Handling Missing Notifications from Network to QoD API for Successful Resource Allocation

[Chintanlodariya]

Scenario:

As per the standard flow, when a QoD session creation request is received from the application server to the QoD API, the session creation request is forwarded to the NEF/PCF. The PCF then enforces the new policy towards the enforcement function (PGW/SMF) and sends an acknowledgement back to the PCF/NEF. Based on this acknowledgement, a 201 response is forwarded to the external application server via the QoD API, and the QoS status is marked as "requested." Once the PGW enforces the policy and allocates the resource to the user, it notifies the PCF, which in turn notifies the NEF and then the QoD API about the successful resource allocation, changing the QoS status to "available."

Question:

What should be the course of action if, for any reason, the notification for "successful resource allocation" is not received by the QoD API from the network? Should the QoD API inform the application server about a QoD failure in such a case?

[eric-murray]

If network resources are never allocated for the requested QoS profile but no error is received from the network, then the session will remain in REQUESTED state before moving to UNAVAILABLE when the session is terminated for whatever reason.

In principle, the session could remain in REQUESTED state indefinitely, waiting for the API consumer to cancel it. In practice, it is probably wise for the API implementation to terminate the session before that, after waiting a reasonable time for the network to respond.

But if that happens frequently, it suggests that there is a problem with the network implementation, as the network itself should either allocate resources or respond with an error within a reasonable period of time.