School of Specs 24.501v20.0.0

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

9.11.4.10 PDU address

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

The purpose of the PDU address information element is to assign to the UE:

  • an IPv4 address associated with a PDU session;
  • an interface identifier for the IPv6 link local address associated with the PDU session; or
  • an IPv4 address and an interface identifier for the IPv6 link local address, associated with the PDU session.

This purpose of the PDU address information element is also to enable the W-AGF acting on behalf of the FN-RG to provide an interface identifier for the IPv6 link local address associated with the PDU session suggested to be allocated to the FN-RG, and to enable the SMF to provide SMF's IPv6 link local address to the W-AGF acting on behalf of the FN-RG.

The PDU address information element is coded as shown in figure 9.11.4.10.1 and table 9.11.4.10.1.

The PDU address is a type 4 information element with minimum length of 7 octets and a maximum length of 31 octets.

87654321
PDU address IEIoctet 1
Length of PDU address contentsoctet 2
0Spare0Spare0Spare0SpareSI6LLAPDU session type valueoctet 3
PDU address informationoctet 4octet n
SMF's IPv6 link local addressoctet (n+1)*octet (n+16)*

Figure 9.11.4.10.1: PDU address information element

Table 9.11.4.10.1: PDU address information element

PDU session type value (octet 3, bits 1 to 3)
Bits
321
001IPv4
010IPv6
011IPv4v6
All other values are reserved.
SI6LLA (SMF's IPv6 link local address) bit (octet 3, bit 4) (see NOTE)
Bit
4
0SMF's IPv6 link local address field is absent
1SMF's IPv6 link local address field is present
Bits 5 to 8 of octet 3 are spare and shall be coded as zero.
PDU address information (octet 4 to n)
If the PDU session type value indicates IPv4, the PDU address information in octet 4 to octet 7 contains an IPv4 address.
If the PDU session type value indicates IPv6, the PDU address information in octet 4 to octet 11 contains an interface identifier for the IPv6 link local address.
If the PDU session type value indicates IPv4v6, the PDU address information in octet 4 to octet 11 contains an interface identifier for the IPv6 link local address and in octet 12 to octet 15 contains an IPv4 address.
SMF's IPv6 link local address (octet n+1 to n+16)
SMF's IPv6 link local address field contains SMF's IPv6 link local address.
NOTE: In the UE to network direction, the SI6LLA bit shall be set to "SMF's IPv6 link local address field is absent".