PCF: 'NULL' events on successful N5 (npcf) request

[oktavlachs]

Hi there and thank you so much for managing this awesome project 😺

I am testing the N5 interface between P-CSCF and PCF and discovered that for a successful request towards the PCF I get weird event values in the response message.

Request type: POST /npcf-policyauthorization/v1/app-sessions

Request body:

{
 "ascReqData": {
  "afAppId": "IMS Services", 
  "dnn": "internet", 
  "medComponents": {
   "0": {
    "medCompN": 0,
    "medSubComps": {
     "0": {
      "fNum": 0,
      "fDescs": ["permit out ip from 10.46.0.3 59999 to 192.168.0.146 5060", "permit in ip from 192.168.0.146 5060 to 10.46.0.3 59999"],
      "flowUsage": "AF_SIGNALLING"
     }
    }, 
    "medType": "CONTROL",
    "codecs": ["downlink\noffer\n", "uplink\nanswer\n"],
    "fStatus": "ENABLED"
   }
  },
  "evSubsc": {
   "events": [{
     "event": "CHARGING_CORRELATION"
    }, {
     "event": "ANI_REPORT",
     "notifMethod": "ONE_TIME"
   }]
  },
  "notifUri": "/some-uri",
  "sponStatus": "SPONSOR_DISABLED",
  "supi": "imsi-001011234567895",
  "suppFeat": "2",
  "ueIpv4": "172.22.0.24"
 }
}

PCF response body (Status Code is 201):

{
 "ascReqData": {
  "afAppId": "IMS Services",
  "dnn": "internet",
  "evSubsc": {
   "events": [{
     "event": "NULL"
    }, {
     "event": "NULL",
     "notifMethod": "ONE_TIME"
    }]
  },
  "medComponents": {
   "0": {
    "codecs": ["downlink\noffer\n", "uplink\nanswer\n"],
    "fStatus": "ENABLED",
    "medCompN": 0,
    "medSubComps": {
     "0": {
      "fNum": 0,
      "fDescs": ["permit out ip from 10.46.0.3 59999 to 192.168.0.146 5060", "permit in ip from 192.168.0.146 5060 to 10.46.0.3 59999"],
      "flowUsage": "AF_SIGNALLING"
     }
    },
    "medType": "CONTROL"
   }
  },
  "notifUri": "/some-uri",
  "sponStatus": "SPONSOR_DISABLED",
  "supi": "imsi-001011234567895",
  "suppFeat": "2",
  "ueIpv4": "172.22.0.24"
 }
}

The OpenAPI specs do not offer NULL value for an 'AfEvent' type though, only the ones documented here
Do you agree that this is a bug in the PCF?

Cheers!

[acetcom]

Hi @oktavlachs

It's an Open5GS bug. I've modified and updated it to the main branch on github.
Note that VoNR feature is not fully implemented. As such, further testing may not be possible.

Thank you for sharing it!
Sukchan

[oktavlachs]

Fantastic, thanks for taking care of this!
Any roadmap for VoNR? Should I report more bugs while I am testing or come up with own PRs?

I am looking into this topic with @herlesupreeth

Cheers

[acetcom]

@oktavlachs

Both issues and pull requests are welcome. Just choose the method you like best.

I am concentrating on what I do for a living. For the time being, it looks like no new features will be added unless requested by the sponsor.

Let me know if you have any further questions.

Thanks a lot!
Sukchan

[oktavlachs]

@acetcom
You can close this issue, as it was fixed :)

Thanks!

[carloplazz]

Hi @oktavlachs
How did you configured the PCF in order to receive messages from the N5 interface?
Sorry for the dumb question :)

[oktavlachs]

Hi @carloplazz
I have not worked on this recently so unfortunately I cannot recall. But I am pretty sure it worked out of the box after deploying the ng-voice IMS.
Maybe you can elaborate a bit more on what your issue is?

[carloplazz]

No problem, I've resolved that problem.
Now I'm facing your same issue of 'NULL' events on successful request using the Update PATCH method.
Also if I send a GET request to read an existing Individual Application Session Context the PCF responds me with '403 Invalid HTTP method'
GET read session error.zip.zip