Data Communication and Networks

BNC are the T-shaped connectors, used to connect the cable, at two ends and NIC's .

Photodiode is used at a receiving end of an optical fiber. They convert optical signals back into electrical impulses that are used by the receiving end of the fiber optic data, video or audio link.

It has a multiring functionality, so we can say, it looks like a FDDI. Both species 100 mbps token passing rings, two rings and one ring for a backbone.

X.25 is a subset of HDLC protocol. It enables to form a logical link connection, besides all the other characterstics of HDLC.

Full Duplex is communication in both directions, at a same time, like in the case of telecommunication, the user and the sender, comminicate with each other at a same time.

Increase in data transmission rate leads to a higher number of packets, being transmitted at the same time.

Presentation layer does the duty of encryption and decryption.

 Session layer is responsible for token management service. Tokens are used to identify the side, that may perform the critical operation.

Repeater is a device used to regenerate the electric signal, in order to extend the LAN segment beyond its physical limits. It works on the physical layer because of signals.

Usually traffic is measured in telephone network by erlangs. Erlangs is a measure of transmission, of the telephone network.

All of the above answers are incorrect because subnet usually comprises the Network layer. The Network Layer is known as the communication subnet layer, which controls operations of subnets by determining how packets are to be distributed /routed between the networks (subnets).

Layer -4 is a transport layer in which UDP (user datagram protocol ) and IP (internet protocol ) are present. There are five classes of standards for transport layer, which differ in degree of error recovery. 

TDR stands for Time Domain Reflectometry. It is a method for detecting fault and breaks in the cable. TDR measures the time it takes for signal, to travel down the cable and reflect back.

All the above answers are incorrect because frame format of CSMA/CD and Ethernet protocol, differ in size of preamble and address blocks.

Limited bandwidth limits the data rate, and leads to distortion, in the signal shape.

Trans-receiver is used for carrier detection and collision detection in LAN's. These detections are called CSMA/CD.

QAM is used in high speed modem. QAM - Quadrature Amplitude modulation is a combination of amplitude and phase modulation to obtain greater throughput in a given channel.

FDDI can spread over 200 kms. For large networks, it requires more repeaters.

All the above answers are wrong, because half duplex operations involves data flow in only one direction at a time. It is a two wire transmission with medium cost and efficiency.

Frame relay uses connection oriented switching technique because synchronous frames of data are routed to different destinations depending on header information.

Switches are better than the hubs. Switches amplify the bandwidth, so that the same throughput is provided, to each of the machines, connected to the switch. On the other hand, hub simply divides the throughput equally among various nodes, connected to it.

The 10 base 5 permits five cable segments, multiple 10 base 5 segments may be connected through repeaters to form a larger network, that still consists of a single collision domain. A repeater regenerates the signals from receiving it from one cable segment, and transmitting to all cables.

Range of ip address is from 224.0.0.0 to 239.255.255.255 used for multicast packets. It is used to transmit the same packet, from a single source, to a group of selected destinations.

Protocols are the rules of communication. Protocols are the rules that govern a communication exchange.

 A transmission of digital signal, at origianal frequency, without modulation, is called baseband signaling, which does not require any modulation technique.