Question

Host a sends a tcp segment (seq = 43, ack = 103), to which host b replies with a tcp segment (seq = 103, ack = 57). the payload of the first tcp segment is

Answer 1

TCP sequence numbers are random to start. An analyzer like Wireshark, though, can (and maybe does by default?) show the sequence numbers RELATIVE to what they were when the session started.Assuming relative sequence numbers are used, the first packet from host A containing a payload, after the three way handshake, should have Seq 1, Ack 1.The response from host B would indicate the ACK from the handshake, 1, incremented by the number of bytes received.