Hierarchical routing etc. The routing algorithms go hand in hand with the operations of all the routers in the networks. The routers are the main participants in these algorithms.

Correct answer is (c) network address & HOST address

Easy EXPLANATION: An ip address which is 32 bits long, that means it is of 4 bytes and is composed of a network and host portion and it depends on address class. The size of the host address and network address depends upon the class of the address in CLASSFUL IP addressing.

Right choice is (d) error control

The BEST EXPLANATION: In the OSI MODEL, network layer is the third layer and it provides data routing paths for network COMMUNICATIONS. Error control is a function of the data LINK layer and the transport layer.

The correct answer is (c) packets

The best explanation: In computer networks, the data from the application layer is sent to the transport layer and is converted to SEGMENTS. These segments are then transferred to the NETWORK layer and these are CALLED packets. These packets are then sent to data LINK layer where they are encapsulated into frames. These frames are then transferred to physical layer where the frames are converted to BITS.

The CORRECT choice is (a) piggybacking

The explanation: Piggybacking is a technique in which the acknowledgment is TEMPORARILY delayed so as to be hooked with the next outgoing DATA FRAME. It SAVES a lot of channel bandwidth as in non-piggybacking system, some bandwidth is reserved for acknowledgement.

The correct answer is (c) Both CSMA/CD & CSMA/CA

For explanation: In CSMA/CD, it DEALS with detection of collision after collision has occurred, whereas CSMA/CA deals with PREVENTING collision. CSMA/CD is abbreviation for Carrier Sensing MULTIPLE ACCESS/Collision detection. CSMA/CA is abbreviation for Carrier Sensing Multiple Access/Collision Avoidance. These protocols are used for efficient multiple channel access.

The correct ANSWER is (d) all of the mentioned

The explanation is: There are many data link layer PROTOCOLS. Some of them are SDLC (synchronous data link protocol), HDLC (High level data link CONTROL), SLIP (serial LINE interface protocol), PPP (Point to point protocol) etc. These protocols are used to provide the LOGICAL link control function of the Data Link Layer.

Right answer is (a) cyclic redundancy CHECK

Best explanation: Cyclic redundancy check is a code that is added to a data which helps us to identify any ERROR that occurred during the TRANSMISSION of the data. CRC is only able to DETECT errors, not correct them. CRC is inserted in the frame trailer.

Right answer is (b) burst error

Explanation: When a SINGLE BIT error occurs in a data, it is CALLED single bit error. When more than a single bit of data is corrupted or has error, it is called burst error. If a single bit error occurs, the bit can be simply repaired by inverting it, but in CASE of a burst error, the sender has to send the frame again.

Correct option is (a) logical link control sublayer

The explanation is: The logical link control is a sublayer of data link layer whose main function is to manage traffic, flow and error control. The automatic repeat request error management mechanism is provided by the LLC when an error is FOUND in the RECEIVED FRAME at the receiver’s end to inform the sender to re-send the frame.

Right answer is (d) all of the mentioned

To explain: In a frame, the header is a PART of the data that CONTAINS all the REQUIRED information about the transmission of the file. It contains information like synchronization bytes, ADDRESSES, frame identifier etc. It also contains error control information for reducing the errors in the transmitted frames.

The correct OPTION is (B) media access control sublayer

The BEST I can explain: Media access control (MAC) deals with transmission of data packets to and from the network-interface card, and ALSO to and from another remotely shared channel. The MAC sublayer also prevents collision using protocols like CSMA/CD.

Right option is (d) channel coding

The best I can EXPLAIN: Channel coding is the FUNCTION of physical layer. DATA link layer mainly deals with framing, ERROR control and flow control. Data link layer is the layer where the packets are encapsulated into FRAMES.

Correct option is (a) network layer

The best explanation: In computer networks, the data from application layer is sent to transport layer and is converted to SEGMENTS. These segments are then transferred to the network layer and these are CALLED packets. These packets are then sent to data link layer where they are encapsulated into FRAMES. These frames are then transferred to physical layer where the frames are converted to bits. Error control and FLOW control data is inserted in the frames at the data link layer.

Right answer is (d) all of the mentioned

To ELABORATE: Wireless transmission is carried out by radio waves, MICROWAVES and IR waves. These waves RANGE from 3 Khz to above 300 GHZ and are more suitable for wireless transmission. Radio waves can penetrate through walls and are used in radio communications, microwaves and infrared (IR) waves cannot penetrate through walls and are used for satellite communications and device communications respectively.

Correct answer is (c) multiplexing

The best I can explain: In communication and COMPUTER networks, the main goal is to share a scarce RESOURCE. This is DONE by multiplexing, where multiple analog or digital signals are combined into one signal over a shared medium. The multiple KINDS of signals are designated by the transport layer which is the layer present on a higher level than the physical layer.

Correct answer is (a) DATA link layer

The BEST I can explain: Physical layer accepts data or information from the data link layer and converts it into HARDWARE specific operations so as to transfer the message through physical cables. Some examples of the cables USED are OPTICAL fiber cables, twisted pair cables and co-axial cables.

The correct option is (d) all of the mentioned

To explain I would say: The physical layer is RESPONSIBLE for line CODING, channel coding and modulation that is needed for the transmission of the information. The physical configuration including PINS, connectors and the electric current used is dealt in the physical layer based on the requirement of the NETWORK application.

The correct option is (C) both start & stop signalling and flow control

The best explanation: In asynchronous SERIAL COMMUNICATION, the communication is not synchronized by clock signal. Instead of a start and stop SIGNALING and flow control METHOD is followed. Unlike asynchronous serial communication, in synchronous serial communication a clock signal is used for communication, so the start and stop method is not really required.

Right choice is (a) physical signalling sublayer

Explanation: The portion of physical layer that INTERFACES with the medium ACCESS control sublayer is Physical Signaling Sublayer. The main function of this layer is character encoding, RECEPTION, decoding and performs optional isolation functions. It handles which media CONNECTION the signal should be forwarded to PHYSICALLY.

The correct ANSWER is (a) digital MODULATION

The EXPLANATION is: In analog modulation, digital low frequency baseband signal (digital bit stream) is TRANSMITTED over a higher frequency. Whereas in digital modulation the only difference is that the base band signal is of discrete amplitude level. The bits are REPRESENTED by only two frequency levels, one for high and one for low.

Correct option is (c) optical fiber

The best I can explain: Fiber optics is considered to have the HIGHEST transmission speed among the all mentioned above. The fiber optics transmission runs at 1000Mb/s. It is called as 1000Base-Lx WHEREAS IEEE STANDARD for it is 802.3z. It is popularly USED for modern day network CONNECTIONS due to its high transmission rate.

Right OPTION is (a) bit-by-bit delivery

To explain: Physical layer deals with bit to bit delivery in networking. The data UNIT in the physical layer is bits. Process to process delivery or the PORT to port delivery is DEALT in the TRANSPORT layer. The various transmission mediums aid the physical layer in performing its functions.