Skip to main content

Quality of Service Marking in Virtual eXtensible Local Area Network
draft-xia-nvo3-vxlan-qosmarking-01

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Expired".
Authors Frank Xia , Behcet Sarikaya
Last updated 2014-11-10
RFC stream (None)
Formats
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-xia-nvo3-vxlan-qosmarking-01
Network Working Group                                             F. Xia
Internet-Draft                                               B. Sarikaya
Expires: May 14, 2015                      Huawei Technologies Co., Ltd.
                                                       November 10, 2014

  Quality of Service Marking in Virtual eXtensible Local Area Network
                 draft-xia-nvo3-vxlan-qosmarking-01.txt

Abstract

   The Virtual eXtensible Local Area Network enables multiple tenants to
   operate in a data center.  Each tenant needs to be assigned a
   priority group to prioritize their traffic.  Cloud carriers wish to
   use quality of service to differentiate different applications.  For
   these purposes, six bits are assigned in the eXtensible Local Area
   Network header.  How these bits are assigned and are processed in the
   network are explained in detail.

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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://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
   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 May 14, 2015.

Copyright Notice

   Copyright (c) 2014 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of

Xia & Sarikaya            Expires May 14, 2015                  [Page 1]
Internet-Draft         Quality of Service Marking          November 2014

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   3
   4.  QoS Bits in VXLAN Header  . . . . . . . . . . . . . . . . . .   3
   5.  Quality of Service Operation at VXLAN Decapsulation Point . .   6
   6.  Quality of Service Operation at VXLAN encapsulation point . .   6
   7.  QoS processing for VXLAN outer IP header  . . . . . . . . . .   7
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   9.  IANA considerations . . . . . . . . . . . . . . . . . . . . .   8
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     11.1.  Normative References . . . . . . . . . . . . . . . . . .   8
     11.2.  Informative References . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   Data center networks are being increasingly used by telecom operators
   as well as by enterprises.  An important requirement in data center
   networks is multitenancy, i.e. multiple tenants each with their own
   isolated network domain.  Virtual eXtensible Local Area Network
   (VXLAN) is a solution that is gaining polularity in industry
   [RFC7348].  VXLAN overlays a Layer 2 network over a Layer 3 network.
   Each overlay is identified by the VXLAN Network Identifier (VNI).
   VXLAN tunnel end point (VTEP) can be hosted at the the hypervisor on
   the server or higher above in the network.  VXLAN encapsulation with
   a UDP header is only known to the VTEP, the Virtual Machines (VM)
   never sees it.

   It should be noted that in this document, VTEP plays the role of the
   Network Virtualization Edge (NVE) according to NVO3 architecture for
   overlay networks like VXLAN or NVGRE defined in [I-D.ietf-nvo3-arch].
   NVE interfaces the tenant system underneath with the L3 network
   called the Virtual Network (VN).

   Since VXLAN allows multiple tenants to operate data center operators
   are facing the problem of treating their traffic.  There is interest
   to provide different quality of service to the tenants based on their
   service level agreements.

   Cloud carriers have interest in different quality of service to
   different applications such as voice, video, network control
   applications, etc.  In this case, quality of service marking can be

Xia & Sarikaya            Expires May 14, 2015                  [Page 2]
Internet-Draft         Quality of Service Marking          November 2014

   done using deep packet inspection (DPI) in order to detect the type
   of application in each packet.

   In this document, we develop Quality of Service marking solution for
   VXLAN.  The solution is compatible with IP level Differentiated
   Services model or diffserv described in [RFC2474] and [RFC2475].
   Configuration guidelines are described in [RFC4594].  Diffserv
   interconnection classes and interconnection practice are described in
   [I-D.geib-tsvwg-diffserv-intercon].

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].  The
   terminology in this document is based on the definitions in
   [RFC7348].

3.  Problem Statement

   In a VXLAN network multiple tenants are supported.  There is interest
   in assigning different priority to each tenant's traffic based on the
   premium that tenant paies, etc.  In another words, cloud carriers
   would like to categorize tenants into different traffic classes such
   as diamond, gold, silver and bronze classes.

   Cloud carriers wish to categorize the traffic based on the
   application such as voice, video, etc.  Based on the type of the
   application different traffic classes may be identified and different
   priority levels can be assigned to each.

   In order to do these, quality of service marking is needed in VXLAN.

   The solution proposed in this document is based on using VXLAN header
   to mark by Network Virtualization Edge (NVE) when the frames are
   introduced by the virtual machines.

4.  QoS Bits in VXLAN Header

   Six bits are reserved in VXLAN header flags field shown as QoS-flag
   in Figure 1.

   6 bits called QoS-flag are reserved to indicate the quality of
   service class that this packet belongs.  These bits will be assigned
   according to the type of traffic carried in this flow, e.g. video,
   voice, critical application, etc.  These assignments will be made
   adopting IP level Differentiated Services model, diff serv bits or DS
   field, see Section 7.

Xia & Sarikaya            Expires May 14, 2015                  [Page 3]
Internet-Draft         Quality of Service Marking          November 2014

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |R|R|R|R|I|    QoS    |            Reserved                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                VXLAN Network Identifier (VNI) |   Reserved    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 1: QoS Flag in VXLAN Header

   The first three bits (bits 5-7) are precedence bits.  They are
   assigned according to [RFC0791].  Precedence values '110' and '111'
   are selected for routing traffic.

   The last three bits (bits 8-10) are class selector bits.  Thet are
   assigned as follows:

   001 - BK or background traffic

   000 - BE or best effort traffic

   010 - EE or Excellent Effort

   011 - CA or Critical Applications

   100 - VI or Video

   101 - VO or Voice

   110 - IC or Internetwork Control

   111 - NC or Network Control

   '111' has the highest priority while '001' has the lowest, for
   example, video traffic has higher priority than web surfing which is
   best effort traffic.

   As can be seen the markings are the same as in IEEE 802.1p
   [IEEE802.1D] which is supported by most switches currently deployed
   that have the QoS capabilities.

   Bits 5,6 and 7 previously reserved are used to assign precedence.
   Bits 8, 9 and 10 previously reserved are used to assign the class
   selector bits.  The sender SHOULD assign bits 8-10 with bits assigned
   values as above if the quality of service treatment is needed on this
   packet.  The sender SHOULD assign the same bit pattern to all the

Xia & Sarikaya            Expires May 14, 2015                  [Page 4]
Internet-Draft         Quality of Service Marking          November 2014

   packets of the same flow.  The sender MUST assign all other reserved
   bits to zero.

   In real deployment, there are two different mappings to make use of
   the class selector QoS field.

   The first one is based on application priorities.  NVE uses some
   mechanism such as Deep Packet Inspection (DPI) to identify
   application types, and fills in the QoS field of VXLAN encapsulation
   based on the identified application types.  The below is a possible
   mapping.

   001 - Reserved

   000 - ftp/email

   010 - web surfing

   011 - instant Message

   100 - video

   101 - voice

   110 - High Performance computation

   111 - Reserved

   The second one is based on tenancy priorities.  A cloud carrier could
   exploit the QoS bits in another different way.  The cloud carrier
   categorizes its tenants into different groups such as diamond, gold,
   silver, bronze, standard and so on.  All traffic for a diamond tenant
   has a high priority to be forwarded regardless of application types.
   The below is a possible mapping option.

   001 - Reserved

   000 - Standard

   010 - Bronze

   011 - Silver

   100 - Gold

   101 - Diamond

   110 - Emergency

Xia & Sarikaya            Expires May 14, 2015                  [Page 5]
Internet-Draft         Quality of Service Marking          November 2014

   111 - Reserved

5.  Quality of Service Operation at VXLAN Decapsulation Point

   There are two types of VXLAN packets receivers, that is, a VXLAN
   enabled NVE or a VXLAN gateway [I-D.sarikaya-nvo3-proxy-vxlan].

   When the VXLAN enabled NVE receives the packet, it decapsulates the
   packet and delivers it downstream to a corresponding VM.  If there
   are multiple packets to be processed, packets with high priority
   (that is higher QoS value) should be processed first.

   The QoS operation is different for the VXLAN gateway processing.  The
   gateway which provides VXLAN tunnel termination functions could be
   ToR/access switches or switches higher up in the data center network
   topology.  For incoming frames on the VXLAN connected interface, the
   gateway strips out the VXLAN header and forwards to a physical port
   based on the destination MAC address of the inner Ethernet frame.  If
   inner VLAN is included in the VXLAN frame or a VLAN is supposed to be
   added based on configuration, the VXLAN gateway decapsulates the
   VXLAN packet and remarks the QoS field of the outgoing Ethernet frame
   based on VXLAN class selector QoS bits.  The switch SHOULD copy the
   class selector Q-Flags of VXLAN encapsulation into IEEE 802.1p Priory
   Code Point (PCP) field in VLAN tag.

6.  Quality of Service Operation at VXLAN encapsulation point

   There are two types of VXLAN packet senders, that is, a VXLAN enabled
   NVE or a VXLAN gateway.

   For a VXLAN enabled NVE, the upstream procedure is:

   Reception of Frames

      The VXLAN enabled NVE receives an Ethernet packet from a hosting
      VM.

   Lookup

      Making use of the destination of the Ethernet packet, the VXLAN
      enabled NVE looks up MAC-NVE mapping table, and retrieves IP
      address of destination NVE.

   Acquisition of QoS parameters

      There are two different ways to acquire QoS parameters for VXLAN
      encapsulation.  The first is a dynamic one which requires a VXLAN
      enabled NVE has Deep Packet Inspection (DPI) capability and can

Xia & Sarikaya            Expires May 14, 2015                  [Page 6]
Internet-Draft         Quality of Service Marking          November 2014

      identify different application types.  The second is a static one
      which requires a VM manager to assign QoS parameters to different
      VNIs based on premium that different tenancies pay.

   Encapsulation of frames

      The NVE then encapsulates the packet using VXLAN format with
      acquired QoS parameters and VNI.  The specific format is given in
      Section 4.  After the frame is encapsulated it is sent out
      upstream to the network.

   For a VXLAN gateway, packets are encapsulated using VXLAN format with
   QoS field in a similar way.  Once the VXLAN gateway receives a packet
   from a non-VXLAN domain, it encapsulates the packet with QoS
   parameters which are acquired through DPI or priorities of tenancies.

7.  QoS processing for VXLAN outer IP header

   QoS is user experience of end-to-end network operation.  A packet
   from VM A to VM B normally traverses such network entities
   sequentially as virtual switch A which is co-located with VM A, TOR
   switch A, aggregation switch A, a core switch, aggregation switch B,
   TOR switch B, virtual switch B.  VXLAN processing only takes place in
   virtual switches, and all other network entities only execute IP
   forwarding.  VXLAN QoS mapping to outer IP header at virtual switch A
   is needed to achieve end-to-end QoS.

   Six bits of the Differentiated Services Field (DS field) are used as
   a codepoint (DSCP) to select the per hop behaviour (PHB) a packet
   experiences at each node in a Differentiated Services Domain
   [RFC2474].  DS field is 8 bits long, 6 bits of it are used as DSCP
   and two bits are unused.  DS field is carried in both IPv4 and IPv6
   packet headers.  The first three bits of DS field are used for IP
   precedence and the last three are used as diff serv bits.  VXLAN
   outer IP header's DSCP field SHOULD be copied from VXLAN header QoS
   bits.

   Similarly, when a packet forwarded from non-VXLAN domain to VXLAN
   domain through a VXLAN gateway, DSCP field of outer IP header should
   be marked based on VXLAN QoS.

8.  Security Considerations

   Special security considerations in [RFC7348] are applicable.

Xia & Sarikaya            Expires May 14, 2015                  [Page 7]
Internet-Draft         Quality of Service Marking          November 2014

9.  IANA considerations

   IANA is requested to assign the Q-Flags bits in VXLAN reserved bits
   in the header.

10.  Acknowledgements

   The authors are grateful to David Black and Brian Carpenter for their
   constructive comments on our work.

11.  References

11.1.  Normative References

   [RFC0826]  Plummer, D., "Ethernet Address Resolution Protocol: Or
              converting network protocol addresses to 48.bit Ethernet
              address for transmission on Ethernet hardware", STD 37,
              RFC 826, November 1982.

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791, September
              1981.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474, December
              1998.

   [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
              and W. Weiss, "An Architecture for Differentiated
              Services", RFC 2475, December 1998.

   [RFC2597]  Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski,
              "Assured Forwarding PHB Group", RFC 2597, June 1999.

   [RFC4594]  Babiarz, J., Chan, K., and F. Baker, "Configuration
              Guidelines for DiffServ Service Classes", RFC 4594, August
              2006.

   [I-D.ietf-nvo3-arch]
              Black, D., Hudson, J., Kreeger, L., Lasserre, M., and T.
              Narten, "An Architecture for Overlay Networks (NVO3)",
              draft-ietf-nvo3-arch-02 (work in progress), October 2014.

Xia & Sarikaya            Expires May 14, 2015                  [Page 8]
Internet-Draft         Quality of Service Marking          November 2014

   [IEEE802.1D]
              IEEE, "Virtual Bridged Local Area Networks", IEEE Std
              802.1D-2005, May 2006.

11.2.  Informative References

   [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
              eXtensible Local Area Network (VXLAN): A Framework for
              Overlaying Virtualized Layer 2 Networks over Layer 3
              Networks", RFC 7348, August 2014.

   [I-D.geib-tsvwg-diffserv-intercon]
              Geib, R. and D. Black, "DiffServ interconnection classes
              and practice", draft-geib-tsvwg-diffserv-intercon-07 (work
              in progress), October 2014.

   [I-D.sarikaya-nvo3-proxy-vxlan]
              Sarikaya, B. and F. Xia, "Virtual eXtensible Local Area
              Network over IEEE 802.1Qbg", draft-sarikaya-nvo3-proxy-
              vxlan-00 (work in progress), October 2014.

Authors' Addresses

   Frank Xia
   Huawei Technologies Co., Ltd.
   101 Software Avenue, Yuhua District
   Nanjing,  Jiangsu  210012, China

   Phone: ++86-25-56625443
   Email: xiayangsong@huawei.com

   Behcet Sarikaya
   Huawei Technologies Co., Ltd.
   5340 Legacy Dr. Building 3
   Plano, TX  75024

   Phone: +1 972-509-5599
   Email: sarikaya@ieee.org

Xia & Sarikaya            Expires May 14, 2015                  [Page 9]