11 - Transport Layer Flashcards
What is the transport layer responsible for?
Process to process delivery.
Which layer holds port numbers?
Transport layer.
Which layer holds IP addresses?
Network layer.
What is unique about UDP? Why is it unreliable?
- Provides process-to-process communication instead of host-to-host communication
- No error or flow control
What are UDP data units called?
User datagrams.
How do you calculate a UDP length?
IP length - IP header’s length
Describe the what happens with sequence numbers in a SYN segment?
- Cannot carry data
- Consumes one sequence number
Describe the what happens with sequence numbers in a SYN+ACK segment?
- Cannot carry data
- Consumes one sequence number
Describe the what happens with sequence numbers in a ACK segment?
Consumes NO sequence number if carrying no data
Describe the what happens with sequence numbers in a FIN segment?
Consumes ONE sequence number if carrying no data
Describe the what happens with sequence numbers in a FIN+ACK segment?
Consumes one sequence number if carrying no data
What happens in the slow-start algorithm?
Size of congestion window increases exponentially until it reaches a threshold.
What happens in the congestion avoidance algorithm?
Size of congestion window increases additively until congestion is detected.
What determines the congestion window (cwnd) value?
The network
How is window size determined?
The minimum value between rwnd, cwnd.
