The TCP congestion control protocol serves as the cornerstone of reliable internet communication. However, as new applications require more specific guarantees regarding data rate and delay, network management must adapt. Thus, service providers are shifting from decentralized to centralized control of the network using a software-defined network controller (SDN). The SDN classifies applications and allocates logically separate resources called slices, over the physical network. We propose TCP Slice, a congestion control algorithm that meets specific delay and bandwidth guarantees. Obtaining closed-form delay bounds for a client is challenging due to dependencies on other clients and their traffic stochasticity. We use network calculus to derive the client's delay bound and incorporate it as a constraint in the Network Utility Maximization problem. We solve the resulting optimization using dual decomposition and obtain a semi-distributed TCP protocol that can be implemented with the help of SDN controller and the use of an Explicit Congestion Notification (ECN) bit. Additionally, we also propose a proactive approach for congestion control using digital twin. TCP Slice represents a significant step towards accommodating evolving internet traffic patterns and the need for better network management in the face of increasing application diversity.

翻译：TCP拥塞控制协议是可靠互联网通信的基石。然而，随着新应用对数据速率和延迟提出更具体的保障要求，网络管理必须随之调整。因此，服务提供商正借助软件定义网络（SDN）控制器，从分布式网络控制转向集中式控制。SDN对应用进行分类，并在物理网络上分配逻辑上独立的资源（称为切片）。我们提出TCP Slice，一种满足特定延迟和带宽保障的拥塞控制算法。由于客户端延迟界限依赖于其他客户端及其流量随机性，获取其闭式延迟界限具有挑战性。我们利用网络演算推导客户端的延迟界限，并将其作为约束条件纳入网络效用最大化问题中。通过对偶分解求解所得优化问题，得到一种半分布式TCP协议，该协议可借助SDN控制器和显式拥塞通知（ECN）比特实现。此外，我们还提出了一种利用数字孪生的主动式拥塞控制方法。TCP Slice在适应不断演变的互联网流量模式以及应对日益增长的应用多样性对更好网络管理的需求方面，迈出了重要一步。