a$)$ Suppose a process in Host C has a UDP socket with port number $6789.$ Suppose both Host A and Host

B each send a UDP segment to Host C with destination port number $6789.$ Will both of these segments

be directed to the same socket at Host C$?$ If so$,$ how will the process at Host C know that these two

segments originated from two different hosts? $(5$ marks$)$

b$)$ Suppose you wanted to do a transaction from a remote client to a server as fast as possible. Would you

use UDP or TCP$?$ Why? $(10$ marks$)$

c$)$ The Internet's connection$-$oriented service comes bundled with such services as reliable transport,

flow control, and congestion control. Briefly explain each. $(6$ marks$).$

d$)$ Mention two occasions when a router recalculates its distance vector. $(4$ marks$)$