In a normal TCP conversation, the client acknowledges every byte received by transmitting an acknowledgment, with the ACK field value set as the next expected byte. When more than one acknowledgment is sent by the client (with the same ACK field value), this is said to be a duplicate acknowledgment.
To understand what a duplicate acknowledgment is, let's step through a standard TCP transaction:
- In the course of a normal TCP data transaction, TCP sequences and acknowledges every byte of data.
- The client acknowledges the data received by setting the ACK flag in the TCP header, as shown here:
The TCP-ACK flag ...
