Open APIs

Hello Experts,

I would like to clarify my understanding for cardinality between instance of ResourceFacingService (RFS) and CustomerFacingService (CFS).

In GB922-service-v23-0-0 (snapshot below), I could see one Instance of RFS is associated with multiple instances of the CFS (cardinality from RFS to CFS is 0..*).

But, in TMF638_Service_Inventory_userguide, I could see the 'composition' association between 'ServiceReforValue' and 'Service', this would mean one instance of RFS is associated with one instance of CFS only.

Resource model:

Can you please help to clarify, what should be the recommended behavior? Should one instance of RFS associated with multiple instances of CFS?

Thanks.

Hi Prashant,

This is a very good question, because it is not documented very clearly how this works.

In the API the supportingService is a one directional relationship, linking CFS to a set of RFS. Although the same supportingService could be used to link an RFS to a set of CFS it is not best practise to model both directions of a relationship because it is cumbersome and errorprone.

Lets illustrate this with an example.

A CSP offers a internet service (CFS1) with public IPv6 and private IPv4 (behind Carrier Grade NAT). Optionally customers can also book a public IPv4 service without NAT (CFS2).

CFS1 requires a Radius Profile (RFS1) and a CPE PPPoE configuration (RFS2).

CFS2 requires a Radius Profile (RFS1) and will modify the IP AddressPool used by the Radius Profile.

In the Inventory, CFS1 will have 2 supportingServices (RFS1) and (RFS2). CFS2 will have one supportingService(RFS1), which is the same instance as already referenced by CFS1.

If there is a need to find out the cardinality of this relationship from the RFS1 side, one would simply search for CFS having this RFS1 as supportingService. This would return both CFS1 and CFS2.

I hope this description sheds some light on how OpenAPI and SID handle relationships differently to achieve the same result.

Regards

Hi Koen,

Thank you for sharing your insights.

With respect to given example, if product associated with 'public IPv4 service without NAT (CFS2)' is ceased, then wouldn't it result in cease of RFS1? How this case will be handled?