Focus Questions

1.    What type of numbers is used to keep track of different conversations that cross the network at the same time?
Both TCP and UDP use port numbers to pass information to the upper layers. Port numbers are used to keep track of different conversations that cross the network at the same time.

2.    What is the name of a protocol that combines connectionless and connection-oriented service?
The Internet Protocol (IP) includes both TCP (connection-oriented) and UDP (connectionless) protocols.

3.    What is the difference between TCP and UDP?
User Datagram Protocol (UDP) is the connectionless transport protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams, without acknowledgments or guaranteed delivery. Error processing and retransmission must be handled by other protocols.
TCP hosts establish a connection-oriented session with one another using a three-way handshake.
A three-way handshake/open connection sequence synchronizes a connection at both ends before data is transferred. This exchange of introductory sequence numbers during the connection sequence is important because it ensures that any data that is lost due to transmission problems can be recovered.
4.    What is the field in a TCP segment that ensures correct sequencing of the arriving data?
TCP provides sequencing of bytes with a forward reference acknowledgment. The sequence number in the TCP header is associated with the first byte in the user data area. At the receiving station, TCP reassembles the segments into a complete message

5.    Which protocols use UDP?
Trivial File Transfer Protocol (TFTP)
Simple Network Management Protocol (SNMP)
Dynamic Host Control Protocol (DHCP)
Domain Name System (DNS)
BOOTP

6.    What range of port numbers is reserved for public applications?
Numbers below 255 are used for public applications.

7.    Which window type has a window size that is negotiated dynamically during the TCP session?
The “sliding” part of sliding window refers to the fact that the window size is negotiated dynamically during the TCP session.

8.    Which network application uses the direct interface that the application layer provides?
The application layer provides a direct interface, by using network applications (for instance, WWW, e-mail, FTP, Telnet), or an indirect interface, by using standalone applications (for instance, word processors, spreadsheets, presentation managers, network redirector).

9.    Where is the server side of a client/server application located?
These applications (such as FTP, web browsers, and e-mail) all have two components that allow them to function: the client side and the server side. The client side is located on the local computer and is the requestor of the services. The server side is located on a remote computer and provides services in response to the client’s requests.

10.    What is the looped routine that a client/server application constantly repeats?
A client/server application works by constantly repeating the following looped routine: client-request, server-response; client-request, server-response; and so on.

11.    What does DNS do?
Domain name system (DNS) is a service or application running on a network that manages domain names and responds to requests from clients to translate domain names into the associated IP addresses. --

12.    Which protocol do file utility programs use to copy and move files between remote sites?
File utility programs use the FTP protocol for copying and moving files between remote sites.

13.    Which protocol do remote-access programs use to directly connect to remote resources?
Remote-access programs use the Telnet protocol for directly connecting to remote resources.

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Review Questions


1.    Which of the following layers provides transport services from the host to the destination?
A.    Application
B.    Presentation
C.    Session
D.    Transport

2.    Which of the following best describes the function of the transport layer?
A.    It establishes, manages, and terminates applications.
B.    It provides transport services from the host to the destination.
C.    It supports communication among programs such as electronic mail, file transfer, and web browsers.
D.    It translates between different data formats such as ASCII and EBCDIC.

3.    Which of the following methods best describes flow control?
A.    A method to manage limited bandwidth
B.    A method of connecting two hosts synchronously
C.    A method to ensure data integrity
D.    A method to check data for viruses prior to transmission

4.    Which of the following functions best describes flow control?
A.    It checks data packets for integrity and legitimacy prior to transmission.
B.    It avoids traffic backup by cycling hosts quickly through alternate send and receive modes during peak traffic periods.
C.    It connects two hosts over an exclusive high-speed link for critical data transfer.
D.    It avoids the problem of a host at one side of the connection, overflowing the buffers in the host at the other side.

5.    Which of the following occurs in the transport layer when a connection is first established between computers in a network?
A.    Acknowledgment and retransmission
B.    Encapsulation and broadcasting
C.    Synchronization and acknowledgment
D.    Recovery and flow control

6.    Which of the following occurs in the transport layer when data congestion occurs?
A.    Broadcasting
B.    Windowing
C.    Error recovery
D.    Flow control
 
7.    Which of the following layers handles flow control and error recovery?
A.    Application
B.    Presentation
C.    Transport
D.    Network

8.    Which of the following techniques allows multiple applications to share a transport connection?
A.    Broadcasting
B.    Synchronicity
C.    Encapsulation
D.    Segmentation

9.    Which of the following best describes segmentation?
A.    It breaks data into smaller packets for faster transmission.
B.    It switches hosts from send to receive mode continuously during peak traffic periods.
C.    It allows multiple applications to share a transport connection.
D.    It transfers data from the presentation layer to the network layer for encoding and encapsulation.

10.    Which of the following methods controls the amount of information transferred end-to-end and helps to enable TCP reliability?
A.    Broadcasting
B.    Windowing
C.    Error recovery
D.    Flow control

11.    If the window size were set to 1, when would an acknowledgment of data packet receipt be sent back to the source?
A.    After one packet
B.    After two packets
C.    After three packets
D.    After four packets

12.    If the window size were set to 3, when would an acknowledgment of data packet receipt be sent back to the source?
A.    After one packet
B.    After three packets
C.    After six packets
D.    After nine packets

 
13.    Which of the following layers supports communication between programs, such as e-mail, file transfer, and web browsers?
A.    Application
B.    Presentation
C.    Session
D.    Transport

14.    Which of the following best describes the function of the application layer?
A.    It establishes, manages, and terminates applications.
B.    It supports communication between programs such as e- mail, file transfer, and web browsers.
C.    It provides transport services from the host to the destination.
D.    It translates between different data formats such as ASCII and EBCDIC.

15.    Which of the following is a network application?
A.    E-mail
B.    Word processor
C.    Web browser
D.    Spreadsheet

16.    Which of the following is a computer application?
A.    Remote access
B.    File transfer
C.    Web browser
D.    E-mail

17.    E-mail and file transfer are typical functions of which layer?
A.    Transport
B.    Network
C.    Application
D.    Presentation



Source CCNA Sem 1 v3