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XaaS                                                     3


                                                        Annex B


              Functional components on mapping between physical and virtualized networks
                                  (This annex forms an integral part of this Recommendation.)


            This annex describes the functional components on mapping between physical and virtualized networks.

            NOTE – A virtualized network can be seen as a specific realization of a NS whose resources are provided on top of
            physical resources that constitute a physical network.
            In  order  to  realize  the  functionality  for  mapping  between  physical  and  virtualized  networks  (refer  to
            clauses 7.7.1 and I.4), specialized mapping functional components are necessary.
            The resource abstraction and control functional component [ITU-T Y.3502] is used by NaaS CSPs to:

            –       Provide access to the physical computing resources through software abstraction;
            –       Ensure efficient, secure, and reliable usage of the underlying infrastructure;
            –       Enable a NaaS CSP to offer qualities such as rapid elasticity, resource pooling and on-demand self-
                    service.
            The  resource  abstraction  and  control  functional  component  can  include  software  elements  such  as
            hypervisors, virtual machines, virtual data storage, and time-sharing.
            The physical resources functional component [ITU-T Y.3502] includes hardware resources, such as computer,
            networks (routers, firewall, switches, network links and network connectors), storage components and other
            physical computing infrastructure elements.
            The  resource  abstraction  and  control  functional  component  and  the  physical  resources  functional
            component can be instantiated to realise the functionality described in clause 7.7.1, as shown in Figure B.1.























                                  Figure B.1 – Functional components on mapping between
                                             physical and virtualized networks

            B.1     Physical network
            Physical  network  functional  component  provides  physical  agents  of  physical  network  elements,  such  as
            physical nodes, ports, switches and links.
            NOTE – Physical agents are the representations of actual physical network nodes, ports, switches, links, etc.










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