Architecting for Edge Diversity: Supporting Rich Services Over an Unbundled Transport
The end-to-end nature of today's transport protocols is increasingly being questioned by the growing heterogeneity of networks and devices, and the need to support in-network services. To address these challenges, the authors present Tapa, a transport architecture that systematically combines two concepts. First, it unbundles today's transport such that network specific functions (e.g., congestion control) are implemented on a per-segment basis, where a segment spans a part of the end-to-end path that is homogeneous (e.g., wired Internet or an access network) while functions that relate to application semantics (e.g., data ordering) are still implemented end-to-end. Second, it has an explicit notion of in-network services (e.g., caching, opportunistic content retrieval, etc) that can be supported while maintaining precise end-to-end application semantics.