1.
***Modern (1990s and beyond) data communication networks are characterized by:
Correct Answer
E. Distributed systems that rely heavily on networking
Explanation
Modern data communication networks are characterized by distributed systems that rely heavily on networking. This means that data is not stored in a central location but is distributed across multiple systems connected through a network. These systems communicate with each other to share and exchange data, allowing for efficient and seamless data transfer. This approach allows for increased scalability, reliability, and flexibility in data communication networks.
2.
***In 1983, the Internet was split into two parts, one dedicated solely to the military and one dedicated to university research centers. The two parts were called:
Correct Answer
C. Milnet and Internet
Explanation
In 1983, the Internet was divided into two parts - Milnet and Internet. Milnet was dedicated solely to military use, while the Internet was dedicated to university research centers and other non-military purposes. This division allowed for separate networks and infrastructure to support the specific needs of the military and non-military users.
3.
***A backbone network is:
Correct Answer
A. A high speed central network that connects other networks in a distance spanning up to several miles.
Explanation
A backbone network is a high-speed central network that connects other networks over a distance spanning up to several miles. It serves as the main infrastructure for communication between different networks, allowing them to exchange data and information efficiently. The backbone network acts as a central hub, providing a reliable and fast connection for data transmission between various networks within its range.
4.
***The ____________ layer of the OSI model is responsible for data format translation.
Correct Answer
B. Presentation
Explanation
The presentation layer of the OSI model is responsible for data format translation. This layer ensures that the data is properly formatted and compatible with the receiving system. It takes care of tasks such as data compression, encryption, and decryption. By translating the data into a standard format, the presentation layer allows different systems to communicate effectively, regardless of their specific data formats.
5.
***In the Internet model, the application layer corresponds to the ________, layer(s) s of the OSI model.
Correct Answer
B. Session, presentation and application
Explanation
In the Internet model, the application layer corresponds to the session, presentation, and application layers of the OSI model. This means that the application layer in the Internet model performs similar functions as the session, presentation, and application layers in the OSI model. These layers are responsible for managing communication sessions, data formatting and encryption, and providing user interfaces and application services.
6.
***Which is not a function of the physical layer:
Correct Answer
C. Providing error-free transmission of data.
Explanation
The physical layer of a network is responsible for transmitting bits, defining the rules for transmitting ones and zeroes, providing the physical connection between sender and receiver, and specifying the type of connection and signals that pass through it. However, it is not responsible for providing error-free transmission of data. Error detection and correction is typically handled by higher layers of the network protocol stack, such as the data link layer or transport layer.
7.
***Which of the following is a function of the transport layer?
Correct Answer
D. Breaking long messages into several smaller messages
Explanation
The transport layer is responsible for breaking long messages into several smaller messages. This process is known as segmentation. By dividing large messages into smaller chunks, the transport layer ensures efficient and reliable transmission of data over the network. This segmentation allows for better utilization of network resources and facilitates error control and flow control mechanisms.
8.
***Which of the following is a term used to group together the physical and data link layers?
Correct Answer
B. Hardware layers
Explanation
The term "Hardware layers" refers to the grouping of the physical and data link layers in a network. These layers are responsible for the physical transmission of data, including the hardware components such as cables, connectors, and network devices. The physical layer deals with the actual transmission of bits over a physical medium, while the data link layer handles the framing and error detection of these bits. By grouping these layers together, it helps in organizing and understanding the different components and protocols involved in the lower levels of a network.
9.
***The network layer of the Internet model uses the _____________ protocol to route messages though the network.
Correct Answer
E. IP
Explanation
The network layer of the Internet model uses the IP (Internet Protocol) to route messages through the network. IP is responsible for addressing and routing packets across different networks. It assigns a unique IP address to each device connected to the network, allowing them to communicate with each other. IP is a connectionless protocol, which means it does not establish a direct connection between sender and receiver but rather sends packets individually, choosing the best path for each packet to reach its destination.
10.
***The three stages of the de juro standardization process are ______________________.
Correct Answer
A. Specification, identification of choices and acceptance.
Explanation
The three stages of the de juro standardization process are specification, identification of choices, and acceptance. In the specification stage, the standards are defined and documented. This involves determining the specific requirements and criteria that the standard should meet. In the identification of choices stage, different options and alternatives are explored and evaluated. This allows for a thorough analysis of the available choices and helps in selecting the most suitable standard. Finally, in the acceptance stage, the chosen standard is officially adopted and implemented. This ensures that the standard is recognized and followed by the relevant stakeholders.
11.
***______________, or the algorithms or business logic programmed into the application, can be simple or complex depending on the application.
Correct Answer
C. Application logic
Explanation
The given statement suggests that the algorithms or business logic programmed into the application can vary in complexity depending on the application. This implies that the application logic, which refers to the set of rules and processes that govern the behavior of the application, can be simple or complex. The complexity of the application logic is determined by the specific requirements and functionalities of the application.
12.
***________ is the presentation of information to the user and the acceptance of the user’s commands.
Correct Answer
D. Presentation logic
Explanation
Presentation logic refers to the part of a computer program or system that is responsible for presenting information to the user and accepting the user's commands. It handles tasks such as displaying data, formatting the user interface, and capturing user input. This logic is typically separate from other components such as data storage, data access logic, and application logic, which handle different aspects of the system's functionality. Therefore, presentation logic is the correct answer as it accurately describes the role and function described in the question.
13.
***Each server on a network that needs to act as a web server needs an application layer software package called a (n) ______________.
Correct Answer
C. Web server
Explanation
A web server is a software package that is required on each server on a network in order for it to act as a web server. The web server software allows the server to receive and respond to requests from clients, such as web browsers, and deliver web pages and other web content to them. Therefore, the correct answer is web server.
14.
***Which of the following is not a user agent package?
Correct Answer
B. Microsoft Word
Explanation
Microsoft Word is not a user agent package because it is a word processing software used for creating and editing documents, while user agent packages are software applications or programs that act as a client on behalf of a user, typically used for accessing and interacting with internet resources such as web pages or email.
15.
***The two basic types of media are:
Correct Answer
B. Guided and wireless
Explanation
The correct answer is guided and wireless. Guided media refers to the physical media that are used to transmit signals, such as cables or wires, which provide a direct path for the signals. Wireless media, on the other hand, refers to the transmission of signals through the air using electromagnetic waves, without the need for physical cables. These two types of media represent the different ways in which data can be transmitted from one point to another.
16.
***The type of media usually installed on homes and businesses by the telephone company is called ____________.
Correct Answer
C. Twisted pair
Explanation
The type of media usually installed on homes and businesses by the telephone company is called twisted pair. Twisted pair refers to a type of cable that consists of two insulated copper wires twisted together. This type of cable is commonly used for telephone and data transmission because it provides good signal quality and is cost-effective.
17.
***_____________ can be thought of as dividing the circuit horizontally.
Correct Answer
A. Frequency division multiplexing
Explanation
Frequency division multiplexing (FDM) is a technique that divides the available bandwidth of a communication channel into multiple frequency bands. Each band is then assigned to a different signal or data stream, allowing multiple signals to be transmitted simultaneously. In this context, FDM can be thought of as dividing the circuit horizontally because it partitions the available frequency range into separate bands, each dedicated to a specific signal. This allows for efficient and simultaneous transmission of multiple signals over a single channel.
18.
***Microwave transmission:
Correct Answer
E. All of the above
Explanation
Microwave transmission is a type of high frequency radio communication that requires a clear line-of-sight path. It is typically used for long distance data transmission and does not require the laying of any cable. Therefore, the correct answer is "all of the above" as all the statements mentioned are true for microwave transmission.
19.
***_____________ is not a form of modulation used to transform digital data into analog signals.
Correct Answer
A. Synchronous time division
Explanation
Synchronous time division is not a form of modulation used to transform digital data into analog signals. The other options, such as amplitude shift keying, amplitude modulation, frequency modulation, and phase modulation, are all forms of modulation commonly used for this purpose.
20.
***If the highest frequency of a circuit is 10KHZ and the lowest frequency is 900 Hz, the bandwidth available for this circuit is :
Correct Answer
C. 9100 Hz
Explanation
The bandwidth available for this circuit is 9100 Hz because it is calculated by subtracting the lowest frequency from the highest frequency. In this case, 10 kHz - 900 Hz = 9100 Hz.
21.
***If each sample uses 16 bits and the number of samples taken each second is 8000; then the transmission speed on the circuit is?
Correct Answer
A. 128 Kbps
Explanation
The transmission speed on the circuit can be calculated by multiplying the number of bits per sample (16 bits) with the number of samples taken each second (8000 samples/sec). This gives us a total of 128,000 bits per second, which is equivalent to 128 Kbps.
22.
***Time (non-statistical) division multiplexing differs from frequency division multiplexing because it:
Correct Answer
B. Splits the communication circuit vertically (with time slots) instead of horizontally
Explanation
Time division multiplexing (TDM) differs from frequency division multiplexing (FDM) because it splits the communication circuit vertically (with time slots) instead of horizontally. In TDM, the available bandwidth is divided into discrete time slots, and each slot is assigned to a different signal. This allows multiple signals to be transmitted sequentially over the same communication circuit. In contrast, FDM divides the bandwidth into separate frequency channels, with each channel carrying a different signal simultaneously. Therefore, TDM and FDM differ in how they allocate the resources of the communication circuit to transmit multiple signals.
23.
***As part of the five-layer network model used in this textbook, the data link layer sits directly between:
Correct Answer
E. The pHysical and the network layers
Explanation
The data link layer sits directly between the physical and the network layers. This layer is responsible for the reliable transfer of data between adjacent network nodes, ensuring error-free transmission over the physical layer. It handles tasks such as framing, error detection and correction, and flow control. The network layer, on the other hand, is responsible for routing and forwarding data packets between different networks. Therefore, the correct answer is that the data link layer sits directly between the physical and the network layers.
24.
***Media access control:
Correct Answer
C. Is not very important in a point-to-point with a half duplex configuration
25.
***Which of the following is true about roll call polling?
Correct Answer
E. It typically involves some waiting because the server has to wait for a response from the polled client or terminal.
Explanation
Roll call polling is a method of media access control that involves the server polling clients or terminals one by one to determine their needs or status. This process typically requires some waiting because the server has to wait for a response from each polled client or terminal before moving on to the next one. This ensures that all clients or terminals are given equal opportunity to communicate and prevents any client or terminal from dominating the network.
26.
***With contention:
Correct Answer
A. Computers wait until the circuit is free before they send data
Explanation
The explanation for the given correct answer is that computers wait until the circuit is free before they send data. This means that when multiple computers are connected to a circuit, they take turns sending data instead of trying to send data simultaneously. This helps to avoid collisions or conflicts where two computers may try to send data at the same time, which can lead to data loss or corruption. By waiting for the circuit to be free, the computers ensure that the data transmission is smooth and efficient.
27.
***With odd parity (assume that the parity bit (in bold) has been placed at the end of each of the following) and a 7-bit ASCII code, which of the following is incorrect?
Correct Answer
B. 00011011
Explanation
The given code uses odd parity, which means that the number of 1s in each code word should be odd. Looking at the binary codes, we can count the number of 1s in each code word. For 01101011, there are 5 1s, for 00011011 there are 4 1s, for 00100101 there are 3 1s, for 10110110 there are 6 1s, and for 11111110 there are 7 1s. Therefore, the code word 00011011 has an even number of 1s, making it the incorrect option.
28.
***The ____________ layer links the application layer with the network layer and is responsible for end-to-end delivery of messages.
Correct Answer
B. Transport
Explanation
The transport layer is responsible for the end-to-end delivery of messages between the application layer and the network layer. It ensures reliable and efficient transmission of data by breaking it into smaller segments, adding sequence numbers, and providing error detection and correction. This layer also handles flow control and congestion control to prevent network congestion and ensure smooth communication between the sender and receiver.
29.
***The source port number tells the destination station _____________.
Correct Answer
C. Which application layer process the packet is from.
Explanation
The source port number in a TCP packet identifies the specific application or process on the sending computer that generated the packet. This allows the destination station to determine which application layer process the packet is from.
30.
***Server name resolution is done using the:
Correct Answer
E. Domain Name Service
Explanation
Server name resolution is done using the Domain Name Service (DNS). DNS is responsible for translating domain names into IP addresses, allowing users to access websites and other resources on the internet using easy-to-remember names instead of numerical IP addresses. When a user enters a domain name in their browser, the DNS server is queried to find the corresponding IP address for that domain name. This process is crucial for the functioning of the internet, as it enables communication between servers and clients using human-readable domain names.
31.
***_____________ provide information about resources on the network that are available to the users, such as shared printers, file servers and application software.
Correct Answer
B. Directory Services
Explanation
Directory services provide information about resources on the network that are available to the users, such as shared printers, file servers, and application software. These services help users locate and access these resources efficiently by maintaining a centralized database of network resources and their attributes. This allows users to easily search for and connect to the resources they need, improving productivity and collaboration within the network.
32.
***Which of the following is not true about CSMA/CD?
Correct Answer
B. It is used in token ring protocol LANs
33.
***Switch-based Ethernet:
Correct Answer
E. Usually enables all attached circuits to send or receive packets simultaneously
Explanation
Switch-based Ethernet usually enables all attached circuits to send or receive packets simultaneously. This is because switches use a technique called packet switching, where they analyze the destination address of each incoming packet and forward it to the appropriate port. This allows for more efficient use of network bandwidth as multiple devices can transmit and receive data at the same time without interference. Unlike hubs, which share the bandwidth among all connected devices, switches provide dedicated bandwidth to each port, ensuring better performance and faster data transfer rates.
34.
***Each of the circuits connected to a switch is a separate _______________ circuit connecting the switch to a device on the network.
Correct Answer
B. Point-to-point
Explanation
Each of the circuits connected to a switch is a separate point-to-point circuit connecting the switch to a device on the network. This means that each circuit provides a dedicated connection between the switch and a specific device, allowing for direct communication without interference from other devices. This type of circuit is commonly used in networks where devices need to communicate directly with each other, such as in a local area network (LAN) setup.
35.
***Which of the following is not a WLAN standard?
Correct Answer
C. 802.3
Explanation
802.3 is not a WLAN standard because it is actually an Ethernet standard. WLAN stands for Wireless Local Area Network, which refers to wireless communication within a limited area. On the other hand, 802.3 is an Ethernet standard that defines the physical and data link layer specifications for wired Ethernet networks. Therefore, 802.3 is not applicable to WLANs.
36.
***CSMA/CA is an acronym for:
Correct Answer
C. Carrier Sense Multiple Access with Collision Avoidance
Explanation
CSMA/CA stands for Carrier Sense Multiple Access with Collision Avoidance. This protocol is used in wireless networks to avoid collisions when multiple devices try to transmit data simultaneously. Before transmitting, a device checks the channel for any ongoing transmissions (carrier sense). If the channel is clear, the device waits for a random amount of time (backoff) to further reduce the chances of collisions. This random backoff helps in avoiding multiple devices from transmitting at the same time, thus reducing collisions and improving network efficiency.
37.
***Which of the following is not determined by a site survey?
Correct Answer
C. The security of the WLAN
Explanation
A site survey is conducted to gather information about the physical environment and assess factors that can affect the performance and coverage of a wireless network. It helps in determining the feasibility of desired coverage, identifying potential sources of interference, estimating the number of access points needed, and identifying the current locations of the wired network. However, the security of the WLAN is not directly determined by a site survey. Security measures such as encryption protocols, authentication methods, and firewall configurations are implemented separately to ensure the security of the WLAN.