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

Versions: (draft-vasseur-mpls-number-0-bw-te-lsps) 00 01 02 03 04 05 06 07 08 09 10 11 12 RFC 5330

Networking Working Group                                JP. Vasseur, Ed.
Internet-Draft                                        Cisco Systems, Inc
Expires: November 25, 2006                             Matthew. R. Meyer
                                                         Global Crossing
                                                               K. Kumaki
                                                        KDDI Corporation
                                                   Alberto. Tempia Bonda
                                                          Telecom Italia
                                                            May 24, 2006


 A Link-Type sub-TLV to convey the number of Traffic Engineering Label
                  Switch Paths signalled across a link
                 draft-ietf-mpls-number-0-bw-te-lsps-01

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   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/ietf/1id-abstracts.txt.

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

   This Internet-Draft will expire on November 25, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   Several Link-type sub-TLVs have been defined for OSPF and ISIS in the
   context of MPLS Traffic Engineering in order to convery some link



Vasseur, et al.         Expires November 25, 2006               [Page 1]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


   characteristics such as the available bandwidth, traffic enginering
   metric, adminstrative group and so on.  There are various
   circumstances where it would be useful to also advertise the number
   of unconstrained Traffic Engineering Label Switched Path(s) (TE LSP)
   signalled across a link.  This document specifies a new Link-type
   Traffic Engineering sub-TLV used to advertise the number of
   unconstrained TE LSP(s) signalled across a link.

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 RFC 2119 [RFC2119].


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Protocol extensions . . . . . . . . . . . . . . . . . . . . . . 4
     3.1.  IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
     3.2.  OSPF  . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   4.  Elements of procedure . . . . . . . . . . . . . . . . . . . . . 5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 5
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 7
   Intellectual Property and Copyright Statements  . . . . . . . . . . 8




















Vasseur, et al.         Expires November 25, 2006               [Page 2]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


1.  Introduction

   A set of Link-type sub-TLVs have been defined for OSPF and ISIS (see
   [I-D.ietf-isis-te-bis] and [RFC3630]) in the context of MPLS Traffic
   Engineering in order to advertise various link characteristics such
   as the available bandwidth, traffic enginering metric, administrative
   group and so on.  There are various circumstances where it would be
   useful to also advertise the number of unconstrained Traffic
   Engineering Label Switch Path(s) (TE LSP).

   It is not uncommon to deploy MPLS Traffic Engineering for the sake of
   fast recovery relying on a local protection recovery mechanism such
   as MPLS TE Fast Reroute (see [RFC4090]).  In this case, a deployment
   model consists of deploying a full mesh of unconstrained TE LSPs
   between a set of LSRs and protect these TE LSPs with pre-established
   backup tunnels against link, SRLG and/or node failures.  The traffic
   routed onto such unconstrained TE LSP simply follows the IGP shortest
   path but is protected with MPLS TE Fast Reroute.

   With MPLS Traffic Engineering a usual rerouting criteria is the
   discovery of a better path for a TE LSP where a better path is
   defined as a path with a lower cost according to a specific metric;
   other metric such that the percentage of reserved bandwidth or the
   number of hops can also be used.  Unfortunately, for instance in the
   presence of ECMPs (Equal Cost Multi-Paths) in symetrical networks
   when unconstrained TE LSP are used, such metrics are usually
   inneffective and may lead to poorly load balanced traffic.  If the
   number of unconstrained TE LSPs traversing each link in the network
   is known, various algorithms can be designed so as to efficiently
   load balance the traffic carried by such unconstrained TE LSPs.  As
   currently defined in [RFC3630] and [I-D.ietf-isis-te-bis] the
   information related to the number of unconstrained TE LSP(s) is not
   available.  This document specifies a new Link-type Traffic
   Engineering sub-TLV used to indicate the number of unconstrained TE
   LSP signalled across a link.

   Note that the specification of load balancing algorithms is outside
   of the scope of this document and merely listed for the sake of
   illustration of the motivation for gathering such information.

   Furthermore, the knowledge of the number of unconstrained TE LSPs
   signalled across each link can be used for other purposes (e.g.
   management, ...).


2.  Terminology

   Terminology used in this document



Vasseur, et al.         Expires November 25, 2006               [Page 3]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


   LSA: Link State Advertisement.

   LSP: Link State Packet.

   LSR: Label Switching Router.

   TE LSP: Traffic Engineering Label Switched Path.

   Unconstrained TE LSP: A TE LSP signalled with a bandwidth metric
   equal to 0.


3.  Protocol extensions

   A new Sub-TLV named NB-O-BW-LSP is defined that specifies the number
   of unconstrained TE LSPs signalled across a link.

3.1.  IS-IS

   The NB-0-BW-LSP TLV is OPTIONAL and MUST appear at most once within
   the extended IS reachability TLV (type 22) specified in [I-D.ietf-
   isis-te-bis].

   The IS-IS NB-0-BW-LSP TLV format is defined below:

   Type (1 octet): To be assigned by IANA (suggested value = 19)

   Length (1 octet): 4

   Value (4 octets): number of unconstrained TE LSP(s) signalled across
   the link.

3.2.  OSPF

   The NB-0-BW-LSP is OPTIONAL and MUST appear at most once within the
   Link TLV (Type 2) that is itself carried within the Traffic
   Engineering LSA specified in [RFC3630].

   The OSPF NB-0-BW-LSP TLV format is defined below:

   Type (2 octets): To be assigned by IANA (suggested value = 19)

   Length (2 octets): 4

   Value (4 octets): number of unconstrained TE LSP(s) signalled across
   the link.





Vasseur, et al.         Expires November 25, 2006               [Page 4]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


4.  Elements of procedure

   An implementation may decide to implement a dual-thresholds mechanism
   to govern the origination of updated OSPF LSA () or ISIS LSP ().
   Similalry to other MPLS Traffic Engineering link characteristics,
   LSA/LSP origination trigger mechanisms are outside of the scope of
   this document.


5.  IANA Considerations

   IANA will assign a new code point for the newly defined IS-IS sub-TLV
   (NB-0-BW-LSP) carried within the TLV 22 (suggested value =19)

   IANA will assign a new code point for the newly defined OSPF sub-TLV
   (NB-0-BW-LSP) carried within the Link TLV (Type 2) of the Traffic
   Engineering LSA (suggested value=19).


6.  Security Considerations

   This document raises no new security issues for IS-IS and OSPF.


7.  Acknowledgements

   The authors would like to thank Jean-Louis Le Roux for his useful
   inputs.


8.  References

8.1.  Normative References

   [I-D.ietf-isis-te-bis]
              Li, T. and H. Smit, "IS-IS extensions for Traffic
              Engineering", draft-ietf-isis-te-bis-00 (work in
              progress), September 2005.

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

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630,
              September 2003.






Vasseur, et al.         Expires November 25, 2006               [Page 5]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


8.2.  Informative References

   [RFC4090]  Pan, P., Swallow, G., and A. Atlas, "Fast Reroute
              Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
              May 2005.














































Vasseur, et al.         Expires November 25, 2006               [Page 6]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


Authors' Addresses

   JP Vasseur (editor)
   Cisco Systems, Inc
   1414 Massachusetts Avenue
   Boxborough, MA  01719
   USA

   Email: jpv@cisco.com


   Matthew R. Meyer
   Global Crossing
   3133 Indian Valley Tr.
   Howell, MI  48855
   USA

   Email: mrm@gblx.net


   Kenji Kumaki
   KDDI Corporation
   Garden Air Tower Iidabashi, Chiyoda-ku,
   Tokyo,   102-8460
   JAPAN

   Email: ke-kumaki@kddi.com


   Alberto Tempia Bonda
   Telecom Italia
   via G. Reiss Romoli 274
   Torino,   10148
   ITALIA

   Email: alberto.tempiabonda@telecomitalia.it















Vasseur, et al.         Expires November 25, 2006               [Page 7]


Internet-Draft   draft-ietf-mpls-number-0-bw-te-lsps-01         May 2006


Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.


Disclaimer of Validity

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Copyright Statement

   Copyright (C) The Internet Society (2006).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.


Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.




Vasseur, et al.         Expires November 25, 2006               [Page 8]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/