Standard transport protocols like TCP operate as a blind, FIFO conveyor belt for data, a model that is increasingly suboptimal for latency-sensitive and interactive applications. This paper challenges this model by introducing CATS (Conductor-driven Asymmetric Transport Scheme), a framework that provides TCP with the semantic awareness necessary to prioritize critical content. By centralizing scheduling intelligence in a transport-native "Conductor", CATS significantly improves user-perceived performance by delivering essential data first. This architecture directly confronts a cascade of historical performance workarounds and their limitations, including the high overhead of parallel connections in HTTP/1.1, the transport-layer Head-of-Line blocking in HTTP/2, and the observed implementation heterogeneity of prioritization in HTTP/3 over QUIC. Built upon TCP BBR, our ns-3 implementation demonstrates this principle by reducing the First Contentful Paint by over 78% in a representative webpage download configured as a deliberate worst-case scenario, with no penalty to total page load time compared to the baseline.

翻译：标准传输协议（如TCP）以盲目的先进先出方式传输数据，这种模式对于延迟敏感型与交互式应用日益显现出不足。本文通过引入CATS（指挥驱动式非对称传输方案）对这一传统模型提出挑战，该框架赋予TCP识别关键内容语义并实施优先级调度的能力。通过将调度智能集中于传输层原生的“指挥器”中，CATS通过优先传输核心数据显著提升了用户可感知的性能。该架构直接应对了历史上诸多性能优化方案及其局限性，包括HTTP/1.1中多路并行连接的高开销、HTTP/2中的传输层队头阻塞问题，以及HTTP/3 over QUIC在实际部署中表现出的优先级调度异构性。基于TCP BBR构建的ns-3仿真实现验证了该方案的有效性：在刻意设置的最劣化网页加载场景中，首次内容绘制时间降低超过78%，且相较于基线方案未造成整体页面加载时间的损失。