BGP Remote-Next-Hop
draft-vandevelde-idr-remote-next-hop-05

The information below is for an old version of the document
Document Type Active Internet-Draft (individual)
Last updated 2014-01-17
Replaced by draft-ietf-idr-tunnel-encaps
Stream (None)
Intended RFC status (None)
Formats pdf htmlized (tools) htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
IDR                                                      G. Van de Velde
Internet-Draft                                                  K. Patel
Intended status: Standards Track                                  D. Rao
Expires: July 21, 2014                                     Cisco Systems
                                                               R. Raszuk
                                                            NTT MCL Inc.
                                                                 R. Bush
                                               Internet Initiative Japan
                                                        January 17, 2014

                          BGP Remote-Next-Hop
                draft-vandevelde-idr-remote-next-hop-05

Abstract

   The BGP Remote-Next-Hop is a new optional transitive attribute
   intended to facilitate automatic tunneling across an AS on a per
   address family basis.  The attribute carries one or more tunnel end-
   points for a NLRI.  Additionally, tunnel encapsulation information is
   communicated to successfully setup these tunnels.

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 July 21, 2014.

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

Van de Velde, et al.      Expires July 21, 2014                 [Page 1]
Internet-Draft                                              January 2014

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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Tunnel Encapsulation attribute versus BGP Remote-Next-Hop
       attribute . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.   BGP Remote-Next-Hop attribute TLV Format . . . . . . . . . .   4
     4.1.  Encapsulation sub-TLVs for virtual network overlays . . .   5
       4.1.1.  Encapsulation sub-TLV for VXLAN . . . . . . . . . . .   6
       4.1.2.  Encapsulation sub-TLV for NVGRE . . . . . . . . . . .   7
       4.1.3.  Encapsulation sub-TLV for GTP . . . . . . . . . . . .   8
   5.  Use Case scenarios  . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  Stateless user-plane architecture for virtualized EPC
           (vEPC)  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     5.2.  Multi-homing for IPv6 . . . . . . . . . . . . . . . . . .   8
     5.3.  Dynamic Network Overlay Infrastructure  . . . . . . . . .   9
     5.4.  The Tunnel end-point is NOT the originating BGP speaker .   9
     5.5.  Networks that do not support BGP Remote-Next-Hop
           attribute . . . . . . . . . . . . . . . . . . . . . . . .   9
     5.6.  Networks that do support BGP Remote-Next-Hop attribute  .   9
   6.  BGP Remote-Next-Hop Community . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
     8.1.  Protecting the validity of the BGP Remote-Next-Hop
           attribute . . . . . . . . . . . . . . . . . . . . . . . .  10
   9.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  11
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   11. Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .  11
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  11
     12.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   [RFC5512] defines an attribute attached to an NLRI to signal tunnel
   end-point encapsulation information between two BGP speakers for a
   single tunnel.  It assumes that the exchanged tunnel endpoint is the
   NLRI.

   This document defines a new BGP transitive attribute known as a
   Remote-Next-Hop BGP attribute for Intra-AS and Inter-AS usage which

Van de Velde, et al.      Expires July 21, 2014                 [Page 2]
Internet-Draft                                              January 2014

   removes the assumption of both a single tunel and that the exchanged
   NLRI is the tunnel endpoint.

   The tunnel endpoint information and the tunnel encapsulation
   information is carried within a Remote-Next-Hop BGP attribute.  This
   attribute can be added to any BGP NLRI.  This way the Address Family
   (AF) of the NLRI exchanged is decoupled from the tunnel SAFI address-
   family defined in [RFC5512].

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to
   be interpreted as described in [RFC2119] only when they appear in all
   upper case.  They may also appear in lower or mixed case as English
   words, without any normative meaning.

3.  Tunnel Encapsulation attribute versus BGP Remote-Next-Hop attribute

   The Tunnel Encapsulation attribute [RFC5512] is based on the
   principle that the tunnel end-point is the BGP speaker originating
   the update and is inserted as the NLRI in the exchange, with the
   consequence that it is impossible to set the endpoint to an arbitrary
   address.  It is also assumed that there is only a single tunnel
   between endpoints.

   There are use cases where it is desired that the tunnel end-point
   address should be a different address, or set of addresses, than the
   originating BGP speaker.  It is also useful to be able to signal
   different encapsulation parameters for different prefixes with the
   same remote tunnel end-point.  The BGP Remote-Next-Hop attribute
   provides the ability to have one or more different tunnel end-point
   addresses from IPv4, IPv6 and/or other address-families, and be able
   to signal next-hop encapsulation parameters along with any prefix.

   The sub-TLVs from the Tunnel Encapsulation Attribute [RFC5512] are
   reused for the BGP Next-Hop-Attribute.

   Due to the intrinsic nature of both attributes, the tunnel
   encapsulation end-point assumes that the tunnel end-point is both the
   NLRI exchanged and the originating router, while the BGP Remote-Next-
   Hop attribute is inserted for an exchanged NLRI by adding a set of
   tunnel end-points and hence these two attributes are mutually
   exclusive.

Van de Velde, et al.      Expires July 21, 2014                 [Page 3]
Internet-Draft                                              January 2014

4.  BGP Remote-Next-Hop attribute TLV Format

   This attribute is an optional transitive attribute [RFC1771].

   The BGP Remote-Next-Hop attribute is is composed of a set of Type-
   Length-Value (TLV) encodings.  The type code of the attribute is
   (IANA to assign).  Each TLV contains information corresponding to a
   particular tunnel technology and tunnel end-point address.  The TLV
   is structured as follows:

Van de Velde, et al.      Expires July 21, 2014                 [Page 4]
Internet-Draft                                              January 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Tunnel Type (2 Octets)    |              Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Addr len    |     Tunnel Address (IPv4 or IPv6)               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          AS Number                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   Tunnel Parameters                           |
     ~                                                               ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Tunnel Type (2 octets): identifies the type of tunneling technology
     being signaled.  This document specifies the following types:

     - L2TPv3 over IP [RFC3931]: Tunnel Type = 1
     - GRE [RFC2784]: Tunnel Type = 2
     - IP in IP [RFC2003] [RFC4213]: Tunnel Type = 7

     This document also defines the following types:
     - VXLAN: Tunnel Type = 8
     - NVGRE: Tunnel Type = 9
     - GTP: Tunnel Type = 10

     Unknown types MUST be ignored and skipped upon receipt.

     Length (2 octets): the total number of octets of the value field.

     Tunnel Address Length - Addr len (1 octet): Length of Tunnel
     Address. Set to 4 bytes for an IPv4 address and 16 bytes for an
     IPv6 address.

     AS Number - The AS number originating the BGP Remote-Next-Hop
     attribute  and is either a 2-byte AS or 4-Byte AS number

     Tunnel Parameter - (variable): comprised of multiple sub-TLVs.
     Each sub-TLV consists of three fields: a 1-octet type, 1-octet
     length, and zero or more octets of value.  The sub-TLV definitions
     and the sub-TLV data are described in depth in [RFC5512].

4.1.  Encapsulation sub-TLVs for virtual network overlays

   A VN-ID may need to be signaled along with the encapsulation types
   for DC overlay encapsulations such as [VXLAN] and [NVGRE].  The VN-ID
   when present in the encapsulation sub-TLV for an overlay
   encapsulation, MUST be processed by a receiving device if it is

Van de Velde, et al.      Expires July 21, 2014                 [Page 5]
Internet-Draft                                              January 2014

   capable of understanding it.  The details regarding how such a
   signaled VN-ID is processed and used is defined in specifications
   such as [IPVPN-overlay] and [EVPN-overlay].

4.1.1.  Encapsulation sub-TLV for VXLAN

   This document defines a new encapsulation sub-TLV format, defined in
   [RFC5512], for VXLAN tunnels.  When the tunnel type is VXLAN, the
   following is the structure of the value field in the encapsulation
   sub-TLV:

    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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |V|M|R|R|R|R|R|R|          VN-ID (3 Octets)                   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                 MAC Address (4 Octets)                      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  MAC Address (2 Octets)     |   Reserved                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     V: When set to 1, it indicates that a valid VN-ID is present in the
     encapsulation sub-TLV.
     M: When set to 1, it indicates that a valid MAC Address is present
     in the encapsulation sub-TLV.
     R: The remaining bits in the 8-bit flags field are reserved for
     further use. They MUST be set to 0 on transmit and MUST be ignored
     on receipt.

     VN-ID: Contains a 24-bit VN-ID value, if the 'V' flag bit is set.
     If the 'V' flag is not set, it SHOULD be set to zero and MUST be
     ignored on receipt.

     The VN-ID value is filled in the VNI field in the VXLAN packet
     header as defined in [VXLAN].

     MAC Address: Contains an Ethernet MAC address if the 'M' flag bit
     is set. If the 'M' flag is not set, it SHOULD set to all zeroes and
     MUST be ignored on receipt.

     The MAC address is local to the device advertising the route, and
     should be included as the destination MAC address in the inner
     Ethernet header immediately following the outer VXLAN header, in
     the packets destined to the advertiser.

Van de Velde, et al.      Expires July 21, 2014                 [Page 6]
Internet-Draft                                              January 2014

4.1.2.  Encapsulation sub-TLV for NVGRE

   This document defines a new encapsulation sub-TLV format, defined in
   [RFC5512], for NVGRE tunnels.  When the tunnel type is NVGRE, the
   following is the structure of the value field in the encapsulation
   sub-TLV:

   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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |V|M|R|R|R|R|R|R|          VN-ID (3 Octets)                   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                 MAC Address (4 Octets)                      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  MAC Address (2 Octets)     |   Reserved                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    V: When set to 1, it indicates that a valid VN-ID is present in the
    encapsulation sub-TLV.
    M: When set to 1, it indicates that a valid MAC Address is present
    in the encapsulation sub-TLV.
    R: The remaining bits in the 8-bit flags field are reserved for
    further use. They MUST be set to 0 on transmit and MUST be ignored
    on receipt.

    VN-ID: Contains a 24-bit VN-ID value, if the 'V' flag bit is set.
    If the 'V' flag is not set, it SHOULD be set to zero and MUST be
    ignored on receipt.

    The VN-ID value is filled in the VSID field in the NVGRE packet
    header as defined in [NVGRE].

    MAC Address: Contains an Ethernet MAC address if the 'M' flag bit is
    set. If the 'M' flag is not set, it SHOULD set to all zeroes and
    MUST be ignored on receipt.

    The MAC address is local to the device advertising the route, and
    should be included as the destination MAC address in the inner
    Ethernet header immediately following the outer NVGRE header, in
    the packets destined to
    the advertiser.

Van de Velde, et al.      Expires July 21, 2014                 [Page 7]
Internet-Draft                                              January 2014

4.1.3.  Encapsulation sub-TLV for GTP

   This document defines a new encapsulation sub-TLV format, defined in
   [RFC5512], for GTP tunnels.  When the tunnel type is GTP, the
   following is the structure of the value field in the encapsulation
   sub-TLV:

   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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        TEID (4 Octets)                      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    TEID: Tunnel endpoint identifier (TEID)[RFC6459]is a 32-bit(4-octet)
    field used to multiplex different connections in the same GTP
    tunnel.

5.  Use Case scenarios

   This section provides a short overview of some use-cases for the BGP
   Remote-Next-Hop attribute.  Use of the BGP Remote-Next-Hop is not
   limited to the examples in this section.

5.1.  Stateless user-plane architecture for virtualized EPC (vEPC)

   The full usage case of BGP remote-next-hop regarding vEPC can be
   found in [vEPC], while [RFC6459]documents IPv6 in 3GPP EPS.

   3GPP introduces Evolved Packet Core (EPC) that is fully IP based
   mobile system for LTE and -advanced in their Release-8 specification
   and beyond.  Operators are now deploying EPC for LTE services and
   encounter rapid LTE traffic growth.  There are various activities to
   offload mobile traffic in 3GPP and IETF such as LIPA, SIPTO and DMM.
   The concept is similar that traffic of OTT (Over The Top) application
   is offloaded at entity that is closer to the mobile node (ex. eNodeB
   or closer anchor).

5.2.  Multi-homing for IPv6

   When an end-user IPv6 network is multi-homed to the Internet, it may
   be assigned more than a single prefix originated by various upstream
   ASs.  Each AS prefers to only announce a supernet of all its assigned
   IPv6 prefixes, unlike IPv4 where the AS announced the end-users
   assigned prefix.  The goal of this BGP policy behaviour is to keep
   the number of entries in the IPv6 global BGP table to a minimum, it
   also it also results in well known resiliency improvements.

Van de Velde, et al.      Expires July 21, 2014                 [Page 8]
Internet-Draft                                              January 2014

   For example, if an end-user IPv6 is peering with 2 different Service
   providers AS1 and AS2.  In this case the IPv6 end-user will have at
   least one prefix assigned from each of these service providers.  The
   devices at the IPv6 end-user will each receive an address from these
   prefixes.  The devices will in most cases, when building IPv6
   sessions (TCP, etc...), do so with only a single IPv6 address.  The
   decision which IPv6 address the device will use is documented in
   [RFC3484].

   If one of the links between the end-user and one the neighboring AS's
   fails, a consequence will be that a set of sessions need to be reset,
   or that a section of the end-user network becomes unreachable.

   With usage of the BGP-remote-Next-Hop attribute the service provider
   can tunnel that packet towards an alternate BGP Remote-Next-Hop at
   the end-users alternate provider and restore the network connectivity
   even though the local link towards the end-user is broken.

5.3.  Dynamic Network Overlay Infrastructure

   The BGP Remote-Next-Hop extension allows signaling tunnel
   encapsulations needed to build and dynamically create an overlay
   tunneled network with traffic isolation and virtual private networks.

5.4.  The Tunnel end-point is NOT the originating BGP speaker

   Note that, in each network environment, the originating router is the
   preferred tunnel end-point server.  It may be that the network
   administrator has deployed an independent set of tunnel end-point
   servers across their network, which may or may not speak BGP.  The
   BGP Remote-Next-Hop attribute provides the ability to signal this via
   BGP.

5.5.  Networks that do not support BGP Remote-Next-Hop attribute

   If a device does not support this attribute, and receives this
   attribute, then normal NLRI BGP forwarding is used as the attribute
   is optional and transitive.

5.6.  Networks that do support BGP Remote-Next-Hop attribute

   If a BGP speaker does understand this attribute, and receives this
   attribute, then the BGP speaker MAY, by configuration, skip use or
   not use the information within this attribute.

Van de Velde, et al.      Expires July 21, 2014                 [Page 9]
Internet-Draft                                              January 2014

6.  BGP Remote-Next-Hop Community

   place-holder for an BGP extension to signal valid prefixes allowed to
   be considered as tunnel end-points.  To be completed.

7.  IANA Considerations

   This memo asks the IANA for a new BGP attribute assignment for the
   BGP Remote-Next-Hop attribute.

   This memo also asks the IANA to reserve the following new Tunnel
   Types for signaling VXLAN and NVGRE encapsulations.

   VXLAN: Tunnel Type = 8

   NVGRE: Tunnel Type = 9

   GTP: Tunnel Type = 10

8.  Security Considerations

   This technology could be used as technology as man in the middle
   attack, however with existing RPKI validation for BGP that risk is
   reduced.

   The distribution of Tunnel end-point address information can result
   in potential DoS attacks if the information is sent by malicious
   organisations.  Therefore is it strongly recommended to install
   traffic filters, IDSs and IPSs at the perimeter of the tunneled
   network infrastructure.

8.1.  Protecting the validity of the BGP Remote-Next-Hop attribute

   It is possible to inject a rogue BGP Remote-Next-Hop attribute to an
   NLRI resulting in Monkey-In-The-Middle attack (MITM).  To avoid this
   type of MITM attack, it is strongly recommended to use a technology a
   mechanism to verify that for NLRI it is the expected BGP Remote-Next-
   Hop. We anticipate that this can be done with an expansion of RPKI-
   Based origin validation, see [I-D.ietf-sidr-pfx-validate].

   This does not avoid the fact that rogue AS numbers may be inserted or
   injected into the AS-Path.  To achieve protection against that threat
   BGP Path Validation should be used, see
   [I-D.ietf-sidr-bgpsec-overview].

Van de Velde, et al.      Expires July 21, 2014                [Page 10]
Internet-Draft                                              January 2014

9.  Privacy Considerations

   This proposal may introduce privacy issues, however with BGP security
   mechanisms in place they should be prevented.

10.  Acknowledgements

   The authors would like to thanks Satoru Matsushima, Ryuji Wakikawa
   and Miya Kohno for their usefull vEPC discussions

11.  Change Log

   Initial Version:  16 May 2012

   Hacked for -01:  17 July 2012

   Hacked for -05:  07 January 2014

12.  References

12.1.  Normative References

   [RFC1771]  Rekhter, Y. and T. Li, "A Border Gateway Protocol 4
              (BGP-4)", RFC 1771, March 1995.

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

   [RFC2784]  Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
              Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
              March 2000.

   [RFC3484]  Draves, R., "Default Address Selection for Internet
              Protocol version 6 (IPv6)", RFC 3484, February 2003.

   [RFC3931]  Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling
              Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.

   [RFC4213]  Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms
              for IPv6 Hosts and Routers", RFC 4213, October 2005.

   [RFC5512]  Mohapatra, P. and E. Rosen, "The BGP Encapsulation
              Subsequent Address Family Identifier (SAFI) and the BGP
              Tunnel Encapsulation Attribute", RFC 5512, April 2009.

Van de Velde, et al.      Expires July 21, 2014                [Page 11]
Internet-Draft                                              January 2014

   [RFC6459]  Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
              Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
              Partnership Project (3GPP) Evolved Packet System (EPS)",
              RFC 6459, January 2012.

12.2.  Informative References

   [I-D.ietf-sidr-bgpsec-overview]
              Lepinski, M. and S. Turner, "An Overview of BGPSEC",
              draft-ietf-sidr-bgpsec-overview-04 (work in progress),
              December 2013.

   [I-D.ietf-sidr-pfx-validate]
              Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
              Austein, "BGP Prefix Origin Validation", draft-ietf-sidr-
              pfx-validate-10 (work in progress), October 2012.

   [I-D.mahalingam-dutt-dcops-vxlan]
              Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "VXLAN: A
              Framework for Overlaying Virtualized Layer 2 Networks over
              Layer 3 Networks", draft-mahalingam-dutt-dcops-vxlan-02
              (work in progress), August 2012.

   [I-D.matsushima-stateless-uplane-vepc]
              Matsushima, S. and R. Wakikawa, "Stateless user-plane
              architecture for virtualized EPC (vEPC)", draft-
              matsushima-stateless-uplane-vepc-01 (work in progress),
              July 2013.

   [I-D.sridharan-virtualization-nvgre]
              Sridharan, M., Greenberg, A., Venkataramaiah, N., Wang,
              Y., Duda, K., Ganga, I., Lin, G., Pearson, M., Thaler, P.,
              and C. Tumuluri, "NVGRE: Network Virtualization using
              Generic Routing Encapsulation", draft-sridharan-
              virtualization-nvgre-02 (work in progress), February 2013.

Authors' Addresses

   Gunter Van de Velde
   Cisco Systems
   De Kleetlaan 6a
   Diegem  1831
   Belgium

   Phone: +32 2704 5473
   Email: gvandeve@cisco.com

Van de Velde, et al.      Expires July 21, 2014                [Page 12]
Internet-Draft                                              January 2014

   Keyur Patel
   Cisco Systems
   170 W. Tasman Drive
   San Jose, CA 95124  95134
   USA

   Email: keyupate@cisco.com

   Dhananjaya Rao
   Cisco Systems
   170 W. Tasman Drive
   San Jose, CA 95124  95134
   USA

   Email: dhrao@cisco.com

   Robert Raszuk
   NTT MCL Inc.
   101 S Ellsworth Avenue Suite 350
   San Mateo, CA  94401
   US

   Email: robert@raszuk.net

   Randy Bush
   Internet Initiative Japan
   5147 Crystal Springs
   Bainbridge Island, Washington  98110
   US

   Email: randy@psg.com

Van de Velde, et al.      Expires July 21, 2014                [Page 13]