Call Flows

The following call flow depicts the integration of the IPAM in the SMF.

IPAM Integration Call Flow Description
Step	Description
1	IPAM populates the local cache and cache pod with the data configured under IPAM pool configuration. Split the address ranges according to the split size configured under address range.
2	The Node Manager (NM) receives UPF discovery or registration request.
3	The NM forwards the UPF registration request to IPAM for a given DNN or address type.
4	IPAM finds the pool for the given tag and address type and allocates a free address range against the given UPF key.
5	Register the UPF response, status, and route information.
6	The SMF service performs bring up of PDU session. The NM forwards the request to IPAM for the address allocation request.
7	IPAM receives the request for address allocation for tag, UPF key, Authority and Format Identifier (AFI), and Group Identifier (GrID).
8	IPAM allocates free address from the previously allocated address range and responds with the status and allocated address, and route information.
9	The SMF service performs bring down of PDU session. The NM forwards the request to IPAM for address release request.
10	IPAM receives the request for address release for pool name, UPF key, AFI, and GrID.
11	IPAM adds the address to free list of the reserved address range and responds with the status and route information.
12	IPAM receives UPF deregistration request with tag, UPF key, and AFI.
13	Release all the address ranges from the pool associated to the tag, UPF key, and AFI. Then, move the address range to the free list.
14	IPAM sends the UPF deregistration response along with the status and route information.