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NVO3 Working Group                                          H. Chen, Ed.
INTERNET-DRAFT                                          P. Ashwood-Smith
Intended Status: Informational                                    L. Xia
                                                     Huawei Technologies
                                                              R. Iyengar
                                                                 T. Tsou
                                                 Huawei Technologies USA
                                                              A. Sajassi
                                                      Cisco Technologies
                                                            M. Boucadair
                                                            C. Jacquenet
                                                          France Telecom
                                                              M. Daikoku
                                                        KDDI corporation
                                                             A. Ghanwani
                                                                    Dell
                                                             R. Krishnan
                                                                 Brocade
Expires: April 21, 2016                                 October 19, 2015


     NVO3 Operations, Administration, and Maintenance Requirements
                 draft-ashwood-nvo3-oam-requirements-04


Abstract

   This document provides framework and requirements for Network
   Virtualization Overlay (NVO3) Operations, Administration, and
   Maintenance (OAM).

Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
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   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html



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   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors. All rights reserved.

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   described in the Simplified BSD License.



Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.1.  OSI Definitions of OAM . . . . . . . . . . . . . . . . . .  4
     1.2.  Requirements Language  . . . . . . . . . . . . . . . . . .  6
     1.3.  Relationship with Other OAM Work . . . . . . . . . . . . .  6
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  7
   3. NVO3 Reference Model  . . . . . . . . . . . . . . . . . . . . .  7
   4.  OAM Framework for NVO3 . . . . . . . . . . . . . . . . . . . .  8
     4.1.  OAM Layering . . . . . . . . . . . . . . . . . . . . . . .  9
     4.2.  OAM Domains  . . . . . . . . . . . . . . . . . . . . . . .  9
   5.  NVO3 OAM Requirements  . . . . . . . . . . . . . . . . . . . . 10
     5.1.  Discovery  . . . . . . . . . . . . . . . . . . . . . . . . 10
     5.2.  Connectivity Fault Management  . . . . . . . . . . . . . . 10
       5.2.1.  Connectivity Fault Detection . . . . . . . . . . . . . 10
       5.2.2.  Connectivity Fault Verification  . . . . . . . . . . . 11
       5.2.3.  Connectivity Fault localization  . . . . . . . . . . . 11
       5.2.4.  Connectivity Fault Notification and Alarm
               Suppression  . . . . . . . . . . . . . . . . . . . . . 11
     5.3.  Connectivity Performance Management  . . . . . . . . . . . 11
       5.3.1.  Frame Loss . . . . . . . . . . . . . . . . . . . . . . 11
       5.3.2.  Frame Delay  . . . . . . . . . . . . . . . . . . . . . 11
       5.3.3.  Frame Delay Variation  . . . . . . . . . . . . . . . . 11
       5.3.4.  Frame Throughput . . . . . . . . . . . . . . . . . . . 12
       5.3.5.  Frame Discard  . . . . . . . . . . . . . . . . . . . . 12
     5.4.  Continuity Check . . . . . . . . . . . . . . . . . . . . . 12
     5.5.  Availability . . . . . . . . . . . . . . . . . . . . . . . 12



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     5.6.  Data Path Forwarding . . . . . . . . . . . . . . . . . . . 12
     5.7.  Scalability  . . . . . . . . . . . . . . . . . . . . . . . 13
     5.8.  Extensibility  . . . . . . . . . . . . . . . . . . . . . . 13
     5.9.  Security . . . . . . . . . . . . . . . . . . . . . . . . . 13
     5.10.  Transport Independence  . . . . . . . . . . . . . . . . . 14
     5.11.  Application Independence  . . . . . . . . . . . . . . . . 14
     5.12.  Prioritization  . . . . . . . . . . . . . . . . . . . . . 14
     5.13.  Logging and Traceability Requirements . . . . . . . . . . 14
     5.14.  Live Traffic Monitoring . . . . . . . . . . . . . . . . . 16
   6.  Items for Further Discussion . . . . . . . . . . . . . . . . . 16
   7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 18
   8. Security Considerations . . . . . . . . . . . . . . . . . . . . 18
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     10.1  Normative References . . . . . . . . . . . . . . . . . . . 18
     10.2  Informative References . . . . . . . . . . . . . . . . . . 18



































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1.  Introduction

   This document provides framework and requirements for Network
   Virtualization Overlay (NVO3) Operations, Administration, and
   Maintenance (OAM). Given that this OAM subject is far from new and
   has been under extensive investigation by various IETF working groups
   (and several other standards bodies) for many years, this document
   draws from existing work, starting with [RFC6136].  As a result,
   sections of [RFC6136] have been reused with minor changes with the
   permission of the authors.

   NVO3 OAM requirements are expected to be a subset of IETF/IEEE etc.
   work done so far; however, we begin with a full set of requirements
   and expect to prune them through several iterations of this document.

1.1.  OSI Definitions of OAM

   The scope of OAM for any service and/or transport/network
   infrastructure technologies can be very broad in nature.  OSI has
   defined the following five generic functional areas commonly
   abbreviated as "FCAPS" [NM-Standards]:

   o  Fault Management,

   o  Configuration Management,

   o  Accounting Management,

   o  Performance Management, and

   o  Security Management.

   This document focuses on the Fault, Performance and to a limited
   extent the Configuration Management aspects.  Other functional
   aspects of FCAPS and their relevance (or not) to NVO3 are for further
   study.

   Fault Management can typically be viewed in terms of the following
   categories:

   o  Fault Detection;

   o  Fault Verification;

   o  Fault Isolation;

   o  Fault Notification and Alarm Suppression;




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   o  Fault Recovery.

   Fault detection deals with mechanism(s) that can detect both hard
   failures such as link and device failures, and soft failures, such as
   software failure, memory corruption, misconfiguration, etc. Fault
   detection relies upon a set of mechanisms that first allow the
   observation of an event, then the use of a protocol to dynamically
   notify a network/system operator (or management system) about the
   event occurrence, then the use of diagnostic tools to assess the
   nature and severity of the fault.

   After verifying that a fault has occurred along the data path, it is
   important to be able to isolate the fault to the level of a given
   device or link. Therefore, a fault isolation mechanism is needed in
   Fault Management. A fault notification mechanism should be used in
   conjunction with a fault detection mechanism to notify the devices
   upstream and downstream to the fault detection point. The fault
   notification mechanism should also notify NMS systems.

   The terms "upstream" and "backward" are used here to denote the
   direction(s) from which data traffic is flowing. The terms
   "downstream" and "forward" denote the direction(s) to which data
   traffic is forwarded.

   For example, when there is a client/server relationship between two
   layered networks (e.g., the NVO3 layer is a client of the outer IP
   server layer, while the inner IP layer is a client of the NVO3 server
   layer 2), fault detection at the server layer may result in the
   following fault notifications:

   o  Sending a forward fault notification from the server layer to the
      client layer network(s) using the fault notification format
      appropriate to the client layer.

   o  Sending a backward fault notification to the server layer, if
      applicable, in the reverse direction.

   o  Sending a backward fault notification to the client layer, if
      applicable, in the reverse direction.

   Finally, fault recovery deals with recovering from the detected
   failure by switching to an alternate available data path (depending
   on the nature of the fault) using alternate devices or links. In
   fact, the controller can provision another virtual network, thus
   automatically resolving the reported problem.

   The controller may also directly monitor the status of virtual
   network components such as Network Virtualization Edge elements



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   (NVEs) [RFC7365] in order to respond to their failures. In addition
   to forward and backward fault notifications, the controller may
   deliver notifications to a higher level orchestration component,
   e.g., one responsible for Virtual Machine (VM) provisioning and
   management.

   Note, given that the IP network on which NVO3 resides is usually self
   healing, it is expected that recovery by the NVO3 layer would not
   normally be required, although there may be a requirement for that
   layer to log that the problem has been detected and resolved. The
   special cases of a static IP overlay network, or possibly of a
   centrally controlled IP overlay network, may, however, require NVO3
   involvement in fault recovery.

   Performance Management deals with mechanism(s) that allow determining
   and measuring the performance of the network/services under
   consideration. Performance Management can be used to verify the
   compliance to both the service-level and network-level metric
   objectives/specifications.  Performance Management typically consists
   of measuring performance metrics, e.g., Frame Loss, Frame Delay,
   Frame Delay Variation (aka Jitter), Frame Throughput, Frame Discard,
   etc., across managed entities when the managed entities are in
   available state.  Performance Management is suspended across
   unavailable managed entities.

1.2.  Requirements Language

   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].

1.3.  Relationship with Other OAM Work

   This document leverages requirements that originate with other OAM
   work, specifically the following:

   o  [RFC6136] provides a template and some of the high level
      requirements and introductory wording.

   o  [IEEE802.1Q-2011] is expected to provide a subset of the
      requirements for NVO3 both at the Tenant level and also within the
      L3 Overlay network.

   o  [Y.1731] is expected to provide a subset of the requirements for
      NVO3 at the Tenant level.

   o  Section 3.3.2.1 of [NVO3-DP-Reqs] lists several requirements
      specifically concerning ECMP/LAG.



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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 RFC 2119
      [RFC2119].

      The terminology defined in [RFC7365] and [NVO3-DP-Reqs] is used
      throughout this document. We introduce no new terminology.

3. NVO3 Reference Model

      Figure 1 below reproduces the generic NVO3 reference model as per
      [RFC7365].

        +--------+                                   +--------+
        | Tenant |                                   | Tenant |
        |  End   +--+                            +---|  End   |
        | System |  |                            |   | System |
        +--------+  |    ............... ....    |   +--------+
                    |  +-+--+            +--+-+  |
                    |  | NV |            | NV |  |
                    +--|Edge| L3 Overlay |Edge|--+
                       +-+--+  Network   +--+-+
                      /  .                  .  \
        +--------+   /   .    +----------+  .   \     +--------+
        | Tenant +--+    .    |Controller|  .    +----| Tenant |
        |  End   |       .    |(optional)|  .         |  End   |
        | System |       .    +-------+--+  .         | System |
        +--------+       .            .     .         +--------+
                         .    +----+  .     .
                         .....| NV |.........
                              |Edge|
                              +----+
                                |
                                |
                             +--+-----+
                             | Tenant |
                             |  End   |
                             | System |
                             +--------+

                 Figure 1: Generic NVO3 Reference Model

      Figure 2 below, reproduces the Generic reference model for the NV
      Edge (NVE) as per [NVO3-DP-Reqs].





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                            +-----------------+
                            |    Controller   |(optional)
                            +--------+--------+
                                     |
                                     |
                        +------- L3 Network ------+
                        |                         |
                        |       Tunnel Overlay    |
           +------------+---------^-+       +--------+-------------^-+
           | +----------+------+  | |       | +------+----------+  | |
           | | Overlay Module  |  | |       | | Overlay Module  |  | |
           | +--------+--------+  | |       | +--------+--------+  | |
           |          | VNID      | |       |          | VNID      | |
           |          |         OAM |       |          |         OAM |
           |  +-------+-------+   | |       |  +-------+-------+   | |
           |  |      VNI      |   | |       |  |      VNI      |   | |
      NVE1 |  +-+-----------+-+   | |  NVE2 |  +-+-----------+-+   | |
           |    |   VAPs    |     | |       |    |   VAPs    |     | |
           +----+-----------+-----V-+       +----+-----------+-----V-+
                |           |                 |           |
         -------+-----------+--------------------+-----------+--------
                |           |        Tenant      |           |
                |           |      Service IF    |           |
              Tenant End Systems               Tenant End Systems

        Figure 2: Generic reference model for the NV Edge (NVE)


4.  OAM Framework for NVO3

      Figure 1 shows the generic reference model for a DC network
      virtualization over an L3 (or L3VPN) infrastructure while Figure 2
      showed the generic reference model for the Network Virtualization
      (NV) Edge. As shown in both figure 1 and figure 2, the Controller
      is an optional element that can participate to the support and the
      operation of OAM functions.

      L3 network(s) or L3 VPN networks (either IPv6 or IPv4, or a
      combination thereof), provide transport for an emulated layer 2
      created by NV Edge devices.  Unicast and multicast tunneling
      methods (de-multiplexed by Virtual Network Identifier (VNID)) are
      used to provide connectivity between the NV Edge devices.  The NV
      Edge devices then present an emulated layer 2 network to the
      Tenant End Systems at a Virtual Network Interface (VNI) through
      Virtual Access Points (VAPs).  The NV Edge devices map layer 2
      unicast to layer 3 unicast point-to-point tunnels and may either
      map layer 2 multicast to layer 3 multicast tunnels or may
      replicate packets onto multiple layer 3 unicast tunnels.



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4.1.  OAM Layering

      The emulated layer 2 network is provided by the NV Edge devices to
      which the Tenant End Systems are connected.  This network of NV
      Edges can be operated by a single service provider or can span
      across multiple administrative domains.  Likewise, the L3 Overlay
      Network can be operated by a single service provider or span
      across multiple administrative domains.

      While each of the layers is responsible for its own OAM, each
      layer may consist of several different administrative domains.
      Figure 3 shows an example.

            TENANT    |----------------------------| TENANT

            NV Edge   |----------------------|  NV Edge

            IP(VPN)   |---| IP (VPN) |---| IP(VPN)

                  Figure 3: Example NVO3 OAM Layering

      For example, at the bottom, at the L3 IP overlay network layer
      IP(VPN) and/or Ethernet OAM mechanisms are used to probe link by
      link, node to node etc.  OAM addressing here means physical node
      loopback or interface addresses.

      Further up, at the NV Edge layer, NVO3 OAM messages are used to
      probe the NV Edge to NV Edge tunnels and NV Edge entity status.
      OAM addressing here likely means the physical node loopback
      together with the VNI (to de-multiplex the tunnels).

      Finally, at the Tenant layer, the IP and/or Ethernet OAM
      mechanisms are again used but here they are operating over the
      logical L2/L3 provided by the NV-Edge through the VAP. OAM
      addressing at this layer deals with the logical interfaces on
      Vswitches and Virtual Machines.

4.2.  OAM Domains

      Complex OAM relationships exist as a result of the hierarchical
      layering of responsibility and of breaking up of end-to-end
      responsibility.

      The OAM domain above NVO3, is expected to be supported by existing
      IP and L2 OAM methods and tools.

      The OAM domain below NVO3, is expected to be supported by existing
      IP/L2 and MPLS OAM methods and tools. Where this layer is actually



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      multiple domains spliced together, the existing methods to deal
      with these boundaries are unchanged.  Note however that exposing
      LAG/ECMP detailed behavior may result in additional requirements
      to this domain, the details of which will be specified in the
      future versions of this draft.

      When we refer to an OAM domain in this document, or just 'domain',
      we therefore refer to a closed set of NV Edges or MEPs and the
      tunnels which interconnect them.

      Note, whether for the scenario of inter-domain or multi-layer,
      each domain (or layer) is responsible for its own OAM, no
      correlation of OAM function exists between each domain (or layer).
      When an E2E connection in Tenant layer spans across multiple
      domains and has multiple underlay layers of NV Edge layer and L3
      IP (VPN) layer, current OAM implementation for the E2E connection
      of Tenant layer such as Fault or Performance Management can only
      be performed per domain and layer manually and more manual labor
      is needed.  An automatic coordination process among OAM functions
      of each domain or layer may be useful here for improving
      efficiency and intelligence.

      In the case where a gateway device is use to connect two different
      domains (whether for changing the encapsulation or other reasons),
      it is necessary to provide mechanisms to monitor the path through
      the gateway which involves the removal of one overlay header and
      the creation of a new one.

5.  NVO3 OAM Requirements

5.1.  Discovery

      R1) NVO3 OAM MUST allow an NV Edge device to dynamically discover
      other NV Edge devices that share the same VNI within a given NVO3
      domain. This may be based on a discovery mechanism used to set up
      data path forwarding between NVEs.

5.2.  Connectivity Fault Management

5.2.1.  Connectivity Fault Detection

      R2) NVO3 OAM MUST allow proactive connectivity monitoring between
      two or more NV Edge devices that support the same VNIs within a
      given NVO3 domain.  NVO3 OAM MAY act as a protection trigger.
      That is, automatic recovery from transmission facility failure by
      switchover to a redundant replacement facility may be triggered by
      notifications from NVO3 OAM.




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      R3) NVO3 OAM MAY allow monitoring/tracing of all possible paths in
      the underlay network between a specified set of two or more NV
      Edge devices.  Using this feature, equal cost paths that traverse
      LAG and/or ECMP may be differentiated.

5.2.2.  Connectivity Fault Verification

      R4) NVO3 OAM MUST allow connectivity fault verification between
      two or more NV Edge devices that support the same VNI within a
      given NVO3 domain.

5.2.3.  Connectivity Fault localization

      R5) NVO3 OAM MUST allow connectivity fault localization between
      two or more NV Edge devices that support the same VNI within a
      given NVO3 domain.

5.2.4.  Connectivity Fault Notification and Alarm Suppression

      R6) NVO3 OAM MUST support fault notification to be triggered as a
      result of the faults occurring in the underneath network
      infrastructure.  This fault notification SHOULD be used for the
      suppression of redundant service-level alarms.

5.3.  Connectivity Performance Management

5.3.1.  Frame Loss

      R7) NVO3 OAM MUST support measurement of per VNI frame loss
      between two NV Edge devices that support the same VNI within a
      given NVO3 domain.

5.3.2.  Frame Delay

      R8) NVO3 OAM MUST support measurement of per VNI two-way frame
      delay between two NV edge devices that support the same VNI within
      a given NVO3 domain.

      R9) NVO3 OAM MUST support measurement of per VNI one-way frame
      delay between two NV Edge devices that support the same VNI within
      a given NVO3 domain.


5.3.3.  Frame Delay Variation


      R10) NVO3 OAM MUST support measurement of per VNI frame delay
      variation between two NV Edge devices that support the same VNI



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      within a given NVO3 domain.

5.3.4.  Frame Throughput

      R11) NVO3 OAM MAY support measurement of per VNI frame throughput
      (in frames and bytes) between two NV Edge devices that support the
      same VNI within a given NVO3 domain.  This feature could be an
      effective way to confirm whether or not assigned path bandwidth
      conforms to service level agreement before providing the path
      between two NV Edge devices.

5.3.5.  Frame Discard

      R12) NVO3 OAM MAY support measurement of per VNI frame discard
      between two NV Edge devices that support the same VNI within a
      given NVO3 domain. This feature MAY be effective to monitor bursty
      traffic between two NV Edge devices.

5.4.  Continuity Check

      NVO3 OAM MUST provide functions that allow any arbitrary NV edge
      device to perform a Continuity Check to any other NV edge device.

      NVO3 OAM MUST provide functions that allow any arbitrary NV edge
      device to perform a Continuity Check to any other NV edge device
      using a path associated with a specified flow.

      NVO3 OAM SHOULD provide functions that allow any arbitrary NV edge
      device to perform a Continuity Check to any other NV edge device
      over any section of any selectable least-cost path.

      NVO3 OAM SHOULD provide the ability to perform a Continuity Check
      on sections of any selectable path within the network.

5.5.  Availability

      A service may be considered unavailable if the service
      frames/packets do not reach their intended destination (e.g.,
      connectivity is down) or the service is degraded (e.g., frame loss
      and/or frame delay and/or delay variation threshold is exceeded).
      Entry and exit conditions may be defined for the unavailable
      state. Availability itself may be defined in the context of a
      service type. Since availability measurement may be associated
      with connectivity, frame loss, frame delay, and frame delay
      variation measurements, no additional requirements are specified
      currently.

5.6.  Data Path Forwarding



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      R13) NVO3 OAM frames MUST be forwarded along the same path (i.e.,
      links (including LAG members) and nodes) as the NVO3 data frames.

      R14) NVO3 OAM frames MAY provide a mechanism to exercise/trace all
      data paths that result due to ECMP/LAG hops in the underlay
      network, if these paths have been known.

      NVO3 OAM frame MUST be possible arranged to follow the path taken
      by a specific flow.

      NVE MUST have the ability to identify frames that require OAM
      processing.

      The Controller element MAY be involved in the out-of-band OAM
      design and deployment. Indeed, the Controller is expected to
      maintain an up-to-date global, systemic view of all the network
      paths and their associated status (e.g., available, idle,
      unavailable, faulty, in maintenance, etc.)

5.7.  Scalability

      R15) NVO3 OAM MUST be scalable such that an NV edge device can
      support proactive OAM for each VNI that is supported by the
      device.

5.8.  Extensibility

      R16) NVO3 OAM should be extensible such that new functionality and
      information elements related to this functionality can be
      introduced in the future.

      R17) NVO3 OAM MUST be defined such that devices not supporting the
      OAM are able to forward the OAM frames in a similar fashion as the
      regular NVO3 data frames/packets.

5.9.  Security

      R18) NVO3 OAM frames MUST be prevented from leaking outside their
      NVO3 domain.

      R19) NVO3 OAM frames from outside an NVO3 domain MUST be prevented
      from entering the said NVO3 domain when such OAM frames belong to
      the same level or to a lower-level OAM. (Trivially met because
      hierarchical domains are independent technologies.)

      R20) NVO3 OAM frames from outside an NVO3 domain MUST be
      transported transparently inside the NVO3 domain when such OAM
      frames belong to a higher-level NVO3 domain. (Trivially met



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      because hierarchical domains are independent technologies).

5.10.  Transport Independence

      Similar to transport requirement from [RFC6136], we expect NVO3
      OAM will leverage the OAM capabilities of the transport layer
      (e.g., IP underlay).

      R21) NVO3 OAM MAY allow adaptation/interworking with its IP
      underlay OAM functions.  For example, this would be useful to
      allow fault notifications from the IP layer to be sent to the NVO3
      layer. Likewise, LAG/ECMP-originated notifications may affect the
      NVO3 OAM decision process.


5.11.  Application Independence

      R22) NVO3 OAM MAY be independent of the application technologies
      and specific application OAM capabilities.

5.12.  Prioritization

      R23) NVO3 OAM messages MUST be preferentially treated in NVE and
      between NVEs, since NVO3 OAM MAY be used to trigger protection
      switching.  As noted above (R2), protection switching is the
      automatic replacement of a failed transmission facility with a
      working one providing equal or greater capacity, typically within
      a few tens of milliseconds from fault detection.

5.13.  Logging and Traceability Requirements

      Logging is required at the Network Virtualization Authority (NVA)
      and the Network Virtualization Edge (NVE) [and the NVO3 Gateway,
      but the framework does not mention such a beast] in support of
      fault management and configuration management.

      R24) All logs MUST contain a (sufficiently accurate) timestamp to
      allow the reporting functional instance (i.e., NVA, NVE) to
      precisely determine the sequence of events. Clocks on different
      functional instances SHOULD be synchronized to allow similar
      accuracy when comparing logs from different devices.

      R25) All logs MUST contain information that unambiguously
      identifies the reporting functional instance

      R26) Implementations MUST be capable of reporting the following
      fault-related events:




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      1.  Loss and resumption of connectivity

      These reports SHOULD identify the affected VNI(s), but when the
      loss affects a large number of VNIs simultaneously the report
      SHOULD identify the underlying entity (e.g., route) if available.

      2.  Loss and resumption of NVE responsiveness

      These reports will be generated by adjacent NVAs or NVEs. They
      MUST identify the NVE concerned.

      3.  NVA or NVE change of operational state

      These reports will be generated by the NVA or NVE concerned.  They
      MUST indicate the old and new operational states and the cause.

      4.  Loss and resumption of a VAP

      These reports will be generated by adjacent NVAs or NVEs.  They
      MUST identify the VAP concerned.

      R27) Implementations MUST be capable of reporting the following
      events in support of configuration management and auditing.  It
      MUST be possible to generate the reports at both the originating
      and executing entities.  The report generated at the originating
      entity MUST identify the executing entity and the report at the
      executing entity MUST identify the originating entity.  Both
      reports MUST indicate the result of the transaction.

      1.  Virtual Access Point (VAP) creation or deletion

      These reports MUST identify the VAP, the Tenant System, and the
      port supporting the VAP.

      2.  VNI creation or deletion

      These reports MUST identify the VNI and the VAP.

      3.  VNI renumbering

      These reports MUST identify the VAP and the old and new VNI
      numbers.

      4.  Reachability and forwarding information update

      These reports MUST identify the previous and new file identifiers.
      (Assumption: reachability and forwarding information is passed as
      files, which are retained at the originating and executing



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      entities for a fixed period for auditing purposes.)

      R28) As a general requirement, implementations MUST provide a
      means whereby the operator can impose rate limits on the
      generation of specific reports.  Implementations MUST further
      permit the operator to totally suppress reporting of specific
      events.  However, if any report types have been suppressed, non-
      suppressible reports MUST be generated at regular intervals (e.g.,
      once an hour) indicating what report types have been suppressed.

5.14.  Live Traffic Monitoring

      NVO3 OAM implementations MAY provide methods to utilize live
      traffic for troubleshooting and performance monitoring.

6.  Items for Further Discussion

      This section identifies a set of operational items which may be
      elaborated further if these items fall within the scope of the
      NVO3.

      o  VNID renumbering support

         *  Means to change the VNID assigned to a given instance MUST
            be supported.

         *  System convergence subsequent to VNID renumbering MUST NOT
            take longer than a few seconds, to minimize impact on the
            tenant systems.

         *  A NVE MUST be able to map a VNID with a virtual network
            context.

      o  VNI migration and management operations

         *  Means to delete an existing VNI MUST be supported.

         *  Means to add a new VNI MUST be supported.

         *  Means to merge several VNIs MAY be supported.

         *  Means to retrieve reporting data per VNI MUST be supported.

         *  Means to monitor the network resources per VNI MUST be
            supported.

      o  Support of planned maintenance operations on the NVO3
         infrastructure



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         *  Graceful procedure to allow for planned maintenance
            operation on NVE MUST be supported.  This includes undoing
            any configuration changes made for maintenance purposes
            after completion of the maintenance.

      o  Support for communication among virtual networks

         *  For global reachability purposes, communication among
            virtual networks MUST be supported.  This can be enforced
            using a NAT function.

      o  Activation of new network-related services to the NVO3

         *  Means to assist in activating new network services (e.g.,
            multicast) without impacting running service SHOULD be
            supported.

      o  Inter-operator NVO3 considerations

         *  As NVO3 may be deployed over inter-operator infrastructure,
            coordinating OAM actions in each individual domain are
            required to ensure an end-to-end OAM. In particular, this
            assumes existence of agreements on the measurement and
            monitoring methods, fault detection and repair actions,
            extending QoS classes (e.g., DSCP mapping policies), etc.

      o  An automatic coordination process among OAM functions of
         different domains or layers which an E2E connection in Tenant
         layer is tunneled on

         *  NVO3 OAM MAY support the automatic coordination of OAM
            functions among different domains or layers which belong to
            one Tenant layer E2E connection. The automatic coordination
            means OAM function in client layer or one domain triggers
            associated OAM functions in server layer or neighbouring
            domain.  This triggered action performs at the domain
            boundaries, which is also the MEPs of the domain.  Which OAM
            function in client layer or one domain can trigger which OAM
            functions in server layer or neighbouring domain depends on
            specific condition, and can be very flexible.  But the basic
            rule is that the OAM functions performed simultaneously in
            different domains or layers can be synthesized together to
            get the final result.

         *  The OAM MEPs of domains MUST have the capability to know if
            it they need to perform the above automatic coordination
            process. This can be achieved by many ways, i.e., by
            configuration, by checking the flag field in OAM frames.



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         *  When the OAM MEPs perform the automatic coordination, a
            specific global characteristic information MUST be carried
            and mapped between OAM frames used in different domains or
            layers, and be kept the same alone the whole tenant layer
            E2E connection.  The global characteristic information can
            be the tenant network identifier (e.g., VNID), ICMP sequence
            number, etc. It is used for identifying a set of correlated
            OAM results obtained from these domains or layers.  This set
            of OAM results is then synthesized together to get the final
            diagnose result.

         *  NVO3 OAM MUST support a Collection Point for collecting all
            the OAM results and synthesizing them.  It can be the SDN
            controller, NVA, or NMS. An E2E OAM function in tenant
            network can trigger several OAM functions in different
            underlay networks, a Collection Point is needed to collect
            all the OAM results from different OAM MEPs of different
            domains or layers and synthesizes them.

7. IANA Considerations
   This memo includes no request to IANA.

8. Security Considerations
   Security requirements are specified in Section 5.9. For general NVO3
   security considerations, please refer to [NVO3-Security].

9.  Acknowledgements

   The authors are grateful for the contributions of David Black, Dennis
   Qin, Erik Smith, Deepark Kumar, Dapeng Liu, and Ziye Yang to this
   latest version.


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, <http://www.rfc-
              editor.org/info/rfc2119>.




10.2  Informative References

   [IEEE802.1Q-2011] "IEEE Standard for Local and metropolitan area



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              networks - Media Access Control (MAC) Bridges and Virtual
              Bridged Local Area Networks", 2011.

   [NM-Standards] "ITU-T Recommendation M.3400 (02/2000) - TMN
              Management Functions", February 2000.

   [NVO3-DP-Reqs] Bitar, N., Lasserre, M., Balus, F., Morin, T., Jin, L.
              and Khasnabish, B., "NVO3 Data Plane Requirements", draft-
              ietf-nvo3-dataplane-requirements-03(work in progress),
              April 2014.

   [NVO3-Security] Hartman, S., Zhang, D., Wasserman, M., Qiang, Z. and
              Zhang, M., "Security Requirements of NVO3", draft-ietf-
              nvo3-security-requirements-05(work in progress), June
              2015.

   [RFC6136] Sajassi, A. and D. Mohan, "Layer 2 Virtual Private
              Network(L2VPN) Operations, Administration, and
              Maintenance(OAM) Requirements and Framework", March 2011.

   [RFC7365] Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y.
              Rekhter, "Framework for DC Network Virtualization",
              October 2014.

   [Y.1731] "ITU-T Recommendation Y.1731 (02/08) - OAM functions and
              mechanisms for Ethernet based networks", February 2008.


Authors' Addresses

   Hao Chen
   Huawei Technologies
   101 Software Avenue,
   Nanjing 210012
   China

   Phone: +86-25-56624440
   EMail: philips.chenhao@huawei.com

   Peter Ashwood-Smith
   Huawei Technologies
   303 Terry Fox Drive, Suite 400
   Kanata, Ontario K2K 3J1
   Canada

   Phone: +1 613 595-1900
   Email: Peter.AshwoodSmith@huawei.com




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   Liang Xia (Frank)
   Huawei Technologies

   Email: Frank.xialiang@huawei.com

   Ranga Iyengar
   Huawei Technologies USA
   2330 Central Expy
   Santa Clara, CA 95050
   USA

   Email: ranga.Iyengar@huawei.com


   Tina Tsou
   Huawei Technologies USA
   2330 Central Expy
   Santa Clara, CA 95050
   USA

   Email: Tina.Tsou.Zouting@huawei.com

   Ali Sajassi
   Cisco Technologies
   170 West Tasman Drive
   San Jose, CA 95134
   USA


   Email: sajassi@cisco.com

   Mohamed Boucadair
   France Telecom
   Rennes, 35000
   France

   Email: mohamed.boucadair@orange.com

   Christian Jacquenet
   France Telecom
   Rennes, 35000
   France

   Email: christian.jacquenet@orange.com

   Masahiro Daikoku
   KDDI corporation
   3-10-10, Iidabashi, Chiyoda-ku



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   Tokyo 1028460
   Japan

   Email: ms-daikoku@kddi.com

   Anoop Ghanwani
   Dell
   5450 Great America Pkwy
   Santa Clara, CA
   USA

   Email: anoop@alumni.duke.edu

   Ram Krishnan
   Brocade
   130 Holger Way
   San Jose, CA 95134
   USA

   Email: ramk@brocade.com































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