Deck 15: Transport Protocols

Question 1

If there is a single host-node link over which all virtual circuits are multiplexed,the throughput of a transport connection can exceed the data rate of that link.

Answer 1

False

Question 2

In a protocol architecture,the transport protocol sits above application and other upper-layer protocols,and just below the network or internetwork layer.

Answer 2

False

Question 3

To begin a connection establishment a TS user is in a ________ state.

A)CLOSED
B)LISTEN
C)OPEN
D)ESTAB

Answer 3

A

Question 4

The less the network service provides,the more the transport protocol must do.

Question 5

The SYN segment functions both as a connection request and as a connection acknowledgment.

Question 6

An internetwork using IP is an example of a reliable network service.

Question 7

As with IP,the services provided by TCP are defined in terms of primitives and parameters.

Question 8

A credit scheme is a more effective scheme with an unreliable network service.

Question 9

The ________ variable represents a particular TS user at the specified host.

A)Port
B)Host
C)Socket
D)Transport

Question 10

All of the following are ways of the receiving transport entity to cope with the flow control requirement EXCEPT:

A)use a credit scheme
B)do nothing
C)use a fixed sliding-window protocol
D)accept further segments from the network service

Question 11

A transport protocol can be either connection oriented,such as UDP,or connectionless,such as TCP.

Question 12

A retransmission timer is the only timer needed for proper functioning of a transport protocol.

Question 13

The receiver needs to adopt some policy concerning the amount of data it permits the sender to transmit.

Question 14

The credit-based flow control mechanism of TCP was designed to enable a destination to restrict the flow of segments from a source to avoid buffer overflow at the destination.

Question 15

TCP uses a ________ flow control technique.

A)sliding-window
B)upper-layer
C)sequential
D)credit-based

Question 16

Multiple users employing the same transport protocol and distinguished by port numbers or service access points is ________.

A)multiplexing
B)sequencing
C)flowing
D)full duplex

Question 17

The sliding-window technique would work well with a reliable network service.

Question 18

A problem with a two-way handshake is the potential loss of segments and the potential presence of obsolete segments.

Question 19

When a TCP entity detects the presence of congestion in the Internet,it reduces the flow of data onto the Internet until it detects an easing in congestion.

Question 20

There is no need for connection establishment and termination procedures to support connection-oriented service with a reliable network service.

Question 21

________ provides a means of informing the destination TCP user that significant data is in the upcoming data stream.It is up to the destination user to determine appropriate action.

A)Data stream signaling
B)Attention signaling
C)Urgent data signaling
D)Alert signaling

Question 22

Using ________,a sender retransmits a segment before timeout because it infers that the segment was lost.If the sender subsequently receives an acknowledgement that does not cover all of the segments transmitted before this is initiated,the sender may infer that two segments were lost from the current window and retransmit an additional segment.

A)fast retransmit
B)backoff
C)outward data dissemination
D)Karn's Algorithm

Question 23

"Abort connection when no segments are received" is the ________ Transport Protocol Timer.

A)2MSL
B)Keepalive
C)Retransmission
D)Persist

Question 24

A ________ service provides for the establishment,maintenance,and termination of a logical connection between TS users.To date this is the most common type of protocol service available and has a wide variety of applications.

Question 25

In TCP the combination of port and host is referred to as a ________.

Question 26

In addition to data each transmitted segment includes in its header three fields related to flow control: acknowledgment number,window,and ________.

Question 27

TCP uses only a single type of protocol data unit called a ________.

Question 28

A ________ timer is reset with each outgoing segment.If this timer ever expires the protocol entity is required to send a segment,even if it duplicates a previous one.

Question 29

Once the Passive Open command is issued,the transport entity creates a connection object of some sort that is in the ________ state.

A)OPEN
B)LISTEN
C)CLOSED
D)FIN

Question 30

The two facilities that TCP provides for labeling data are push and ________.

Question 31

The TCP header ________ field contains the number of data octets,beginning with the sequence number indicated in the acknowledgment field,that the sender is willing to accept.

A)Window
B)Checksum
C)Options
D)Acknowledgment Number

Question 32

When the system upon which a transport entity is running fails and subsequently restarts,the state information of all active connections is lost.The affected connections become ________ because the side that did not fail does not yet realize the problem.

Question 33

"Listen for connection attempt at specified security and precedence from specified destination" is the description of the TCP Service Request ________ Primitive.

A)Generally Specified Passive Open
B)Unspecified Passive Open
C)Active Open With Data
D)Fully Specified Passive Open

Question 34

Connection establishment in TCP always uses a ________.

A)four-way handshake
B)three-way handshake
C)two-way handshake
D)handshake

Question 35

When a data segment arrives that is in sequence,the receiving TCP entity has two options concerning the timing of acknowledgment: Immediate and

A)Cumulative
B)Controlled
C)Delayed
D)Non-responsive

Question 36

One header must serve to perform all protocol mechanisms.This header has a minimum length of ________ octets.

A)20
B)16
C)8
D)10

Question 37

The TS user can signal to the local TCP entity that it will passively wait for a request with a ________ command.A server program such as time-sharing or a file transfer application might do this.

Question 38

The ________ protocol provides an end-to-end transfer service that shields upper- layer protocols from the details of the intervening network or networks.

Question 39

________ measures the time the transport machine will continue to await an acknowledgment of a transmitted segment after the segment has been retransmitted the maximum number of times.When the timer expires,the transport entity assumes that the other transport entity or intervening network has failed,closes the connection,and signals an abnormal close to the TS user.

Question 40

In the case of a single network,________ refers to an attached network device.

A)Port
B)Host
C)Socket
D)Entity

Question 41

A TCP implementation may employ one of three retransmission strategies: First-only,Individual,and ________.

Question 42

In addition to TCP,the ________ is the other transport-level protocol that is commonly used as part of the TCP/IP protocol suite.

Question 43

TCP mechanisms can be grouped into the categories of data transfer,connection termination,and ________.

Question 44

The ________ field in the TCP header contains the sequence number of the next data octet that the TCP entity expects to receive.

Question 45

RTT Variance Estimation,also known as ________,is the technique specified in the TCP standard that enables a TCP entity to adapt to changes in round-trip time.