Stage 4: Runtime Control

Aether defines an API (and associated GUI) for managing connectivity at runtime. This stage brings up that API/GUI, as implemented by the Runtime Operational Control (ROC) subsystem, building on the physical gNB we connected to Aether in Stage 3. As in the previous stage, we focus on the 5g-radio blueprint, but the same approach applies equally well to 4g-radio and latest.

This stage focuses on the abstractions that the ROC layers on top of the SD-Core. These abstractions are described in Section 6.4 and include Device Groups and Slices. (The full set of model definitions can be found in GitHub.) Initial settings of these ROC-managed parameters are recorded in 5g-radio/roc-5g-models.json. We use these values to bootstrap the ROC database, saving us from a laborious GUI session.

Somewhat confusingly, the Device-Group and Slice information is duplicated between 5g-radio/sd-core-5g-values.yaml and 5g-radio/roc-5g-models.json. This makes it possible to bring up the SD-Core without the ROC, which simplifies the process of debugging an initial installation (as was the case in Stage 3), but having two sources for this information leads to problems keeping them in sync, and should be avoided.

To this end, Aether treats the ROC as the “single source of truth” for Slices, Device Groups, and all the other abstract objects it defines, so we recommend using the GUI or API to make changes over time, and avoiding the override values once you’ve established basic connectivity. And if you want to save this bootstrap state in a text file for a possible restart, we recommend doing so in 5g-radio/roc-5g-models.json. (This is still a “getting started” approach, and not a substitute for the operational practice of backing up the ROC database.)

To make ROC the authoritative source of runtime state, first edit the SA_CORE variable in blueprints/5g-radio/config, setting it to false. This variable indicates whether we want SD-Core to run in Stand Alone mode, which has been the default setting up to this point. Disabling SA_CORE causes the SD-Core to ignore the device-groups and network-slices blocks of the omec-sub-provision section in 5g-radio/sd-core-5g-values.yaml, and to instead retrieve this information from the ROC.

The next step is to edit 5g-radio/roc-5g-models.json to record the same IMSI information you added to 5g-radio/sd-core-5g-values.yaml in Stage 3. This includes modifying, adding and removing sim-card entries as necessary. Note that only the IMSIs need to match the earlier data; the sim-id and display-name values are arbitrary and need only be consistent within 5g-radio/roc-5g-models.json.

"imsi-definition": {
       "mcc": "315",
       "mnc": "010",
       "enterprise": 1,
       "format": "CCCNNNEESSSSSSS"
},
...

"sim-card": [
       {
           "sim-id": "sim-1",
           "display-name": "SIM 1",
           "imsi": "315010999912301"
       },
...

Once you are done with these edits, uninstall the SD-Core you had running in Stage 3, and then bring up the ROC followed by a new instantiation of the SD-Core:

$ make core-clean
$ make 5g-roc
$ make 5g-core

The order is important, since the Core depends on configuration parameters provided by the ROC. Also note that you may need to reboot the gNB, although it typically does so automatically when it detects that the Core has restarted.

To see these initial configuration values using the GUI, open the dashboard available at http://<server-ip>:31194. If you select Configuration > Site from the drop-down menu at top right, and click the Edit icon associated with the Aether Site you can see (and potentially change) the following values:

MCC: 315
MNC: 010

Although we have no need to do so now, you can make changes to these values, and then click Update to save them to the “commit basket”. Similarly, if you select Sim Cards from the drop-down menu at top right, the Edit icon associated with each SIM card allows you to see (and potentially change) the IMSI values associated with each device. You can also disable individual IMSIs. Again, click Update if you make any changes.

The set of registered IMISs can be aggregated into Device-Groups by selecting Device-Groups from the drop-down menu at the top right, and adding a new device group.

Finally, if you do make a set of updates, select the Basket icon at top right when you are done, and click the Commit button. This causes the set of changes to be committed as a single transaction.