How it Works

The SMF supports dual-stack static IP through IPAM in the following ways:

  • Pool to UPF mapping—Based on the number of UPFs available, the IPv4 address-ranges and IPv6 prefix-ranges are split into smaller chunks. Then, the pair (chunk) is configured into the same IPAM pool.

    IPAM assigns all the addresses and prefixes that are configured in one dual-stack pool to a UPF in the manner they are received. The AAA server returns the dual-stack addresses from the same pair. From these addresses, SMF selects one UPF for dual-stack programming.

    The load-balancing of number of addresses and prefixes are managed. IPAM performs only the dual-stack static-pool to UPF mapping.

  • Address-range no-split configuration—IPAM uses the "no-split" configuration to prevent splitting the address-ranges into smaller chunks. This configuration helps to prevent having multiple routes programming for a specific range.

    The following table lists the errors or exceptions and how to handle them:

Error and Exception Handling

Error or Exception

Exception Handling

IPv4 UPF and IPv6 UPF are configured incorrectly

  1. Select an active UPF. In case both the UPFs are active, select the UPF with the IPv4 address.

  2. Reset the IP information of the other stack and update the PDU session type accordingly.

IPv4 address is invalid or null

Select the UPF with IPv4 address and update the PDU session type accordingly.

IPv6 prefix is invalid or null

Select the UPF with IPv6 address and update the PDU session-type accordingly.

IPv4 address and IPv6 prefix are invalid

Both the IPv4 address and IPv6 prefix are rejected.