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OSPF Routing Extension for Links with Variable Discrete Bandwidth
draft-ietf-ccamp-ospf-availability-extension-00

The information below is for an old version of the document.
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This is an older version of an Internet-Draft that was ultimately published as RFC 8330.
Authors Hao Long , Min Ye , Greg Mirsky , Himanshu C. Shah , Alessandro D'Alessandro
Last updated 2014-10-24 (Latest revision 2014-10-08)
Replaces draft-long-ccamp-ospf-availability-extension
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draft-ietf-ccamp-ospf-availability-extension-00
Network Working Group                                     H. Long, M.Ye 
Internet Draft                             Huawei Technologies Co., Ltd         
Intended status: Standards Track                              G. Mirsky 
                                                               Ericsson 
                                                          A. Alessandro 
                                                   Telecom Italia S.p.A 
                                                                H. Shah 
                                                                  Ciena          
Expires: April 2015                                     October 8, 2014  
 
                                      
     OSPF Routing Extension for Links with Variable Discrete Bandwidth 
            draft-ietf-ccamp-ospf-availability-extension-00.txt 

Abstract 

   Packet switching network MAY contain links with variable discrete 
   bandwidth, e.g., copper, radio, etc. The bandwidth of such link MAY 
   change discretely in reaction to changing external environment. 
   Availability is typically used for describing such links during 
   network planning. This document describes an extension for OSPF 
   routing for route computation in a Packet Switched Network (PSN) 
   which contains links with variable discrete bandwidth by introducing 
   an OPTIONAL Availability sub-TLV. 

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 April 8, 2014. 
 
 
 
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Copyright Notice 

   Copyright (c) 2014 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 .................................................... 3 
   3. Extension to OSPF Routing Protocol........................... 4 
      3.1. Interface Switching Capacity Descriptor................. 4 
      3.2. ISCD Availability sub-TLV............................... 5 
      3.3. Signaling Process....................................... 6 
   4. Security Considerations...................................... 6 
   5. IANA Considerations ......................................... 6 
   6. References .................................................. 6 
      6.1. Normative References.................................... 6 
      6.2. Informative References.................................. 7 
   7. Acknowledgments ............................................. 7 
 
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: 

   OSPF    Open Shortest Path First 

   PSN     Packet Switched Network 

   SNR     Signal-to-noise Ratio 

   LSP     Label Switched Path 

   ISCD    Interface Switching Capacity Descriptor 
 
 
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   PE      Provider Edge 

   LSA     Link State Advertisement 

1. Introduction 

   Some data communication technologies allow seamless change of 
   maximum physical bandwidth through a set of known discrete values. 
   For example, in mobile backhaul network, microwave links are very 
   popular for providing connection of last hops. In case of heavy rain, 
   to maintain the link connectivity, the microwave link MAY lower the 
   modulation level since demodulating lower modulation level need 
   lower signal-to-noise ratio (SNR). This is called adaptive 
   modulation technology [EN 302 217]. However, lower modulation level 
   also means lower link bandwidth. When link bandwidth reduced because 
   of modulation down-shifting, high priority traffic can be maintained, 
   while lower priority traffic is dropped. Similarly the cooper links 
   MAY change their effective link bandwidth due to external 
   interference.  

   The parameter availability [G.827, F.1703, P.530] is often used to 
   describe the link capacity during network planning. 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 the nodes to verify bandwidth satisfaction and make 
   bandwidth reservation. The availability information SHOULD be 
   inherited from the availability requirements of the services 
   expected to be carried on 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, the availability information SHOULD be 
   provided along with bandwidth resource information. In this document, 
   an extension on Interface Switching Capacity Descriptor (ISCD) 
   [RFC4202] for availability information is defined to support in 
   routing signaling. The extension reuses the reserved field in the 
   ISCD and also introduces an OPTIONAL Availability sub-TLV.  

   If there is a hop that cannot support the Availability sub-TLV, the 
   Availability sub-TLV SHOULD be ignored. 

2. Overview 

   A node which has link(s) with variable bandwidth attached SHOULD 
   contain a <bandwidth, availability> information list in its OSPF TE 
   LSA messages. The list provides the information that how much 
 
 
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   bandwidth a link can support for a specified availability. This 
   information is used for path calculation by the PE node(s).  

   To setup an label switching path (LSP), a PE node MAY collect link 
   information which is spread in OSPF TE LSA messages by network nodes 
   to get know about the network topology, calculate out an LSP route 
   based on the network topology and send the calculated LSP route to 
   signaling to initiate a PATH/RESV message for setting up the LSP. 

   Availability information is required to carry in the signaling 
   message to better utilize the link bandwidth. The signaling 
   extension for availability can be found in [ASTE]. 

3. Extension to OSPF Routing Protocol 

3.1. Interface Switching Capacity Descriptor 

   The Interface Switching Capacity Descriptor (ISCD) sub-TLV [RFC 4203] 
   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               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      | Switching Cap |   Encoding    |      AI       |   Reserved    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 0              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 1              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 2              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 3              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 4              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 5              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 6              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Max LSP Bandwidth at priority 7              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                  Switching Capacity-specific Information      | 
      |                         (variable)                            | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

 
 
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      A new AI field is defined in this document. 

      AI: ISCD Availability sub-TLV index, 8 bits 

         This new field is the index of Availability sub-TLV for this 
         ISCD sub-TLV.  

3.2. ISCD Availability sub-TLV 

   When the Switching Capability field is PSC-1, PSC-2, PSC-3, PSC-4, 
   the Switching Capability specific information field 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          | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |      Index    |                     Reserved                  | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                   Availability level                          | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                   LSP Bandwidth at Availability level n       | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
      Type: 0x01, 16 bits; 

      Length: 16 bits; 

      Index: 8 bits 

           This field is the index of this Availability sub-TLV, 
           referred by the AI field of the ISCD sub-TLV. 

       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 capacity in the ISCD object which has the AI value 
           equal to Index of this sub-TLV. The value MUST be less than 
           1. 

       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 Availability level 
           which was described in the Availability field.  
 
 
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3.3. Signaling Process 

   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 PE node(s).  

   A node that doesn't support ISCD Availability sub-TLV SHOULD ignore 
   ISCD Availability sub-TLV. 

4. Security Considerations 

   This document does not introduce new security considerations to the    
   existing OSPF protocol. 

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. This document 
   proposes a suggested value for the Availability sub-TLV; it is 
   recommended that the suggested value be granted by IANA. Initial 
   values are as follows: 

   Type    Length            Format                   Description 

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

   0        -                Reserved                 Reserved value 

   0x01      8               see Section 3.2          Availability sub-
                                                     TLV 

6. References 

6.1. Normative References 

   [RFC2210] Wroclawski, J., ''The Use of RSVP with IETF Integrated 
             Services'', RFC 2210, September 1997. 

   [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 
             V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 
             Tunnels", RFC 3209, December 2001. 

 
 
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   [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching            
             (GMPLS) Signaling Resource ReserVation Protocol-Traffic            
             Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 

   [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. 

   [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 

   [EN 302 217] ETSI standard, ''Fixed Radio Systems; Characteristics 
             and requirements for point-to-point equipment and 
             antennas'', April, 2009 

   [ASTE]    H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 
             ''RSVP-TE Signaling Extension for Links with Variable 
             Discrete Bandwidth'', Work in Progress, February, 2014 

6.2. Informative References 

   [MCOS]    Minei, I., Gan, D., Kompella, K., and X. Li, "Extensions           
             for Differentiated Services-aware Traffic Engineered              
             LSPs", Work in Progress, June 2006. 

7. Acknowledgments 

    

    

   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 
   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 
    

 
 
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