Network Working Group                                     H. Long, M.Ye
Internet Draft                             Huawei Technologies Co., Ltd
Intended status: Standards Track                              G. Mirsky
                                                               Ericsson
                                                         A.D'Alessandro
                                                   Telecom Italia S.p.A
                                                                H. Shah
                                                                  Ciena
Expires: February April 2017                                  August 19,                                     October 8, 2016

    OSPF-TE Link Availability Extension for Links with Variable Discrete
                                Bandwidth
            draft-ietf-ccamp-ospf-availability-extension-06.txt
            draft-ietf-ccamp-ospf-availability-extension-07.txt

Abstract

   A network may contain links with variable discrete bandwidth, e.g.,
   copper, radio, etc. The bandwidth of such links may change
   discretely in reaction to changing external environment.
   Availability is typically used for describing such links during
   network planning. This document introduces an optional ISCD
   Availability sub-TLV to extend the Generalized Multi-Protocol Label
   Switching (GMPLS) Open Shortest Path First (OSPF)
   Generalized Multi-Protocol Label Switching (GMPLS). routing protocol.
   This extension can be used for route computation in a network that
   contains links with variable discrete bandwidth. Note, this document
   only covers the mechanisms by which the availability information is
   distributed. The mechanisms by which availability information of a
   link is determined and the use of the distributed information for
   route computation are outside the scope of this document.

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), 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 February 19, April 8, 2016.

Copyright Notice

   Copyright (c) 2016 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.

Table of Contents

   1. Introduction ................................................ 3
   2. Overview .................................................... 4
   3. Extension to OSPF Routing Protocol........................... 4
      3.1. ISCD Availability sub-TLV............................... 4
      3.2. Signaling Process....................................... 5
   4. Security Considerations...................................... 5
   5. IANA Considerations ......................................... 6
   6. References .................................................. 6
      6.1. Normative References.................................... 6
      6.2. Informative References.................................. 6 7
   7. Acknowledgments ............................................. 7 8

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 RFC-2119 [RFC2119].

   The following acronyms are used in this draft:

   GMPLS     Generalized Multi-Protocol Label Switching

   LSA       Link State Advertisement

   ISCD      Interface Switching Capacity Descriptor

   LSP       Label Switched Path

   OSPF      Open Shortest Path First

   PSN       Packet Switched Network

   SNR       Signal-to-noise Ratio

   SONET-SDH Synchronous Optical Network - Synchronous Digital
   Hierarchy

   SPF       Shortest Path First

1. Introduction

   Some data communication plane technologies, e.g., microwave, and copper,   allow
   seamless change of maximum physical bandwidth through a set of known
   discrete values. The parameter availability parameter, availability, as described in
   [G.827], [F.1703], [F.1703] and [P.530] is often used to describe the link capacity during network
   planning.
   capacity. The availability is a time scale, which is representing a proportion
   of the operating time that the requested bandwidth is ensured.
   Assigning different availability classes to different types of
   service over such kind of links provides more efficient planning of
   link capacity. To
   set up an LSP across these links, availability information is
   required for by the nodes to verify the bandwidth
   satisfaction and make before making a
   bandwidth reservation.  Assigning different availability classes
   over such links provides for a more efficient planning of link
   capacity to support different types of services. The link
   availability information should will be inherited determined by the operator and
   statically configured. It will usually be determined from the
   availability requirements of the services expected to be carried on
   the LSP. For example, voice service usually needs "five nines" ''five nines''
   availability, while non-
   real non-real time services may adequately perform at
   four or three nines availability. For the route computation, both
   the availability information and the bandwidth resource information
   are needed. Since different service types may need different
   availabilities
   availability guarantees, multiple <availability, bandwidth> pairs
   may be required when signaling. The signaling extension for links
   with discrete bandwidth is defined in [ETPAI].

   For the route computation, the availability information should to be
   provided along associated with bandwidth resource information. a link.

   In this document, an extension on Interface Switching Capacity
   Descriptor (ISCD) [RFC4202] for availability information is defined.
   The signaling extension to support links with discrete bandwidth is
   defined in [ETPAI].

2. Overview

   A node which has link(s) with variable bandwidth attached should
   include a <bandwidth, availability> < availability, bandwidth> information list in its OSPF TE
   LSA messages. The list provides the mapping between the link nominal
   bandwidth and its availability level. This information is used for
   path calculation by the node(s).The setup of a Label Switched Path
   requires this piece of information to be flooded in the network and used by
   the nodes or the PCE for the path computation. In this document, an
   extension to Interface Switching Capacity Descriptor (ISCD) [RFC4202]
   for availability information is defined. The computed path can then
   be provisioned via the signaling protocol.

   For links with variable discrete bandwidth, Availability protocol[ETPAI].

   Note, the mechanisms described in this document only distribute
   availability information. The methods for measuring the information
   is needed to be carried by
   or using the signaling information for a better link bandwidth
   utilization. Extensions to RSVP-TE can be found in [ETPAI]. route computation are outside the scope
   of this document.

3. TE Metric Extension to OSPF-TE

3.1. ISCD Availability sub-TLV

   The ISCD sub-TLV is defined in Section 1.4 of [RFC4203]. The ISCD
   Availability sub-TLV is defined in this document as is a sub-TLV of ISCD.
   The Switching Capability specific information field of ISCD MAY
   include one or more ISCD Availability sub-TLV(s). The ISCD
   Availability sub-TLV has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |               Type            |               Length          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Availability level                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   LSP Bandwidth at Availability level n       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Type: TBA by IANA, suggested value is 0x01, 16 bits;
      Length: A 16 bits field that expresses the length of the TLV in
    bytes;

       Availability level: 32 bits

           This field is a 32-bit IEEE floating point number which
           describes the decimal value of availability guarantee of the
           switching capability in the ISCD object. The value MUST be
           less than 1. The Availability level is usually expressed in
           the value of 0.99/0.999/0.9999/0.99999.

       LSP Bandwidth at Availability level n: 32 bits

           This field is a 32-bit IEEE floating point number which
           describes the LSP Bandwidth at a certain for the Availability level
           which was described
           represented in the Availability field. The units are bytes
           per second.

3.2. Processing Procedures

   A node which has link(s) with variable bandwidth attached SHOULD
   contain one or more ISCD Availability sub-TLVs in its OSPF TE LSA
   messages. Each ISCD Availability sub-TLV provides the information
   about how much bandwidth a link can support for a specified
   availability. This information SHOULD be used for path calculation
   by the node(s).

   A node that doesn't does not support the ISCD Availability sub-TLV SHOULD
   ignore ISCD Availability sub-TLV. sub-TLV but it SHOULD be included in LSAs
   sent to OSPF neighbors [RFC3630]. If a node who supports ISCD
   Availability sub-TLVs doesn't does not receive the TLV, it indicates SHOULD assume
   that the link is with fixed bandwidth, and the availability can be
   interpreted as the highest availability value, e.g., five nines.
   It's legal not allowed to send multiple ISCD Availability sub-TLVs for the
   same availability level.

4. Security Considerations

   This document extends does not introduce security issues beyond those
   discussed in [RFC4203].  As with [RFC4203], it specifies the contents content
   of an Opaque LSAs in OSPFv2.  As Opaque LSAs are not used for
   Shortest Path First (SPF) computation or normal routing, the
   extensions specified here have no direct effect on IP routing.
   Tampering with GMPLS TE LSAs may have an effect impact on the ability to
   set up connections in the underlying
   transport (optical and/or Synchronous Optical Network - Synchronous
   Digital Hierarchy (SONET-SDH)) data plane network.  [RFC3630] As the
   additional availability information may represent information that
   an operator may wish to keep private, consideration should be given
   to securing this information.[RFC3630] notes that the security
   mechanisms described in [RFC2328] apply to Opaque LSAs carried in
   OSPFv2.  An analysis of the security of OSPF is provided in [RFC6863]
   and applies to the extensions to OSPF as described in this document.
   Any new mechanisms developed to protect the transmission of
   information carried in Opaque LSAs will also automatically protect
   the extensions defined in this document.

   Please refer to [RFC5920] for details on security threats; defensive
   techniques; monitoring, detection, and reporting of security attacks;
   and requirements.

5. IANA Considerations

   This document introduces an Availability sub-TLV of the ISCD sub-TLV
   of the TE Link TLV in the TE Opaque LSA for OSPF v2. IANA will
   created and maintain is
   requested to create a new sub-registry, the "Types ''Types for sub-TLV of
   Interface Switching Capability Descriptor" Descriptor'' registry under the "Open
   Shortest Path First (OSPF) Traffic Engineering TLVs" registry, see
   http://www.iana.org/assignments/ospf-traffic-eng-tlvs.

   This document proposes a suggested value for the Availability sub-
   TLV; it is recommended requested that the suggested value be granted by IANA.

   Type             Description                    Reference

   ---              ------------------             -----------

   0                Reserved                       [This ID]

   0x01             Availability                   [This ID]

   The registration procedure for this registry is Standards Action as
   defined in [RFC5226].

6. References

6.1. Normative References

   [RFC4202] Kompella, K. and Rekhter, Y. (Editors), "Routing ''Routing
             Extensions in Support of Generalized Multi-Protocol Label
             Switching (GMPLS)", RFC 4202, October 2005.

   [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions
             in Support of Generalized Multi-Protocol Label Switching
             (GMPLS)", RFC 4203, October 2005.

6.2. Informative References

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

   [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.

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

   [RFC5226] Narten,T. and H. Alvestrand, "Guidelines ''Guidelines for Writing an
             IANA Considerations Section in RFCs", RFCs'', RFC 5226, May 2008.

   [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS Networks",
             RFC 5920, July 2010.

   [RFC6863] Hartman, S. and D. Zhang, "Analysis of OSPF Security
             According to the Keying and Authentication for Routing
             Protocols (KARP) Design Guide", RFC 6863, March 2013.

   [G.827]  ITU-T Recommendation, "Availability ''Availability performance parameters
             and objectives for end-to-end international constant bit-
             rate digital paths", paths'', September, 2003.

   [F.1703]  ITU-R Recommendation, "Availability ''Availability objectives for real
             digital fixed wireless links used in 27 500 km
             hypothetical reference paths and connections", connections'', January,
             2005.

   [P.530]   ITU-R Recommendation," Recommendation,'' Propagation data and prediction
             methods required for the design of terrestrial line-of-
             sight systems", systems'', February, 2012

   [ETPAI]   H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H.,
             "Ethernet
             ''Ethernet Traffic Parameters with Availability
             Information",
             Information'', Work in Progress, June, 2015

7. Acknowledgments

   The authors would like to thank Acee Lindem, Daniele Ceccarelli, Lou
   Berger for their comments on the document.

   Authors' Addresses

   Hao Long
   Huawei Technologies Co., Ltd.
   No.1899, Xiyuan Avenue, Hi-tech Western District
   Chengdu 611731, P.R.China

   Phone: +86-18615778750
   Email: longhao@huawei.com

   Min Ye
   Huawei Technologies Co., Ltd.
   No.1899, Xiyuan Avenue, Hi-tech Western District
   Chengdu 611731, P.R.China

   Email: amy.yemin@huawei.com

   Greg Mirsky
   Ericsson

   Email: gregory.mirsky@ericsson.com

   Alessandro D'Alessandro
   Telecom Italia S.p.A

   Email: alessandro.dalessandro@telecomitalia.it

   Himanshu Shah
   Ciena Corp.
   3939 North First Street
   San Jose, CA 95134
   US

   Email: hshah@ciena.com