RSVP-TE Signaling Extension for Links with Variable Discrete Bandwidth
draft-long-ccamp-rsvp-te-bandwidth-availability-02

Network Working Group                                           H. Long 
Internet Draft                                                     M.Ye 
Intended status: Standards Track           Huawei Technologies Co., Ltd 
                                                              G. Mirsky 
                                                               Ericsson 
                                                           A Alessandro 
                                                   Telecom Italia S.p.A 
Expires: April 2014                                    October 18, 2013  
 
                                      
        RSVP-TE Signaling Extension for Links with Variable Discrete 
                                Bandwidth 
           draft-long-ccamp-rsvp-te-bandwidth-availability-02.txt 

Abstract 

   Packet switching network may contain 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 label switching 
   path (LSP) in a Packet Switched Network (PSN) network which contains 
   links with discretely variable bandwidth by introducing an optional 
   availability field in RSVP-TE signaling. 

Status of this Memo 

   This Internet-Draft is submitted in full conformance with the 
   provisions of BCP 78 and BCP 79.  

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   This Internet-Draft will expire on April 18, 2014. 
 
 
 
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Copyright Notice 

   Copyright (c) 2013 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 
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   warranty as described in the Simplified BSD License. 

Table of Contents 

   1. Introduction ................................................ 3 
   2. Overview .................................................... 4 
   3. Extension to RSVP-TE Signaling............................... 4 
      3.1. SENDER_TSPEC Object..................................... 4 
         3.1.1. Bandwidth Profile TLV.............................. 5 
      3.2. FLOWSPEC Object......................................... 6 
      3.3. Signaling Process....................................... 6 
   4. Security Considerations...................................... 7 
   5. IANA Considerations ......................................... 7 
      5.1  RSVP Objects Class Types................................ 7 
      5.2  Ethernet Bandwidth Profile TLV ......................... 8 
   6. References .................................................. 9 
      6.1. Normative References.................................... 9 
      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]. 

   The following acronyms are used in this draft: 

   RSVP-TE  Resource Reservation Protocol-Traffic Engineering 

   LSP      Label Switched Path 

   PSN      Packet Switched Network 

 
 
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   SNR      Signal-to-noise Ratio 

   TLV      Type Length Value 

   PE       Provider Edge 

   LSA      Link State Advertisement 

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. 

   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 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 a 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, voice service usually needs ''five 
   nines'' availability, while non-real time services may adequately 
   perform at four or three nines availability. Since different service 
   types may need different availabilities guarantee, multiple 
   <availability, bandwidth> pairs may be required when signaling.  

   To fulfill LSP setup by signaling in these scenarios, this document 
   specifies a new availability sub-TLV as the sub-TLV of Ethernet 
   bandwidth profiles [RFC6003]. Multiple bandwidth profiles with 
   different availability can be carried in the SENDER_TSPEC object. 

 
 
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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, e.g., OSPF TE LSA message, by 
   network nodes to get to know about the network topology, and 
   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. 

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

   When a PE node initiates a PATH/RESV signaling to set up an LSP, the 
   PATH message SHOULD carry the <bandwidth, availability> requirement 
   list as bandwidth request.  Intermediate node(s) will allocate the 
   bandwidth resource for each availability requirement from the 
   remaining bandwidth with corresponding availability. An error 
   message may be returned if any <bandwidth, availability> request 
   cannot be satisfied. 

   If there is a hop that cannot support the availability sub-TLV, the 
   availability sub-TLV is ignored, and the requirement will be treated 
   as the highest availability. 

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    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |   Switching Granularity       |              MTU              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                                                               | 

      ~                              TLVs                             ~ 
      |                                                               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
 
 
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   Switching Granularity (SG): 16 bits 

       See [RFC6003] section 4.  

   MTU: 16bits 

      See [RFC6003] section 4. 

   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. 

       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             | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                              CIR                              |  
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                              CBS                              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                              EIR                              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                              EBS                              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
     

      Type: 0x02, 16 bits; 

      Length: 16 bits; 

      Profile: 8 bits 

         This field is defined as a bit vector of binary flags. In RFC 
         6003, the following flags are defined: 

            Flag 1 (bit 0): Coupling Flag (CF) 

            Flag 2 (bit 1): Color Mode (CM) 
 
 
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         A new flag is defined in this document: 

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

     Index: 8 bits 

     CIR (Committed Information Rate): 32 bits 

      CBS (Committed Burst Size): 32 bits 

      EIR (Excess Information Rate): 32 bits 

     EBS (Excess Burst Size): 32 bits 

       See [RFC6003] section 4.1. 

      When the Flag 3 is set to value 1, there is an availability sub-
      TLV included in this Bandwidth Profile TLV. When the Flag 3 is set 
      to value 0, there won't be an 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          | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                          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. 

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 source node initiates PATH messages including one or more 
   Bandwidth Profile TLVs with different availability value in the 

 
 
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   SENDER_TSPEC object. Each Bandwidth Profile TLV specifies the 
   portion of bandwidth request with referred availability requirement. 

   The destination node checks whether it can satisfy the bandwidth 
   requirements by comparing each bandwidth requirement inside the 
   SENDER_TSPEC objects with the remaining link sub-bandwidth resource 
   with respective availability guarantee when received the PATH 
   message.  

     o   If all bandwidth requirements can be satisfied, it should 
        reserve the bandwidth resource from each remaining sub-
        bandwidth portion to set up this LSP. Optionally, the higher 
        availability bandwidth can be allocated to lower availability 
        request when the lower availability bandwidth cannot satisfy 
        the request. 

     o   If at least one bandwidth requirement cannot be satisfied, it 
        should generate PathErr message with the error code "Admission 
        Control Error" and the error value "Requested Bandwidth 
        Unavailable" (see [RFC2205]). 

4. Security Considerations 

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

5. IANA Considerations 

   IANA maintains registries and sub-registries for RSVP-TE used by 
   GMPLS. IANA is requested to make allocations from these registries 
   as set out in the following sections.  

5.1 RSVP Objects Class Types 

   This document introduces two new Class Types for existing RSVP 
   objects. IANA is requested to make allocations from the "Resource 
   ReSerVation Protocol (RSVP) Parameters" registry using the "Class 
   Names, Class Numbers, and Class Types" sub-registry. 

          Class Number  Class Name                            Reference 

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

          9             FLOWSPEC                              [RFC2205] 

                        Class Type (C-Type): 

 
 
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                        6   Ethernet SENDER_TSPEC             [RFC6003] 

        

          Class Number  Class Name                            Reference 

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

          12            SENDER_TSPEC                          [RFC2205] 

                        Class Type (C-Type): 

                        6   Ethernet SENDER_TSPEC             [RFC6003] 

5.2 Ethernet Bandwidth Profile TLV 

   IANA maintains a registry of GMPLS parameters called ''Generalized 
   Multi-Protocol Label Switching (GMPLS) Signaling Parameters''. 

   IANA has created a new sub-registry called ''Ethernet Bandwidth 
   Profiles'' to contain bit flags carried in the Ethernet Bandwidth 
   Profile TLV of the Ethernet SENDER_TSPEC object. 

   Bits are to be allocated by IETF Standards Action. Bits are numbered 
   from bit 0 as the low order bit. A new bit flag is as follow: 

   Bit     Hex               Description              Reference 

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

   2       0x03              Availability Flag (AF)   [This ID] 

   Sub-TLV types for Ethernet Bandwidth Profiles are to be allocated by 
   IETF Standard Action. Initial values are as follows: 

   Type    Length            Format                   Description 

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

   0        -                Reserved                 Reserved value 

   TBD      4                see Section 3.1          Availability sub-
                                                     TLV 

 
 
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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. 

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

   [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. 

   [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 

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 

   The authors would like to thank Khuzema Pithewan, Lou Berger, Yuji 
   Tochio, Dieter Beller, and Autumn Liu for their comments on the 
   document. 

 
 
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   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 
    
    

 

 
 
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