9.1 Flashcards
Which two characteristics are associated with UDP sessions? (Choose two.)
Destination devices receive traffic with minimal delay.
Transmitted data segments are tracked.
Destination devices reassemble messages and pass them to an application.
Received data is unacknowledged.
Unacknowledged data packets are retransmitted.
- Destination devices receive traffic with minimal delay
- Received data is acknowledge
What happens if part of an FTP message is not delivered to the destination?
- The message is lost because FTP does not use a reliable delivery method.
- The FTP source host sends a query to the destination host.
- The part of the FTP message that was lost is re-sent.
- The entire FTP message is re-sent.
- A host device needs to send a large video file across the network while providing data communication to other users. Which feature will allow different communication streams to occur at the same time, without having a single data stream using all available bandwidth?
window size
multiplexing
port numbers
acknowledgments
- The part of the FTP message that was lost is re-sent.
- multiplexing
- What kind of port must be requested from IANA in order to be used with a specific application?
registered port
private port
dynamic port
source port
- What is a socket?
- the combination of the source and destination IP address and source and destination Ethernet address
- the combination of a source IP address and port number or a destination IP address and port number
- the combination of the source and destination sequence and acknowledgment numbers
- the combination of the source and destination sequence numbers and port numbers
- registered port
- combi of source ip and port number or desti IP add n port number
What is the complete range of TCP and UDP well-known ports?
0 to 255
0 to 1023
256 – 1023
1024 – 49151
0-1023
Which flag in the TCP header is **used in response to a received FIN in order to terminate connectivity between two network devices?
FIN
ACK
SYN
RST
- ACK
In a TCP session, when a device has no more data to send, it will send a segment with the FIN flag set. The connected device that receives the segment will respond with an ACK to acknowledge that segment. The device that sent the ACK will then send a FIN message to close the connection it has with the other device. The sending of the FIN should be followed with the receipt of an ACK from the other device.
A PC is downloading a large file from a server. The TCP window is 1000 bytes. The server is sending the file using 100-byte segments. How many segments will the server send before it requires an acknowledgment from the PC?
1 segment
10 segments
100 segments
1000 segments
- 10 segments
Which factor determines TCP window size?
- the amount of data to be transmitted
- the number of services included in the TCP segment
- the amount of data the destination can process at one time
- the amount of data the source is capable of sending at one time
- the amount of data the desti can process at one time
During a TCP session, a destination device sends an acknowledgment number to the source device. What does the acknowledgment number represent?
- the total number of bytes that have been received
- one number more than the sequence number
- the next byte that the destination expects to receive
- the last sequence number that was sent by the source
- the next byte that d desti expects to receice
Explanation: The window size determines the number of bytes that will be sent before expecting an acknowledgement. The acknowledgement number is the number of the next expected byte. For example, if a host has received 3140 bytes, the host would respond with an acknowledgement number of 3141
hat information is used by TCP to reassemble and reorder received segments?
port numbers
sequence numbers
acknowledgment numbers
fragment numbers
sequence numbers
What does TCP do if the sending source detects network congestion on the path to the destination?
- The source host will send a request for more frequent acknowledgments to the destination.
- The source will decrease the amount of data that it sends before it must receive acknowledgements from the destination.
- The destination will request retransmission of the entire message.
- The source will acknowledge the last segment that is sent and include a request for a smaller window size in the message.
Explain:
- The source will decrease the amount of data that it sends before it must receive acknowledgements from the destination
What is a characteristic of UDP?
- UDP datagrams take the same path and arrive in the correct order at the destination.
- Applications that use UDP are always considered unreliable.
- UDP reassembles the received datagrams in the order they were received.
- UDP only passes data to the network when the destination is ready to receive the data
UDP reassembles the received datagrams in the order they were received
What does a client do when it has UDP datagrams to send?
- It just sends the datagrams.
- It queries the server to see if it is ready to receive data.
- It sends a simplified three-way handshake to the server.
- It sends to the server a segment with the SYN flag set to synchronize the conversation.
It just sends the datagrams.
A host device is receiving live streaming video. How does the device account for video data that is lost during transmission?
- The device will immediately request a retransmission of the missing data.
- The device will use sequence numbers to pause the video stream until the correct data arrives.
- The device will delay the streaming video until the entire video stream is received.
- The device will continue receiving the streaming video, but there may be a momentary disruption.
- The device will continue receiving the streaming video, but there may be a momentary disruption.
( When TCP is used as the transport protocol, data must be received in a specific sequence or all data must be fully received in order for it to be used. TCP will use sequence numbers, acknowledgments and retransmission to accomplish this. However, when UDP is used as the transport protocol, data that arrives out of order or with missing segments may cause a momentary disruption, but the destination device may still be able to use the data that it has received. )
Why does HTTP use TCP as the transport layer protocol?
- to ensure the fastest possible download speed
- because HTTP is a best-effort protocol
- because transmission errors can be tolerated easily
- because HTTP requires reliable delivery
- because HTTP requires reliable delivery
When is UDP preferred to TCP?
- when a client sends a segment to a server
- when all the data must be fully received before any part of it is considered useful
- when an application can tolerate some loss of data during transmission
- when segments must arrive in a very specific sequence to be processed successfully
- when it can tolerate loss of data
