BCT: Modeling Block Completion Time for Transport Protocols

Many applications based on block transmission have strict latency requirements. Existing solutions to reduce latency primarily focus on enhancing packet loss resistance through redundancy and scheduling transmission orders. However, the performance of these algorithms depends on accurate block transmission time estimation. Current evaluation methods, which do not account for the impacts of complex network protocols and packet loss, result in significant estimation errors.In this paper, we propose Block Completion Time (BCT) as a transmission delay index for block-based applications. We develop a BCT distribution model that incorporates packet-level block transmission under complex protocols and apply it to predict BCT for typical TCP and QUIC protocols. As a use case, we demonstrate how our model can assist in optimizing redundancy configurations. The model is evaluated under varying network conditions, application types, and transport protocols, showing improved accuracy in predicting both the mean and distribution of BCT compared to baseline methods.