Thank you everyone who registered for the Comarch DemoFriday on BSS & OSS Stack. We appreciate your interest in the topic and tremendously enjoyed hearing from you. After this event on BSS/ OSS Stack, Comarch’s OSS Product Manager Łukasz Mendyk answered questions from the audience. Please enjoy the below Q&A answers where Łukasz addressed the role YANG plays in software-defined networking and more.
What would you say is essential for hybrid network management?
Comarch: Of most importance is model-driven network management, where Customer Facing Service (CFS using TMF SID terminology) is modeled to be decomposed to Resource Facing Service (RFS – technical services) and to Resources. Logical Resources could be either pNF or VNF. Contrary to what other vendors seem to suggest, other “silos” (ETSI MANO) should not be introduced. Instead, a “modern OSS” can be used to implement network functions virtualization (NFV) orchestrator and generic virtual network function (VNF) manager.
Comarch: For “modern” BSS/OSS systems which already implement model-driven operations (product/catalog driven), the first step is to extend the model to enable modeling of logical resources into pNF and VNF comparable variants. Network inventory should be enhanced to model the network where the nodes are kinds of micro-data centers (NFVI PoPs capable of hosting both VNFs and applications). Another important aspect is that virtualization introduces another layer of abstraction, where logical networks can be “hosted” in many places (many distributed NFVI PoPs).
In addition, the OSS should be perceived as an enabler for SDN by leveraging the “umbrella” capabilities of traditional OSS to provide holistic view of the network and customer services, thus enabling the network to be “programed” according to the needs of the customer applications.
Comarch: It should first be understood that YANG is not a model in itself, but a language to describe the model. This means that, potentially, two VNF vendors can provide the VNF Descriptors in YANG, which would be incompatible without a standardized model. This means that , as described in the answer to question one, the model is the key to success. Whether the model is described in YANG or in an alternative language is not that important.
Having said that, YANG is certainly useful. It should enable the easier on-boarding of VNFs and Network Services, but only when the standard models are defined.
Can you please show the unified model of VNF and PNF?
Comarch: The unified model of pNF and VNF means that, first, the OSS should model pNF as logical function hosted by a physical resource (dedicated hardware in the case of pNF). Then the VNF is described using the Logical Function (VNF) as a function adequate to the pN. So, from the point of view of the Logical Function, pNF and VNF should be modeled in the same way. The difference is in implementation, as VNF would be hosted by VM, which is assigned to Hypervisor hosted by the physical resource (blade).
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