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CFS vs RFS

  • 1.  CFS vs RFS

    TM Forum Member
    Posted Oct 05, 2023 05:12

    Hi,

    I have read some marerials like gb922 product, service, and ig1228 use cases. So, what I understood about CFS, it is just abstraction layer that covers multiple RFSs in order to give intangible products. So, I need to confirm my understanding about it. RFSs are real service applications, cfs is just abstract expression to be given to customer. Is it right? Or can cfs be real service?



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    Myagaa Nm
    MOBICOM CORPORATION LLC
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  • 2.  RE: CFS vs RFS

    TM Forum Member
    Posted Oct 06, 2023 02:40

    Hi Myagaa,
    You are right. Basically, a CFS is an abstraction of a service that you give to your customers. It is technology-agnostic and related to products of the core commerce layer.
    An RFS is a technical implementation for a service. A CFS can be realized by one or more RFSs. In turn, each RFS can use several resources for its implementation.
    As you mentioned, IG1228 is a very good place to find many examples of catalog configurations that use this approach.
    Hope it helps.
    Best regards,



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    Abel Ruiz Huerta
    alvatross by SATEC
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  • 3.  RE: CFS vs RFS

    TM Forum Member
    Posted Apr 26, 2024 23:39

    Hi Abel,

    In service catalog, service spec (resource facing service spec) points array of resource spec. In my opinion, rfs can choose what resources will be used in order to activate the service. So, any rule is needed to choose the resources. Service spec contains constraint reference. Constraint can be policy. If I use policy as rule to choose what resources will be used, I can point the policy in the service spec. Because connections between service spec and resource spec has no policy reference, I couldn't point any policy on the resources. If service spec's reference of resource spec contains policy ref, I can set policy to choose the resource. How can I point the policy? Also, when specific rfs points policy to choose which resources will be used, if I add new resource reference in the service reference, the policy need to be handle the added resource. When I add resource spec ref in the service spec, I need to add logic. So how can it be catalog-driven?



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    Myagaa Nm
    Mobicom Corporation
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  • 4.  RE: CFS vs RFS

    TM Forum Member
    Posted May 02, 2024 07:58

    Hi Myagaa,

    You are correct. To the best of my knowledge, there is currently no standard method for defining policies within the relationships between specifications (e.g., RFS Spec to R Spec, or others). I can tell you that in the Alvatross service catalog, we have developed a method for defining decomposition rules tailored to the purposes you've described. This, however, is a custom extension we implemented.

    It's possible that future versions of SID and APIs might include such features. Does anyone have further information or updates regarding this?

    Best regards,



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    Abel Ruiz Huerta
    alvatross
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  • 5.  RE: CFS vs RFS

    TM Forum Member
    Posted May 03, 2024 03:57

    I think that it should be the service management process to orchestrate these SID entity instances. When a service order is received, it should be mapped to CFS and RFS using both SID specified models with extension and customized policy/rule. When any of the CFS and RFS has modification, a orchestration process flow should be triggered to update each other so that they will be consistent. Another behind the scenes trigger would be resource change (no service change, neither CFS or RFS has changed, but resource has changed therefore the RFS need to be updated). We implement a service-resource inventory as the place holder for the mappings.






  • 6.  RE: CFS vs RFS

    Posted Oct 06, 2023 02:53

    Hello NM

    CFS are customer facing services and RFS are resource facing services, resources could be physical or non-physical in nature.

    CFS could be decomposed into several RFS so that each RFS can be provisioned and activated, this decopmosition is done in catalouge, some operators have two discrete catalouges for sales and service in that case RFS are decomposed in service catalouge. and yes you are right in a way that RFS is the real service provided to customer.



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    Abhishek Gahlaut
    Bharti Airtel Ltd
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  • 7.  RE: CFS vs RFS

    TM Forum Member
    Posted Oct 06, 2023 06:28

    Think of CFS's as 'abstractions' of network/application capabilities that you market to customers. Typically there is a 1:1 relationship between a CFS and a Product, where as CFS:RFS can be 1:1, 1:n (one CFS composed of multiple RFS) and of course the same RFS can be utilised by multiple CFSs.



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    Pieter Eksteen
    Ciena Corporation
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  • 8.  RE: CFS vs RFS

    TM Forum Member
    Posted Oct 06, 2023 06:56

    Comment so far are correct.

    We do have a document on this topic including examples Product & Service Modelling Best Practices – Conforming to ODA v2.0.0 (IG1233) | TM Forum.

    RFS work well for physical networks and equipment.

    However  in virtualised network environment you may need to use Resource Functions to abstract the logical functionality of networks asn equipment.

    see GB922 Resource v23.0.0 | TM Forum 

    The ResourceFunction concept has been used extensively for Networking and Resource Management in several ODA and Open API activities:

    ·        TR 255A/B/C forming part of TR255 Resource Function Activation and Configuration Suite R17.5.0  

    ·        TMF664 Resource Function Activation and Configuration.



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    Dave Milham
    TM Forum, Chief Architect
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  • 9.  RE: CFS vs RFS

    TM Forum Member
    Posted Oct 16, 2023 20:53

    Hi Myagaa,

    Customer Facing Service(CFS) Spec describes the Service as understood by the customer.

    CFS Spec characteristics comproises of:

    ·       Product characteristics needed to establish what needs to be delivered/fulfilled. e.g., Bandwidth of Internet Service, number of Static IP.

    ·       Resources assigned to Customer. e.g., Static IPs assigned to Customer. Configurations the customer might be able to do to use the Service per their needs. e.g., BGP

    CFS is made up of one or more RFS.

    Resource Facing Service(RFS) Spec describes the Service as in the network. RFS Spec abstracts/hides the technology details that are not relevant to customer. Reuse of the model and processes is also one of the consideration while modelling the RFS Spec, with-out compromising on the RFS Spec still depicting a Service.

    RFS Spec characteristics comprises:

    ·       CFS characteristics to be provisioned/configured in the network. e.g., Bandwidth of Internet Service, Static IPs to be provisioned in the network, and BGP configuration. Any technical attributes needed to manage the resources and services in the network. e.g., Circuit ID



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    Srinivasa Vellanki
    Jio Platforms Limited
    Any opinions and statements made by me on this forum are purely personal, and do not necessarily reflect the position of my employer or TM Forum.
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  • 10.  RE: CFS vs RFS

    Posted 21 days ago

    hi Srinivasa,

    Based on your description it almost seems like 

    1. The Customer Facing Service(CFS) Spec can be based on IETF's RFC 8299, YANG Data Model for L3VPN Service Delivery -where what how many (no technology)
    2. The Resource Facing Service (RFS) Spec can be based on IETF's RFC 9182, YANG Network Data Model for Layer 3 VPNs -technology, but still vendor agnostic higher level -can be further transformed/mapped to individual vendor/openconfig config models

    Would the above be correct please?



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    Adam Vitkovsky
    TO BE VERIFIED
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  • 11.  RE: CFS vs RFS

    TM Forum Member
    Posted 20 days ago

    Hi Adam,

    Agree with your view, very nicely articulated and thank you for sharing the RFCs. Not sure the term "Delivery" would mean in "L3VPN Service Delivery". Service Models CFS/RFS are also meant to be used to assure(support service assurance processes) the Service in addition to deliver or fulfill the Service.



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    Srinivasa Vellanki
    Jio Platforms Limited
    Any opinions and statements made by me on this forum are purely personal, and do not necessarily reflect the position of my employer or TM Forum.
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  • 12.  RE: CFS vs RFS

    TM Forum Member
    Posted 20 days ago

    Folks we do have some general guidance about Product Service model published in: 

    IG1233 Product & Service Modelling Best Practices update to support B2B Use Cases v3 (E2E-167) - End to end ODA - TM Forum Confluence

    There is also an unpublished document on RFS resource modelling available to members 

    ODA Solution Design: "vertical" Product / Service Resource /Guideline: How to model sellable product offerings including service and resource specification with ODA and the TM Forum Information Framework - End to end ODA - TM Forum Confluence

    We do also have some document publishing modelling proposal for specific technologies such as:

    IG1211 ODA 5G Management Implementation Guidelines v1.0.1 – TM Forum

    For members there is a updated discussion of this specific technology at:

    Modelling for 3GPP Network Slice Use Case - Components and Canvas - TM Forum Confluence

     
    what I am wondering is if we could do with public web page where we can published worked examples of extensions?

     

     



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    Dave Milham
    TM Forum, Chief Architect
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  • 13.  RE: CFS vs RFS

    TM Forum Member
    Posted 20 days ago

    I can also suggest the official Product modelling playbook that also provides the TMF publications that we regularly reference in this community.

    And TMF has a dedicated instructor-led training (online + onsite case study) on PSR catalogue modeling.



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    Kind regards,

    Matthieu Hattab
    Lyse Platform
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