School of Specs 24.501v20.0.0

3GPP 24.501 v20.0.0 — the document's own text

6.2.4.3 Additional RG related requirements for IP address allocation

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

If IPv6 PDU session type or IPv4v6 PDU session type is selected, an IPv6 address, one or more IPv6 prefixes or both are allocated to the 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device).

If the 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) receives a Router Advertisement Message as specified in IETF RFC 4861 [38B] with the "Managed address configuration" flag set to zero, the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device):

  • shall obtain /64 IPv6 prefix via IPv6 stateless address autoconfiguration as specified in 3GPP TS 23.501 [8] and IETF RFC 4862 [39];
  • may obtain IPv6 configuration parameters via stateless DHCPv6 as specified in IETF RFC 9915 [33D]; and
  • may request additional IPv6 prefixes using DHCPv6. If the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) request IPv6 prefixes using DHCPv6, the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) shall act as a "Requesting Router" as described in IETF RFC 9915 [33D], shall perform procedures described in clause 6.2.4.2a. Additionally, the 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) may include DHCPv6 OPTION_ORO option with the OPTION_PD_EXCLUDE option code as specified in IETF RFC 6603 [40A] in the DHCP.

If the 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) receives a Router Advertisement Message as specified in IETF RFC 4861 [38B] with the "Managed address configuration" flag set to one, the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device):

  • shall obtain an IPv6 address via DHCPv6 and the DHCPv6 Identity association for non-temporary addresses option as specified in IETF RFC 9915 [33D];
  • may obtain IPv6 configuration parameters via DHCPv6 as specified in IETF RFC 9915 [33D]; and
  • may request IPv6 prefixes using DHCPv6. If the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) requests IPv6 prefixes using DHCPv6, the 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) shall act as a "Requesting Router" as described in IETF RFC 9915 [33D], shall perform procedures described in clause 6.2.4.2a. Additionally, the 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) may include DHCPv6 OPTION_ORO option with the OPTION_PD_EXCLUDE option code as specified in IETF RFC 6603 [40A] in the DHCP message. The 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) may include both IA_PD option and IA_NA option to request the delegated prefix together with the IPv6 address in the same DHCPv6 message.

NOTE: The 5G-RG and the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) can send multiple DHCPv6 requests with different DHCPv6 Identity association for non-temporary addresses options when the 5G-RG or the FN-RG acts as a DHCP relay for devices behind the 5G-RG or the FN-RG.

The 5G-RG may obtain ACS information via DHCP as specified in clause 3.1 of BBF TR-069 [49] or in BBF TR-369 [50] R-DIS.1 and R-DIS.2.