How demultiplexing works o host receives IP datagrams o each datagram has source 32 bits IP address destination ip address source port dest port o each datagram carries 1 transport-layer segment other header fields o each segment has source destination port number (recall: well-known port application numbers for specific data applications. ( message) o host uses IP addresses& port numbers to direct segment to appropriate socket TCP/UDP segment format Transport Layer 3-9Transport Layer 3-9 How demultiplexing works host receives IP datagrams each datagram has source IP address, destination IP address each datagram carries 1 transport-layer segment each segment has source, destination port number (recall: well-known port numbers for specific applications) host uses IP addresses & port numbers to direct segment to appropriate socket source port # dest port # 32 bits application data (message) other header fields TCP/UDP segment format