TCP serial number and confirmation number

The TCP protocol works in the OSI transmission layer and is a reliable connection-oriented data stream protocol. The reason why TCP is reliable is that it ensures the order of transmitted data packets. The sequence is ensured by a serial number. The response package also contains a serial number, indicating that the receiver has prepared the packet with this serial number. When a packet is transmitted over TCP, it puts the packet into the resend queue and starts the timer. If the packet is confirmed, the packet is deleted from the queue, if you still do not receive the confirmation message when the timer times out, You Need To resend the packet. In addition, TCP uses serial numbers in data segments to ensure that all transmitted data can be reorganized in the normal order, thus ensuring the integrity of data transmission.

 

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Daoke Baba: Explanation of TCP serial number and Validation Code