SCION Data Plane

This document describes the Data Plane of SCION (Scalability, Control, and Isolation On Next-generation networks), a path-aware, inter-domain network architecture. Unlike IP-based forwarding, SCION embeds inter-domain forwarding directives in the packet header, enabling endpoints to construct and select end-to-end paths from segments discovered by the Control Plane. The role of the Data Plane is to combine such segments into end-to-end paths, and to forward data according to the specified path. This document describes the SCION packet format, header structure, and extension headers. It also describes the cryptographic mechanisms used for path authorization, processing at routers including a life of a packet example. This document contains new approaches to secure path aware networking. It is not an Internet Standard, has not received any formal review of the IETF, nor was the work developed through the rough consensus process. The approaches offered in this work are offered to the community for its consideration in the further evolution of the Internet.