TCP/UDP sharding

Differences:

The Application Layer calls TCP to send a data packet. If the data packet size exceeds MTU, it will be split on the TCP layer (PMTU probe will be applied to it), and then calls the ip_queue_xmit function.

Directly assemble the package into an IP address and send it out;

If it is UDP, ip_append_data is called directly. This function splits the entire data packet that the user enters into parts, and in the receiver, the IP Group is sliced into the original UDP data packet.

 

The direct effect is:

TCP data packets are streaming, and users cannot define data packets at the application layer.

If the UDP packet does not exceed the maximum (65535) of the IP packet, the original packet is still reached at the receiver.