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Versions: 00                                                            
Network Working Group                                        Yuanlin Bao
Internet-Draft                                               Faming Yang
Intended status: Informational                                  Xihua Fu
Expires: September 1, 2010                               ZTE Corporation
                                                       February 28, 2010


 Requirements For Path Ownership Transfer Between Management Plane And
                   Control Plane In A MPLS-TP Network
              draft-bao-mpls-tp-path-transfer-reqs-00.txt

Abstract

   From a carrier perspective, the possibility of transferring the
   ownership and control of an existing and in-use path between the
   management plane and the control plane, without actually affecting
   data plane traffic being carried over it, is a valuable option.  This
   memo sets out the requirements for such procedures.

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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   This Internet-Draft will expire on September 1, 2010.

Copyright Notice

   Copyright (c) 2010 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



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   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 BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Conventions used in this document . . . . . . . . . . . . . 3
   2.  Requirements for MPLS-TP Path Transfer  . . . . . . . . . . . . 3
     2.1.  General Requirements for LSP and PW . . . . . . . . . . . . 4
     2.2.  Special Requirements for LSP  . . . . . . . . . . . . . . . 4
   3.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
   4.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     5.1.  Normative References  . . . . . . . . . . . . . . . . . . . 5
     5.2.  Informative References  . . . . . . . . . . . . . . . . . . 5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 6




























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1.  Introduction

   As described in the architecture for Multi-Protocol Label Switching
   Transport Profile (MPLS-TP) [MPLS-TP-Fwk], the overall architecture
   framework for MPLS-TP is based on a profile of the MPLS and
   Pseudowire (PW) procedures as specified for the MPLS and (MS-)PW
   architectures defined in [RFC3031], [RFC3985] and [RFC5085].  Thus
   MPLS-TP path includes LSP and PW which is beared in LSP.  MPLS-TP
   path can be configured and controlled by means of a Network
   Management System (NMS) operating within the Management Plane (MP).
   NMS/MP is the owner of MPLS-TP path, being responsible of it's set
   up, tear down and maintenance.

   The adoption of control plane in a MPLS-TP network that is already in
   service - controlled by NMS at MP level - introduces the need for a
   procedure able to coordinate a controlled transfer of PW from MP to
   CP.  In addition, the control transfer in the opposite direction,
   from CP to MP should be possible as well.

   This memo considers the requirements of MPLS-TP path ownership
   transfer between management plane and control plane.  Note, some
   aspects of a control-plane-initiated connection must be capable of
   being queried/controlled by the management plane.  These aspects
   should be independent of how the connection was established.

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].


2.  Requirements for MPLS-TP Path Transfer

   [RFC5493] describes the requirements for the conversion between
   permanent connection (PC) and switched connection (SC) in a GMPLS
   Network.  However, MPLS-TP network supports unidirectional,
   associated bidirectional, co-routed bidirectional point-to-point
   transport paths and unidirectional point-to-multipoint transport
   paths.  So, some requirements listed in [RFC5493] also apply to
   MPLS-TP path transfer.  However, due to the particularity of MPLS-TP
   path including LSP and PW, there are still some different
   requirements.  This section will lists all the requirements for the
   MPLS-TP path transfer.







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2.1.  General Requirements for LSP and PW

   This section lists the general requirements for LSP and PW.

   1)  No disruption of user traffic

       The MPLS-TP path transfer process MUST NOT cause any disruption
       of user traffic flowing over the path whose control is being
       transferred or over any other path in the network.  If transfer
       fails, it's affection SHOULD be limited to the control plane or
       management plane, and the data plane MUST not be affected.

       The MPLS-TP path ownership transfer SHALL occur without
       generating alarms towards the end users or the NMS.

   2)  Data Plane PW Consistency

       The MPLS-TP transport path MUST stay in place throughout the
       whole control transfer process.  That is to say, LSP and PW MUST
       follow the same transport path through the network and MUST use
       the same network resources.

   3)  Synchronization of State among Nodes during Conversion

       It MUST be assured that the state of the LSP and PW is
       synchronized among all nodes traversed by it before the
       conversion is considered complete.

   4)  Transfer between Management Plane and Control Plane

       It MUST be possible to transfer the ownership of a MPLS-TP path
       from the management plane to the control plane.  It SHOULD be
       possible to transfer the ownership of a MPLS-TP path from the
       control plane to the management plane.

   5)  Revertion after Transfer Failure

       It's possible that PW transfer may fail.  If PW fails to transfer
       from one plane to the other, a revertion mechnism MUST be
       possible to ensure LSP and PW status revert to the initial one
       before the transfer process starts.

2.2.  Special Requirements for LSP

   For associated bidirectional LSP, it is comprised of two independent
   unidirectional LSP.  The edge nodes and transit nodes belonging to
   the same associated bidirectional transport path, must be aware about
   the pairing relationship of the forward and the backward directions



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   belonging to the same associated bidirectional transport path.  So,
   the pairing relationship MUST be created in CP when the associated
   bidirectional LSP from management transfers from MP to CP. s


3.  Security Considerations

   TBD.


4.  Acknowledgements

   The RFC text was produced using Marshall Rose's xml2rfc tool.


5.  References

5.1.  Normative References

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

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

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

   [RFC5036]  Andersson, L., Minei, I., and B. Thomas, "LDP
              Specification", RFC 5036, October 2007.

   [RFC5493]  Caviglia, D., Bramanti, D., Li, D., and D. McDysan,
              "Requirements for the Conversion between Permanent
              Connections and Switched Connections in a Generalized
              Multiprotocol Label Switching (GMPLS) Network", RFC 5493,
              April 2009.

5.2.  Informative References

   [DYNAMIC-MS-PW]
              Luca Martini, Matthew Bocci, and Florin Balus, "Dynamic
              Placement of Multi Segment Pseudo Wires",
              draft-ietf-pwe3-dynamic-ms-pw-10.txt .

   [MPLS-TP-CP]
              Loa Andersson, Lou Berger, and Luyuan Fang, "MPLS-TP
              Control Plane Framework",



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              draft-abfb-mpls-tp-control-plane-framework-01.txt .

   [SEG-PW]   Luca Martini and Chris Metz, "Segmented Pseudowire",
              draft-ietf-pwe3-segmented-pw-13.txt .


Authors' Addresses

   Yuanlin Bao
   ZTE Corporation
   5F, R&D Building 3, ZTE Industrial Park, XiLi LiuXian Road
   Nanshan District, Shenzhen  518055
   P.R.China

   Phone: +86 755 26773731
   Email: bao.yuanlin@zte.com.cn
   URI:   http://www.zte.com.cn/


   Faming Yang
   ZTE Corporation
   4F, R&D Building 3, ZTE Industrial Park, XiLi LiuXian Road
   Nanshan District, Shenzhen  518055
   P.R.China

   Phone: +86 755 26773731
   Email: yang.faming@zte.com.cn
   URI:   http://www.zte.com.cn/


   Xihua Fu
   ZTE Corporation
   West District,ZTE Plaza,No.10,Tangyan South Road,Gaoxin District
   Xi An  710065
   P.R.China

   Phone: +8613798412242
   Email: fu.xihua@zte.com.cn
   URI:   http://www.zte.com.cn/












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