APPLICATION LAYER
SOCKET INTERFACE PROGRAMMING
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Detailed explanation-1: -Note that a UDP-based server only has one listening socket, not one per client. When a packet reaches the destination IP address (via network layer), the destination port is looked up to identify the correct socket to deliver the message to. That is, the demux “key” is the 2-tuple (destination IP, destination port).
Detailed explanation-2: -Each socket pair is described by a unique 4-tuple consisting of source and destination IP addresses and port numbers, i.e. of local and remote socket addresses. As discussed above, in the TCP case, a socket pair is associated on each end of the connection with a unique 4-tuple.
Detailed explanation-3: -According to “Computer networking: a top-down approach", Kurose et al., a UDP socket is fully identified by destination IP and destination port.