Transport congestion events detection (TCED): towards decorrelating congestion detection from TCP

摘要

TCP (Transmission Control Protocol) uses a loss-based algorithm to estimate whether the network is congested or not.udThe main difficulty for this algorithm is to distinguish spurious from real network congestion events. Other research studies have proposed to enhance the reliability of this congestion estimation by modifying the internal TCP algorithm.udIn this paper, we propose an original congestion event algorithm implemented independently of the TCP source code. Basically, we propose a modular architecture to implement a congestion event detection algorithm to cope with the increasing complexity of the TCP code and we use it to understand why some spurious congestion events might not beuddetected in some complex cases. We show that our proposal is able to increase the reliability of TCP NewReno congestion detection algorithm that might help to the design of detection criterion independent of the TCP code. We find out that solutions based only on RTT (Round-Trip Time) estimation are not accurate enough to cover all existing cases. udFurthermore, we evaluate our algorithm with and without network reordering where other inaccuracies, not previouslyudidentified, occur.