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Questions about ONAP Schema definitions for TMF Service Specifications

  • 1.  Questions about ONAP Schema definitions for TMF Service Specifications

    Posted Sep 29, 2021 03:13
    The TMF 641 Spec has the bellow illustrations, with the "@schemaLocation" pointing to certail urls for Service Characteristic and for Service Specification Ref.
    1. Is the @schemaLocation "http://nbi/api/v4/serviceSpecification/ONAPvCPE_Spec/specificationInputSchema" referred to for the Service Specification defined by ONAP for CPE type of resource? Since the Url is not a real Url, where can I find the actual schema definition for CPE Specification? Similarly are there ONAP defined schemas in existence for other types of resources such as Network Slices?

    2. The @schemaLocation in ServiceSpecificationRef points to "http://my.schema/ONAPServiceSpecificationRef.json". While this url is also an unreal one, why is this on a different domain from the above one? Is the thinking that the schema for ONAP Service Specification "Reference" (with just id, href, name etc agnostic to the actual Service Specification contents) will be more static and immutable, whereas the schemas for Service Specifications themselves such as vCPE have a more dynamic existence and will be hosted separately?
    In otherwords, if there is a Service type that a Provider wants to provided for which there is not a schema defined by ONAP, this Provider can define and host its own Service Specification, and still use ONAPServiceSpecificationRef to refer to this Specification url and id?

    "serviceCharacteristic": [
    {
    "id": "452-gh6",
    "name": "vCPE",
    "valueType": "object",
    "value": {
    "@type": "vCPE",
    "@schemaLocation": "http://nbi/api/v4/serviceSpecification/ONAPvCPE_Spec/specificationInputSchema",
    "vCPE_IP": "193.218.236.21",
    "MaxTxRate": 300,
    "TransmitPower": "11 dBm",
    "maxTream": "OFF"
    }
    }
    ],
    "serviceSpecification": {
    "@type": "ONAPServiceSpecificationRef",
    "@schemaLocation": "http://my.schema/ONAPServiceSpecificationRef.json",
    "id": "ONAPvCPE_Spec",
    "href": "http://../serviceSpecification/ONAPvCPE_Spec",
    Service Ordering Management API User Guide
    © TM Forum 2021. All Rights Reserved Page 26 of 66
    "name": "vCPE",
    "version": "1",
    "invariantUUID": "456-852-357",
    "toscaModelURL": "http//..."
    }

    ------------------------------
    Kannan Jayaprakasam
    TO BE VERIFIED
    ------------------------------


  • 2.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Sep 30, 2021 05:53
    Hi Kannan
    The examples in Open API User Guides (we prefer to call them guides rather than specs) are just that, examples. Although we try to create realistic examples, there is no intention that they be authoritative. So mention of ONAP (for example) is purely illustrative.
    In practice, a real implementation of any API that uses schema extension would include publication of a proper location for the schema extension files.
    Adding @Kamal Maghsoudlou for his thoughts.
    Hope it helps​

    ------------------------------
    Jonathan Goldberg
    Amdocs Management Limited
    Any opinions and statements made by me on this forum are purely personal, and do not necessarily reflect the position of the TM Forum or my employer.
    ------------------------------



  • 3.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    Posted Sep 30, 2021 22:05
    Hi Jonathan
    I had figured that a real API implementation should be using real published schema locations, but my question is more specifically around who hosts these schemas - 

    1. Is there a globally common published schema url that specifies that a ServiceSpecification  should be composed of Characteristics and Features

    2. Then who defines individual Service and Resource types, for example assume there is a ServiceSpecification (using the schema for the ServiceSpecification from (1), whoever makes it available) published to a catalogue that defines a NetworkSlice ServiceSpecification with a Characteristic named DownlinkBandwidth with a guaranteed_bandwidth and a maximum_bandwidth. Is this ServiceSpecification schema for NetworkSlice going to be hosted by a particular Service Provider on their own servers and publish it to their Consumers for calling them? That will require a client to write code separately for requesting a NetworkSlice from Ericsson and for requesting one from AT&T.
    Alternately can there be a one globally defined ServiceSpecification for NetworkSlice by a common body so a client code does not have to change when requesting it from different providers?





  • 4.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 01, 2021 07:33
    Hi Kannan
    TMF does not (currently, at any rate) have standards for modeling products and services (and resources). Best practices are starting to emerge as part of the work in the ODA project, you might want to take a look at IG1228 publication here. But I don't know of any immediate plan to convert these into concrete JSON schemas.
    Other standards bodies, e.g. MEF, are collaborating with TMF and have adopted Open APIs to manage specific lines of business. @Ludovic Robert may have additional info on that - again I don't know if this has gone to the level of actually publishing schemas that would be compatible with the TMF Open API P/S/R model.
    Hope it helps



    ------------------------------
    Jonathan Goldberg
    Amdocs Management Limited
    Any opinions and statements made by me on this forum are purely personal, and do not necessarily reflect the position of the TM Forum or my employer.
    ------------------------------



  • 5.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    Posted Oct 12, 2021 09:00
    Hi Jonathan
    A few followup questions.
    About the specific Resource and Service specifications in terms of Characteristics and Features etc, for example a prescribed way of representing a NetworkSlice, I understand from your reply that there is no such published schema. 
    While the above clarifies the state of the schema for the industry specific resources and services, what about the schema for ServiceOrder or ServiceSpecificationRef for example, that appear to be independent of the industry using them? Are there globally published schema urls, so that a client code doing Service Ordering doesn't have to change, except for the specific Service and Resource schemas part that vary with industry / vertical? 
    These are noob questions so please feel to point me to any existing resources I can read in this regard.

    ------------------------------
    Kannan Jayaprakasam
    TO BE VERIFIED
    ------------------------------



  • 6.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 13, 2021 03:19
    The models for items like ServiceOrder and ServiceSpecfiicationRef (and indeed for all Open API resources) are embedded in the published Open API swagger files for each API (API table here gives access to the published assets). These swaggers are generated from underlying JSON schemas, but TMF has not (yet) published the individual entity schemas independently.
    Hope it helps

    ------------------------------
    Jonathan Goldberg
    Amdocs Management Limited
    Any opinions and statements made by me on this forum are purely personal, and do not necessarily reflect the position of the TM Forum or my employer.
    ------------------------------



  • 7.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 13, 2021 06:09

    @Jonathan Goldberg wrote:

    |  TMF has not (yet) published the individual entity schemas independently.

    Nor have they been name spaced, a separate ​issue (AP-2285). I like to highlight the distinction because publishing has organizational governance implications while name spacing is a technical requirement.  The JSON Schema specification requires that URIs are used to uniquely identify schemas however it is not necessary that they function to provided the resource. Although internally TMF tooling, used to generate Swagger, works from common schema files each Swagger file is mostly self contained, so it can be argued that external references aren't required. I personally would argue the other side. 



    ------------------------------
    Vance Shipley
    SigScale
    ------------------------------



  • 8.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 13, 2021 04:16
    Edited by Dave Milham Oct 13, 2021 08:15
    You might want to read the following for inspiration  but I don't believe we have yet created the full formal open API schemas 

    IG1211 ODA 5G Management Implementation Guidelines v1.0.1

    IG1217 Resource Inventory of 3GPP NRM for Service Assurance v1.0.1

    @Vance Shipley  was the originator and may be able to advise 



    ------------------------------
    Dave Milham
    TM Forum, Chief Architect
    ------------------------------



  • 9.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 13, 2021 06:17
    In IG1217 we described techniques to map 3GPP information models (NRM) to TM Forum SID and Open APIs. One of the decisions you need to make is whether you want to avoid or embrace polymorphism. I have personally vacillated a bit on this point. Either way though the industry would benefit by agreed upon Resource[Function]Specifications for the common NRMs like NetworkSlice and NetworkSliceSubnet. In IG1211 we do provide an (informative) example as a starting point.

    ------------------------------
    Vance Shipley
    SigScale
    ------------------------------



  • 10.  RE: Questions about ONAP Schema definitions for TMF Service Specifications

    TM Forum Member
    Posted Oct 13, 2021 04:24
    We just published in e2eODA project  a best practice with some examples see 

    IG1233 Product & Service Modelling Best Practices – Conforming to ODA v2.0.0

    The email example with give you some ideas about how to tackle the use of characteristics  in the product and services domains

    You can look at the  SID guides for some explanation of use of characteristics 
    GB922 Product v21.0.0GB922 Product v21.0.0
    GB922 Resource v21.0.0

    ------------------------------
    Dave Milham
    TM Forum, Chief Architect
    ------------------------------