1.
At what Open System Interconnection (OSI) layer are virtual circuits established, maintained and terminated?
Correct Answer
D. Transport
Explanation
Virtual circuits are established, maintained, and terminated at the Transport layer of the Open System Interconnection (OSI) model. This layer is responsible for end-to-end communication and ensures reliable and error-free delivery of data between network hosts. It establishes connections, manages flow control, and handles error recovery. The Transport layer protocols, such as TCP (Transmission Control Protocol), provide the necessary mechanisms for establishing virtual circuits and ensuring the delivery of data packets in the correct order.
2.
Which of the following is an example of a video compression standard?
Correct Answer
A. Motion Picture Experts Group-4 (MPEG-4)
Explanation
Motion Picture Experts Group-4 (MPEG-4) is an example of a video compression standard. It is a widely used format for video compression and is known for its ability to provide high-quality video while maintaining relatively small file sizes. MPEG-4 allows for efficient compression by using various techniques such as motion compensation, transform coding, and entropy coding. It is commonly used for streaming video over the internet, video conferencing, and multimedia applications.
3.
In the Open System Interconnect (OSI) model, a layer will communicate with three other OSI layers. Which one is not one of those layers?
Correct Answer
C. Lowest layer
Explanation
The OSI model consists of seven layers, each responsible for a specific set of functions. In this context, the "lowest layer" refers to the Physical layer, which is responsible for the actual transmission and reception of data over a physical medium. The other layers mentioned in the question - layer above, layer below, and peer layer - are all valid layers in the OSI model.
4.
What data communication protocol uses characters or "handshaking" to control the link and represent information?
Correct Answer
B. Binary synchronous protocol
Explanation
Binary synchronous protocol is a data communication protocol that uses characters or "handshaking" to control the link and represent information. This protocol ensures reliable and error-free transmission of data by using start and stop bits to frame data packets and by implementing error checking mechanisms. It also incorporates flow control techniques to regulate the flow of data between the sender and receiver.
5.
In binary-synchronous protocol, which characters establishes and maintains character synchronization prior to the message block and during transmission?
Correct Answer
B. SYN
Explanation
In binary-synchronous protocol, the character "SYN" is used to establish and maintain character synchronization prior to the message block and during transmission. This means that the "SYN" character is responsible for ensuring that the sender and receiver are in sync and can properly interpret the transmitted data. It helps in avoiding any errors or misinterpretations that may occur during transmission.
6.
Which data communication protocol is based on bits and the position of the bits?
Correct Answer
B. Bit-oriented
Explanation
Bit-oriented is the correct answer because this data communication protocol is based on bits and the position of the bits. In bit-oriented protocols, the data is transmitted and interpreted bit by bit, with specific bit patterns indicating the start and end of a message. These protocols focus on the individual bits rather than grouping them into characters or packets. This approach allows for more precise control and synchronization in data transmission.
7.
Which data communication protocol is a transmission code that supports a variety of link types and topologies?
Correct Answer
C. Synchronous Data Link Control (SDLC)
Explanation
SDLC is a data communication protocol that supports various link types and topologies. It is a synchronous protocol, meaning that data is transmitted in a continuous stream without any gaps or delays. SDLC is widely used in telecommunications and computer networks for its reliability and efficiency. It provides error checking and correction mechanisms, as well as flow control and synchronization capabilities. With its versatility and compatibility with different link types and topologies, SDLC is a suitable choice for data communication in various environments.
8.
Which network layer protocol matches a known Internet protocol (IP) address for a destination device to a Media Access Control (MAC) address?
Correct Answer
B. Address Resolution Protocol (ARP)
Explanation
The correct answer is Address Resolution Protocol (ARP). ARP is a network layer protocol that is used to match a known IP address for a destination device to its corresponding MAC address. This is necessary because IP addresses are used for routing packets across networks, while MAC addresses are used for communication within a local network. ARP allows devices to discover and store the MAC address of a device on the same network, enabling them to communicate directly.
9.
Which Network layer protocol provides messaging that can help with troubleshooting?
Correct Answer
D. Internet Control Message Protocol (ICMP)
Explanation
ICMP is a network layer protocol that provides messaging for troubleshooting purposes. It is used by network devices to send error messages and operational information, allowing network administrators to identify and resolve issues within the network. ICMP messages include error reporting, network congestion notifications, and network testing tools such as ping. Therefore, ICMP is the correct answer as it facilitates troubleshooting by providing essential information about network connectivity and performance.
10.
Which Transport layer protocol provides reliable data delivery services?
Correct Answer
C. Transmission Control Protocol (TCP)
Explanation
Transmission Control Protocol (TCP) is the correct answer because it provides reliable data delivery services. TCP ensures that data is delivered in the correct order and without errors by using acknowledgments, retransmissions, and flow control mechanisms. It establishes a connection between the sender and receiver, breaks the data into packets, and reassembles them at the destination. TCP also implements error detection and correction techniques to ensure reliable delivery of data.
11.
Which Application layer protocol is used to synchronize the clocks of computers on a network?
Correct Answer
C. Network Time Protocol (NTP)
Explanation
Network Time Protocol (NTP) is used to synchronize the clocks of computers on a network. It is designed to keep all the devices on a network in sync by exchanging time information between them. NTP uses a hierarchical structure with primary time servers at the top, which are connected to secondary servers, and so on. This protocol ensures that all devices on the network have accurate and synchronized time, which is crucial for various applications and services that rely on time synchronization, such as authentication, logging, and coordination of distributed systems.
12.
Which network Class has the most addresses for hosts?
Correct Answer
A. A
Explanation
Class A networks have the most addresses for hosts because they use the first octet of the IP address to identify the network, leaving the remaining three octets for host addresses. This allows for a large number of possible host addresses, making Class A networks suitable for large organizations or ISPs that require a large number of hosts on their network.
13.
How many subnet bits are required to support 90 subnets on a Class B network?
Correct Answer
C. Seven
Explanation
To support 90 subnets on a Class B network, seven subnet bits are required. This is because with each additional subnet bit, the number of subnets doubles. Starting with a Class B network, which has 16 bits for the network portion, adding seven subnet bits would give us a total of 23 bits for the network portion. This allows for 2^7 (128) subnets, which is more than enough to support 90 subnets.
14.
Internet protocol version 6 (IPv6) addresses are represented by
Correct Answer
B. 8 groups of hexadecimal numbers
Explanation
IPv6 addresses are represented by 8 groups of hexadecimal numbers. This is because IPv6 uses a 128-bit address space, which is much larger than the 32-bit address space used by IPv4. Hexadecimal notation allows for more compact representation of the large address space, as each group represents 16 bits. Each group is separated by a colon, resulting in a total of 8 groups in an IPv6 address.
15.
Teredo has four tunneling components. Which one is not one of them?
Correct Answer
D. Agent
Explanation
Teredo is an IPv6 transition technology that allows IPv6 packets to be transmitted over an IPv4 network. It consists of four tunneling components: Host-specific relay, Client, Server, and Agent. The Agent is not one of the tunneling components in Teredo.
16.
Which device has multiport connectivity that directs data between nodes on a network?
Correct Answer
B. Router
Explanation
A router is a device that has multiport connectivity and is responsible for directing data between nodes on a network. It acts as a central hub, receiving data packets from multiple devices and determining the most efficient path for the data to reach its destination. Routers operate at the network layer of the OSI model and use IP addresses to forward data between different networks. Unlike bridges, gateways, and repeaters, routers have the ability to make intelligent decisions based on network protocols and routing tables, making them the correct answer for this question.
17.
Which routing protocol do internet backbones use?
Correct Answer
A. Border Gateway Protocol (BGP).
Explanation
Internet backbones use the Border Gateway Protocol (BGP) as their routing protocol. BGP is specifically designed for large-scale networks and is used to exchange routing information between autonomous systems (AS). It allows internet service providers (ISPs) to determine the most efficient paths for data to travel across the internet, ensuring reliable and efficient routing. BGP is the protocol of choice for internet backbone networks due to its scalability, robustness, and ability to handle complex routing policies.
18.
Which router port is used for initial configuration?
Correct Answer
B. Console
Explanation
The correct answer is Console. The console port on a router is used for the initial configuration. It is a physical port that allows direct access to the router's command-line interface (CLI) through a console cable. This port is typically used for initial setup, troubleshooting, and password recovery. The console port provides a direct, physical connection to the router, allowing administrators to configure the router without the need for network connectivity.
19.
When configuring a router, you control access to privileged EXEC mode by configuring which password?
Correct Answer
C. Enable
Explanation
When configuring a router, access to privileged EXEC mode can be controlled by configuring the "Enable" password. This password is used to secure the router's privileged EXEC mode, which provides access to advanced configuration and management commands. By setting an "Enable" password, only authorized users will be able to enter privileged mode and make changes to the router's configuration.
20.
On a router’s serial interface connection, what provides the timing signal for the communication link?
Correct Answer
A. Data communications equipment
Explanation
Data communications equipment provides the timing signal for the communication link on a router's serial interface connection. This equipment is responsible for transmitting and receiving data over the network, and it also ensures that the timing of the data transmission is synchronized between the sender and receiver. By providing the timing signal, the data communications equipment ensures that the data is transmitted and received accurately and in a timely manner, allowing for efficient communication between devices on the network.
21.
Virtual Private Networks (VPNs) allow the AF to extend network resources across a/an
Correct Answer
D. A public network
Explanation
Virtual Private Networks (VPNs) allow the Air Force (AF) to extend network resources across a public network. This means that the AF can securely connect to and access its network resources from any location, even when connected to an untrusted or public network such as the internet. VPNs use encryption and other security measures to ensure that data transmitted over the public network remains private and secure. This allows the AF to maintain the confidentiality and integrity of its network communications while still being able to access resources remotely.
22.
Which topology defines the way in which devices communicate and data is transmitted throughout the network?
Correct Answer
B. Logical
Explanation
Logical topology defines the way in which devices communicate and data is transmitted throughout the network. It describes how the network appears to the devices that use it, regardless of the physical layout. Logical topology determines how data flows between devices and how they communicate with each other, regardless of the physical connections. This includes protocols, addressing schemes, and the paths that data takes from one device to another.
23.
Which topology has the stations connected in the form of a circle?
Correct Answer
B. Ring
Explanation
A ring topology has the stations connected in the form of a circle. In this type of network, each station is connected to two other stations, forming a closed loop. Data travels in one direction around the ring, passing through each station until it reaches its destination. This topology is commonly used in token ring networks, where a token is passed around the ring to control access to the network.
24.
Which topology combines two or more different physical topologies in a single network?
Correct Answer
D. Hybrid
Explanation
A hybrid topology combines two or more different physical topologies in a single network. This means that it can have a combination of bus, ring, star, or any other topologies. In a hybrid topology, different sections of the network may use different topologies depending on the requirements of that section. This allows for flexibility and scalability in the network design, as different topologies can be used to optimize different parts of the network.
25.
Which device subdivides a network into smaller logical pieces, or segments?
Correct Answer
A. Switch
Explanation
A switch is a device that subdivides a network into smaller logical pieces or segments. It operates at the data link layer of the OSI model and uses MAC addresses to forward data packets to the appropriate destination. By creating separate segments, a switch improves network performance and reduces collisions. It allows for efficient communication between devices within the same segment while preventing unnecessary traffic from congesting the entire network. Therefore, a switch is the correct device to subdivide a network into smaller logical pieces.
26.
The time it takes a switch to figure out where to forward a data unit is called its
Correct Answer
C. Latency
Explanation
Latency refers to the time it takes for a switch to determine the appropriate destination for a data unit. It is the delay caused by the switch in processing and forwarding the data. The term "lag" refers to a delay or interruption in data transmission, but it does not specifically relate to the switch's decision-making process. "Hop" refers to the number of devices a data unit passes through before reaching its destination, not the time it takes for the switch to make a forwarding decision. "Time zone" is unrelated to the switch's processing time.
27.
Which of the following is not a distinct layer of a hierarchical network design?
Correct Answer
C. Transport
Explanation
The transport layer is not a distinct layer of a hierarchical network design. In a hierarchical network design, the layers typically include the core layer, distribution layer, and access layer. The transport layer, on the other hand, is a layer in the OSI model that is responsible for end-to-end communication and ensures reliable delivery of data across the network. It is not considered a distinct layer in the hierarchical network design model.
28.
How many broadcast domains forms a Virtual LAN (VLAN)?
Correct Answer
B. 2
Explanation
A Virtual LAN (VLAN) is a logical grouping of devices on a network, regardless of their physical locations. It allows for the segmentation of a network into multiple broadcast domains. In this case, the correct answer is 2 because a VLAN creates two broadcast domains - one for devices within the VLAN and another for devices outside of the VLAN. This segregation helps to improve network performance, security, and manageability.
29.
What allows transportation of all active Virtual LANs (VLAN) between switches using a single physical link?
Correct Answer
A. VLAN trunks
Explanation
VLAN trunks allow the transportation of all active VLANs between switches using a single physical link. A VLAN trunk is a connection that carries multiple VLANs over a single link, allowing for efficient use of network resources. It enables switches to differentiate between different VLANs by adding a VLAN tag to the Ethernet frame, ensuring that the correct VLAN information is maintained throughout the network. This allows for the consolidation of VLAN traffic onto a single link, simplifying network design and management.
30.
Which of the following will minimize EtherChannel configuration problems?
Correct Answer
B. Configure all interfaces to operate at the same speed and duplex mode.
Explanation
Configuring all interfaces to operate at the same speed and duplex mode will minimize EtherChannel configuration problems. This ensures that all interfaces within the EtherChannel have consistent settings, preventing any potential mismatches or conflicts that could lead to configuration issues. By having uniform speed and duplex mode, the interfaces can effectively communicate and work together as a bundle, improving overall performance and stability.
31.
Which Institute of Electrical Electronics Engineers (IEEE) specification is least susceptible to interference caused by household appliances and medical devices?
Correct Answer
A. 802.11a
Explanation
The 802.11a specification is least susceptible to interference caused by household appliances and medical devices. This is because it operates on a higher frequency band (5 GHz) compared to 802.11b and 802.11g (2.4 GHz), which is more crowded and prone to interference. Additionally, 802.11a uses a different modulation scheme (OFDM) that provides better resistance to interference. Therefore, 802.11a is the best choice in environments with potential interference from household appliances and medical devices.
32.
Which wireless design phase accounts for the amount of users on the network, the training required for the users and the security and integrity requirements of the network data?
Correct Answer
A. Planning
Explanation
The correct answer is Planning. During the planning phase of wireless design, various factors are taken into account, including the number of users on the network, the training required for the users, and the security and integrity requirements of the network data. This phase involves determining the goals and objectives of the wireless network, conducting a site survey, and creating a detailed plan for the implementation of the network.
33.
What identifier differentiates one wireless local area network (WLAN) from another?
Correct Answer
C. Service Set Identifier (SSID)
Explanation
The Service Set Identifier (SSID) is the correct answer because it is a unique name that differentiates one wireless local area network (WLAN) from another. The SSID is broadcasted by the wireless access point and is used by devices to identify and connect to a specific WLAN. The hostname is a label assigned to a device on a network, the network name is a general term that refers to the name of a network, and the Virtual LAN Identifier (VLAN ID) is used to differentiate between different virtual LANs within a network.
34.
A Management Information Base (MIB) is a collection of information that is organized
Correct Answer
B. Hierarchically
Explanation
A Management Information Base (MIB) is a collection of information that is organized hierarchically. This means that the information is structured in a hierarchical manner, with higher-level categories or groups containing lower-level subcategories or individual objects. This hierarchical organization helps in organizing and managing the information effectively, allowing for easy navigation and retrieval of specific information within the MIB.
35.
Simple Network Management Protocol (SNMP) is a tool used by network administrators to manage network performance, investigate and solve network problems and help plan for
Correct Answer
A. Future growth
Explanation
SNMP is a tool used by network administrators to manage network performance, investigate and solve network problems, and help plan for future growth. By monitoring network devices and collecting data, SNMP allows administrators to identify areas where the network may need to be expanded or upgraded to accommodate future demands. This helps ensure that the network can handle increased traffic, new devices, and additional users as the organization grows.
36.
Which physical security action can you take to ensure network equipment supports the widest range of security services?
Correct Answer
A. Configure the equipment with the maximum amount of memory possible.
Explanation
By configuring the network equipment with the maximum amount of memory possible, it ensures that the equipment can handle a wide range of security services. Memory plays a crucial role in the performance and functionality of network devices, allowing them to process and store data efficiently. With more memory, the equipment can support various security services simultaneously, such as encryption, authentication, and intrusion detection systems. This enables the network to be more secure by providing a robust defense against potential threats and vulnerabilities.
37.
In general, you should deny direct dial-in access to a network device by disabling which port?
Correct Answer
B. Auxiliary
Explanation
The correct answer is "Auxiliary." The auxiliary port on a network device is typically used for out-of-band management, allowing administrators to remotely access and configure the device. By denying direct dial-in access to the auxiliary port, you can enhance security by preventing unauthorized access to the device. Disabling the console port would prevent local access to the device, disabling the interface would impact network connectivity, and disabling the virtual terminal would prevent remote access via Telnet or SSH.
38.
Individual pulses within a digital signal are
Correct Answer
A. Bits
Explanation
Individual pulses within a digital signal are referred to as bits. In digital communication, a bit is the basic unit of information that represents either a 0 or a 1. These binary values are used to encode and transmit data in various forms such as text, images, and videos. Each pulse in a digital signal represents a single bit, allowing for the transmission and storage of information in a digital format. Therefore, bits are the correct answer in this context.
39.
What is most commonly used in data systems to express signaling speed?
Correct Answer
C. Bits per second
Explanation
Bits per second is the most commonly used term in data systems to express signaling speed. Baud rate refers to the number of signal changes per second, while interface speed is a more general term. Baud per second is not a recognized term. Therefore, bits per second is the correct answer as it directly represents the number of bits transmitted or received per second in a data system.
40.
Which option is a characteristic of synchronous data operation?
Correct Answer
D. All data bits are the same length in time.
Explanation
The characteristic of synchronous data operation that is being described in the given options is that all data bits are the same length in time. In synchronous data transmission, the sender and receiver must be synchronized in order to transmit and receive data accurately. This synchronization is achieved by dividing the data into fixed-length units, where each unit represents a data bit. By ensuring that all data bits are the same length in time, the sender and receiver can easily synchronize their clocks and accurately interpret the transmitted data.
41.
A digital signal that contains synchronizing bits within the signal stream describes
Correct Answer
B. Asynchronous operation.
Explanation
A digital signal that contains synchronizing bits within the signal stream describes asynchronous operation. Synchronizing bits are used to maintain the timing and synchronization between the sender and receiver in an asynchronous communication system. These bits are inserted at regular intervals within the signal stream to ensure accurate transmission and reception of data. Therefore, the presence of synchronizing bits indicates that the operation is asynchronous, where data is transmitted independently of a clock signal.
42.
How many voltage levels does a binary signal have?
Correct Answer
B. 2
Explanation
A binary signal has two voltage levels. In digital communication, a binary signal represents information using only two distinct values, typically represented as 0 and 1. These values are usually represented by different voltage levels, where one voltage level represents a logical low (0) and the other represents a logical high (1).
43.
In what type of digital signal does the signal level move to one of the discrete signal levels, but returns to the zero level after a predetermined time?
Correct Answer
D. Return-to-zero.
Explanation
In a return-to-zero (RZ) digital signal, the signal level moves to one of the discrete signal levels (usually a high or low level) and then returns to the zero level after a predetermined time. This means that the signal alternates between the two levels and includes zero level transitions, which helps in clock synchronization and signal recovery. In contrast, non-return-to-zero (NRZ) signals do not return to the zero level during a bit interval.
44.
Digital coding techniques such as binary with eight-zero substitution (B8ZS) are becoming more popular because they are designed to
Correct Answer
D. Maintain ones density standards.
Explanation
Digital coding techniques such as binary with eight-zero substitution (B8ZS) are designed to maintain ones density standards. Ones density refers to the number of consecutive ones in a digital signal. Maintaining ones density is important in telecommunications because it helps to ensure that the signal is properly synchronized and that data can be accurately transmitted and received. B8ZS is a coding technique that replaces sequences of eight zeros with specific patterns of ones and zeros, which helps to maintain ones density and prevent errors in the transmission of data.
45.
Which statement best describes a binary with eight-zero substitution (B8ZS) signal?
Correct Answer
D. Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros.
Explanation
B8ZS is a line coding technique used in telecommunications to ensure the accuracy of data transmission. It intentionally inserts bipolar violations into a data signal to break up long strings of zeros. This is done to prevent synchronization issues and maintain the integrity of the transmitted data. By inserting these violations, the receiver can easily differentiate between consecutive zeros and ensure reliable decoding of the information being transmitted.
46.
How many bits are in the extended superframe format (ESF) framing sequence?
Correct Answer
C. 24
Explanation
The extended superframe format (ESF) framing sequence consists of 24 bits.
47.
The signaling equipment has three types of communications signals that functions to
Correct Answer
A. Process switch addressing
Explanation
The signaling equipment has three types of communication signals that function to process switch addressing. This means that the signals are responsible for handling the addressing of switches, which is crucial for the proper functioning of the equipment. By processing switch addressing, the signaling equipment can ensure that calls are routed correctly and efficiently. This is an essential aspect of the equipment's operation, as it directly affects the overall performance and effectiveness of the communication system.
48.
Which communications control signal uses a two-frequency dialing combination?
Correct Answer
B. Tone
Explanation
Tone is the correct answer because it is the communications control signal that uses a two-frequency dialing combination. In telecommunications, tone dialing, also known as dual-tone multi-frequency (DTMF), is the method used to input digits or send control signals over a telephone line. It uses a combination of two specific frequencies to represent each digit or control signal, allowing for more efficient and reliable communication.
49.
In common associated signaling (CAS), what is the seventh bit in frames 6 and 12 used for?
Correct Answer
A. Bit robbing
Explanation
The seventh bit in frames 6 and 12 in common associated signaling (CAS) is used for bit robbing. Bit robbing is a technique used to steal one bit from each frame to carry signaling information. This allows for additional signaling information to be transmitted without the need for extra frames, maximizing the efficiency of the signaling system.
50.
How is supervisory signaling information transferred in common channel signaling (CCS)?
Correct Answer
D. Separate network channel
Explanation
Supervisory signaling information is transferred in common channel signaling (CCS) through a separate network channel. This means that the signaling information is transmitted separately from the voice or data traffic, ensuring that it does not interfere or disrupt the main communication channel. By using a separate network channel, CCS allows for efficient and reliable transfer of supervisory signaling information, enabling effective control and management of the communication system.