3GPP 23.501 v20.2.0 — the document's own text

5.17.7.2.1 Addressing

Taught in 19. Living next to 4G (The 5G system architecture, in depth), 7. Roaming, other accesses, the edge and the outside (The 5G system architecture, overview).

All the Configuration Transfer messages contain the addresses of the source and destination RAN nodes.

An gNB node is addressed by the Target NG-RAN node identifier as described in TS 38.413 [34].

An eNodeB is addressed by the Target eNodeB identifier as described in TS 36.413 [100].