Domain Name System Procedures; Stage 3
The present document describes Domain Name System (DNS) Procedures for the Evolved Packet System. This document covers the Evolved Packet Core gateway node selection using DNS (e.g. SGW and PGW nodes) excluding all User Equipment (UE) initiated DNS-based discovery and selection procedures.
The present document specifies functions, procedures and information which apply to GERAN Iu mode. However, functionality related to GERAN Iu mode is neither maintained nor enhanced.
The present document also describes the Domain Name System (DNS) Procedures for the Evolved Packet System interworking with the 5G System, as specified in 3GPP TS 23.501 [28] and 3GPP TS 23.502 [29].