TCP: Transmission Control Protocol Flashcards
What flags are set in the TCP header when a connection is initiated?
SYN
SYN-ACK
ACK
What type of protocol is TCP?
A stream protocol.
What TCP header flags are set during a connection tear down?
FIN
ACK
FIN
ACK
What does the ACK flag stand for?
Acknowledgement
What does the SYN flag stand for?
Synchronize sequence numbers
What does the RST flag stand for?
Reset connection.
What does the PSH flag stand for?
Push data from buffer to receiving process
What does the FIN flag stand for?
Finish. The sender is finished sending data
What does the URG flag stand for?
Urgent
What does TCP use for addressing?
Port numbers
What causes the TCP sequence number to increment?
Each byte of data
What does the acknowledgement number in a TCP header represent?
The sequence number of the next byte the host expects to receive
What two events cause TCP to retransmit a segment?
Time out interval expires
or
3 duplicate ACKs from receiver
What does MSS stand for in a TCP header?
Maximum Segment Size
When is the Maximum Segment Size for a TCP session determined?
At the start of the session
What does the Window Size specify in a TCP header?
Maximum amount of data the receiver is willing to accept
Who sets the Window Size for a TCP stream?
The receiver/client
What is a delayed ACK?
It’s when the receiver waits for the next TCP segment with data to send an ACK.
What is the purpose of a delayed ACK?
Delayed ACKs can reduce the total amount of segments sent by allowing the ACK flag to piggyback on a segment with data.
What happens when a receiver has a window size of 0?
The sender sends keep-alive segments containing no data until the window size is greater than zero.
