ORAN O-Cloud Registration story

[vjayaramrh]

Background: As part of Nephio R4, we now have O2 IMS operator implementation that supports cluster creation using ProvisionioningTemplate CRD and a FOCOM operator implementation. The next step would be to discuss and firm up the stories and acceptance criteria for below (if and where it makes sense.)

1. If O2IMS operator is installed, can we try adding support in IMS to invoke the FOCOM endpoint for registering the IMS?
2. If a cluster has been created using O2IMS operator, could FOCOM query for list of clusters created? Which IMS API should be implemented?
3. Would returning the list of blueprint packages registered with PORCH be considered returning O-Cloud templates?

References: https://docs.google.com/document/d/1g7Z9XIGnBAXnwvISgS69maMXzifsxpJsKJu28lC_PyU/edit?tab=t.0#heading=h.gjdgxs (O-Cloud Registration document in Nephio)

[NMSVishal]

Also, the communication between FOCOM and IMS will it be based on O-RAN standards i.e. (based on O2IMS APIs)?

[scbjurstrom]

Hello Vishal, thanks for your question. Yes the plan is to align in Nephio towards the O2ims standard API:s. What we did in R4 was a K8s API/CRD based pre-standard O2ims implementation that followed the O-RAN defined stage 2 information model, because the stage 3 spec was not ready at that time. Now the stage 3 O2ims provisioning service interface specification has been defined in O-RAN so we can start looking into how to support it in Nephio. The key difference is that O-RAN specifies a traditional REST API for the O2ims ProvisioningRequest, so the payload is not based on the Kubernetes Resource Model. But it should be quite possible to implement a thin adapter layer on the Nephio IMS side that just converts internally to the currently supported K8s/CRD API. And then correspondingly on the FOCOM client side we will need to update the operator to send the ProvisioningRequest in the O-RAN standardized format. It would be really great if you are interested in picking up some of this implementation work!

[NMSVishal]

Thanks @scbjurstrom for reply, I understand your point . Surely we can pick it up , if you have the O2IMS stage 3 spec please send it to me ,or I will check it on ORAN portal.

Let me analyses the O2IMS cluster creation APIs first.

[NMSVishal]

We have studied both the operators (FOCOM and IMS ) codebase and have tested both the operators on local setup , if any code contribution is needed on either of the operator ,we can pick it up.

[scbjurstrom]

Here are my comments on the bullets above, we discussed this in one of the previous Nephio O-RAN meetings:

1. The endpoint for O-Cloud registration into SMO is defined in chapter 3.6.5.1.1 in https://specifications.o-ran.org/download?id=822. But I see some problems/limitations in the spec here. I don´t think it is defined how the IMS is configured with the end point URI or FQDN of the SMO/FOCOM that will be the receiver of the "Notification.Callback" URI. There is a POST defined as the HTTP method but the actual URI that is supposed to be used is not defined in this chapter. It might be better described in the referred SOL015 spec, I have not checked it. But in any way, there must be a way to first register the SMO target endpoint in the IMS, and also register mTLS encryption and authentication credentials/certificates that allows the IMS to communicate with the SMO. Then in the payload of this notification message there is just an "IMS_EP" defined but the credentials required for the SMO to communicate with the IMS are missing. I am not sure how O-RAN wants this information to be communicated if it is not present here? Unfortunately this Notification does not contain any "extensions" parameter, otherwise we could have used that one to carry the credentials. We need to discuss how we should continue here, if we still implement the notification with some additional attributes for credentials?
2. Yes, once FOCOM retreives a status on the O2ims Provisioning Request that the cluster has been successfully created it should query up both the Node Cluster and Deployment Manager. The Provisioning Request status should thus return the id of both these O2ims resources so that FOCOM can query for them. I have noted that the latest O2ims ProvisioningRequest specification have support to return the Node Cluster ID, but so far not the Deployment Manager ID, but I think we still can just include that one as well in the Nephio implementation. On the O2ims API the API for /deploymentManagers/{deploymentManagerId} has been specified (in the same doc linked above) but the Node Cluster is only specified in the Information model (https://specifications.o-ran.org/download?id=820). But I don´t really see a problem for us to to a pre-standard API for this one, we can just follow the same pattern as for the deploymentManager URI and payload. What is most concerning I think is that in the /deploymentManagers/ object the credentials (e.g. Kubeconfig) to authenticate towards the newly created cluster are missing. I have seen though that OSC has defined a couple of extensions that carries cluster credentials so we can use these at least in our first implementation. https://docs.o-ran-sc.org/projects/o-ran-sc-pti-o2/en/latest/oran-o2-api.html#tag/O2IMS-InfrastructureInventory/operation/Get%20Deployment%20Manager%20Information
3. It is only a sub-set of the O-Cloud internal information that shall be returned as O-Cloud Template information to the SMO. So we should not expose the whole Nephio IMS level blueprints. We need to discuss how this O2ims API will look like, it is not yet specified.

[NMSVishal]

Hi @scbjurstrom ,

PFA of the O2IMS and FOCOM side implementation approach.

We are studying the specification ,once we are ready with the API understanding's , we will start the implementation.

[NMSVishal]

Hi @scbjurstrom,

Below are the APIs available in O2IMS stage 3 spec( O-RAN.WG6.TS.O2IMS-INTERFACE-R004-v08.00 )

And I don't see the provisioning APIs in it ,which is needed for cluster provisioning.

Instead the spec provides below API's.

• O2ims_InfrastructureInventor y Services
• O2ims_InfrastructureMonitori ng Services
• O2ims_InfrastructurePerforma nce Services
• O2ims_InfrastructureLogging Services

Can you please provide your comments.

[joey-moloney]

Hi @NMSVishal,

The v08.00 spec you are referencing does not include the provisioning but the v09.00 that was updated as part of the March train and will be published sometime in June/July has the provisioning included. Do you have access to the O-RAN internal wiki?

[NMSVishal]

Hi @joey-moloney ,

Thank you for your reply,I am not sure on the wiki access , can you please share the the wiki URL ,let me try it.

[NMSVishal]

Hi @joey-moloney ,

I am able to login to O-RAN wiki but I dont see any space on my dashboard.