Multiplexing/demultiplexing Multiplexing gathering data from multiple 32 bits app processes, enveloping data with header later used source port dest port for demultiplexing other header fields multiplexing/demultiplexing g based on sender receiver port numbers, IP addresses application o source, dest port #s in data each segment ( message) o recall: well-known port numbers for specific applications TCP/UDP segment format 3: Transport Layer 3a-53: Transport Layer 3a-5 Multiplexing/demultiplexing multiplexing/demultiplexing:  based on sender, receiver port numbers, IP addresses  source, dest port #s in each segment  recall: well-known port numbers for specific applications gathering data from multiple app processes, enveloping data with header (later used for demultiplexing) source port # dest port # 32 bits application data (message) other header fields TCP/UDP segment format Multiplexing: