Z3d152 02 1511 (Volume 2 Edit Code 1511)
Z3D152 02 1511, Edit Code 02
AFSC 3D152
Volume 2, most up to date since I was unable to locate one at the time (5/11/2016)
Questions and Answers
- 1.
At what Open System Interconnection (OSI) layer are virtual circuits established, maintained and terminated?
- A.
Network
- B.
Phisical
- C.
Data Link
- D.
Transport
Correct Answer
D. TransportExplanation
Virtual circuits are established, maintained, and terminated at the Transport layer of the OSI model. The Transport layer is responsible for end-to-end communication between hosts and provides reliable and ordered delivery of data. It establishes connections, manages flow control, and handles error recovery. Virtual circuits, which are logical connections created over a physical network, are implemented at this layer using protocols like TCP (Transmission Control Protocol).Rate this question:
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- 2.
Which of the following is an example of a video compression standard?
- A.
Motion Picture Experts Group–4 (MPEG–4).
- B.
Joint Photographic Experts Group (JPEG).
- C.
Transfer Protocol (FTP).
- D.
G.711.
Correct Answer
A. Motion Picture Experts Group–4 (MPEG–4).Explanation
MPEG-4 is an example of a video compression standard. It is a widely used format for compressing audio and video files, allowing for efficient storage and transmission. MPEG-4 supports high-quality video and audio, as well as advanced features such as interactive content and streaming. It is commonly used for online streaming, video conferencing, and multimedia applications.Rate this question:
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- 3.
(202) In the Open System Interconnect (OSI) model, a layer will communicate with three other OSI layers. Which one is not one of those layers?
- A.
Layer above.
- B.
Layer below.
- C.
Lowest layer.
- D.
Peer layer.
Correct Answer
C. Lowest layer.Explanation
In the Open System Interconnect (OSI) model, each layer communicates with three other layers. The layer above communicates with the layer below, the layer below communicates with the layer above, and the layer communicates with its peer layer. However, the lowest layer does not have a layer below it, so it does not communicate with a lower layer. Therefore, the lowest layer is not one of the layers that a layer in the OSI model communicates with.Rate this question:
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- 4.
- What data communication protocol uses characters or “handshaking” to control the link and represent information?
- A.
Asynchronous protocol.
- B.
Binary synchronous protocol
- C.
Synchronous Data Link Control (SDLC).
- D.
High-Level Data Link Control (HDLC).
Correct Answer
B. Binary synchronous protocolExplanation
Binary synchronous protocol is a data communication protocol that uses characters or "handshaking" to control the link and represent information. It is a synchronous protocol, meaning that the sender and receiver are synchronized and data is transmitted in a continuous stream. The protocol uses start and stop bits to mark the beginning and end of each character, and it also incorporates error checking mechanisms to ensure data integrity. Therefore, the correct answer is Binary synchronous protocol.Rate this question:
- 5.
(203) In binary-synchronous protocol, which characters establishes and maintains character synchronization prior to the message block and during transmission?
- A.
SEQ.
- B.
SYN.
- C.
STX.
- D.
EST.
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. It is responsible for indicating the start of a message and ensuring that the sender and receiver are in sync with each other. By using SYN characters, the protocol ensures that the data is transmitted correctly and prevents any errors or misinterpretations during communication.Rate this question:
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- 6.
Which data communication protocol is based on bits and the position of the bits?
- A.
Character-oriented
- B.
Bit-oriented.
- C.
Network.
- D.
Routing.
Correct Answer
B. Bit-oriented.Explanation
Bit-oriented data communication protocol is based on the individual bits and their positions. It focuses on the structure and arrangement of the bits to transmit and receive data. This protocol ensures that the bits are correctly encoded, synchronized, and interpreted, making it suitable for efficient and reliable data transmission. Character-oriented protocols, on the other hand, are based on characters or groups of characters, rather than individual bits. Network and routing are not directly related to the concept of data communication protocols based on bits and positions.Rate this question:
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- 7.
(203) Which data communication protocol is a transmission code that supports a variety of link types and topologies?
- A.
Asynchronous protocol.
- B.
Binary synchronous protocol.
- C.
Synchronous Data Link Control (SDLC).
- D.
High-Level Data Link Control (HDLC).
Correct Answer
C. Synchronous Data Link Control (SDLC).Explanation
SDLC is a data communication protocol that supports a variety of link types and topologies. It is a synchronous protocol, meaning that data is transmitted in a synchronized manner, with the sender and receiver maintaining a constant communication rate. SDLC is widely used in telecommunications and computer networks for reliable and efficient data transmission. Asynchronous protocol does not support a variety of link types and topologies, while Binary Synchronous Protocol (BSP) and High-Level Data Link Control (HDLC) are specific protocols that are based on SDLC.Rate this question:
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- 8.
(204) Which network layer protocol matches a known Internet protocol (IP) address for a destination device to a Media Access Control (MAC) address?
- A.
IP
- B.
Address Resolution Protocol (ARP).
- C.
Reverse Address Resolution Protocol (RARP).
- D.
Internet Control Message Protocol (ICMP).
Correct Answer
B. Address Resolution Protocol (ARP).Explanation
The correct answer is Address Resolution Protocol (ARP). ARP is a network layer protocol that matches an IP address to a MAC address. It is used to find the MAC address of a device on the same network when only the IP address is known. When a device wants to send data to another device on the same network, it needs to know the MAC address of the destination device. ARP resolves this by broadcasting a request asking "Who has this IP address?" and the device with the matching IP address responds with its MAC address.Rate this question:
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- 9.
(204) Which Network layer protocol provides messaging that can help with troubleshooting? a. Internet protocol (IP).
- A.
Internet protocol (IP).
- B.
Address Resolution Protocol (ARP).
- C.
Reverse Address Resolution Protocol (RARP).
- D.
Internet Control Message Protocol (ICMP).
Correct Answer
D. Internet Control Message Protocol (ICMP).Explanation
ICMP is a network layer protocol that provides messaging for troubleshooting purposes. It is used to send error messages and operational information about network conditions. ICMP messages can be used to diagnose network connectivity issues, determine if a destination is reachable, and identify network congestion or errors. Therefore, ICMP is the correct answer as it provides messaging that can help with troubleshooting.Rate this question:
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- 10.
(204) Which Transport layer protocol provides reliable data delivery services?
- A.
Internet Protocol (IP).
- B.
User Datagram Protocol (UDP).
- C.
Transmission Control Protocol (TCP).
- D.
Internet Control Message Protocol (ICMP).
Correct Answer
C. Transmission Control Protocol (TCP).Explanation
Transmission Control Protocol (TCP) is the correct answer because it is a reliable transport layer protocol. TCP ensures that data is delivered in the correct order and without errors by using acknowledgments and retransmissions. It also provides flow control and congestion control mechanisms to manage the transmission of data. In contrast, User Datagram Protocol (UDP) does not provide reliable data delivery services as it does not have mechanisms for error detection, error correction, or flow control. Internet Protocol (IP) is a network layer protocol that is responsible for routing packets, while Internet Control Message Protocol (ICMP) is used for network diagnostics and error reporting.Rate this question:
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- 11.
(204) Which Application layer protocol is used to synchronize the clocks of computers on a network?
- A.
Simple Network Management Protocol (SNMP).
- B.
Dynamic Host Configuration Protocol (DHCP).
- C.
Network Time Protocol (NTP).
- D.
Packet Internet Groper (PING).
Correct Answer
C. Network Time Protocol (NTP).Explanation
The Network Time Protocol (NTP) is used to synchronize the clocks of computers on a network. NTP is a protocol that allows computers to accurately synchronize their time with a reference time source, such as a time server. By synchronizing the clocks, NTP ensures that all computers on the network have the same time, which is essential for various network operations and applications that rely on accurate timekeeping. SNMP, DHCP, and PING are not specifically designed for clock synchronization and serve different purposes in network communication.Rate this question:
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- 12.
(205) Which network Class has the most addresses for hosts?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
A. AExplanation
Class A network has the most addresses for hosts. Class A networks have a very large network portion and a small host portion, allowing for a large number of hosts to be connected to the network. The first octet of a Class A network is reserved for the network portion, while the remaining three octets are used for the host portion. This allows for a maximum of 16,777,214 hosts to be connected to a Class A network.Rate this question:
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- 13.
(205) How many subnet bits are required to support 90 subnets on a Class B network?
- A.
Three
- B.
Five
- C.
Seven
- D.
Nine
Correct Answer
C. SevenExplanation
To support 90 subnets on a Class B network, seven subnet bits are required. In a Class B network, the default subnet mask is 255.255.0.0, which provides for 16,384 possible subnets. However, since only 90 subnets are needed, additional subnet bits need to be borrowed to create enough subnets. By borrowing seven subnet bits, it creates a total of 128 subnets (2^7) which is more than enough to support the required 90 subnets. Therefore, the correct answer is seven.Rate this question:
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- 14.
(206) Internet protocol version 6 (IPv6) addresses are represented by
- A.
8 groups of dotted decimal numbers.
- B.
8 groups of hexadecimal numbers.
- C.
4 dotted decimal numbers.
- D.
128 decimal numbers.
Correct Answer
B. 8 groups of hexadecimal numbers.Explanation
IPv6 addresses are represented by 8 groups of hexadecimal numbers. Each group is separated by a colon. This is different from IPv4 addresses, which are represented by 4 groups of decimal numbers separated by periods. IPv6 was introduced to replace IPv4 due to the limited number of available addresses, and the use of hexadecimal numbers allows for a much larger address space.Rate this question:
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- 15.
(206) Teredo has four tunneling components. Which one is not one of them?
- A.
Host-specific relay.
- B.
Client.
- C.
Server.
- D.
Agent.
Correct Answer
D. Agent.Explanation
The correct answer is "Agent." Teredo is an IPv6 transition technology that allows IPv6 packets to be transmitted over an IPv4 network. It consists of four tunneling components: client, server, relay, and bubble. The agent is not one of the components in Teredo.Rate this question:
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- 16.
(207) Which device has multiport connectivity that directs data between nodes on a network?
- A.
Bridge.
- B.
Router.
- C.
Gateway.
- D.
Repeater.
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 analyzes the data packets and determines the most efficient path for them to reach their destination. Unlike bridges, gateways, and repeaters, routers operate at the network layer of the OSI model and can connect multiple networks together. Therefore, a router is the correct answer for this question.Rate this question:
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- 17.
(207) Which routing protocol do internet backbones use?
- A.
Border Gateway Protocol (BGP).
- B.
Open Shortest Path First (OSPF).
- C.
Routing Information Protocol (RIP).
- D.
Enhanced Interior Gateway Routing Protocol (EIGRP).
Correct Answer
A. Border Gateway Protocol (BGP).Explanation
Internet backbones use Border Gateway Protocol (BGP) as their routing protocol. BGP is designed to exchange routing information between autonomous systems (AS) on the internet. It allows routers in different ASes to communicate and make routing decisions based on various factors such as network policies, path preferences, and network reachability. BGP is widely used by internet service providers and large organizations to ensure efficient and reliable routing across the internet backbone.Rate this question:
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- 18.
(208) Which router port is used for initial configuration?
- A.
Auxiliary.
- B.
Console.
- C.
Ethernet.
- D.
Telnet.
Correct Answer
B. Console.Explanation
The console port on a router is used for initial configuration. This port allows direct access to the router's command-line interface (CLI) using a console cable. By connecting a computer to the console port, network administrators can configure the router's settings, such as IP addresses, passwords, and routing protocols, before the router is connected to the network. The console port provides a reliable and secure method for initial configuration and troubleshooting purposes.Rate this question:
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- 19.
(208) When configuring a router, you control access to privileged EXEC mode by configuring which password?
- A.
Line Console
- B.
Line VTY
- C.
Enable
- D.
Secret
Correct Answer
C. EnableExplanation
When configuring a router, the password used to control access to privileged EXEC mode is the "Enable" password. This password is set in order to restrict unauthorized access to the router's privileged mode, which allows for more advanced configuration and management tasks. By setting a strong "Enable" password, network administrators can ensure that only authorized individuals are able to access and make changes to the router's settings.Rate this question:
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- 20.
(208) On a router’s serial interface connection, what provides the timing signal for the communication link?
- A.
Data communications equipment.
- B.
Data terminal equipment.
- C.
Internal oscillator.
- D.
Atomic clock.
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 encoding, transmitting, and receiving data over the network. It ensures that the data is synchronized and transmitted at the appropriate timing to maintain reliable communication between devices.Rate this question:
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- 21.
(209) Virtual Private Networks (VPNs) allow the AF to extend network resources across a/an
- A.
Department of Defense network.
- B.
Air Force network.
- C.
Local area network.
- D.
A public network.
Correct Answer
D. A public network.Explanation
Virtual Private Networks (VPNs) allow the AF (Air Force) to extend network resources across a public network. This means that the AF can securely access and utilize network resources from anywhere, even when connected to an untrusted or public network. VPNs provide encryption and authentication mechanisms to ensure the confidentiality and integrity of the data transmitted over the public network, making it a suitable option for extending network resources.Rate this question:
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- 22.
(210) Which topology defines the way in which devices communicate and data is transmitted throughout the network?
- A.
Physical
- B.
Logical
- C.
Hybrid
- D.
Star
Correct Answer
B. LogicalExplanation
Logical topology refers to the way in which devices communicate and data is transmitted throughout the network. It focuses on the logical connections between devices, rather than the physical layout of the network. This includes defining how devices are connected, the paths that data takes, and the protocols used for communication. The logical topology can be different from the physical topology, as devices may be physically connected in a different way than how they communicate. Therefore, logical topology is the correct answer to the question.Rate this question:
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- 23.
(210) Which topology has the stations connected in the form of a circle?
- A.
Bus
- B.
Ring
- C.
Star
- D.
Hybrid
Correct Answer
B. RingExplanation
A ring topology has the stations connected in the form of a circle. In this topology, each station is connected to exactly two other stations, forming a closed loop. Data travels in only one direction around the ring, passing through each station until it reaches its destination. This topology provides equal access to all stations and is reliable as data can still flow even if one station fails.Rate this question:
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- 24.
(210) Which topology combines two or more different physical topologies in a single network?
- A.
Bus
- B.
Ring
- C.
Star
- D.
Hybrid
Correct Answer
D. HybridExplanation
A hybrid topology combines two or more different physical topologies in a single network. This means that it can have multiple types of connections, such as a combination of bus, ring, and star topologies. This allows for flexibility and scalability in the network, as different types of connections can be used based on the specific needs and requirements.Rate this question:
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- 25.
(211) Which device subdivides a network into smaller logical pieces, or segments?
- A.
Switch
- B.
Firewall
- C.
Gateway
- D.
Repeater
Correct Answer
A. SwitchExplanation
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 only to the intended recipient. By connecting multiple devices to different ports on a switch, it allows for efficient communication within a network by creating separate collision domains and increasing available bandwidth. Unlike a repeater, which simply amplifies and regenerates signals, a switch provides more advanced functionality and intelligence in managing network traffic. Firewalls and gateways, on the other hand, are designed for network security and routing purposes respectively.Rate this question:
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- 26.
(211) The time it takes a switch to figure out where to forward a data unit is called its
- A.
Lag
- B.
Hop
- C.
Latency
- D.
Time Zone
Correct Answer
C. LatencyExplanation
Latency refers to the time it takes for a switch to determine the appropriate destination for a data unit. It represents the delay or time lag in the forwarding process. Unlike lag, which typically refers to a delay or slowness in general, latency specifically relates to the time it takes for the switch to make a decision on where to send the data. Hop refers to the number of devices a data unit must pass through to reach its destination, and time zone is unrelated to the switch's forwarding process.Rate this question:
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- 27.
(211) Which of the following is not a distinct layer of a hierarchical network design?
- A.
Core
- B.
Access
- C.
Transport
- D.
Distribution
Correct Answer
C. TransportExplanation
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 ensuring reliable delivery of data between hosts. It is not directly related to the hierarchical network design.Rate this question:
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- 28.
(211) How many broadcast domains forms a Virtual LAN (VLAN)?
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
A. 1Explanation
A Virtual LAN (VLAN) is a logical grouping of devices in a network that behave as if they are on their own separate network. Each VLAN creates a separate broadcast domain, meaning that broadcast traffic is contained within that VLAN and does not spread to other VLANs. Therefore, a VLAN forms its own broadcast domain, and as per the given answer, only one broadcast domain is formed by a VLAN.Rate this question:
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- 29.
(211) What allows transportation of all active Virtual LANs (VLAN) between switches using a single physical link?
- A.
VLAN Trunks
- B.
VLAN Frames
- C.
VLAN Links
- D.
VLAN Ports
Correct Answer
A. VLAN TrunksExplanation
VLAN trunks allow transportation of all active VLANs between switches using a single physical link. Trunks are configured on the switch ports to carry traffic from multiple VLANs, allowing them to be transmitted over the same physical link. This enables efficient use of network resources and simplifies network management by reducing the number of physical connections required for each VLAN.Rate this question:
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- 30.
(211) Which of the following will minimize EtherChannel configuration problems?
- A.
Disable all the interfaces after creating the EtherChannel.
- B.
Configure all interfaces to operate at the same speed and duplex mode.
- C.
Configure all interfaces for the same parameters as the last port configured.
- D.
Assign all interfaces in the EtherChannel to a different Virtual LAN (VLAN).
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 in the EtherChannel have consistent settings, preventing any mismatch or compatibility issues that could lead to configuration problems. By having the same speed and duplex mode, the interfaces can effectively communicate and work together as a bundle, improving overall performance and reducing the likelihood of errors or conflicts.Rate this question:
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- 31.
(212) Which Institute of Electrical Electronics Engineers (IEEE) specification is least susceptible to interference caused by household appliances and medical devices?
- A.
802.11a
- B.
802.11b
- C.
802.11g
- D.
802.11r
Correct Answer
A. 802.11aExplanation
The IEEE specification 802.11a is least susceptible to interference caused by household appliances and medical devices. This is because 802.11a operates on a different frequency band (5 GHz) compared to 802.11b and 802.11g (2.4 GHz). The 5 GHz band is less crowded and has less interference from common household devices such as microwaves and cordless phones. Therefore, 802.11a provides a more stable and reliable wireless connection in environments where interference from these devices is a concern.Rate this question:
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- 32.
(212) 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?
- A.
Planning
- B.
Securing
- C.
Deployment
- D.
Management
Correct Answer
A. PlanningExplanation
The correct answer is Planning. During the planning phase of wireless design, various factors are taken into consideration, including the number of users on the network, the training required for these users, and the security and integrity requirements of the network data. This phase involves analyzing the requirements and objectives of the wireless network and developing a detailed plan to meet these requirements effectively.Rate this question:
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- 33.
(212) What identifier differentiates one wireless local area network (WLAN) from another?
- A.
Hostname
- B.
Network Name
- C.
Service Set Identifier (SSID)
- D.
Virtual LAN Identifier (VLAN ID)
Correct Answer
C. Service Set Identifier (SSID)Explanation
The Service Set Identifier (SSID) is the correct answer because it is a unique identifier that distinguishes one wireless local area network (WLAN) from another. The SSID is a case-sensitive alphanumeric string that is set by the network administrator and is used by wireless devices to connect to a specific WLAN. It allows devices to identify and connect to the correct network among multiple available networks in the vicinity. The SSID is broadcasted by the wireless access point, and users can select the desired network by choosing the corresponding SSID from the available options.Rate this question:
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- 34.
(213) 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
- A.
Future growth.
- B.
Network security.
- C.
Remote monitoring.
- D.
Network contingencies.
Correct Answer
A. Future growth.Explanation
SNMP is a tool that allows network administrators to monitor and manage network performance, troubleshoot issues, and plan for future growth. It provides a framework for collecting and organizing information about devices on the network, allowing administrators to track performance metrics and make informed decisions about network expansion and upgrades. While SNMP can also be used for network security, remote monitoring, and network contingencies, the primary focus is on managing network performance and planning for future growth.Rate this question:
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- 35.
(213) A Management Information Base (MIB) is a collection of information that is organized
- A.
Alphabetically
- B.
Hierarchically
- C.
Numerically
- D.
Objectively
Correct Answer
B. HierarchicallyExplanation
A Management Information Base (MIB) is a collection of information that is organized hierarchically. This means that the information is arranged in a structured manner, with different levels of hierarchy or levels of importance. This allows for easy navigation and retrieval of information, as it follows a logical and systematic order. By organizing the information hierarchically, it becomes easier to understand and manage the data within the MIB.Rate this question:
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- 36.
(214) Which physical security action can you take to ensure network equipment supports the widest range of security services?
- A.
Configure the equipment with the maximum amount of memory possible.
- B.
Configure the equipment to use a line console password.
- C.
Power cycle the equipment at the end of the duty day.
- D.
Configure the equipment using setup mode.
Correct Answer
A. Configure the equipment with the maximum amount of memory possible.Explanation
By configuring the equipment with the maximum amount of memory possible, it allows for better performance and the ability to support a wider range of security services. With more memory, the equipment can handle more processes and store more data, which is essential for implementing and running various security services effectively. This ensures that the network equipment is capable of meeting the demands of different security measures, enhancing the overall security of the network.Rate this question:
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- 37.
(214) In general, you should deny direct dial-in access to a network device by disabling which port?
- A.
Console
- B.
Auxiliary
- C.
Interface
- D.
Virtual Terminal
Correct Answer
B. AuxiliaryExplanation
The correct answer is Auxiliary. In general, direct dial-in access to a network device should be denied by disabling the Auxiliary port. The Auxiliary port is typically used for connecting modems or other external devices, and disabling it helps prevent unauthorized access to the network device.Rate this question:
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- 38.
(215) Individual pulses within a digital signal are
- A.
Bits
- B.
Bytes
- C.
Codes
- D.
Blocks
Correct Answer
A. BitsExplanation
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 bits are used to encode and transmit data in binary form, allowing for efficient and accurate communication between devices. Therefore, in the context of a digital signal, the correct term to describe the individual pulses is bits.Rate this question:
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- 39.
(215) What is most commonly used in data systems to express signaling speed?
- A.
Baud rate
- B.
Interface speed
- C.
Bits per second
- D.
Baud per second
Correct Answer
C. Bits per secondExplanation
In data systems, the most commonly used term to express signaling speed is "bits per second." This term refers to the number of bits that can be transmitted or processed in one second. It is a measure of the data transfer rate and is used to determine the speed at which information can be transmitted or received in a data system. Baud rate, interface speed, and baud per second are not as commonly used or accurate in expressing signaling speed as bits per second.Rate this question:
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- 40.
(216) Which option is a characteristic of synchronous data operation?
- A.
Timing pulses are transmitted within the signal stream.
- B.
Start and stop pulses control data transmission.
- C.
System timing is not of critical importance.
- D.
All data bits are the same length in time.
Correct Answer
D. All data bits are the same length in time.Explanation
In synchronous data operation, all data bits are the same length in time. This means that each bit in the data stream is transmitted for the same duration, ensuring that the receiver can accurately interpret the data. This characteristic allows for precise synchronization between the sender and receiver, as they both operate on the same timing. By maintaining consistent bit lengths, the receiver can easily distinguish between different bits and decode the transmitted information accurately.Rate this question:
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- 41.
(216) A digital signal that contains synchronizing bits within the signal stream describes
- A.
Synchronous operation.
- B.
Asynchronous operation.
- C.
Synchronous and/or isochronous operation.
- D.
Asynchronous and/or synchronous operation.
Correct Answer
B. Asynchronous operation.Explanation
A digital signal that contains synchronizing bits within the signal stream describes asynchronous operation. This is because synchronizing bits are used to maintain alignment and timing between the sender and receiver in asynchronous communication. Synchronous operation, on the other hand, uses a clock signal to synchronize the sender and receiver. The answer of synchronous and/or isochronous operation is incorrect as isochronous operation refers to a specific type of synchronous operation where data is transmitted at a constant rate.Rate this question:
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- 42.
(217) How many voltage levels does a binary signal have?
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
B. 2Explanation
A binary signal has two voltage levels, typically represented as 0 and 1. This is because binary signals are based on the binary numbering system, where each digit can only be 0 or 1. These voltage levels are used to represent the two states of the signal, which can be interpreted as off and on, low and high, or any other pair of distinct states.Rate this question:
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- 43.
(217) 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?
- A.
Non-return-to-zero (NRZ) level.
- B.
NRZ mark.
- C.
NRZ space.
- D.
Return-to-zero.
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 (either high or low) and then returns to the zero level after a predetermined time. This means that the signal alternates between the two levels, with each level representing a binary value. This type of signal is commonly used in digital communication systems to transmit data.Rate this question:
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- 44.
(218) Digital coding techniques such as binary with eight-zero substitution (B8ZS) are becoming more popular because they are designed to
- A.
Provide error-free signaling.
- B.
Operate at higher data rates.
- C.
Eliminate bipolar violations.
- D.
Maintain ones density standards.
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 requirement of having a balanced number of ones and zeros in a digital signal. B8ZS replaces a sequence of eight zeros with a special code to ensure that ones density is maintained, preventing long runs of zeros that could cause synchronization and clocking issues. This technique is important for maintaining the integrity and reliability of high-speed digital communications.Rate this question:
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- 45.
(218) Which statement best describes a binary with eight-zero substitution (B8ZS) signal?
- A.
The information is transmitted in three different voltage levels.
- B.
A logic one is transmitted as positive voltage if the previous logic one was negative.
- C.
The level always returns to zero for 50 percent of the bit cycle after every transition.
- D.
Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros.
Correct Answer
D. Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros.Explanation
B8ZS stands for Binary with Eight-Zero Substitution. In this signaling technique, bipolar violations are intentionally inserted into the data signal to break up long strings of zeros. This is done to ensure that the receiving end can accurately detect and interpret the data. By inserting these violations, the signal maintains a balance between positive and negative voltages, preventing the loss of synchronization and ensuring reliable transmission.Rate this question:
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- 46.
(219) How many bits are in the extended superframe format (ESF) framing sequence?
- A.
8
- B.
12
- C.
24
- D.
48
Correct Answer
C. 24Explanation
The extended superframe format (ESF) framing sequence consists of 24 bits.Rate this question:
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- 47.
(220) The signaling equipment has three types of communications signals that functions to
- A.
Process switch addressing.
- B.
Control digit translations
- C.
Control and process calls
- D.
Provide a clear signal.
Correct Answer
C. Control and process callsExplanation
The signaling equipment has three types of communications signals that control and process calls. This means that the signals are responsible for managing and handling telephone calls, ensuring that they are properly routed and connected. The signals play a crucial role in initiating, maintaining, and terminating calls, allowing for effective communication between callers.Rate this question:
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- 48.
(220) Which communications control signal uses a two-frequency dialing combination?
- A.
Pulse
- B.
Tone
- C.
Digit
- D.
Address
Correct Answer
B. ToneExplanation
The correct answer is "Tone." Tone is the communications control signal that uses a two-frequency dialing combination. It is commonly used in telephone systems to transmit signals and control various functions such as dialing and call routing. Unlike pulse dialing, which uses a series of intermittent pulses to represent numbers, tone dialing utilizes specific frequencies to generate tones that correspond to the desired numbers or control signals. This method is more efficient and faster than pulse dialing, making it the preferred choice in modern telecommunications.Rate this question:
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- 49.
(221) In common associated signaling (CAS), what is the seventh bit in frames 6 and 12 used for?
- A.
Bit robbing
- B.
Bit stuffing
- C.
Frame correction
- D.
Frame enhancement
Correct Answer
A. Bit robbingExplanation
The seventh bit in frames 6 and 12 in common associated signaling (CAS) is used for bit robbing. Bit robbing refers to the process of stealing one bit from each frame to carry signaling information. This allows for additional signaling information to be transmitted within the existing frame structure without the need for additional overhead.Rate this question:
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- 50.
(221) How is supervisory signaling information transferred in common channel signaling (CCS)?
- A.
Bit robbing.
- B.
Bit stuffing.
- C.
Frame correction.
- D.
Separate network channel.
Correct Answer
D. Separate network channel.Explanation
In common channel signaling (CCS), supervisory signaling information is transferred through a separate network channel. This means that the signaling information is transmitted on a different channel than the voice or data traffic. This allows for more efficient and reliable signaling, as it is not affected by congestion or interference on the main channel. By using a separate network channel, the signaling information can be transmitted and received without any loss or distortion, ensuring accurate communication between the signaling entities.Rate this question:
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Mar 20, 2023Quiz Edited by
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May 11, 2016Quiz Created by
Davidedpg10
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