RSVP-TE Signaling Extension for Bandwidth availability
draft-long-ccamp-rsvp-te-bandwidth-availability-00

Network Working Group                                           H. Long 
Internet Draft                                                     M.Ye 
Intended status: Standards Track           Huawei Technologies Co., Ltd 
Expires: August 2013                                  February 18, 2013  
 
                                      
           RSVP-TE Signaling Extension for Bandwidth availability 
           draft-long-ccamp-rsvp-te-bandwidth-availability-00.txt 

Abstract 

   Packet switching network usually contains links with variable 
   bandwidth, e.g., copper, radio, etc. The bandwidth of such link is 
   sensitive to external environment. Availability is typically used 
   for describing the link during network planning. This document 
   describes an extension for RSVP-TE signaling for setting up a LSP in 
   a PSN network which contains variable bandwidth link by introducing 
   an optional availability field in RSVP-TE signaling. 

Status of this Memo 

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Copyright Notice 

   Copyright (c) 2013 IETF Trust and the persons identified as the 
   document authors. All rights reserved. 

 
 
 
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   This document is subject to BCP 78 and the IETF Trust's Legal 
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   (http://trustee.ietf.org/license-info) in effect on the date of 
   publication of this document. Please review these documents 
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Table of Contents 

   1. Introduction ................................................ 2 
   2. Extension to RSVP-TE Signaling............................... 3 
   3. Extension to Routing Protocol................................ 6 
   4. Security Considerations...................................... 8 
   5. IANA Considerations ......................................... 8 
   6. References .................................................. 8 
      6.1. Normative References.................................... 8 
      6.2. Informative References.................................. 9 
   7. Acknowledgments ............................................. 9 
 
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]. 

1. Introduction 

   The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473] 
   specify the signaling message including the bandwidth request for 
   setting up a label switching path in a PSN network. 

   In some networks, there may be some links with variable bandwidth. 
   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 will lower the 
   modulation format since demodulating lower modulation format need 
   lower signal-to-noise ratio (SNR). This is called adaptive 
   modulation technology. However, lower modulation format also means 
   lower link bandwidth. Similarly the cooper links may change their 
   link bandwidth due to external interference.  

   The parameter, availability [G.827, F.1703], is often used to 
   describe the link capacity during network planning. A link may 
   provide different bandwidth for different availability requirement. 
 
 
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   To set up a LSP across such kind of 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. Since different service types may 
   need different availabilities guarantee, multiple <availability, 
   bandwidth> pairs may be required to be signaled. In addition, for 
   the routing computation, the availability information should also be 
   provided with bandwidth resource information. 

   To fulfill LSP setup by signaling in these scenarios, this document 
   specifies the following extensions: 

     o A new SENDER_TSPEC object is defined which includes multiple 
        bandwidth profiles with different availability. This object is 
        an extension on the Ethernet SENDER_TSPEC defined by [RFC6003] 
        which support multiple bandwidth profile TLVs, but limited in 
        the scope of Ethernet. The extension uses the object 
        generically, and amends availability information in the 
        bandwidth profile TLV. 

     o An extension on Interface Switching Capacity Descriptor (ISCD) 
        [RFC4202] for availability information support in routing 
        signaling. The extension reuses the reserved field in the ISCD 
        and also introduces an optional availability sub-TLV. 

         

2. Overview 

   A PSN tunnel may span one or more links in a network. To setup a 
   label switching path (LSP), a PE node may collect link information 
   which is spread in routing message by network nodes, and calculate 
   out a LSP route, and initiate a PATH/RESV signaling for setting up 
   the LSP. 

   In case that there is(are) link(s) with variable bandwidth in a 
   network, a <bandwidth, availability> requirement list should be 
   specified for a LSP. Each <bandwidth, availability> pair in the list 
   means a bandwidth with specified availability is required. The list 
   could be inherited from the result of service planning for the LSP. 

   A node which has link(s) with variable bandwidth attached should 
   contain a similar <bandwidth, availability> information list in its 
   routing messages. The list provides the information that how much 
   bandwidth a link can support for a specified availability. This 
   information is used for path calculation by the PE node(s). 
 
 
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   When a PE node initiates a PATH/RESV signaling for setting up the 
   LSP, the PATH message should carry the <bandwidth, availability> 
   requirement list as bandwidth request, and the intermediate node(s) 
   will allocate the bandwidth resource for each availability 
   requirement from the remained bandwidth with corresponding 
   availability. An error message may be returned if any <bandwidth, 
   availability> request cannot be satisfied. 

3. Extension to RSVP-TE Signaling 

3.1. SENDER_TSPEC Object 

   The SENDER_TSPEC object (Class-Num = 12) 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 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |            Length             | Class-Num (12)|     C-Type    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |             Class-Specific Information (Optional)             | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                                                               | 
      ~                              TLVs                             ~ 
      |                                                               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    

   Class-Specific Information: 32 bits 

      This field indicates the specific information for each C-Type.  

   TLV (Type-Length-Value): 

      The SENDER_TSPEC object MUST include at least one TLV and MAY 
       include more than one TLV. 

3.1.1. Bandwidth Profile TLV 

   The Bandwidth Profile 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               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |    Profile    |     Index     |          Reserved             | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                            ... ...                            | 
      ~                      Traffic Parameters                       ~ 
      |                            ... ...                            | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     

      Type: TBD, 16 bits; 

      Length: 16 bits; 

      Profile: 8 bits 

         This field is defined as a bit vector of binary flags.  The      
         following flags are defined: 

            Flag 3 (bit 2): Availability Flag (AF) 

         When The Flag 3 is set to value 1, there is an availability 
         sub-TLV included in this Bandwidth Profile TLV. The 
         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                         | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

           Type (2 octets): TBD 
           Length (2 octets): 4 
           Availability (4 octets): a 32-bit floating number describes 
           availability requirement for this bandwidth request. The 
           value must be less than 1. 
      

     Index: 8 bits 

       See [RFC6003] section 4.1. 

 
 
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     Traffic Parameters: 

       This field includes the traffic parameters information. The 
         format is different for different C-Type. 

         C-Type = IntServ: See [RFC2210]; 
         C-Type = Ethernet: See [RFC6003]; 
    

3.2. FLOWSPEC Object 

   The FLOWSPEC object (Class-Num = 9, Class-Type = TBD) has the same 
   format as the Ethernet SENDER_TSPEC object. 

3.3. Signaling Process 

   The sender initiates PATH messages including one or more Bandwidth 
   Profile TLVs with different availability value in the SENDER_TSPEC 
   object. Each Bandwidth Profile TLV specifies the portion of 
   bandwidth request with referred availability requirement. 

   The receiving nodes check whether it can satisfy the bandwidth 
   requirement by comparing each bandwidth requirement inside the 
   SENDER_TSPEC objects with the unallocated link bandwidth resource 
   with respective availability guarantee.  

     o   If all bandwidth requirements can be satisfied, it should 
        allocate the bandwidth resource from each unallocated bandwidth 
        portion for this LSP. 

     o   If at least one bandwidth requirement cannot be satisfied, it 
        should generate PathErr messages. 

4. Extension to Routing Protocol 

4.1. Interface Switching Capacity Descriptor 

   The Interface Switching Capacity Descriptor (ISCD) sub-TLV [RFC 4203] 
   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               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      | Switching Cap |   Encoding    |      AI       |   Reserved    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      ~                  Switching Capacity Information               ~ 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

      Type: TBD, 16 bits; 

      Length: 16 bits; 

      AI: ISCD Availability sub-TLV index, 8 bits 

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

4.2. ISCD Availability sub-TLV 

   The 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 Information                    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

      Type: TBD, 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 Information: 32 bits 

           This field is a 32-bit IEEE floating point number which 
           describes the availability guarantee of the switching 

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

5. Security Considerations 

   This document does not introduce new security considerations to the    
   existing RSVP-TE and OSPF signaling protocols. 

6. IANA Considerations 

   TBD 

7. References 

7.1. 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. 

   [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. 

   [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 
             October 2010. 

   [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. 

 
 
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7.2. 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. 

8. Acknowledgments 

    

    

   Authors' Addresses 

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

 
 
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