Feature Description

IPAM is the core component of the subscriber management system. Traditional IPAM functionalities prove insufficient in the Cloud Native network deployments. Hence, IPAM requires more functionalities to work with the Cloud Native subscriber management system.

The Static IP Support feature enables the support of static IP on the SMF using IPAM. This feature supports the following functionalities:

  • Static pool configuration—dynamic addition and deletion of static IP pool or static IP address range when the system is running.

  • Splits static address ranges into smaller chunks and associates them with the configured UPFs

  • Enables program routes according to static address range reservation during UPF association

  • Enables secondary authentication under the DNN profile

  • Selects UPF based on reserved address range and Framed-IP received from the Authentication response

  • Handle UPF addition, deletion, and Sx path failure

  • Add a DNN to an existing UPF

Calls with Static IP Address

The SMF supports calls with static IP address and validates if the IP address belongs to the static pool.

The SMF supports Create Session Request with static IP address and also handles Create Session Request received with PAA. The SMF validates if the requested IP address is configured under static pool and assigns the same IP address for the session. If the IP address is not configured under static pool, then SMF rejects the session.

Important

In Release 2021.02, the SMF does not support fallback to dynamic IP allocation.

The following behavior is applicable only to sessions with static IP address.

  • If the SMF receives static IP in Subscription Response from UDM during the 5G Session Create procedure, it assigns the same IP address to the UE session if the IP is configured under static pool. If the IP address is not configured under static pool, then SMF rejects the session.

  • If the RADIUS interface is enabled and if the RADIUS server returns the static IP address, then SMF ignores the IP address received in Create Session Request or Subscription Response.