Path Segment Identifier (PSID) in SRv6 (Segment Routing in IPv6)

Segment Routing (SR) allows for a flexible definition of end-to-end paths by encoding an ordered list of instructions, called "segments". The SR architecture can be implemented over an MPLS data plane as well as an IPv6 data plane. Currently, Path Segment Identifier (PSID) has been defined to identify an SR path in SR-MPLS networks, and is used for various use- cases such as end-to-end SR Path Protection and Performance Measurement (PM) of an SR path. This document defines the PSID to identify an SRv6 path in an IPv6 network.