In one embodiment, segment routing network processing of packets is performed, including using segment routing packet policies and functions providing segment routing processing signaling and packet forwarding efficiencies in a network. A segment routing node signals to another segment routing node using a signaled segment identifier in a segment list of a segment routing packet with the segments left identifying a segment list element above the signaled segment identifier. A downstream segment routing node receives the segment routing packet, obtains this signaled segment identifier, and performs processing of one or more packets based thereon. In one embodiment, a provider edge node replaces its own segment identifier in a received customer packet, with a downstream customer node using the replaced (signaling) segment identifier (of a provider edge node/segment routing function) for accessing a return path through the provider network.