$1.$ Short Answer

a$.$ How many bytes are there in the UDP packet header? How many in the TCP header?

b$.$ Is the following statement true or false?$$ With UDP Sockets, a server can easily determine the IP address of the client, from the data returned via a socket read.$$ Answer the same question $($true or false$)$ for TCP sockets.$$ Briefly explain your answers.

c$.$ Briefly describe TCP$\text{'}$s slowstart algorithm. What causes the TCP slowstart algorithm to end, and TCP congestion avoidance to begin?

d$.$ Consider a TCP connection between hosts A and B$.$ Suppose that the TCP segments from A to B have source port number x and destination port number y$.$ What are the source and destination port numbers for the segments traveling from B to A$?$

e$.$ It is said that a TCP connection "probes" the network path it uses for available bandwidth.$$ What is meant by that?

f$.$ Explain the process of a three$-$way handshake in TCP that initiates communications on the Internet.

g$.$ The UDP server described in class needed only one socket, whereas the TCP server needed two sockets.$$ Why?$$ If the TCP server were to support N simultaneous connections, each from a different client host, how many sockets would the TCP server need? Express your answer as an equation.

h$.$ How does the congestion window $($cwnd$)$ increase on the receipt of an ACK during slow$-$start? During congestion avoidance?

i$.$ What controls when the transition between slow$-$start and congestion avoidance occurs?

j$.$ In the basic TCP Tahoe, what happens to cwnd and the slow$-$start threshold when loss is detected?