I need to know how does wireshark or any other program knows the protocol next from TCP. I mean, for instance:
- The Ethernet layer has a field named Type which carry the IPv04
- The Internet protocol has a filed named Protocol which identify the next TCP header
- The TCP header doesn't have any of this
But any way wireshark, chrome or any other program undertant that the protocol is HTTP or FTP or something else. Any idea of how this works?