Internet DRAFT - draft-bernardos-intarea-vim-discovery

draft-bernardos-intarea-vim-discovery







INTAREA WG                                                 CJ. Bernardos
Internet-Draft                                                      UC3M
Intended status: Experimental                                  A. Mourad
Expires: March 14, 2022                                     InterDigital
                                                      September 10, 2021


 IPv6-based discovery and association of Virtualization Infrastructure
 Manager (VIM) and Network Function Virtualization Orchestrator (NFVO)
                draft-bernardos-intarea-vim-discovery-06

Abstract

   Virtualized resources do not need to be limited to those available in
   traditional data centers, where the infrastructure is stable, static,
   typically homogeneous and managed by a single admin entity.
   Computational capabilities are becoming more and more ubiquitous,
   with terminal devices getting extremely powerful, as well as other
   types of devices that are close to the end users at the edge (e.g.,
   vehicular onboard devices for infotainment, micro data centers
   deployed at the edge, etc.).  It is envisioned that these devices
   would be able to offer storage, computing and networking resources to
   nearby network infrastructure, devices and things (the fog paradigm).
   These resources can be used to host functions, for example to
   offload/complement other resources available at traditional data
   centers, but also to reduce the end-to-end latency or to provide
   access to specialized information (e.g., context available at the
   edge) or hardware.

   This document describes mechanisms allowing dynamic discovery of
   virtualization resources and orchestrators in IPv6-based networks.
   In the current version, mechanisms based on piggybacking options on
   IPv6 neighbor discovery are explored.  New IPv6 neighbor discovery
   options are defined.  Additional mechanisms will be explored in
   future releases of this document.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any



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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 14, 2022.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Network Function Virtualization . . . . . . . . . . . . . . .   5
   4.  Fog Virtualization Overview . . . . . . . . . . . . . . . . .   7
   5.  Problem statemement . . . . . . . . . . . . . . . . . . . . .   9
   6.  Advertisement and discovery of mobile resources (VIM+NFVI)  .  11
     6.1.  IPv6 ND-based discovery . . . . . . . . . . . . . . . . .  12
     6.2.  VIM+NFVI options  . . . . . . . . . . . . . . . . . . . .  13
       6.2.1.  Available Virtualized Compute Resources . . . . . . .  14
       6.2.2.  Available Virtualized Storage Resources . . . . . . .  16
       6.2.3.  Available Virtualized Networking Resources  . . . . .  16
       6.2.4.  Type of virtualization  . . . . . . . . . . . . . . .  17
       6.2.5.  Power profile . . . . . . . . . . . . . . . . . . . .  18
       6.2.6.  Volatility profile  . . . . . . . . . . . . . . . . .  19
       6.2.7.  URI of the VIM  . . . . . . . . . . . . . . . . . . .  20
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  20
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   9.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  20
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  21
     10.2.  Informative References . . . . . . . . . . . . . . . . .  21
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  22







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1.  Introduction

   The telecommunications sector is experiencing a major revolution that
   will shape the way networks and services are designed and deployed
   for the next decade.  We are witnessing an explosion in the number of
   applications and services demanded by users, which are now really
   capable of accessing them on the move.  In order to cope with such a
   demand, some network operators are looking at the cloud computing
   paradigm, which enables a potential reduction of the overall costs by
   outsourcing communication services from specific hardware in the
   operator's core to server farms scattered in data centers.  These
   services have different characteristics if compared with conventional
   IT services that have to be taken into account in this cloudification
   process.  Also the transport network is affected in that it is
   evolving to a more sophisticated form of IP architecture with trends
   like separation of control and data plane traffic, and more fine-
   grained forwarding of packets (beyond looking at the destination IP
   address) in the network to fulfill new business and service goals.

   Virtualization of functions also provides operators with tools to
   deploy new services much faster, as compared to the traditional use
   of monolithic and tightly integrated dedicated machinery.  As a
   natural next step, mobile network operators need to re-think how to
   evolve their existing network infrastructures and how to deploy new
   ones to address the challenges posed by the increasing customers'
   demands, as well as by the huge competition among operators.  All
   these changes are triggering the need for a modification in the way
   operators and infrastructure providers operate their networks, as
   they need to significantly reduce the costs incurred in deploying a
   new service and operating it.  Some of the mechanisms that are being
   considered and already adopted by operators include: sharing of
   network infrastructure to reduce costs, virtualization of core
   servers running in data centers as a way of supporting their load-
   aware elastic dimensioning, and dynamic energy policies to reduce the
   monthly electricity bill.  However, this has proved to be tough to
   put in practice, and not enough.  Indeed, it is not easy to deploy
   new mechanisms in a running operational network due to the high
   dependency on proprietary (and sometime obscure) protocols and
   interfaces, which are complex to manage and often require configuring
   multiple devices in a decentralized way.

   Network function virtualization (NFV) [etsi_nfv_whitepaper] and
   software defined networking (SDN) [onf_sdn_architecture] are changing
   the way the telecommunications sector will deploy, extend and operate
   their networks.  The ETSI NFV Industry Specification Group (ISG) is
   developing the baseline NFV architecture, under some assumptions to
   make this development easier.  One of these assumptions is that the
   resources used to run the virtualized functions are well known in



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   advance by the management and orchestration entities, as well as
   stable.  This document goes beyond this assumption [RFC8568], by
   describing mechanisms allowing dynamic discovery of virtualization
   resources and orchestrators in IPv6-based networks.  Note that future
   evolutions of mobile networks beyond 5G already hint the extension of
   the network towards the edge, including end-user devices, making the
   need of dynamic resource discovery even more relevant.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   While [RFC2119] describes interpretations of these key words in terms
   of protocol specifications and implementations, they are used in this
   document to describe requirements for the SFC mechanisms to
   efficiently enable fog RAN.

   The following terms used in this document are defined by the ETSI NFV
   ISG, the ONF and the IETF:

      NFV Infrastructure (NFVI): totality of all hardware and software
      components which build up the environment in which VNFs are
      deployed

      NFV Management and Orchestration (NFV-MANO): functions
      collectively provided by NFVO, VNFM, and VIM.

      NFV Orchestrator (NFVO): functional block that manages the Network
      Service (NS) lifecycle and coordinates the management of NS
      lifecycle, VNF lifecycle (supported by the VNFM) and NFVI
      resources (supported by the VIM) to ensure an optimized allocation
      of the necessary resources and connectivity.

      Virtualized Infrastructure Manager (VIM): functional block that is
      responsible for controlling and managing the NFVI compute, storage
      and network resources, usually within one operator's
      Infrastructure Domain.

      Virtualized Network Function (VNF): implementation of a Network
      Function that can be deployed on a Network Function Virtualisation
      Infrastructure (NFVI).

      Virtualized Network Function Manager (VNFM): functional block that
      is responsible for the lifecycle management of VNF.





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3.  Network Function Virtualization

   The ETSI ISG NFV is a working group which, since 2012, aims to evolve
   quasi-standard IT virtualization technology to consolidate many
   network equipment types into industry standard high volume servers,
   switches, and storage.  It enables implementing network functions in
   software that can run on a range of industry standard server hardware
   and can be moved to, or loaded in, various locations in the network
   as required, without the need to install new equipment.  The ETSI NFV
   is one of the predominant NFV reference framework and architectural
   footprints [nfv_sota_research_challenges].  The ETSI NFV framework
   architecture framework is composed of three domains (Figure 1):

   o  Virtualized Network Function, running over the NFVI.

   o  NFV Infrastructure (NFVI), including the diversity of physical
      resources and how these can be virtualized.  NFVI supports the
      execution of the VNFs.

   o  NFV Management and Orchestration, which covers the orchestration
      and life-cycle management of physical and/or software resources
      that support the infrastructure virtualization, and the life-cycle
      management of VNFs.  NFV Management and Orchestration focuses on
      all virtualization specific management tasks necessary in the NFV
      framework.


























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   +-------------------------------------------+  +---------------+
   |   Virtualized Network Functions (VNFs)    |  |               |
   |  -------   -------   -------   -------    |  |               |
   |  |     |   |     |   |     |   |     |    |  |               |
   |  | VNF |   | VNF |   | VNF |   | VNF |    |  |               |
   |  |     |   |     |   |     |   |     |    |  |               |
   |  -------   -------   -------   -------    |  |               |
   +-------------------------------------------+  |               |
                                                  |               |
   +-------------------------------------------+  |               |
   |         NFV Infrastructure (NFVI)         |  |      NFV      |
   | -----------    -----------    ----------- |  |  Management   |
   | | Virtual |    | Virtual |    | Virtual | |  |      and      |
   | | Compute |    | Storage |    | Network | |  | Orchestration |
   | -----------    -----------    ----------- |  |               |
   | +---------------------------------------+ |  |               |
   | |         Virtualization Layer          | |  |               |
   | +---------------------------------------+ |  |               |
   | +---------------------------------------+ |  |               |
   | | -----------  -----------  ----------- | |  |               |
   | | | Compute |  | Storage |  | Network | | |  |               |
   | | -----------  -----------  ----------- | |  |               |
   | |          Hardware resources           | |  |               |
   | +---------------------------------------+ |  |               |
   +-------------------------------------------+  +---------------+

                       Figure 1: ETSI NFV framework

   The NFV architectural framework identifies functional blocks and the
   main reference points between such blocks.  Some of these are already
   present in current deployments, whilst others might be necessary
   additions in order to support the virtualization process and
   consequent operation.  The functional blocks are (Figure 2):

   o  Virtualized Network Function (VNF).

   o  Element Management (EM).

   o  NFV Infrastructure, including: Hardware and virtualized resources,
      and Virtualization Layer.

   o  Virtualized Infrastructure Manager(s) (VIM).

   o  NFV Orchestrator.

   o  VNF Manager(s).

   o  Service, VNF and Infrastructure Description.



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   o  Operations and Business Support Systems (OSS/BSS).

                                                  +--------------------+
   +-------------------------------------------+  | ----------------   |
   |                 OSS/BSS                   |  | | NFV          |   |
   +-------------------------------------------+  | | Orchestrator +-- |
                                                  | ---+------------ | |
   +-------------------------------------------+  |    |             | |
   |  ---------     ---------     ---------    |  |    |             | |
   |  | EM 1  |     | EM 2  |     | EM 3  |    |  |    |             | |
   |  ----+----     ----+----     ----+----    |  | ---+----------   | |
   |      |             |             |        |--|-|    VNF     |   | |
   |  ----+----     ----+----     ----+----    |  | | manager(s) |   | |
   |  | VNF 1 |     | VNF 2 |     | VNF 3 |    |  | ---+----------   | |
   |  ----+----     ----+----     ----+----    |  |    |             | |
   +------|-------------|-------------|--------+  |    |             | |
          |             |             |           |    |             | |
   +------+-------------+-------------+--------+  |    |             | |
   |         NFV Infrastructure (NFVI)         |  |    |             | |
   | -----------    -----------    ----------- |  |    |             | |
   | | Virtual |    | Virtual |    | Virtual | |  |    |             | |
   | | Compute |    | Storage |    | Network | |  |    |             | |
   | -----------    -----------    ----------- |  | ---+------       | |
   | +---------------------------------------+ |  | |        |       | |
   | |         Virtualization Layer          | |--|-| VIM(s) +-------- |
   | +---------------------------------------+ |  | |        |         |
   | +---------------------------------------+ |  | ----------         |
   | | -----------  -----------  ----------- | |  |                    |
   | | | Compute |  | Storage |  | Network | | |  |                    |
   | | | hardware|  | hardware|  | hardware| | |  |                    |
   | | -----------  -----------  ----------- | |  |                    |
   | |          Hardware resources           | |  |  NFV Management    |
   | +---------------------------------------+ |  | and Orchestration  |
   +-------------------------------------------+  +--------------------+

                 Figure 2: ETSI NFV reference architecture

4.  Fog Virtualization Overview

   Virtualization is invading all domains of the E2E 5G network,
   including the access, as a mean to achieve the necessary flexibility
   in support of the E2E slicing concept.  The ETSI NFV framework is the
   cornerstone for making virtualization such a promising technology
   that can be matured in time for 5G.  Typically, virtualization has
   been mostly envisaged in the core network, where sophisticated data
   centers and clouds provided the right substrate.  And mostly, the
   framework focused on virtualizing network functions, so called VNFs
   (virtualized network functions), which were somewhat limited to



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   functions that are delay tolerant, typically from the core and
   aggregation transport.

   As the community has recently been developing the 5G applications and
   their technical requirements, it has become clear that certain
   applications would require very low latency which is extremely
   challenging and stressing for the network to deliver through a pure
   centralized architecture.  The need to provide networking, computing,
   and storage capabilities closer to the users has therefore emerged,
   leading to what is known today as the concept of intelligent edge.
   ETSI has been the first to address this need recently by developing
   the framework of mobile edge computing (MEC).

   Such an intelligent edge could not be envisaged without
   virtualization.  Beyond applications, it raises a clear opportunity
   for networking functions to execute at the edge benefiting from
   inherent low latencies.

   Whilst it is appreciated the particular challenge for the intelligent
   edge concept in dealing with mobile users, the edge virtualization
   substrate has been largely assumed to be fixed or stationary.
   Although little developed, the intelligent edge concept is being
   extended further to scenarios where for example the edge computing
   substrate is on the move, e.g., on-board a car or a train, or that it
   is distributed further down the edge, even integrating resources from
   different stakeholders, into what is known as the fog.  The
   challenges and opportunities for such extensions of the intelligent
   edge remain an exciting area of future research.

   Figure 3 shows a diagram representing the fog virtualization concept.
   The fog is composed by virtual resources on top of heterogeneous
   resources available at the edge and even further in the RAN and end-
   user devices.  These resources are therefore owned by different
   stakeholders who collaboratively form a single hosting environment
   for the VNFs to run.  As an example, virtual resources provided to
   the fog might be running on eNBs, APs, at micro data centers deployed
   in shopping malls, cars, trains, etc.  The fog is connected to data
   centers deeper into the network architecture (at the edge ir the
   core).  On the top part of the figure, an example of user and control
   plane VNFs is shown.  User plane VNFs are represented as "fx", and
   control ones as "ctrlx".  Depending on the functionality implemented
   by these VNFs and the service requirements, these VNFs would be
   mapped (i.e., instantiated) differently to the physical resouces (as
   described in [I-D.aranda-sfc-dp-mobile]).







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            --------                        ---------   ---------
   control  | ctr1 |........................| ctrl2 |...| ctrl3 |
   plane    --------                        ---------   ---------
   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                ------         ------     ------
                               .| f3 |.........| f5 |.....| f6 |
          ------       ------ . ------         ------     ------
    user  | f1 |.......| f2 |.                    .
   plane  ------       ------ . ------            .
                               .| f4 |.............
                                ------
   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
         +--------------------------------+  +-------------------+
         | -------   --------   --------  |  |      ----------   |
         | |     |   |      |   |      |  |  |    ---------- |   |
         | | @UE |   | @car |   | @eNB |  |  |  ---------- | |   |
         | -------   --------   --------  |  |  |  Data  | | |   |
         |                                |  |  | Center | | -   |
         | -------- Heterogeneous ------- |  |  |  (DC)  |-      |
    phy  | |      |   computing   |     | |  |  ----------       |
   infra | |@train|    devices    | @AP | |==|      ----------   |
         | --------    forming    ------- |  |    ---------- |   |
         |             the fog            |  |  ---------- | |   |
         | ---------        ------------  |  |  |  Data  | | |   |
         | |       |        |          |  |  |  | Center | | -   |
         | | @mall |        | @localDC |  |  |  |  (DC)  |-      |
         | ---------        ------------  |  |  ----------       |
         |              FOG               |  |       CLOUD       |
         +--------------------------------+  +-------------------+
         <--------- fog and edge ----------------->
                                     <--- edge & central cloud --->

                       Figure 3: Fog virtualization

5.  Problem statemement

   Virtualized resources do not need to be limited to those available in
   traditional data centers, where the infrastructure is stable, static,
   typically homogeneous and managed by a single admin entity.
   Computational capabilities are becoming more and more ubiquitous,
   with terminal devices getting extremely powerful, as well as other
   types of devices that are close to the end users at the edge (e.g.,
   vehicular onboard devices for infotainment, micro data centers
   deployed at the edge, etc.).  It is envisioned that these devices
   would be able to offer storage, computing and networking resources to
   nearby network infrastructure, devices and things (the fog paradigm).
   These resources can be used to host functions, for example to
   offload/complement other resources available at traditional data



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   centers, but also to reduce the end-to-end latency or to provide
   access to specialized information (e.g., context available at the
   edge) or hardware.

   In this draft, we consider that a mobile terminal may: (i) provide
   resources for others to be used, by integrating them into an existing
   virtualization infrastructure (either fixed or mobile); and/or (ii)
   consume resources offered by others, by integrating them into the set
   of resources under the management of the given mobile terminal.  WE
   look at how to enable virtualization infrastructures to dynamically
   integrate resources that are mobile and volatile (because either the
   terminal hosting the resources is mobile/volatile or the terminal
   controlling them is mobile/volatile).  Since the fog resources are
   volatile, i.e. may dynamically appear and disappear, and may be
   mobile, i.e. may move from one place to another, mechanisms to
   discover and advertise virtualized fog resources are required.

   Taking the ETSI NFV architecture (see Section 3) as a baseline for
   the virtualization of the fog nodes, the discovery of a
   virtualization resource can be done either through (i) the discovery
   of NFVI from a VIM; or through (ii) the discovery of VIMs and
   associated NFVI from an NFVO.  In this draft, we focus on the
   alternative (ii), that is, the discovery of the VIMs and NFVI1 from
   an NFVO.  Both mobile VIM+NFVI, and mobile NFVO are in the scope of
   the document.

   The relationship between an NFVO and the resources it is capable to
   orchestrate through a VIM is statically defined according to the
   current ETSI NFV specifications [etsi_nfv_002] [etsi_nfv_ifa_005].
   The interface Or-Vi (between NFVO and VIM) [etsi_nfv_ifa_005] does
   not include any discovery and automatic registration of (mobile) VIMs
   from a (mobile) NFVO.  Therefore, currently there is no standardized
   mechanism defined for such a discovery and registration specified by
   ETSI or any other SDO.  This is the gap addressed by this draft.

   We cover two different scenarios:

   o  A mobile terminal (hosting mobile resources) joins a network where
      there is an existing virtualization infrastructure.  The mobile
      terminal hosts both some kind of NFVI (resources) plus a VIM (in
      charge of managing those resources and providing an appropriate
      interfaces for others to use and control them).

   o  A mobile terminal (looking for available resources) joins a
      network where there are virtualization resources available.  The
      mobile terminal hosts a NFVO, capable of integrating and
      controlling others' virtual resources.




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6.  Advertisement and discovery of mobile resources (VIM+NFVI)

   This document describes IPv6 extensions to allow discovery of
   virtualization resources, in the form of a VIM + associated NFVI.
   Examples of scenarios where this is useful are shown in Figure 4 and
   Figure 5, including also a high-level view of the solution.

                                                    __
                  ___________                     _(  )_
    ----------  _(           )_    -----------  _(      )_
    | device |-(_  VIM--NFVI  _)   | network |-(_  NFVO  _)
    ----------   (___________)     -----------   (_    _)
        |                               |          (__)
       XXX (1. attachment)              |
        |                               |
        +---2. Advertisement----------->|
        |                               |
        |<......(3. VIM Registration)..>|
        |                               |

                     Figure 4: VIM+NFVI advertisement

   Figure 4 shows an scenario in which a mobile device with available
   resources (NFVI, and associated VIM) attaches to a network (step 1).
   Then, it advertises (step 2) that it has virtualization resources
   (and their characteristics, such as the type of VIM) that could be
   eventually used.  An NFVO sitting in the network can then decide to
   register the VIM for later use (step 3).  This document specifies
   some options for step 2 based on IP signaling.  Step 3 is
   implementation dependent and very much VIM-NFVO specific.

   Similarly, Figure 5 shows a scenario with a mobile NFVO.  A mobile
   device with an embedded NFVO attaches to a network (step 1).  Then,
   it queries the network (step 2) to learn if there are virtualization
   resources available.  If so, the network conveys that information
   (step 3).  The NFVO can then decide to register the VIM for later use
   (step 4).  This document specifies some options for steps 2 and 3
   based on IP signaling.  Step 4 is implementation dependent and very
   much VIM-NFVO specific.












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                                                      ___________
                                                    _(           )_
                    ______                        _(      +-NFVI   )_
    ------------  _(      )_       -----------  _(       /           )_
    | terminal |-(_  NFVO  _)      | network |-(_  VIM(s)---NFVI      _)
    ------------   (______)        -----------   (_      \          _)
        |                               |          (_     +-NFVI  _)
       XXX (1. attachment)              |            (___________)
        |                               |
        +---2. Request----------------->|
        |                               |
        |<-----------3. Advertisement---|
        |                               |
        |<..(4. VIM Registration)......>|
        |                               |

                       Figure 5: VIM+NFVI discovery

6.1.  IPv6 ND-based discovery

   This section describes a solution based on IPv6 Neighbor Discovery
   [RFC4861].  The solution is based on defining a new set of options to
   convey information about available virtualization resources,
   including optional attributes.  In such a way, it is possible to
   discover VIM+NFVI resources available at:

   o  A mobile device connecting to the network, such as a smartphone or
      a device embedded in a vehicle.  This device might have some
      available resources that other mobile devices, or the network
      infrastructure can opportunistically use.

   o  The network infrastructure, e.g., at the edge, like micro-data
      centers deployed at the very edge of the network.  Mobile devices
      can use these available resources to computationally offload some
      tasks that require low latency and/or information that is only
      available at the edge (such as radio related information).

   The discovery of available resources (VIM+NFVI) is based on a
   combination of proactive and reactive advertisement.  IPv6 Neighbor
   Discovery (ND) [RFC4861] is a very good approach to convey this
   information as, (i) it is widely deployed, (ii) it is very
   lightweight and easy to implement, (iii) it allows dynamic updates
   due to network topology updates (e.g., a device connecting/
   disconnecting from a network), and (iv) it is independent on the
   network access technology.

   The basic operation of ND-based VIM+NFVI discovery consists in the
   advertisement of virtual resources in IPv6 ND messages from the



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   device hosting those virtual resources.  This can be done, for
   example by a mobile host sending unsolicited Neighbor Advertisement
   (NA) messages (or in response to a Neighbor Solicitation, NS)
   including the new VIM+NFVI options -- as shown in Figure 6 -- or even
   including them in Router Solicitations.  Another example would be the
   network infrastructure advertising available resources by including
   VIM+NFVI options in Router Advertisement (RA) or Neighbor
   Advertisement messages -- as shown in Figure 7.

                                                    __
                  ___________                     _(  )_
    ----------  _(           )_    -----------  _(      )_
    | device |-(_  VIM--NFVI  _)   | network |-(_  NFVO  _)
    ----------   (___________)     -----------   (_    _)
        |                               |          (__)
        +--Unsolicited Neigh. Advert.-->|
        |  (incld. VIM+NFVI opt.)       |
        |                               |

      Figure 6: Example of VIM+NFVI advertisement via unsolicited NA

                                                      ___________
                                                    _(           )_
                    ______                        _(      +-NFVI   )_
    ------------  _(      )_       -----------  _(       /           )_
    | terminal |-(_  NFVO  _)      | network |-(_  VIM(s)---NFVI      _)
    ------------   (______)        -----------   (_      \          _)
        |                               |          (_     +-NFVI  _)
        |<--------Router Advertisement--+            (___________)
        |        (incld. VIM+NFVI opt.) |
        |                               |

            Figure 7: Example of VIM+NFVI advertisement via RA

6.2.  VIM+NFVI options

   New ND VIM+NFVI options are defined to be used with Neigbor
   Solicitation, Neighbor Advertisement, Router Solicitation and Router
   Advertisement options.  The presence of any of these options is used
   to signal the availability of VIM+NFVI.  These options are used to
   convey information of associated attributes, like:

   o  Available Virtualized Compute Resources.

   o  Available Virtualized Storage Resources.

   o  Available Virtualized Networking Resources.




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   o  Type of virtualization e.g., full virtualization, para
      virtualization, hybrid virtualization.

   o  Available hypervisor e.g., bare metal or hosted hypervisor.

   o  Supported virtual machine images or container format.

   o  Power profile, e.g., battery or mains powered, battery capacity,
      charge status, etc.

   o  Volatility profile, e.g., expected availability.

   o  Type of VIM and version.

   o  Protocol APIs supported by the VIM.

   o  URI of the VIM.

   The format of these options is described next.  Note that this list
   is just an example and that additional options could be added.

6.2.1.  Available Virtualized Compute Resources

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |N|        Reserved0            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    cpuArch    | numVirtualCpu |       virtualCpuClock         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  accelCapab   | vCpuOP| vMemOP|        virtualMemSize         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Reserved1                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      2

   N



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      1-bit NUMA supported flag.  When set, indicates that the memory
      allocation can be cognisant of the relevant process/core
      allocation.

   Reserved0

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

   cpuArch

      8-bit identifier indicating the type CPU architecture type.
      Examples are: 1 (x86), 2 (ARM).

   numVirtualCpu

      8-bit unsigned integer.  Indicates the number of virtual CPUs.

   virtualCpuClock

      16-bit unsigned integer.  Indicates the Minimum virtual CPU clock
      rate (in MHz).

   accelCapab

      8-bit mask indicating the acceleration capabilities.  Examples
      are: 1 (crypto), 2 (GPU).

   vCpuOP

      8-bit unsigned integer.  Indicates the CPU core oversubscription
      policy, e.g. the relation of virtual CPU cores to physical CPU
      cores/threads.  A value of 0 indicates that no concrete policy is
      defined.

   vMemOP

      8-bit unsigned integer.  Indicates the memory core
      oversubscription policy in terms of virtual memory to physical
      memory on the platform.  A value of 0 indicates that no concrete
      policy is defined.

   Reserved1

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.





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6.2.2.  Available Virtualized Storage Resources

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |         sizeOfStorage         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Reserved                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      1

   sizeOfStorage

      16-bit unsigned integer.  Indicates the Size of virtualised
      storage resource (in GB).

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

6.2.3.  Available Virtualized Networking Resources

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |            bandwidth          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  networkType  |                  Reserved                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type




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      To be assigned by IANA.

   Length

      1

   bandwidth

      16-bit unsigned integer.  Indicates the minimum network bandwidth
      (in Mbps).

   networkType

      8-bit unsigned identifier.  Indicates the type of network that
      maps to the virtualised network.  Examples are: 1 (local), 2
      (vlan), 3 (vxlan), 4(gre).

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

6.2.4.  Type of virtualization

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |   virtType    |   hypervisor  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Reserved                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      1

   virtType






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      8-bit identifier indicating the type of virtualization.  Examples
      are: 1 (full virtualization), 2 (para virtualization), 3 (hybrid
      virtualization).

   hypervisor

      8-bit identifier indicating the type of hypervisor (if
      applicable).  Examples are: 0 (not applicable), 1 (type 1), 2
      (type 2).

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

6.2.5.  Power profile

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |B|C|   BatStat |   Reserved0   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Reserved1                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      1

   B

      1-bit Battery-powered flag.  When set, indicates that the sending
      device is battery powered.

   C

      1-bit Charging flag.  If the B flag is set to 0, this MUST be set
      to 0.  When set, indicates that the battery is charging.

   BatStat



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      6-bit integer indicating the charge of the charge of the Battery.
      If the B flag is set to 0, this MUST be set to 0.  A value of 64
      indicates that the battery is full.

   Reserved0

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

   Reserved1

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

6.2.6.  Volatility profile

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |      ExpectedAvailability     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Reserved                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      1

   ExpectedAvailability

      16-bit integer indicating the expected availability (in units of
      seconds).  This is an estimation from the sender.  How this is set
      is implementation dependent.

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.





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6.2.7.  URI of the VIM

   The format of this option is shown below.  This option should be
   padded when necessary to ensure that they end on their natural 64-bit
   boundaries, as specified in [RFC4861].

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type        |    Length     |            Reserved           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             VimUri                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type

      To be assigned by IANA.

   Length

      1

   Reserved

      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.

   VimUri

      A variable-length encoded string containing the URI of the VIM.

7.  IANA Considerations

   TBD.

8.  Security Considerations

   TBD.

9.  Acknowledgments

   The work in this draft will be further developed and explored under
   the framework of the H2020 5G-DIVE project (Grant 859881).








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10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              DOI 10.17487/RFC4861, September 2007,
              <https://www.rfc-editor.org/info/rfc4861>.

10.2.  Informative References

   [etsi_nfv_002]
              ISG, E. N., ""Network Functions Virtualization (NFV);
              Architectural Framework," ETSI GS NFV 002 v1.1.1", October
              2013.

   [etsi_nfv_ifa_005]
              ISG, E. N., ""Network Functions Virtualisation (NFV)
              Release 2; Management and Orchestration; Or-Vi reference
              point - Interface and Information Model Specification,"
              ETSI GS NFV-IFA 005 V2.3.1", August 2017.

   [etsi_nfv_whitepaper]
              ISG, E. N., "Network Functions Virtualisation (NFV). White
              Paper 2", October 2014.

   [I-D.aranda-sfc-dp-mobile]
              Gutierrez, P. A. A., Gramaglia, M., Lopez, D. R., and W.
              Haeffner, "Service Function Chaining Dataplane Elements in
              Mobile Networks", draft-aranda-sfc-dp-mobile-04 (work in
              progress), June 2017.

   [nfv_sota_research_challenges]
              Mijumbi, R., Serrat, J., Gorricho, J-L., Bouten, N., De
              Turck, F., and R. Boutaba, "Network Function
              Virtualization: State-of-the-art and Research Challenges",
              IEEE Communications Surveys & Tutorials Volume: 18, Issue:
              1, September 2015.

   [onf_sdn_architecture]
              (ONF), O. N. F., "SDN Architecture (Issue 1.1), ONF TR-
              521", February 2016.




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   [RFC8568]  Bernardos, CJ., Rahman, A., Zuniga, JC., Contreras, LM.,
              Aranda, P., and P. Lynch, "Network Virtualization Research
              Challenges", RFC 8568, DOI 10.17487/RFC8568, April 2019,
              <https://www.rfc-editor.org/info/rfc8568>.

Authors' Addresses

   Carlos J. Bernardos
   Universidad Carlos III de Madrid
   Av. Universidad, 30
   Leganes, Madrid  28911
   Spain

   Phone: +34 91624 6236
   Email: cjbc@it.uc3m.es
   URI:   http://www.it.uc3m.es/cjbc/


   Alain Mourad
   InterDigital Europe

   Email: Alain.Mourad@InterDigital.com
   URI:   http://www.InterDigital.com/




























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