[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-yong-trill-o-pw) 00 01 02 03 04 05 06 RFC 7173

TRILL Working Group                                            Lucy Yong
INTERNET-DRAFT                                           Donald Eastlake
Intended status: Proposed Standard                            Sam Aldrin
                                                     Huawei Technologies
                                                              Jon Hudson
                                                                 Brocade
Expires: April 19, 2014                                 October 20, 2013


                  Transport of TRILL Using Pseudowires
                     <draft-ietf-trill-o-pw-01.txt>


Abstract

   This document specifies how to interconnect a pair of TRILL
   (Transparent Interconnection of Lots of Links) switch ports using
   pseudowires under existing TRILL and PWE3 (Pseudowire Emulation End-
   to-End) standards.


Status of This Memo

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

   Distribution of this document is unlimited. Comments should be sent
   to the authors.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
   Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.












L. Yong, et al                                                  [Page 1]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Table of Contents

      1. Introduction............................................3
      1.1 Conventions used in this document......................3

      2. PWE3 Interconnection of TRILL Switches..................4
      2.1 PWE3 Type Independent Details..........................4
      2.2 PPP PWE3 Transport of TRILL............................5

      3. IANA Considerations.....................................6
      4. Security Considerations.................................6

      Appendix A: Use of Other Pseudowire Types..................7
      Appendix Z: Change History.................................8

      Acknowledgements...........................................9
      Normative References.......................................9
      Informative References.....................................9
      Authors' Addresses........................................11

































L. Yong, et al                                                  [Page 2]

INTERNET-DRAFT                                      PWE3 TRILL Transport


1. Introduction

   The IETF has standardized the TRILL (Transparent Interconnection of
   Lots of Links) protocol [RFC6325] that provides optimal pair-wise
   data frame routing without configuration in multi-hop networks with
   arbitrary topology. TRILL supports multipathing of both unicast and
   multicast traffic. Devices that implement TRILL are called TRILL
   Switches or RBridges (Routing Bridges).

   Links between TRILL Switches can be based on arbitrary link
   protocols, for example PPP [RFC6361], as well as Ethernet [RFC6325].
   A set of connected TRILL Switches together form a TRILL campus which
   is bounded by end stations and layer 3 routers.

   This document specifies how to interconnect a pair of TRILL Switch
   ports using a pseudowire under existing TRILL and PWE3 (Pseudowire
   Emulation End-to-End) standards.



1.1 Conventions used in this document

   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].

   Acronyms used in this document include the following:

      IS-IS - Intermediate System to Intermediate System [IS-IS]

      MPLS - Multi-Protocol Label Switching

      PPP - Point-to-Point Protocol [RFC1661]

      PW - Pseudowire [RFC3985]

      PWE3 - PW Emulation End-to-End

      RBridge - Routing Bridge, an alternative name for a TRILL Switch

      TRILL - Transparent Interconnection of Lots of Links [RFC6325]

      TRILL Switch - A device implementing the TRILL protocol









L. Yong, et al                                                  [Page 3]

INTERNET-DRAFT                                      PWE3 TRILL Transport


2. PWE3 Interconnection of TRILL Switches

   When a pseudowire is used to interconnect a pair of TRILL Switch
   ports, a PPP [RFC4618] pseudowire is used as described below. The
   pseudowire between such ports can be auto-configured [RFC4447] or
   manually configured. In this context, the TRILL Switch ports at the
   ends of the pseudowire are acting as native service processing
   elements (NSP [RFC3985]) and, assuming the pseudowires are over MPLS
   or IP [RFC4023] networks, as label switched or IP routers at the
   TRILL Switch ports.

   Pseudowires provide transparent transport and the two TRILL Switch
   ports appear directly interconnected with a transparent link.  With
   such an interconnection the TRILL adjacency over the link is
   automatically discovered and established through TRILL IS-IS control
   messages [RFC6327bis].

   A pseudowire is carried over a packet switched network tunnel
   [RFC3985].  For example, an MPLS or MPLS-TP label switched path
   tunnel in MPLS networks. Either a signaling protocol or manual
   configuration can be used to configure a label switched path tunnel
   between two TRILL Switch ports. This application needs no additions
   to the existing pseudowire standards.



2.1 PWE3 Type Independent Details

   The sending pseudowire TRILL Switch port MUST copy the priority of
   the TRILL Data packets being sent to the 3-bit Traffic Class field of
   the pseudowire label [RFC5462] so the priority will be visible to
   pseudowire transit devices and they can take the priority into
   account. TRILL IS-IS PDUs critical to establishing and maintaining
   adjacency (Hello and MTU PDUs) SHOULD be send with Traffic Class 7
   while other TRILL IS-IS PDUs SHOULD be sent with Traffic Class 6.

   If a pseudowire supports fragmentation and re-assembly, there is no
   reason to do TRILL MTU testing on it and the pseudowire will not be a
   constraint on the TRILL campus wide Sz (see Section 4.3.1 [RFC6325]).
   If the pseudowire does not support fragmentation, then the available
   TRILL IS-IS packet payload size over the pseudowire (taking into
   account MPLS encapsulation with a control word) or some lower value,
   MUST be used in helping to determine Sz (see Section 5
   [ClearCorrect]).

   An intervening MPLS label switched router or similar packet switched
   network device has no awareness of TRILL. Such devices will not
   change the TRILL Header hop count.




L. Yong, et al                                                  [Page 4]

INTERNET-DRAFT                                      PWE3 TRILL Transport


2.2 PPP PWE3 Transport of TRILL

   For a PPP pseudowire (PW type = 0x0007), the two TRILL Switch ports
   being connected are configured to form a pseudowire with PPP
   encapsulation [RFC4618]. After the pseudowire is established and
   TRILL use is negotiated within PPP, the two TRILL Switch ports appear
   directly connected with a PPP link [RFC1661] [RFC6361].

   If pseudowire interconnection of two TRILL Switch ports is auto-
   configured [RFC4447], the initiating TRILL Switch port MUST attempt
   the connection set-up with pseudowire type PPP (0x0007).

   Behavior for TRILL with a PPP pseudowire continues to follow that of
   TRILL over PPP as specified in Section 3 of [RFC6361].






































L. Yong, et al                                                  [Page 5]

INTERNET-DRAFT                                      PWE3 TRILL Transport


3. IANA Considerations

   No IANA actions are required by this document. RFC Editor: Please
   remove this section before publication.




4. Security Considerations

   For PPP link TRILL security considerations, see [RFC6361].

   For security considerations introduced by carrying PPP TRILL links
   over pseudowires, see [RFC3985].

   Not all implementations need to include specific security mechanisms
   at the pseudowire layer, for example if they are designed to be
   deployed only in cases where the networking environment is trusted or
   where other layers provide adequate security.  A complete enumeration
   of possible deployment scenarios and associated threats and options
   is not possible and is outside the scope of this document.  For
   applications involving sensitive data, end-to-end security should
   always be considered, in addition to link security, to provide
   security in depth. In this context, such end-to-end security should
   be between the end stations involved so as to protect the entire path
   to, through, and from the TRILL campus.

   For general TRILL protocol security considerations, see [RFC6325].
























L. Yong, et al                                                  [Page 6]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Appendix A: Use of Other Pseudowire Types

   This informational Appendix briefly discusses use of pseudowire types
   other than PPP.

   The use of Ethernet pseudowires [RFC4448] was examined by the authors
   and would be possible; however, they would require an additional 12
   or 16 bytes per packet.

   It would also be possible to specify a new pseudowire type for TRILL
   traffic but the authors feel that any efficiency gain over PPP
   pseudowires would be too small to be worth the complexity of adding
   such a specification. Furthermore using PPP pseudowire encoding means
   that any traffic dissector that understands TRILL PPP encoding
   [RFC6361] and understands PPP pseudowires [RFC4618] will
   automatically be able to recursively decode TRILL transported by
   pseudowire.



































L. Yong, et al                                                  [Page 7]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Appendix Z: Change History

   From -00 to -01

   Add information on Traffic Classes that should be used for TRILL IS-
   IS PDUs.

   Other changes to resolve WG Last Call comments:

      Change title from "TRILL Over Psuedowires".

      Change "Class of Service" to "Traffic Class".

      Expand informational paragraph about the consideration of using
      other pseudowire types for the transport of TRILL and make that
      paragraph into Appendix A.

      Add this Change History Appendix Z.


































L. Yong, et al                                                  [Page 8]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Acknowledgements

   Thanks for the valuable comments from the following:

      Yakov Stein

   The document was prepared in raw nroff. All macros used were defined
   within the source file.



Normative References

   [RFC1661] - Simpson, W., Ed., "The Point-to-Point Protocol (PPP)",
         STD 51, RFC 1661, July 1994.

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

   [RFC4447] - Martini, L., Ed., Rosen, E., El-Aawar, N., Smith, T., and
         G. Heron, "Pseudowire Setup and Maintenance Using the Label
         Distribution Protocol (LDP)", RFC 4447, April 2006.

   [RFC4618] - Martini, L., "Encapsulation Methods for Transport of
         PPP/High-Level Data Link Control (HDLC) over MPLS Networks",
         BCP 116, RFC 4618, September 2006.

   [RFC5462] - Andersson, L. and R. Asati, "Multiprotocol Label
         Switching (MPLS) Label Stack Entry: "EXP" Field Renamed to
         "Traffic Class" Field", RFC 5462, February 2009.

   [RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
         Ghanwani, "Routing Bridges (RBridges): Base Protocol
         Specification", RFC6325, July 2011.

   [RFC6361] - Carlson, J., and D. Eastlake, "PPP Transparent
         Interconnection of Lots of Links (TRILL) Protocol Control
         Protocol", RFC6361, August 2011.

   [ClearCorrect] - Eastlake, D., M. Zhang, A. Ghanwani, V. Manral, and
         A. Banerjee, "TRILL: Clarifications, Corrections, and Updates",
         draft-ietf-trill-clear-correct, in RFC Editor's queue.



Informative References






L. Yong, et al                                                  [Page 9]

INTERNET-DRAFT                                      PWE3 TRILL Transport


   [IS-IS] - International Organization for Standardization,
         "Intermediate system to Intermediate system intra-domain
         routing information exchange protocol for use in conjunction
         with the protocol for providing the connectionless-mode Network
         Service (ISO 8473)", ISO/IEC10589:2002, Second Edition, Nov
         2002

   [RFC3985] - Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation
         Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005.

   [RFC4023] - Worster, T., Rekhter, Y., and E. Rosen, Ed.,
         "Encapsulating MPLS in IP or Generic Routing Encapsulation
         (GRE)", RFC 4023, March 2005.

   [RFC4448] - Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
         "Encapsulation Methods for Transport of Ethernet over MPLS
         Networks", RFC 4448, April 2006.

   [RFC6327bis] - Eastlake 3rd, D., Perlman, R., Ghanwani, A., Howard,
         Y., and V. Manral, "TRILL: Adjacency", draft-ietf-trill-
         rfc6327bis, work in progress.































L. Yong, et al                                                 [Page 10]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Authors' Addresses

   Lucy Yong
   Huawei Technologies
   5340 Legacy Drive
   Plano, TX 75025 USA

   Phone: +1-469-227-5837
   Email: lucy.yong@huawei.com


   Donald E. Eastlake, 3rd
   Huawei Technologies
   155 Beaver Street
   Milford, MA 01757 USA

   Phone: +1-508-333-2270
   Email: d3e3e3@gmail.com


   Sam Aldrin
   Huawei Technologies
   2330 Central Expressway
   Santa Clara, CA 95050 USA

   Phone: +1-408-330-4517
   Email: sam.aldrin@huawei.com


   Jon Hudson
   Brocade
   130 Holger Way
   San Jose, CA 95134 USA

   Phone: +1-408-333-4062
   jon.hudson@gmail.com
















L. Yong, et al                                                 [Page 11]

INTERNET-DRAFT                                      PWE3 TRILL Transport


Copyright and IPR Provisions

   Copyright (c) 2013 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
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.  The definitive version of
   an IETF Document is that published by, or under the auspices of, the
   IETF. Versions of IETF Documents that are published by third parties,
   including those that are translated into other languages, should not
   be considered to be definitive versions of IETF Documents. The
   definitive version of these Legal Provisions is that published by, or
   under the auspices of, the IETF. Versions of these Legal Provisions
   that are published by third parties, including those that are
   translated into other languages, should not be considered to be
   definitive versions of these Legal Provisions.  For the avoidance of
   doubt, each Contributor to the IETF Standards Process licenses each
   Contribution that he or she makes as part of the IETF Standards
   Process to the IETF Trust pursuant to the provisions of RFC 5378. No
   language to the contrary, or terms, conditions or rights that differ
   from or are inconsistent with the rights and licenses granted under
   RFC 5378, shall have any effect and shall be null and void, whether
   published or posted by such Contributor, or included with or in such
   Contribution.





















L. Yong, et al                                                 [Page 12]


Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/