Description : Engaged tone is generated in the: (A) Telephone instrument of calling subscriber (B) Telephone instrument of called subscriber (C) Exchange (D) Repeater
Last Answer : (C) Exchange
Description : The situation when both transmitter and receiver have to work in tandem is referred to as (A) parallel (B) serial (C) synchronous (D) asynchronous
Last Answer : (C) synchronous
Description : Network with point-to-point link is known as (A) Fully Connected Network (B) Half Connected Network (C) Duplex Connected Network (D) None of these
Last Answer : (A) Fully Connected Network
Description : A special service circuit connecting two private branch exchanges (PBX). A. Phantom line B. Private line C. Tie trunk D. Tandem trunk
Last Answer : C. Tie trunk
Description : What are the different ways of designing 100 line exchange using uni selector and two motion selectors? Show at least three variations. Which is the best option?
Last Answer : Here three different designing methods for 100 line exchange are discussed: Design 1: Here, Strowger switching system is designed using one two-motion selector for each subscriber. A ... only under certain specific traffic conditions and generally lead to higher blocking probabilities.
Description : Explain crossbar exchange, with all call processing steps and diagrams
Last Answer : The basic idea of crossbar switching is to provide a matrix of n x m sets of contacts with only n + m activators or less to select one of the n x m sets of contacts. This form of ... a contact is established at the cross point 6 such that the subscriber B is connected to the subscriber C.
Description : In a hundred-line exchange 24 two-motion selectors are used. Draw the schematic you suggest for this exchange and explain its working. How many simultaneous calls can be made during peak hour in this exchange?
Last Answer : The desired schematic for 100 lines exchange with 24 two motion selectors is shown in Fig. In the case, 24 simultaneous calls can be put through the switch . Typically, a 24- ... selector. At the next step, the two-motion selector responds to the dial pulses for appropriate connection.
Description : Write short notes (i)Telephone hand set and it’s working. (ii) CPU based exchange
Last Answer : (i) A standard telephone set is comprised of a transmitter, a receiver, and electrical network for equalization, associated circuitry to control side tone levels and to regulate signal power, ... commands are designed to be of variable length necessitating the use of an end-of-command symbol
Description : Name the switching schemes used in a digital exchange. How call processing takes place?
Last Answer : The different switching systems used are: 1. Strowger Switching System 2. Cross bar Switching. 3. Electronic Switching System Basic Call Procedure: Fig. Shows a simplification ... machine detects an open circuit on that loop and then drops the connections through the switch.
Description : Using a combination of uniselectors and two motion selectors, draw a schematic of thousand line exchange and explain its working.
Last Answer : The schematic diagram for such an exchange is given in Fig. Each subscriber is connected to a single rotary pre-selector switch at the exchange, the outputs from this switch being ... further digits, connection is established, providing the called subscriber's to answer his telephone.
Description : Trunks are the lines that run between (A) Subscribers and exchange (B) Switching system and power plant (C) Local area network (D) Switching stations
Last Answer : (D) Switching stations
Description : Signalling transfer point (STP) exist in (A) Strowger exchange (B) SS7 (C) Local area network (D) PABX
Last Answer : (B) SS7
Description : Trunks are the lines that run between (A) subscribers and exchange (B) switching system and power plant (C) Local Area Network (D) switching systems
Last Answer : (B) switching system and power plant
Description : SPC is used for (A) Carrying Exchange Control Functions (B) Carrying Subscriber Control Functions (C) Exchange Hardware (D) Signalling Purpose
Last Answer : (A) Carrying Exchange Control Functions
Description : Trunks are the lines that run between (A) Subscribers and exchange (B) switching system and power plant (C) Local area network. (D) Switching stations.
Last Answer : (D) Switching stations.
Description : A distributed network configuration in which all data/information pass through a central computer is (A) Bus network (B) Star network (C) Ring network (D) Point to point network
Last Answer : (B) Star network
Description : Ethernet 10 Base 2 is an example of ______network topology. (A) Bus (B) Ring (C) Star (D) Mesh
Last Answer : (A) Bus
Description : In step by step switching line finders are connected to the (A) Calling subscriber. (B) Switching network. (C) Called subscriber. (D) Between exchanges.
Last Answer : (A) Calling subscriber.
Description : The final selector is connected to the (A) calling subscriber. (B) switching network. (C) called subscriber. (D) line finder.
Last Answer : (C) called subscriber
Description : Using_________each connected device is assigned a time slot whether or not the device has any thing to send. (A) WDM (B) FDM (C) TDM (D) STDM
Last Answer : (C) TDM
Description : A large numbers of computers in a wide geographical area can be efficiently connected using (A) twisted pair lines (B) coaxial cables (C) Communication satellites (D) all of the above
Last Answer : (D) all of the above
Description : The number of point to point links required in a fully connected network for 50 entities is (A) 1250 (B) 1225 (C) 2500 (D) 50
Last Answer : Ans: (C)
Description : A ________is a device in which the stations are completely unaware of its existence. A) passive hub B) repeater C) simple bridge D) transparent bridge
Last Answer : transparent bridge
Description : A ______ has a tableused in filtering decisions. A) passive hub B) repeater C) bridge D) none of the above
Last Answer : bridge
Description : A _______ can check the MAC addresses contained inthe frame. A) passive hub B) repeater C) bridge D) route
Description : A ________operates in both thephysical andthe data link layer. A) passive hub B) repeater C) bridge D) router
Description : A __________ forwards every frame; it has no filteringcapability. A) passive hub B) repeater C) bridge D) router
Last Answer : repeater
Description : A ________receivesa signal and,before it becomes too weak or corrupted, regenerates the original bit pattern. It thensends the refreshed signal. A) passive hub B) repeater C) bridge D) router
Description : Which of the following device is used to connect two systems, especially if the systems use differentprotocols? A. hub B. bridge C. gateway D. repeater E. None of the above
Last Answer : gateway
Description : If all devices are connected to a central hub, then topology is called A) Bus Topology B) Ring Topology C) Star Topology D) Tree Topology
Last Answer : C) Star Topology
Description : In a star network each node (file server, workstations and peripherals) is connected to a central device called a _____: a) Bug b) Center c) Hub d) None of These
Last Answer : c) Hub
Description : What do you mean by numbering and addressing? Draw the ISDN address structure and explain how the addressing works?
Last Answer : Numbering and Addressing: In telephone and data networks, the end equipments are more often single units than multiple devices units like PABX or LAN. Historically, a telephone, a computer, or a ... as reference point may also be addressed by using direct inward dialing (DID) feature.
Description : Explain the process of inter-register signalling.
Last Answer : Registers are used in common control exchanges to store and analyze routing data. They are provided on a common basis is a single register provides routing data for a number of speech circuits. Once a call ... it is released and the originating register signals to the next register.
Description : Draw a centralized SPC organization and explain how it works under load sharing operation.
Last Answer : In centralized control, all the control equipment is replaced by a single processor which must be quite powerful. It must be capable of processing 10 to 100 calls per second, depending on the ... both the processors are active simultaneously and share the load and the resources dynamically.
Description : Explain FDM and show how CCITT standards help in building the base band?
Last Answer : Frequency Division Multiplexing: It is the process of combining several information channels by shifting their signals to different frequency groups within the spectrum so that they can be transmitted simultaneously ... of 24 channels were assembled together in one stage of modulation.
Description : What are transmission bridges? How do they help in satisfying the connectivity?
Last Answer : A typical transmission bridge is shown in Fig. The series capacitance and the shunt inductances of the two relays provide a high-pass filter to transmit the AC speech signals, while the relays respond independently to the DC loop/disconnect signals from the calling and called customer.
Description : How numbering plan is achieved in modern telephony? Give the structure with example.
Last Answer : The objective of numbering plan is to uniquely identify every subscriber connected to a telecommunication network. A numbering plan may be open, semiopen or closed. An open-numbering plan permits wide ... known as the subscriber number which is the number listed in the telephone directory.
Description : How does a touch tone receiver differs from pulsed dial receiver? Explain with schematic.
Last Answer : Pulse dialing: 1. Generated through make and break contact. 2. DC Current pulse is generated. 3. Each number is separated by a short pause to prevent overlapping. 4. Codes ... dialing pulse is not misinterpreted as the phone being returned to its on-hook (idle) condition.
Description : Discuss different Routing plan adopted in a Telephone network.
Last Answer : Hierarchical networks are capable of handing heavy traffic where required, and at the same time use minimal number of trunk groups. Three methods are used for deciding on the route for a ... selection methods can be implemented. Computer based routing is a standard feature in data networks.
Description : Discuss briefly subscriber loop system. Give some technical specification for subscriber lines.
Last Answer : Subscriber Loop System: Every subscriber in a telephone network is connected generally to the nearest switching office by means of a dedicated pair of wires. Subscriber loop refers to this pair of wires. It is un ... 1. Diameter of wire 2. D.C. resistance per Km 3. Attenuation per Km
Description : What is Traffic Engineering? Define the term busy hour, traffic intensity and grade of service.
Last Answer : Traffic engineering provides the basis for analysis and design of telecommunication network to carry a given traffic at a particular loss probability. It provides a means to determine the quantum of common equipments ... A0 Where A= offered traffic A0 = carried traffic A-A0= lost traffic
Description : Explain topology method used in LAN technology in detail.
Last Answer : LAN Topologies: Network topology is a physical schematic which shows interconnection of the many users. There are four basic topologies as under: (i) Direct Connection or one to all topology ( ... temporarily, inserting the new node and then reestablishing the complete ring path.
Description : List all seven layer of OSI model and describe function of application layer.
Last Answer : The layers of OSI model are as follows: (1) The Physical Layer: This defines an interface in terms of the connections, voltage levels and data rate, in order for signals to ... with the applications programs needed. Examples include electronic mail, word processing, banking transactions, etc.
Description : Find the total number of link L having five entities? Explain differences between folded and non-folded network.
Last Answer : Folded network: When all the inlets/outlets are connected to the subscriber lines, the logical connection appears as shown in Fig. In this case, the output lines are folded back to the input ... non-folded network to be non-blocking, the network should support N simultaneous switching paths.
Description : Explain simple telephone communication system with circuit and equation of current flow in microphone?
Last Answer : Simple Telephone Communication: In the simplest form of a telephone circuit, there is one way communication involving two entities, one receiving (listening) and the other transmitting (talking). ... carrier wave in AM system. The quantity m is equivalent to the modulation index in AM.
Description : What are the advantages and disadvantages of packet switching over circuit switching?
Last Answer : The comparison of packet switching and circuit switching showing advantages and disadvantages of packet switching over circuit switching is given below:
Description : What is a Modem? What is the need of MODEM in data communication? Explain at least one modulation technique used for high speed modems.
Last Answer : Modems are essentially used to interface digital circuits to transmit information on analogue channels like telephone systems. Modem (from modulator-demodulator) is a device that modulates an analogue carrier ... caused by the lines makes the detection even harder than amplitude modulation.
Description : What are the advantages of CCS over in-channel signalling?
Last Answer : The advantages of CCS over in-channel signalling are listed below: a. Information can be exchange between the processors much more rapidly than when channel associated signaling is used. b ... for functions other than call processing, for example for maintenance or network management purposes.
Description : Explain the CCITT hierarchical structure of switching and routing using block schematic.
Last Answer : Hierarchical network are capable of handing heavy traffic where required, and at the same time use minimal number of trunk groups. A 5-level switching hierarchy is recommended by CCITT as ... A strictly hierarchical network suffers from serious drawback i.e. its poor fault tolerance future.