GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc4328

Network Working Group D. Papadimitriou, Ed. Request for Comments: 4328 Alcatel Updates: 3471 January 2006 Category: Standards Track

         Generalized Multi-Protocol Label Switching (GMPLS)
 Signaling Extensions for G.709 Optical Transport Networks Control

Status of This Memo

 This document specifies an Internet standards track protocol for the
 Internet community, and requests discussion and suggestions for
 improvements.  Please refer to the current edition of the "Internet
 Official Protocol Standards" (STD 1) for the standardization state
 and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

 Copyright (C) The Internet Society (2006).

Abstract

 This document is a companion to the Generalized Multi-Protocol Label
 Switching (GMPLS) signaling documents.  It describes the technology-
 specific information needed to extend GMPLS signaling to control
 Optical Transport Networks (OTN); it also includes the so-called
 pre-OTN developments.

Table of Contents

 1. Introduction ....................................................2
    1.1. Conventions Used in This Document ..........................3
 2. GMPLS Extensions for G.709 - Overview ...........................3
 3. Generalized Label Request .......................................4
    3.1. Common Part ................................................5
         3.1.1. LSP Encoding Type ...................................5
         3.1.2. Switching Type ......................................6
         3.1.3. Generalized-PID (G-PID) .............................6
    3.2. G.709 Traffic Parameters ...................................8
         3.2.1. Signal Type (ST) ....................................8
         3.2.2. Number of Multiplexed Components (NMC) ..............9
         3.2.3. Number of Virtual Components (NVC) .................10
         3.2.4. Multiplier (MT) ....................................10
         3.2.5. Reserved Fields ....................................10
 4. Generalized Label ..............................................10
    4.1. ODUk Label Space ..........................................11
    4.2. Label Distribution Rules ..................................13

Papadimitriou Standards Track [Page 1] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

    4.3. Optical Channel Label Space ...............................14
 5. Examples .......................................................14
 6. RSVP-TE Signaling Protocol Extensions ..........................16
 7. Security Considerations ........................................16
 8. IANA Considerations ............................................16
 9. Acknowledgements ...............................................18
 10. References ....................................................18
    10.1. Normative References .....................................18
    10.2. Informative References ...................................19
 11. Contributors ..................................................19
 Appendix A. Abbreviations .........................................21
 Appendix B. G.709 Indexes .........................................22

1. Introduction

 Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945] extends
 MPLS from supporting Packet Switching Capable (PSC) interfaces and
 switching to include support of four new classes of interfaces and
 switching: Layer-2 Switching (L2SC), Time-Division Multiplex (TDM),
 Lambda Switch (LSC), and Fiber-Switch (FSC) Capable.  A functional
 description of the extensions to MPLS signaling that are needed to
 support these new classes of interfaces and switching is provided in
 [RFC3471].  [RFC3473] describes the RSVP-TE-specific formats and
 mechanisms needed to support all four classes of interfaces.
 This document presents the technology details that are specific to
 G.709 Optical Transport Networks (OTN) as specified in the ITU-T
 G.709 recommendation [ITUT-G709] (and referenced documents),
 including pre-OTN developments.  Per [RFC3471], G.709 technology-
 specific parameters are carried through the signaling protocol in
 dedicated traffic parameter objects.
 The G.709 traffic parameters defined hereafter (see Section 3.2) MUST
 be used when the label is encoded as defined in this document.
 Moreover, the label MUST be encoded as defined in Section 4 when
 these G.709 traffic parameters are used.
 In the context of this memo, by pre-OTN developments, one refers to
 Optical Channel, Digital Wrapper and Forward Error Correction (FEC)
 solutions that are not fully G.709 compliant.  Details concerning
 pre-OTN Synchronous Optical Network (SONET)/Synchronous Digital
 Hierarchy (SDH) based solutions including Section/Regenerator Section
 overhead (SOH/RSOH) and Line/Multiplex Section overhead (LOH/MSOH)
 transparency are covered in [RFC3946].

Papadimitriou Standards Track [Page 2] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

  • Note on ITU-T G.709 Recommendation *
 The views on the ITU-T G.709 OTN Recommendation presented in this
 document are intentionally restricted to the GMPLS perspective within
 the IETF CCAMP WG context.  Hence, the objective of this document is
 not to replicate the content of the ITU-T OTN recommendations.
 Therefore, readers interested in more details concerning the
 corresponding technologies are strongly invited to consult the
 corresponding ITU-T documents (also referenced in this memo).

1.1. 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 [RFC2119].
 In addition, the reader is assumed to be familiar with the
 terminology used in ITU-T [ITUT-G709], as well as [RFC3471] and
 [RFC3473].  Abbreviations used in this document are detailed in
 Appendix 1.

2. GMPLS Extensions for G.709 - Overview

 [ITUT-G709] defines several networking layers constituting the
 optical transport hierarchy:
  1. with full functionality:

. Optical Transmission Section (OTS)

   . Optical Multiplex Section (OMS)
   . Optical Channel (OCh)
 - with reduced functionality:
   . Optical Physical Section (OPS)
   . Optical Channel with reduced functionality (OChr)
 It also defines two layers constituting the digital transport
 hierarchy:
  1. Optical Channel Transport Unit (OTUk)
  2. Optical Channel Data Unit (ODUk)
 However, only the OCh and the ODUk layers are defined as switching
 layers.  Both OCh (but not OChr) and ODUk layers include the overhead
 for supervision and management.  The OCh overhead is transported in a
 non-associated manner (also referred to as the non-associated
 overhead naOH) in the Optical Transport Module (OTM) Overhead Signal
 (OOS), together with the OTS and OMS non-associated overhead.  The
 OOS is transported via a dedicated wavelength, referred to as the
 Optical Supervisory Channel (OSC).  It should be noticed that the

Papadimitriou Standards Track [Page 3] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 naOH is only functionally specified and as such, it is open to
 vendor-specific solutions.  The ODUk overhead is transported in an
 associated manner as part of the digital ODUk frame.
 As described in [ITUT-G709], in addition to the support of ODUk
 mapping into OTUk (k = 1, 2, 3), G.709 supports ODUk multiplexing.
 It refers to the multiplexing of ODUj (j = 1, 2) into an ODUk (k > j)
 signal, in particular:
  1. ODU1 into ODU2 multiplexing
  2. ODU1 into ODU3 multiplexing
  3. ODU2 into ODU3 multiplexing
  4. ODU1 and ODU2 into ODU3 multiplexing
 Adapting GMPLS to control G.709 OTN can be achieved by creating:
  1. a Digital Path layer, by extending the previously defined

"Digital Wrapper" in [RFC3471] corresponding to the ODUk

     (digital) path layer.
   - an Optical Path layer, by extending the "Lambda" concept (defined
     in [RFC3471]) to the OCh (optical) path layer.
   - a label space structure, by considering a tree whose root is an
     OTUk signal and leaves the ODUj signals (k >= j); enabling the
     identification of the exact position of a particular ODUj signal
     in an ODUk multiplexing structure.
 Thus, the GMPLS signaling extensions for G.709 need to cover the
 Generalized Label Request, the Generalized Label as well as the
 specific technology dependent objects included in the so-called
 traffic parameters as specified in [RFC3946] for SONET/SDH networks.
 Moreover, because multiplexing in the digital domain (such as ODUk
 multiplexing) has been specified in the amended version of the G.709
 ITU-T recommendation (October 2001), this document also proposes a
 label space definition suitable for that purpose.  Notice also that
 one uses the G.709 ODUk (i.e., Digital Path) and OCh (i.e., Optical
 Path) layers directly in order to define the corresponding label
 spaces.

3. Generalized Label Request

 The Generalized Label Request, as defined in [RFC3471], includes a
 common part (i.e., used for any switching technology) and a
 technology dependent part (i.e., the traffic parameters).  In this
 section, both parts are extended to accommodate GMPLS Signaling to
 the G.709 transport plane recommendation (see [ITUT-G709]).

Papadimitriou Standards Track [Page 4] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

3.1. Common Part

 As defined in [RFC3471], the LSP Encoding Type, the Switching Type
 and the Generalized Protocol Identifier (Generalized-PID) constitute
 the common part of the Generalized Label Request.  The encoding of
 the RSVP-TE GENERALIZED_LABEL_REQUEST object is specified in
 [RFC3473] Section 2.1.
 As mentioned above, this document extends the LSP Encoding Type, the
 Switching Type, and G-PID (Generalized-PID) values to accommodate
 G.709 Recommendation [ITUT-G709].

3.1.1. LSP Encoding Type

 Because G.709 Recommendation defines two networking layers (ODUk
 layers and OCh layer), the LSP Encoding Type code-points can reflect
 these two layers defined in [RFC3471] Section 3.1 as "Digital
 Wrapper" and "Lambda" code.  The LSP Encoding Type is specified per
 networking layer or, more precisely, per group of functional
 networking layers: the ODUk layers and the OCh layer.
 Therefore, an additional LSP Encoding Type code-point for the G.709
 Digital Path layer is defined; it enlarges the existing "Digital
 Wrapper" code-point defined in [RFC3471].  The former MUST be
 generated when the interface or tunnel on which the traffic will be
 transmitted supports G.709 compliant Digital Path layer encoding.
 The latter MUST only be used for non-G.709 compliant Digital Wrapper
 layer(s) encoding.  A transit or an egress node (receiving a Path
 message containing a GENERALIZED_LABEL_REQUEST object) MUST generate
 a PathErr message, with a "Routing problem/Unsupported Encoding"
 indication, if the requested LSP Encoding Type cannot be supported on
 the corresponding incoming interface.
 In the same way, an additional LSP Encoding Type code-point for the
 G.709 Optical Channel layer is defined; it enlarges the existing
 "Lambda" code-point defined in [RFC3471].  The former MUST be
 generated when the interface or tunnel on which the traffic will be
 transmitted supports G.709-compliant Optical Channel layer encoding.
 The latter MUST only be used for non-G.709 compliant Lambda layer(s)
 encoding.  A transit or an egress node (receiving a Path message that
 contains a GENERALIZED_LABEL_REQUEST object) MUST generate a PathErr
 message with a "Routing problem/Unsupported Encoding" indication, if
 the requested LSP Encoding Type cannot be supported on the
 corresponding incoming interface.

Papadimitriou Standards Track [Page 5] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 Consequently, the following additional code-points for the LSP
 Encoding Type are defined:
      Value           Type
      -----           ----
      12             G.709 ODUk (Digital Path)
      13             G.709 Optical Channel
 Moreover, the code-point for the G.709 Optical Channel (OCh) layer
 will indicate the requested capability of an end-system to use the
 G.709 non-associated overhead (naOH), i.e., the OTM Overhead Signal
 (OOS) multiplexed into the OTM-n.m interface signal.

3.1.2. Switching Type

 The Switching Type indicates the type of switching that should be
 performed at the termination of a particular link (see [RFC4202]).
 No additional Switching Type values are to be considered in order to
 accommodate G.709 switching types, because an ODUk switching (and
 thus LSPs) belongs to the TDM class, while an OCh switching (and thus
 LSPs) belong to the Lambda class (i.e., LSC).
 Intermediate and egress nodes MUST verify that the value indicated in
 the Switching Type field is supported on the corresponding incoming
 interface.  If the requested value can not be supported, the node
 MUST generate a PathErr message with a "Routing problem/Switching
 Type" indication.

3.1.3. Generalized-PID (G-PID)

 The G-PID (16 bits field), as defined in [RFC3471], identifies the
 payload carried by an LSP, i.e., an identifier of the client layer of
 that LSP.  This identifier is used by the endpoints of the G.709 LSP.
 The G-PID can take one of the following values when the client
 payload is transported over the Digital Path layer, in addition to
 the payload identifiers defined in [RFC3471]:
  1. CBRa: asynchronous Constant Bit Rate (i.e., mapping of STM-16/OC-

48, STM-64/OC-192 and STM-256/OC-768)

  1. CBRb: bit synchronous Constant Bit Rate (i.e., mapping of STM-

16/OC-48, STM-64/OC-192 and STM-256/OC-768)

  1. ATM: mapping at 2.5, 10 and 40 Gbps
  2. BSOT: non-specific client Bit Stream with Octet Timing (i.e.,

Mapping of 2.5, 10 and 40 Gbps Bit Stream)

  1. BSNT: non-specific client Bit Stream without Octet Timing (i.e.,

Mapping of 2.5, 10 and 40 Gbps Bit Stream)

Papadimitriou Standards Track [Page 6] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

  1. ODUk: transport of Digital Paths at 2.5, 10 and 40 Gbps
  2. ESCON: Enterprise Systems Connection
  3. FICON: Fiber Connection
 The G-PID can take one of the following values when the client
 payload is transported over the Optical Channel layer, in addition to
 the payload identifiers defined in [RFC3471]:
  1. CBR: Constant Bit Rate (i.e., mapping of STM-16/OC-48, STM-64/OC-

192 and STM-256/OC-768)

  1. OTUk/OTUkV: transport of Digital Section at 2.5, 10 and 40 Gbps
 Also, when client payloads such as Ethernet MAC/PHY and IP/PPP are
 encapsulated through the Generic Framing Procedure (GFP), as
 described in ITU-T G.7041, dedicated G-PID values are defined.
 In order to include pre-OTN developments, the G-PID field can take
 one of the values (currently defined in [RFC3471]) when the following
 client payloads are transported over a so-called lambda LSP:
  1. Ethernet PHY (1 Gbps and 10 Gbps)
  2. Fiber Channel
 The following table summarizes the G-PID with respect to the LSP
 Encoding Type:
 Value     G-PID Type                       LSP Encoding Type
 -----     ----------                       -----------------
  47       G.709 ODUj                       G.709 ODUk (with k > j)
  48       G.709 OTUk(v)                    G.709 OCh
                                            ODUk mapped into OTUk(v)
  49       CBR/CBRa                         G.709 ODUk, G.709 OCh
  50       CBRb                             G.709 ODUk
  51       BSOT                             G.709 ODUk
  52       BSNT                             G.709 ODUk
  53       IP/PPP (GFP)                     G.709 ODUk (and SDH)
  54       Ethernet MAC (framed GFP)        G.709 ODUk (and SDH)
  55       Ethernet PHY (transparent GFP)   G.709 ODUk (and SDH)
  56       ESCON                            G.709 ODUk, Lambda, Fiber
  57       FICON                            G.709 ODUk, Lambda, Fiber
  58       Fiber Channel                    G.709 ODUk, Lambda, Fiber
 Note: Values 49 and 50 include mapping of SDH.

Papadimitriou Standards Track [Page 7] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 The following table summarizes the update of the G-PID values defined
 in [RFC3471]:
 Value     G-PID Type                 LSP Encoding Type
 -----     ----------                 -----------------
  32       ATM Mapping                SDH, G.709 ODUk
  33       Ethernet PHY               SDH, G.709 OCh, Lambda, Fiber
  34       Sonet/SDH                  G.709 OCh, Lambda, Fiber
  35       Reserved (SONET Dep.)      G.709 OCh, Lambda, Fiber

3.2. G.709 Traffic Parameters

 When G.709 Digital Path Layer or G.709 Optical Channel Layer is
 specified in the LSP Encoding Type field, the information referred to
 as technology dependent (or simply traffic parameters) is carried
 additionally to the one included in the Generalized Label Request.
 The G.709 traffic parameters are defined as follows:
    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Signal Type  |   Reserved    |              NMC              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              NVC              |        Multiplier (MT)        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Reserved                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 In this frame, NMC stands for Number of Multiplexed Components, NVC
 for Number of Virtual Components, and MT for Multiplier.  Each of
 these fields is tailored to support G.709 LSP requests.
 The RSVP-TE encoding of the G.709 traffic-parameters is detailed in
 Section 6.

3.2.1. Signal Type (ST)

 This field (8 bits) indicates the type of G.709 Elementary Signal
 that comprises the requested LSP.  The permitted values are:
    Value     Type
    -----     ----
      0       Not significant
      1       ODU1 (i.e., 2.5 Gbps)
      2       ODU2 (i.e., 10  Gbps)
      3       ODU3 (i.e., 40  Gbps)
      4       Reserved (for future use)

Papadimitriou Standards Track [Page 8] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

      5       Reserved (for future use)
      6       OCh at 2.5 Gbps
      7       OCh at 10  Gbps
      8       OCh at 40  Gbps
      9-255   Reserved (for future use)
 The value of the Signal Type field depends on LSP Encoding Type value
 defined in Section 3.1.1 and [RFC3471]:
  1. if the LSP Encoding Type value is the G.709 Digital Path layer,

then the valid values are the ODUk signals (k = 1, 2 or 3).

  1. if the LSP Encoding Type value is the G.709 Optical Channel

layer, then the valid values are the OCh at 2.5, 10, or 40 Gbps.

  1. if the LSP Encoding Type is "Lambda" (which includes the pre-OTN

Optical Channel layer) then the valid value is irrelevant (Signal

     Type = 0).
   - if the LSP Encoding Type is "Digital Wrapper", then the valid
     value is irrelevant (Signal Type = 0).
 Several transforms can be sequentially applied on the Elementary
 Signal to build the Final Signal that is actually requested for the
 LSP.  Each transform application is optional and must be ignored if
 zero; this does not include the Multiplier (MT), which cannot be zero
 and must be ignored if equal to one.  Transforms must be applied
 strictly in the following order:
  1. First, virtual concatenation (by using the NVC field) can be

optionally applied directly on the Elementary Signal to form a

     Composed Signal
   - Second, a multiplication (by using the Multiplier field) can be
     optionally applied, either directly on the Elementary Signal, or
     on the virtually concatenated signal obtained from the first
     phase.  The resulting signal is referred to as Final Signal.

3.2.2. Number of Multiplexed Components (NMC)

 The NMC field (16 bits) indicates the number of ODU tributary slots
 used by an ODUj when multiplexed into an ODUk (k > j) for the
 requested LSP.  This field is not applicable when an ODUk is mapped
 into an OTUk and irrelevant at the Optical Channel layer.  In both
 cases, it MUST be set to zero (NMC = 0) when sent and should be
 ignored when received.
 When applied at the Digital Path layer, in particular for ODU2
 connections multiplexed into one ODU3 payload, the NMC field
 specifies the number of individual tributary slots (NMC = 4) that
 constitute the requested connection.  These components are still
 processed within the context of a single connection entity.  For all

Papadimitriou Standards Track [Page 9] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 other currently defined multiplexing cases (see Section 2), the NMC
 field is set to 1.

3.2.3. Number of Virtual Components (NVC)

 The NVC field (16 bits) is dedicated to ODUk virtual concatenation
 (i.e., ODUk Inverse Multiplexing) purposes.  It indicates the number
 of ODU1, ODU2, or ODU3 Elementary Signals that are requested to be
 virtually concatenated to form an ODUk-Xv signal.  By definition,
 these signals MUST be of the same type.
 This field is set to 0 (default value) to indicate that no virtual
 concatenation is requested.
 Note that the current usage of this field only applies for G.709 ODUk
 LSPs, i.e., values greater than zero, are only acceptable for ODUk
 Signal Types.  Therefore, it MUST be set to zero (NVC = 0), and
 should be ignored when received, when a G.709 OCh LSP is requested.

3.2.4. Multiplier (MT)

 The Multiplier field (16 bits) indicates the number of identical
 Elementary Signals or Composed Signals that are requested for the
 LSP, i.e., that form the Final Signal.  A Composed Signal is the
 resulting signal from the application of the NMC and NVC fields to an
 elementary Signal Type.  GMPLS signaling currently implies that all
 the Composed Signals must be part of the same LSP.
 This field is set to one (default value) to indicate that exactly one
 instance of a signal is being requested.  Intermediate and egress
 nodes MUST verify that the node itself and the interfaces on which
 the LSP will be established can support the requested multiplier
 value.  If the requested values cannot be supported, the receiver
 node MUST generate a PathErr message (see Section 6).
 Zero is an invalid value for the MT field.  If received, the node
 MUST generate a PathErr message (see Section 6).

3.2.5. Reserved Fields

 The reserved fields (8 bits in row 1 and 32 bits in row 3) are
 dedicated for future use.  Reserved bits SHOULD be set to zero when
 sent and MUST be ignored when received.

4. Generalized Label

 This section describes the Generalized Label value space for Digital
 Paths and Optical Channels.  The Generalized Label is defined in

Papadimitriou Standards Track [Page 10] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 [RFC3471].  The format of the corresponding RSVP-TE GENERALIZED_LABEL
 object is specified in [RFC3473] Section 2.3.
 The label distribution rules detailed in Section 4.2 follow (when
 applicable) the ones defined in [RFC3946].

4.1. ODUk Label Space

 At the Digital Path layer (i.e., ODUk layers), G.709 defines three
 different client payload bit rates.  An Optical Data Unit (ODU) frame
 has been defined for each of these bit rates.  ODUk refers to the
 frame at bit rate k, where k = 1 (for 2.5 Gbps), 2 (for 10 Gbps), or
 3 (for 40 Gbps).
 In addition to the support of ODUk mapping into OTUk, the G.709
 label space supports the sub-levels of ODUk multiplexing.  ODUk
 multiplexing refers to multiplexing of ODUj (j = 1, 2) into an ODUk
 (k > j), in particular:
  1. ODU1 into ODU2 multiplexing
  2. ODU1 into ODU3 multiplexing
  3. ODU2 into ODU3 multiplexing
  4. ODU1 and ODU2 into ODU3 multiplexing
 More precisely, ODUj into ODUk multiplexing (k > j) is defined when
 an ODUj is multiplexed into an ODUk Tributary Unit Group (i.e., an
 ODTUG constituted by ODU tributary slots) that is mapped into an
 OPUk.  The resulting OPUk is mapped into an ODUk, and the ODUk is
 mapped into an OTUk.
 Therefore, the label space structure is a tree whose root is an OTUk
 signal and whose leaves are the ODUj signals (k >= j) that can be
 transported via the tributary slots and switched between these slots.
 A G.709 Digital Path layer label identifies the exact position of a
 particular ODUj signal in an ODUk multiplexing structure.
 The G.709 Digital Path Layer label or ODUk label 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
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                   Reserved                |     t3    | t2  |t1|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Reserved bits MUST be set to zero when sent and SHOULD be ignored
 when received.

Papadimitriou Standards Track [Page 11] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 The specification of the fields t1, t2, and t3 self-consistently
 characterizes the ODUk label space.  The value space for the t1, t2,
 and t3 fields is defined as follows:
 1. t1 (1-bit):
      - t1=1 indicates an ODU1 signal.
      - t1 is not significant for the other ODUk signal types (i.e.,
        t1 value MUST be set to 0 and ignored).
 2. t2 (3-bit):
      - t2=1 indicates an ODU2 signal that is not further sub-
        divided.
      - t2=[2..5] indicates the tributary slot (t2th-2) used by the
        ODU1 in an ODTUG2 mapped into an ODU2 (via OPU2).
      - t2 is not significant for an ODU3 (i.e., t2 value MUST be
        set to 0 and ignored).
 3. t3 (6-bit):
      - t3=1 indicates an ODU3 signal that is not further sub-
        divided.
      - t3=[2..17] indicates the tributary slot (t3th-1) used by the
        ODU1 in an ODTUG3 mapped into an ODU3 (via OPU3).
      - t3=[18..33] indicates the tributary slot (t3th-17) used by
        the ODU2 in an ODTUG3 mapped into an ODU3 (via OPU3).
 Note: in case of ODU2 into ODU3 multiplexing, 4 labels are required
 to identify the 4 tributary slots used by the ODU2; these tributary
 time slots have to be allocated in ascending order.
 If the label sub-field value t[i]=1 (i, j = 1, 2 or 3) and t[j]=0 (j
 > i), the corresponding ODUk signal ODU[i] is directly mapped into
 the corresponding OTUk signal (k=i).  This is referred to as the
 mapping of an ODUk signal into an OTUk of the same order.  Therefore,
 the numbering starts at 1; zero is used to indicate a non-significant
 field.  A label field equal to zero is an invalid value.
 Examples:
  1. t3=0, t2=0, t1=1 indicates an ODU1 mapped into an OTU1
  2. t3=0, t2=1, t1=0 indicates an ODU2 mapped into an OTU2
  3. t3=1, t2=0, t1=0 indicates an ODU3 mapped into an OTU3
  4. t3=0, t2=3, t1=0 indicates the ODU1 in the second tributary slot

of the ODTUG2 mapped into an ODU2 (via OPU2) mapped into an OTU2

  1. t3=5, t2=0, t1=0 indicates the ODU1 in the fourth tributary slot

of the ODTUG3 mapped into an ODU3 (via OPU3) mapped into an OTU3

Papadimitriou Standards Track [Page 12] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

4.2. Label Distribution Rules

 In case of ODUk in OTUk mapping, only one label can appear in the
 Generalized Label.  The unique label is encoded as a single 32-bit
 label value (as defined in Section 4.1) of the GENERALIZED_LABEL
 object (Class-Num = 16, C-Type = 2).
 In case of ODUj in ODUk (k > j) multiplexing, the explicit ordered
 list of the labels in the multiplex is given (this list can be
 restricted to only one label when NMC = 1).  Each label indicates a
 component (ODUj tributary slot) of the multiplexed signal.  The order
 of the labels must reflect the order of the ODUj into the multiplex
 (not the physical order of tributary slots).  This ordered list of
 labels is encoded as a sequence of 32-bit label values (as defined in
 Section 4.1) of the GENERALIZED_LABEL object (Class-Num = 16, C-Type
 = 2).
 In case of ODUk virtual concatenation, the explicit ordered list of
 all labels in the concatenation is given.  Each label indicates a
 component of the virtually concatenated signal.  The order of the
 labels must reflect the order of the ODUk to concatenate (not the
 physical order of time-slots).  This representation limits virtual
 concatenation to remain within a single (component) link.  In case of
 multiplexed virtually concatenated signals, the first set of labels
 indicates the components (ODUj tributary slots) of the first
 virtually concatenated signal, the second set of labels indicates the
 components (ODUj tributary slots) of the second virtually
 concatenated signal, and so on.  This ordered list of labels is
 encoded as a sequence of 32-bit label values (as defined in Section
 4.1) of the GENERALIZED_LABEL object (Class-Num = 16, C-Type = 2).
 In case of ODUk virtual concatenation, the number of label values is
 determined by the NVC value.  Multiplexed ODUk virtual concatenation
 additionally uses the NMC value to determine the number of labels per
 set (equal in size).
 In case of multiplication (i.e., when using the MT field), the
 explicit ordered list of all labels taking part in the composed
 signal is given.  The above representation limits multiplication to
 remain within a single (component) link.  In case of multiplication
 of multiplexed virtually concatenated signals, the first set of
 labels indicates the components of the first multiplexed virtually
 concatenated signal, the second set of labels indicates components of
 the second multiplexed virtually concatenated signal, and so on.
 This ordered list of labels is encoded as a sequence of 32-bit label
 values (as defined in Section 4.1) of the GENERALIZED_LABEL object
 (Class-Num = 16, C-Type = 2).  In case of multiplication of (equal)
 ODUk virtual concatenated signals, the number of label values per
 signal is determined by the NVC value.  Multiplication of multiplexed

Papadimitriou Standards Track [Page 13] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 (equal) ODUk virtual concatenation additionally uses the NMC value to
 determine the number of labels per set (equal in size).

4.3. Optical Channel Label Space

 At the Optical Channel layer, the label space must be consistently
 defined as a flat space whose values reflect the local assignment of
 OCh identifiers that correspond to the OTM-n.m sub-interface signals
 (m = 1, 2 or 3).  Note that these identifiers do not cover OChr
 because the corresponding Connection Function (OChr-CF) between OTM-
 nr.m/OTM-0r.m is not defined in [ITUT-G798].
 The OCh label space values are defined by either absolute values
 (i.e., channel identifiers or Channel ID, also referred to as
 wavelength identifiers) or relative values (channel spacing, also
 referred to as inter-wavelength spacing).  The latter is strictly
 confined to a per-port label space, whereas the former could be
 defined as a local or a global (per node) label space.  Such an OCh
 label space is applicable to both OTN Optical Channel layer and pre-
 OTN Optical Channel layer.
 Optical Channel label encoding (and distribution) rules are defined
 in [RFC3471].  They MUST be used for the Upstream Label, the
 Suggested Label, and the Generalized Label.

5. Examples

 The following examples are given in order to illustrate the
 processing described in the previous sections of this document.
 1. ODUk in OTUk mapping: when one ODU1 (ODU2 or ODU3) signal is
    directly transported in an OTU1 (OTU2 or OTU3), the upstream node
    requests results simply in an ODU1 (ODU2 or ODU3) signal request.
    In such conditions, the downstream node has to return a unique
    label because the ODU1 (ODU2 or ODU3) is directly mapped into the
    corresponding OTU1 (OTU2 or OTU3).  Because a single ODUk signal
    is requested (Signal Type = 1, 2 or 3), the downstream node has to
    return a single ODUk label, which can be, for instance, one of the
    following when the Signal Type = 1:
  1. t3=0, t2=0, t1=1 indicating a single ODU1 mapped into an OTU1
  2. t3=0, t2=1, t1=0 indicating a single ODU2 mapped into an OTU2
  3. t3=1, t2=0, t1=0 indicating a single ODU3 mapped into an OTU3
 2. ODU1 into ODUk multiplexing (k > 1): when one ODU1 is multiplexed
    into the payload of a structured ODU2 (or ODU3), the upstream node
    requests results simply in an ODU1 signal request.

Papadimitriou Standards Track [Page 14] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

    In such conditions, the downstream node has to return a unique
    label because the ODU1 is multiplexed into one ODTUG2 (or ODTUG3).
    The latter is then mapped into the ODU2 (or ODU3) via OPU2 (or
    OPU3) and then mapped into the corresponding OTU2 (or OTU3).
    Because a single ODU1 multiplexed signal is requested (Signal Type
    = 1 and NMC = 1), the downstream node has to return a single ODU1
    label, which can take, for instance, one of the following values:
  1. t3=0,t2=4,t1=0 indicates the ODU1 in the third TS of the ODTUG2
  2. t3=2,t2=0,t1=0 indicates the ODU1 in the first TS of the ODTUG3
  3. t3=7,t2=0,t1=0 indicates the ODU1 in the sixth TS of the ODTUG3
 3. ODU2 into ODU3 multiplexing: when one unstructured ODU2 is
    multiplexed into the payload of a structured ODU3, the upstream
    node requests results simply in an ODU2 signal request.
    In such conditions, the downstream node has to return four labels
    since the ODU2 is multiplexed into one ODTUG3.  The latter is
    mapped into an ODU3 (via OPU3) and then mapped into an OTU3.
    Since an ODU2 multiplexed signal is requested (Signal Type = 2,
    and NMC = 4), the downstream node has to return four ODU labels
    which can take for instance the following values:
  1. t3=18, t2=0, t1=0 (first part of ODU2 in first TS of ODTUG3)
  2. t3=22, t2=0, t1=0 (second part of ODU2 in fifth TS of ODTUG3)
  3. t3=23, t2=0, t1=0 (third part of ODU2 in sixth TS of ODTUG3)
  4. t3=26, t2=0, t1=0 (fourth part of ODU2 in ninth TS of ODTUG3)
 4. When a single OCh signal of 40 Gbps is requested (Signal Type =
    8), the downstream node must return a single wavelength label as
    specified in [RFC3471].
 5. When requesting multiple ODUk LSP (i.e., with a multiplier (MT)
    value > 1), an explicit list of labels is returned to the
    requestor node.
    When the downstream node receives a request for a 4 x ODU1 signal
    (Signal Type = 1, NMC = 1 and MT = 4) multiplexed into an ODU3, it
    returns an ordered list of four labels to the upstream node: the
    first ODU1 label corresponds to the first signal of the LSP, the
    second ODU1 label corresponds to the second signal of the LSP,
    etc.  For instance, the corresponding labels can take the
    following values:
  1. First ODU1: t3=2, t2=0, t1=0 (in first TS of ODTUG3)
  2. Second ODU1: t3=10, t2=0, t1=0 (in ninth TS of ODTUG3)
  3. Third ODU1: t3=7, t2=0, t1=0 (in sixth TS of ODTUG3)
  4. Fourth ODU1: t3=6, t2=0, t1=0 (in fifth TS of ODTUG3)

Papadimitriou Standards Track [Page 15] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

6. RSVP-TE Signaling Protocol Extensions

 This section specifies the [RFC3473] protocol extensions needed to
 accommodate G.709 traffic parameters.
 The G.709 traffic parameters are carried in the G.709 SENDER_TSPEC
 and FLOWSPEC objects.  The same format is used both for SENDER_TSPEC
 object and FLOWSPEC objects.  The content of the objects is defined
 above in Section 3.2. The objects have the following class and type
 for G.709:
  1. G.709 SENDER_TSPEC Object: Class = 12, C-Type = 5
  2. G.709 FLOWSPEC Object: Class = 9, C-Type = 5
 There is no Adspec associated with the G.709 SENDER_TSPEC.  Either
 the Adspec is omitted or an Int-serv Adspec with the Default General
 Characterization Parameters and Guaranteed Service fragment is used,
 see [RFC2210].
 For a particular sender in a session, the contents of the FLOWSPEC
 object received in a Resv message SHOULD be identical to the contents
 of the SENDER_TSPEC object received in the corresponding Path
 message.  If the objects do not match, a ResvErr message with a
 "Traffic Control Error/Bad Flowspec value" error SHOULD be generated.
 Intermediate and egress nodes MUST verify that the node itself, and
 the interfaces on which the LSP will be established, can support the
 requested Signal Type, NMC, and NVC values (as defined in Section
 3.2).  If the requested value(s) cannot be supported, the receiver
 node MUST generate a PathErr message with a "Traffic Control
 Error/Service unsupported" indication (see [RFC2205]).
 In addition, if the MT field is received with a zero value, the node
 MUST generate a PathErr message with a "Traffic Control Error/Bad
 Tspec value" indication (see [RFC2205]).

7. Security Considerations

 This document introduces no new security considerations to [RFC3473].

8. IANA Considerations

 Two values have been defined by IANA for this document:
 Two RSVP C-Types in registry:
           http://www.iana.org/assignments/rsvp-parameters

Papadimitriou Standards Track [Page 16] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

  1. A G.709 SENDER_TSPEC object: Class = 12, C-Type = 5 - see

Section 6.

  1. A G.709 FLOWSPEC object: Class = 9, C-Type = 5 - see

Section 6.

 IANA will also track the code-point spaces extended and/or updated by
 this document.  For this purpose, the following new registry entries
 have been added in the newly requested registry entry:
 http://www.iana.org/assignments/gmpls-sig-parameters
  1. LSP Encoding Type:

Name: LSP Encoding Type

   Format: 8-bit number
   Values:
      [1..11]         defined in [RFC3471]
      12              defined in Section 3.1.1
      13              defined in Section 3.1.1
   Allocation Policy:
      [0..239]        Assigned by IANA via IETF Standards Track RFC
                      Action.
      [240..255]      Assigned temporarily for Experimental Usage.
                      These will not be registered with IANA
  1. Switching Type:

Name: Switching Type

   Format: 8-bit number
   Values: defined in [RFC3471]
   Allocation Policy:
      [0..255]        Assigned by IANA via IETF Standards Track RFC
                      Action.
  1. Generalized PID (G-PID):

Name: G-PID

   Format: 16-bit number
   Values:
      [0..31]         defined in [RFC3471]
      [32..35]        defined in [RFC3471] and updated by Section
                      3.1.3
      [36..46]        defined in [RFC3471]
      [47..58]        defined in Section 3.1.3
   Allocation Policy:
      [0..31743]      Assigned by IANA via IETF Standards Track RFC
                      Action.
      [31744..32767]  Assigned temporarily for Experimental Usage

Papadimitriou Standards Track [Page 17] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

      [32768..65535]  Not assigned.  Before any assignments can be
                      made in this range, there MUST be a Standards
                      Track RFC that specifies IANA Considerations
                      that covers the range being assigned.
 Note: per [RFC3471], Section 3.1.1, standard Ethertype values are
 used as G-PIDs for packet and Ethernet LSPs.

9. Acknowledgements

 The authors would like to thank Jean-Loup Ferrant, Mathieu Garnot,
 Massimo Canali, Germano Gasparini, and Fong Liaw for their
 constructive comments and inputs as well as James Fu, Siva
 Sankaranarayanan, and Yangguang Xu for their useful feedback.  Many
 thanks to Adrian Farrel for having thoroughly reviewed this document.
 This document incorporates (upon agreement) material and ideas from a
 work in progress, "Common Label and Label Request Specification for
 Automatic Switched Transport Network", by Zhi Lin.

10. References

10.1. Normative References

 [RFC2119]    Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC2205]    Braden, R., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version
              1 Functional Specification", RFC 2205, September 1997.
 [RFC2210]    Wroclawski, J., "The Use of RSVP with IETF Integrated
              Services", RFC 2210, September 1997.
 [RFC3471]    Berger, L., "Generalized Multi-Protocol Label Switching
              (GMPLS) Signaling Functional Description", RFC 3471,
              January 2003.
 [RFC3473]    Berger, L., "Generalized Multi-Protocol Label Switching
              (GMPLS) Signaling Resource ReserVation Protocol-Traffic
              Engineering (RSVP-TE) Extensions", RFC 3473, January
              2003.
 [RFC3946]    Mannie, E. and D. Papadimitriou, "Generalized Multi-
              Protocol Label Switching (GMPLS) Extensions for
              Synchronous Optical Network (SONET) and Synchronous
              Digital Hierarchy (SDH) Control", RFC 3946, October
              2004.

Papadimitriou Standards Track [Page 18] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 [RFC4202]    Kompella, K., Ed. and Y. Rekhter, Ed., "Routing
              Extensions in Support of Generalized Multi-Protocol
              Label Switching (GMPLS)", RFC 4202, September 2005.

10.2. Informative References

 [RFC3945]    Mannie, E., "Generalized Multi-Protocol Label Switching
              (GMPLS) Architecture", RFC 3945, October 2004.
 For information on the availability of the following documents,
 please see http://www.itu.int
 [ITUT-G709]  ITU-T, "Interface for the Optical Transport Network
              (OTN)," G.709 Recommendation (and Amendment 1), February
              2001 (October 2001).
 [ITUT-G798]  ITU-T, "Characteristics of Optical Transport Network
              Hierarchy Equipment Functional Blocks," G.798
              Recommendation, October 2001.

11. Contributors

 Alberto Bellato (Alcatel)
 Via Trento 30,
 I-20059 Vimercate, Italy
 EMail: alberto.bellato@alcatel.it
 Sudheer Dharanikota (Consult)
 EMail: sudheer@ieee.org
 Michele Fontana (Alcatel)
 Via Trento 30,
 I-20059 Vimercate, Italy
 EMail: michele.fontana@alcatel.it
 Nasir Ghani (Sorrento Networks)
 9990 Mesa Rim Road,
 San Diego, CA 92121, USA
 EMail: nghani@sorrentonet.com
 Gert Grammel (Alcatel)
 Lorenzstrasse, 10,
 70435 Stuttgart, Germany
 EMail: gert.grammel@alcatel.de

Papadimitriou Standards Track [Page 19] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

 Dan Guo (Turin Networks)
 1415 N. McDowell Blvd,
 Petaluma, CA 94954, USA
 EMail: dguo@turinnetworks.com
 Juergen Heiles (Siemens)
 Hofmannstr. 51,
 D-81379 Munich, Germany
 EMail: juergen.heiles@siemens.com
 Jim Jones (Alcatel)
 3400 W. Plano Parkway,
 Plano, TX 75075, USA
 EMail: jim.d.jones@alcatel.com
 Zhi-Wei Lin (Lucent)
 101 Crawfords Corner Rd, Rm 3C-512
 Holmdel, New Jersey 07733-3030, USA
 EMail: zwlin@lucent.com
 Eric Mannie (Consult)
 EMail: eric_mannie@hotmail.com
 Maarten Vissers (Alcatel)
 Lorenzstrasse, 10,
 70435 Stuttgart, Germany
 EMail: maarten.vissers@alcalel.de
 Yong Xue (WorldCom)
 22001 Loudoun County Parkway,
 Ashburn, VA 20147, USA
 EMail: yong.xue@wcom.com

Papadimitriou Standards Track [Page 20] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

Appendix A. Abbreviations

 BSNT         Bit Stream without Octet Timing
 BSOT         Bit Stream with Octet Timing
 CBR          Constant Bit Rate
 ESCON        Enterprise Systems Connection
 FC           Fiber Channel
 FEC          Forward Error Correction
 FICON        Fiber Connection
 FSC          Fiber Switch Capable
 GCC          General Communication Channel
 GFP          Generic Framing Procedure
 LSC          Lambda Switch Capable
 LSP          Label Switched Path
 MS           Multiplex Section
 naOH         non-associated Overhead
 NMC          Number of Multiplexed Components
 NVC          Number of Virtual Components
 OCC          Optical Channel Carrier
 OCG          Optical Carrier Group
 OCh          Optical Channel (with full functionality)
 OChr         Optical Channel (with reduced functionality)
 ODTUG        Optical Date Tributary Unit Group
 ODU          Optical Channel Data Unit
 OH           Overhead
 OMS          Optical Multiplex Section
 OMU          Optical Multiplex Unit
 OOS          OTM Overhead Signal
 OPS          Optical Physical Section
 OPU          Optical Channel Payload Unit
 OSC          Optical Supervisory Channel
 OTH          Optical Transport Hierarchy
 OTM          Optical Transport Module
 OTN          Optical Transport Network
 OTS          Optical Transmission Section
 OTU          Optical Channel Transport Unit
 OTUkV        Functionally Standardized OTUk
 PPP          Point to Point Protocol
 PSC          Packet Switch Capable
 RES          Reserved
 RS           Regenerator Section
 TTI          Trail Trace Identifier
 TDM          Time Division Multiplex

Papadimitriou Standards Track [Page 21] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

Appendix B. G.709 Indexes

  1. Index k: The index "k" is used to represent a supported bit rate

and the different versions of OPUk, ODUk and OTUk. k=1 represents an

 approximate bit rate of 2.5 Gbit/s, k=2 represents an approximate bit
 rate of 10 Gbit/s, k = 3 an approximate bit rate of 40 Gbit/s and k =
 4 an approximate bit rate of 160 Gbit/s (under definition).  The
 exact bit-rate values are in kbits/s:
  . OPU: k=1: 2 488 320.000, k=2:  9 995 276.962, k=3: 40 150 519.322
  . ODU: k=1: 2 498 775.126, k=2: 10 037 273.924, k=3: 40 319 218.983
  . OTU: k=1: 2 666 057.143, k=2: 10 709 225.316, k=3: 43 018 413.559
  1. Index m: The index "m" is used to represent the bit rate or set of

bit rates supported on the interface. This is a one or more digit

 "k", where each "k" represents a particular bit rate.  The valid
 values for m are (1, 2, 3, 12, 23, 123).
  1. Index n: The index "n" is used to represent the order of the OTM,

OTS, OMS, OPS, OCG and OMU. This index represents the maximum number

 of wavelengths that can be supported at the lowest bit rate supported
 on the wavelength.  It is possible that a reduced number of higher
 bit rate wavelengths are supported.  The case n=0 represents a single
 channel without a specific wavelength assigned to the channel.
  1. Index r: The index "r", if present, is used to indicate a reduced

functionality OTM, OCG, OCC and OCh (non-associated overhead is not

 supported).  Note that for n=0 the index r is not required as it
 implies always reduced functionality.

Editor's Address

 Dimitri Papadimitriou (Alcatel)
 Francis Wellesplein 1,
 B-2018 Antwerpen, Belgium
 Phone: +32 3 240-8491
 EMail: dimitri.papadimitriou@alcatel.be

Papadimitriou Standards Track [Page 22] RFC 4328 GMPLS Signaling Extensions for G.709 January 2006

Full Copyright Statement

 Copyright (C) The Internet Society (2006).
 This document is subject to the rights, licenses and restrictions
 contained in BCP 78, and except as set forth therein, the authors
 retain all their rights.
 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

 The IETF takes no position regarding the validity or scope of any
 Intellectual Property Rights or other rights that might be claimed to
 pertain to the implementation or use of the technology described in
 this document or the extent to which any license under such rights
 might or might not be available; nor does it represent that it has
 made any independent effort to identify any such rights.  Information
 on the procedures with respect to rights in RFC documents can be
 found in BCP 78 and BCP 79.
 Copies of IPR disclosures made to the IETF Secretariat and any
 assurances of licenses to be made available, or the result of an
 attempt made to obtain a general license or permission for the use of
 such proprietary rights by implementers or users of this
 specification can be obtained from the IETF on-line IPR repository at
 http://www.ietf.org/ipr.
 The IETF invites any interested party to bring to its attention any
 copyrights, patents or patent applications, or other proprietary
 rights that may cover technology that may be required to implement
 this standard.  Please address the information to the IETF at
 ietf-ipr@ietf.org.

Acknowledgement

 Funding for the RFC Editor function is provided by the IETF
 Administrative Support Activity (IASA).

Papadimitriou Standards Track [Page 23]

/data/webs/external/dokuwiki/data/pages/rfc/rfc4328.txt · Last modified: 2006/01/06 23:55 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki