When we send the same data over a network twice, does this means that we are sending the same packets twice?
I am trying to understand how my decoder works, so I command using an application on phone, and I click on the buttons: power on, power off, and power on once again.
so does this mean the packets that are sent the first and last time are the same or there are some differences like the headers?
If I understand your question correctly, you want to know if the UDP and IP headers are identical if you send the same data over UDP twice.
I think this will depend on the operating system; I just tested this with Linux:
Linux will put an individual "ID" field in the IP header. So if you send the same UDP data twice, the IP header of the two packets contain a different "ID" field.
I assume that the same is true if a TCP packet is re-sent.
When we send the same data over a network twice, does this means that we are sending the same packets twice?
Define "the same". Any copy of digital data is identical to any other copy.
Define "data". For user data encapsulated by a transport-layer protocol: no, the packets are not the same usually (they might though, e.g. with UDP). For an entire packet that is resent, it's the same packet (see above).
