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Versions: (draft-long-ccamp-rsvp-te-bandwidth-availability) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14

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


        RSVP-TE Signaling Extension for Links with Variable Discrete
                                Bandwidth
           draft-ietf-ccamp-rsvp-te-bandwidth-availability-00.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 Extended
   Ethernet Bandwidth Profile TLV and an OPTIONAL Availability sub_TLV
   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.

   Internet-Drafts are working documents of the Internet Engineering
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   http://www.ietf.org/shadow.html



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   This Internet-Draft will expire on April 8, 2014.

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
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   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 RSVP-TE Signaling............................... 5
         3.1.1. Extended Ethernet Bandwidth Profile TLV............ 5
         3.1.2. Availability sub-TLV............................... 6
      3.2. FLOWSPEC Object......................................... 6
      3.3. Signaling Process....................................... 6
   4. Security Considerations...................................... 7
   5. IANA Considerations ......................................... 7
      5.1  Ethernet Sender TSpec TLVs ............................. 7
      5.2  Extended Ethernet Bandwidth Profile TLV ................ 8
   6. References .................................................. 8
      6.1. Normative References.................................... 8
      6.2. Informative References.................................. 9
   7. Acknowledgments ............................................. 9
   Appendix A ..................................................... 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


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   PSN      Packet Switched Network

   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. A more detailed
   example on the bandwidth availability can be found in Appendix A.
   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. Since different service types MAY need different
   availabilities guarantee, multiple <availability, bandwidth> pairs
   MAY be required when signaling.

   If the availability requirement is not specified in the signaling
   message, the bandwidth will be reserved as the highest availability.


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   For example, the bandwidth with 99.999% availability of a link is
   100Mbps; the bandwidth with 99.99% availability is 200Mbps. When a
   video application requests for 120Mbps without availability
   requirement, the system will compare 120Mbps with 100Mbps, therefore
   cannot set up the LSP path. But in fact, video application doesn't
   need 99.999% availability, 99.99% availability is enough. In this
   case, the LSP could be set up if availability is specified in the
   signaling message.

   To fulfill LSP setup by signaling in these scenarios, this document
   specifies an Extended Ethernet Bandwidth Profile and an Availability
   sub-TLV. The Availability sub-TLV can be applicable to any kind of
   physical links with variable discrete bandwidth, such as microwave
   or DSL. Multiple Extended Ethernet Bandwidth Profiles with different
   availability can be carried in the Ethernet SENDER_TSPEC object.

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.

   A node which has link(s) with variable discrete bandwidth attached
   SHOULD contain a <bandwidth, availability> information list in its
   OSPF TE LSA 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). The
   routing extension for availability can be found in [ARTE].

   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.


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3. Extension to RSVP-TE Signaling

   The initial idea is to define an Availability sub_TLV under Ethernet
   Bandwidth Profile TLV [RFC6003]. However the Ethernet Bandwidth
   Profile TLV doesn't have the ability to carry a sub_TLV according to
   RFC6003. Therefore, an Extend Ethernet Bandwidth Profile TLV is
   defined in this document to avoid the backward compatibility issue.
   The Extended Ethernet Bandwidth Profile TLV includes Ethernet BW TLV
   and has variable length. It MAY include Availability sub-TLV which
   is also defined in this document.

3.1.1. Extended Ethernet Bandwidth Profile TLV

   The Extended Ethernet Bandwidth Profile TLV is included in the
   Ethernet SENDER_TSPEC, and MAY be included for more than one time.
   The Extended Ethernet 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               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |Pro|A|         |     Index     |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              CIR                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              CBS                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              EIR                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              EBS                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       sub_TLV(OPTIONAL)                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

  Figure 1: A new ''AF'' filed in Extended Ethernet Bandwidth Profile TLV

   The difference between the Extended Ethernet Bandwidth Profile TLV
   and Ethernet Bandwidth Profile TLV is that a new AF field to
   indicate the sub_TLV is defined in the Extended Ethernet Bandwidth
   Profile TLV. The rest definitions are the same.

   A new filed is defined in this document:

     AF filed (bit 2): Availability Field (AF)




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   If the AF filed is set to 1, Availability sub-TLV MUST be included
   in the Extended Ethernet Bandwidth Profile TLV. If the AF field is
   set to value 0, then an Availability sub-TLV SHOULD NOT be included.

3.1.2. 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                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 2: Availability sub-TLV

      Type (2 octets): TBD

      Length (2 octets): 4

      Availability (4 octets): a 32-bit floating number describes the
      decimal value of availability requirement for this bandwidth
      request. The value MUST be less than 1.

   As the Extended Ethernet Bandwidth Profile TLV can be carried for
   one or more times in the Ethernet SENDER_TSPEC object, the
   Availability sub-TLV can also be present for one or more times.

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
   Extended Bandwidth Profile TLVs with different availability value in
   the SENDER_TSPEC object. Each Extended Bandwidth Profile TLV
   specifies the portion of bandwidth request with referred
   availability requirement.

   The intermediate and destination nodes checks whether they can
   satisfy the bandwidth requirements by comparing each bandwidth
   requirement inside the SENDER_TSPEC objects with the remaining link



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   sub-bandwidth resource with respective availability guarantee when
   received the PATH message.

     o   If all <bandwidth, availability> 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, availability> 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]).

   If two LSPs request for the bandwidth with the same availability
   requirement, a way to resolve the contention is comparing the node
   ID, the node with the higher node ID will win the contention. More
   details can be found in [RFC3473].

   If a node does not support the Extended Bandwidth Profile TLV and
   Availability sub-TLV, it SHOULD generate PathErr message with the
   error code "Extended Class-Type Error" and the error value "Class-
   Type mismatch" (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 Ethernet Sender TSpec TLVs

   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 Sender TSpec
   TLVs / Ethernet Flowspec TLVs'' to contain the TLV type values for
   TLVs carried in the Ethernet SENDER_TSPEC object. A new value is as
   follow:




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   Type       Description                            Reference

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

   TBD        Extended Ethernet Bandwidth Profile    [This ID]

5.2 Extended Ethernet Bandwidth Profile TLV

   IANA has created a new sub-registry called ''Extended Ethernet
   Bandwidth Profiles'' to contain bit flags carried in the Extended
   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 field is as follow:

   Bit     Hex               Description              Reference

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

   0       0x01              Coupling Flag (CF)        [RFC6003]

   1       0x02              Color Mode (CM)           [RFC6003]

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

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

   Type    Length            Format                Description

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

   0        -                Reserved              Reserved value

   0x01     4                see Section 3.1.2     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.

   [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

   [ARTE]    H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H.,
             ''OSPF Routing 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

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

   Appendix A

   Presuming that a link has three discrete bandwidth levels:

   The link bandwidth under modulation level 1, e.g., QPSK, is 100Mbps;

   The link bandwidth under modulation level 2, e.g., 16QAM, is 200Mbps;


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   The link bandwidth under modulation level 3, e.g., 256QAM, is
   400Mbps.

   In sunny day, the modulation level 3 can be used to achieve 400Mbps
   link bandwidth.

   A light rain with X mm/h rate triggers the system to change the
   modulation level from level 3 to level 2, with bandwidth changing
   from 400Mbps to 200Mbps. The probability of X mm/h rain in the local
   area is 52 minutes in a year. Then the dropped 200Mbps bandwidth has
   99.99% availability.

   A heavy rain with Y(Y>X) mm/h rate triggers the system to change the
   modulation level from level 2 to level 1, with bandwidth changing
   from 200Mbps to 100Mbps. The probability of Y mm/h rain in the local
   area is 26 minutes in a year. Then the dropped 100Mbps bandwidth has
   99.995% availability.

   For the 100M bandwidth of the modulation level 1, only the extreme
   weather condition can cause the whole system unavailable, which only
   happens for 5 minutes in a year. So the 100Mbps bandwidth of the
   modulation level 1 owns the availability of 99.999%.

   In a word, the maximum bandwidth is 400Mbps. According to the
   weather condition, the sub-bandwidth and its availability are shown
   as follows:

   Sub-bandwidth(Mbps)    Availability

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

   200                    99.99%

   100                    99.995%

   100                    99.999%













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

   Email: amy.yemin@huawei.com

   Greg Mirsky (editor)
   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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