CCNA 1 v6.0 Chapter 3: Network Protocols and Communications: Check your Understanding Answers
1. Which of the following elements do both human and computer communication systems have in common? (Choose three.)
- Source
- Keyboard
- Channel
- Default gateway
- Receiver
Explanation: All communication, human or machine, requires three elements: a source or sender, a receiver, and a channel to carry the message.
2. What happens to frames that are too long or two short for the channel used?
- They are broken up into smaller pieces.
- They are dropped.
- They clog the network and block the delivery of other frames.
- They are returned to the sender.
- They are delivered but much slower than proper-size frames.
Explanation: The format and contents of a frame are determined by the type of message being sent and the channel being used. Frames that are not correctly formatted are not delivered. Also frames that are too long or too short are dropped.
3. Which message timing factor impacts how much information can be sent and the speed at which it can be delivered?
- Access method
- Delay speed
- Flow control
- Response timeout
Explanation: The access method determines when a message can be sent, flow control affects how much information can be sent and at what speed, and response timeout is how long the device will wait for a response before taking action.
4. What is the name given to a one-to-many message deliver option?
- Unicast
- Multicast
- Broadcast
- Manycast
Explanation: A unicast message is one-to-one, multicast is one-to-many, and broadcast is one-to-all.
5. What name is given to a group of interrelated protocols necessary to perform a communication function?
- Functional collection
- Functional protocol
- Protocol suite
- Protocol stack
Explanation: A protocol suite is a group of interrelated protocols designed to carry out the communication function. A protocol stack is the implementation of the protocol suite.
6. What type of protocol describes communication over a data link and the physical transmission of data on the network media?
- Application protocol
- Transport protocol
- Internet protocol
- Network access protocol
Explanation: Network access protocols control the hardware devices and the media that make up the network.
7. Which of the following are examples of proprietary protocols? (Choose two.)
- TCP/IP
- ISO
- AppleTalk
- Novell NetWare
Explanation: A proprietary protocol is one in which a single vendor controls the definition of a protocol and how it functions. Both AppleTalk and Novell NetWare fall into this category.
8. Which organization is responsible for the standard that defines Media Access Control for wired Ethernet?
- ISOC
- IAB
- IETF
- IEEE
- ISO
Explanation: The Institute of Electrical and Electronics Engineers (IEEE) 802 family of standards deals with LAN and MAN networks, both wired and wireless. The working group deals specifically with Media Access Control for wired Ethernet.
9. What organization is responsible for the overall management and development of Internet standards?
- IAB
- IETF
- IRTF
- IEEE
- ISO
Explanation: The Internet Society (ISOC) oversees the Internet Architecture Board (IAB), which is responsible for the overall management and development of Internet standards.
10. Which organization is responsible for developing communications standards for Voice over IP (VoIP) devices?
- The Electronics Industry Alliance (EIA)
- The Telecommunications Industry Association (TIA)
- The International Telecommunications Union – Telecommunications Standardization Sector (ITU-T)
- The Internet Corporation for Assigned Names and Numbers (ICANN)
Explanation: The Telecommunications Industry Association (TIA) is responsible for developing communication standards in a variety of areas, including radio equipment, cellular towers, VoIP devices, and satellite communications.
11. Which of the following TCP/IP protocols exist at the transport layer of the TCP/IP reference model? (Choose two.)
- HTTP
- FTP
- TCP
- DNS
- UDP
Explanation: User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) exist at the transport layer. Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Domain Name System (DNS) are all application layer protocols.
12. Which of the following OSI model layers have the same functionality as the network access layer in the TCP/IP model? (Choose two.)
- Application
- Transport
- Session
- Physical
- Presentation
- Data link
- Network
Explanation: The TCP/IP model consists of four layers but has all the functionality of the seven layers found in the OSI model. The TCP/IP network access layer has the functionality of both the physical and data link layers in the OSI model. The TCP/IP application layer has the functionality of the OSI application, presentation, and session layers.
13. Which OSI reference model layer is responsible for common representation of the data transferred between application layer services?
- Application
- Transport
- Session
- Physical
- Presentation
- Data link
- Network
Explanation: Data representation is the responsibility of the OSI presentation layer. In the TCP/IP model, the application layer has this functionality as it combines the functionality of the OSI application, presentation, and session layers.
14. What TCP/IP model layer is responsible for providing the best path through the network?
- Application
- Transport
- Internet
- Network access
Explanation: Address in best path is the responsibility of the TCP/IP Internet Layer. In the OSI model, this equates to the OSI network layer.
15. Which application layer protocol allows users on one network to reliably transfer files to and from a host on another network?
- HTTP
- FTP
- IMAP
- TFTP
- DHCP
Explanation: TFTP uses UDP but FTP makes use of TCP, providing reliability in file transfer.
16. What is the transport layer PDU?
- Data
- Segment
- Packet
- Frame
- Bit
Explanation: A PDU is a protocol data unit in the form that the data takes at that specific layer. Data is segmented at the transport layer; thus the PDU is names a segment.
17. What is the correct order of data decapsulation?
- data>segment>packet>frame>bit
- bit>frame>segment>packet>data
- bit>frame>packet>segment>data
- data>frame>packet>segment>bit
- bit>packet>frame>segment>data
Explanation: Decapsulation is the process used by the receiving device to remove control information and reassemble the bit stream into a data message. The bits arrive at the physical layer and are passed to the data link layer (PDU = frame), then the network layer (PDU = packet), then the transport layer (PDU = segment), and then up to the upper layer in the form of data.
18. What pieces of information are required for a host to access resources on the local network? (Choose three.)
- Physical address
- Network address
- Process number (port)
- Default gateway address
- Host name
Explanation: The access local resources, a device must know the source and destination physical addresses, the source and destination logical addresses, and the source and destination port numbers. The default gateway address is only required to access resources on an remote network. Names are not used on a network. Host names are resolved into addresses by DNS.
19. What pieces of information are required for a host to access resources on a remote network? (Choose four.)
- Physical address
- Network address
- Process number (port)
- Default gateway address
- Host name
Explanation: To access remote resources, a device must know the source and destination physical addresses, the source and destination logical addresses, and the source and destination port numbers. The default gateway address is also required to access resource on a remote network as it specifies the way out of the local network. Names are not used on a network. Host names are resolved into addresses by DNS.
20. What are some of the four major responsibilities of network protocols?
Protocols are responsible for many different aspects of communication. This includes such things as encoding, formatting, encapsulation, and timing.