on the correspondency between tcp acknowledgment packet and data packet
At the TCP sender side, the arrival of an ack packet always triggers the sender to send data packets, which establishes a correspondency between the arrived ack packet and the sent data packets. In a TCP connection, the correspondency between every ack packet and its corresponding data packets forms a sequence. This sequence characterizes the sender's behavior. In this paper, we propose a method to estimate this correspondency sequence from the dump trace measured at the receiver side. Because many possible correspondency sequences can be constructed based on the trace, the problem here is an estimation problem, which is to select a most possible one from those candidate sequences. The method proposed first eliminates some candidates that violate basic TCP congestion behavior. Then, it chooses the most possible one among the remaining sequences using the statistical characteristics of delays between the acks and their corresponding data packets under maximum-likelihood criterion. The method can work in the condition when the TCP connection experiences various network delay and loss, and it applies to TCP senders of different versions. Simulations and Internet experiments have been performed to validate the method.
tcp data connection sequence behavior paper method estimates traces select congestion statistics delay experience network version simulation internet maximum-likelihood estimation non-deterministic finite state machine maximum likelihood