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OSPF-TE Link Availability Extension for Links with Variable Discrete Bandwidth
draft-ietf-ccamp-ospf-availability-extension-08

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 8330.
Authors Hao Long , Min Ye , Greg Mirsky , Alessandro D'Alessandro , Himanshu C. Shah
Last updated 2016-11-03 (Latest revision 2016-10-23)
Replaces draft-long-ccamp-ospf-availability-extension
RFC stream Internet Engineering Task Force (IETF)
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Document shepherd Fatai Zhang
Shepherd write-up Show Last changed 2016-08-25
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Responsible AD Deborah Brungard
Send notices to "Fatai Zhang" <zhangfatai@huawei.com>
IANA IANA review state IANA OK - Actions Needed
draft-ietf-ccamp-ospf-availability-extension-08
Network Working Group                                     H. Long, M.Ye 
Internet Draft                             Huawei Technologies Co., Ltd         
Intended status: Standards Track                              G. Mirsky 
                                                             Individual   
                                                         A.D'Alessandro 
                                                   Telecom Italia S.p.A 
                                                                H. Shah 
                                                                  Ciena         
Expires: April 2017                                    October 24, 2016  
                                      
    OSPF-TE Link Availability Extension for Links with Variable Discrete 
                                Bandwidth 
            draft-ietf-ccamp-ospf-availability-extension-08.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 Interface 
   Switching Capability Descriptor (ISCD) Availability sub-TLV to 
   extend the Generalized Multi-Protocol Label Switching (GMPLS) Open 
   Shortest Path First (OSPF) 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. It is intended that technology-
   specific documents will reference this document to describe specific 
   uses. 

    

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. 

 
 
 
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   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 April 24, 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...................................... 6 
   5. IANA Considerations ......................................... 6 
   6. References .................................................. 7 
      6.1. Normative References.................................... 7 
      6.2. Informative References.................................. 7 
   7. Acknowledgments ............................................. 8 
 
Conventions used in this document 

 
 
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   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 Capability 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 

   TE        Traffic Engineering 

   TLV       Type Length Value 

1. Introduction 

   Some data plane technologies, e.g., microwave, and copper,   allow 
   seamless change of maximum physical bandwidth through a set of known 
   discrete values. The parameter, availability, as described in 
   [G.827], [F.1703] and [P.530] is often used to describe the link 
   capacity. The availability is a time scale, representing a proportion 
   of the operating time that the requested bandwidth is ensured. To 
   set up an LSP across these links, availability information is 
   required by the nodes to verify the bandwidth 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 will be determined by the operator and 
   statically configured. It will usually be determined from the 
   availability requirements of the services expected to be carried on 
 
 
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   the LSP. For example, voice service usually needs ''five nines'' 
   availability, while 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 
   availability guarantees, multiple <availability, bandwidth> pairs 
   may be required to be associated with a link.  

   In this document, an extension on Interface Switching Capability 
   Descriptor (ISCD) [RFC4202] for availability information is defined. 
   It is intended that technology-specific documents will reference 
   this document to describe specific uses. 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< availability, bandwidth> information list in its OSPF 
   Traffic Engineering (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 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 Capability 
   Descriptor (ISCD) [RFC4202] for availability information is defined. 
   The computed path can then be provisioned via the signaling protocol 
   [ETPAI]. 

   Note, the mechanisms described in this document only distribute 
   availability information. The methods for measuring the information 
   or using the information for 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 defined in this document 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: 

 
 
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       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 for the Availability level represented in the 
   Availability field. The units are bytes per second.  

3.2. Processing Procedures  

   A node advertising an interface with a Switching Capability which 
   supports 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 MAY be used for path calculation by the node(s). 

   The ISCD Availability sub-TLV MUST NOT be sent in ISCDs with 
   Switching Capability field values that have not been defined to 
   support the ISCD Availability sub-TLV. Non-supporting nodes would 
   see such as a malformed ISCD/LSA. 

   Absence of the ISCD Availability sub-TLV in an ISCD containing 
   Switching Capability field values that have been defined to support 

 
 
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   the ISCD Availability sub-TLV, SHALL be interpreted as representing 
   fixed-bandwidth link with the highest availability value.  

   Only one ISCD Availability sub-TLVs for the specific availability 
   level SHOULD be sent. If multiple are present, only the first ISCD 
   Availability sub-TLV for an availability level carried in the same 
   ISCD SHALL be processed. 

4. Security Considerations 

   This document does not introduce security issues beyond those 
   discussed in [RFC4203].  As with [RFC4203], it specifies the 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 impact on the ability to 
   set up connections in the underlying data plane network. 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. Technology-
   specific documents will reference this document to describe specific 
   use of this Availability sub-TLV. IANA is requested to create a new 
   sub-registry, the ''Types for sub-TLV of Interface Switching 
   Capability 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 requested that the suggested value be granted by IANA.  

 
 
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   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 
             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 words for use in RFCs to Indicate 
             Requirement 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 Engineering 
             (TE) Extensions to OSPF Version 2'', RFC 3630, September 
             2003. 

   [RFC5226] Narten,T. and H. Alvestrand, ''Guidelines for Writing an 
             IANA Considerations Section in 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. 

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

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

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

   [ETPAI]   H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 
             ''Ethernet Traffic Parameters with Availability 
             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 

 
 
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   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 
   Individual 
    
   Email: gregimirsky@gmail.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 
    

 
 
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