open5gs/docs/_docs/tutorial/08-AMF-API-addAndDelete-new-PLMN.md

Tutorial: Dynamically Adding and Removing PLMNs in the AMF

This tutorial describes the different OAM (Operations, Administration and Maintenance) management API calls for the AMF (Access and Mobility Management Function) in Open5GS. The goal is to dynamically add and remove PLMNs without restarting the AMF.
The feature is implemented by extending the SBI, so the API uses HTTP/2.0.

Objective

Implement a RESTful API that allows you to:

1. Query the configuration of PLMNs and slices (S-NSSAI)
2. Dynamically add new PLMNs without restarting the AMF
3. Dynamically delete PLMNs without restarting the AMF and deregister the associated UEs
4. Automatically notify gNBs about configuration changes

API Calls

Method	URL	Description
GET	http://<AMFIP>:7777/namf-oam/v1/plmns	Returns all PLMNs in the current AMF context.
GET	http://<AMFIP>:7777/namf-oam/v1/plmns/{plmnid}	Returns detailed information for the PLMN identified by {plmnid} (composed of MCC and MNC).
POST	http://<AMFIP>:7777/namf-oam/v1/plmns	Adds a new PLMN to the list or a new sst/sd combination if the PLMN already exists; notifies gNBs.
DELETE	http://<AMFIP>:7777/namf-oam/v1/plmns/{plmnid}	Deletes the specified PLMN, deregisters the associated UEs, and notifies the gNBs.

How to use

Get all PLMNs in the AMF

Retrieve all PLMNs (mcc, mnc, s_nssai with stt and sd)

curl --http2-prior-knowledge -X GET http://<AMFIP>:7777/namf-oam/v1/plmns

Example response

{
        "plmns":        [{
                        "plmn_id":      "99970",
                        "mcc":  999,
                        "mnc":  70,
                        "s_nssai":      [{
                                        "sst":  1,
                                        "sd":   "333333"
                                }, {
                                        "sst":  3
                                }]
                }],
        "total_plmns":  1,
        "connected_gnbs":       0,
        "registered_ues":       0
}

Get specific PLMN

Retrieve all entries for the specific PLMN (mcc, mnc, s_nssai with stt and sd) using the PLMN id which is formed using the mcc+mc

curl --http2-prior-knowledge -X GET http://<AMFIP>:7777/namf-oam/v1/plmns/99970

Example response

{
        "plmn_id":      "99970",
        "mcc":  999,
        "mnc":  70,
        "s_nssai":      [{
                        "sst":  1,
                        "sd":   "333333"
                }, {
                        "sst":  3
                }]
}

Add new PLMN in the AMF

Add a new PLMN to the AMF and notify gnBs (send AMFConfigurationUpdate)

curl --http2-prior-knowledge -X POST http://<AMFIP>:7777/namf-oam/v1/plmns \
  -H "Content-Type: application/json" \
  -d '{
    "plmn_id": {
      "mcc": "999",
      "mnc": "70"
    },
    "s_nssai": [
      {"sst": 1, "sd": "333333"},
      {"sst": 3}
    ]
  }'

Example response

{
    "status":       "success",
    "message":      "PLMN added successfully",
    "total_plmns":  1
}

Remove PLMN

Remove a PLMN of the AMF and notify the gnBs (send AMFConfigurationUpdate) and unregister the UEs to avoid the go through the CORE 5G

curl --http2-prior-knowledge -X DELETE http://10.244.0.216:7777/namf-oam/v1/plmns/99970

Example response

{
        "status":       "success",
        "message":      "PLMN deleted successfully",
        "deleted_plmn_id":      "99970",
        "deleted_entries":      1,
        "remaining_plmns":      0
}