Srvcast: Facilitating Host-Transparent and Stateful Anycast for Computing-Aware Networks

6G-driven compute-intensive applications require the collaboration of communication and computing to achieve optimal performance. Such collaboration drives integrated sensing, communication, and computing to support service requirement sensing and on-demand computing task steering within the network. To this end, the Computing-Aware Network proposes to incorporate computing information into the network layer address called service identifier (SID), to implement serviceoriented SID anycast. This integration aims to naturally support dynamic task steering using the anycast mechanism. However, SID represents an abstract service rather than a specific host, making SID anycast incompatible with the TCP communication patterns used by existing socket-based applications. To address this challenge, this paper introduces Srvcast, a host-transparent and stateful anycast solution. Srvcast consists of two stages: WAN routing and edge network forwarding. In WAN routing, it employs a novel service-oriented routing mechanism to ensure connection affinity for anycast. In the edge network forwarding, Srvcast presents ServiceNAT, a P4-based address translation mechanism that enhances SID compatibility with socket-based applications. To implement Srecast, a prototype system is built in a practical WAN environment. The results demonstrate that Srvcast outperforms existing solutions in terms of system complexity and socket connection establishment time. Srvcast can maintain the flexibility of SID anycast while ensuring compatibility with TCP communication patterns at a lower cost.