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Versions: 00 01 02 03 04 05 06 07 08 RFC 3946

   CCAMP Working Group              Eric Mannie (Consulting) - Editor
   Internet Draft                 D. Papadimitriou (Alcatel) - Editor

   Expiration Date: August 2003                         February 2003





         Generalized Multi-Protocol Label Switching Extensions for
                           SONET and SDH Control


                 draft-ietf-ccamp-gmpls-sonet-sdh-08.txt




Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.  Internet-Drafts are
   working documents of the Internet Engineering Task Force (IETF),
   its areas, and its working groups.  Note that other groups may
   also distribute working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other
   documents at any time. It is inappropriate to use Internet-Drafts
   as reference material or to cite them other than as "work in
   progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html



Abstract

   This document is a companion to the Generalized Multi-Protocol
   Label Switching (GMPLS) signaling. It defines the Synchronous
   Optical Network (SONET)/Synchronous Digital Hierarchy (SDH)
   technology specific information needed when using GMPLS signaling.









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1. Introduction

   As described in [GMPLS-ARCH], Generalized MPLS (GMPLS) extends
   MPLS from supporting packet (Packet Switching Capable - PSC)
   interfaces and switching to include support of four new classes of
   interfaces and switching: Layer-2 Switch Capable (L2SC), Time-
   Division Multiplex (TDM), Lambda Switch Capable (LSC) and Fiber-
   Switch Capable (FSC). A functional description of the extensions
   to MPLS signaling needed to support the new classes of interfaces
   and switching is provided in [RFC3471]. [RFC3473] describes RSVP-
   TE specific formats and mechanisms needed to support all five
   classes of interfaces, and CR-LDP extensions can be found in
   [RFC3472]. This document presents details that are specific to
   Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy
   (SDH). Per [RFC3471], SONET/SDH specific parameters are carried in
   the signaling protocol in traffic parameter specific objects.

   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].

   Moreover, the reader is assumed to be familiar with the terminology
   in ANSI [T1.105], ITU-T [G.707] as well as [RFC3471], [RFC3472] and
   [RFC3473]. The following abbreviations are used in this document:

     DCC: Data Communications Channel.
     LOVC: Lower Order Virtual Container
     HOVC: Higher Order Virtual Container
     MS: Multiplex Section.
     MSOH: Multiplex Section overhead.
     POH: Path overhead.
     RS: Regenerator Section.
     RSOH: Regenerator section overhead.
     SDH: Synchronous digital hierarchy.
     SOH: Section overhead.
     SONET: Synchronous Optical Network.
     SPE: Synchronous Payload Envelope.
     STM(-N): Synchronous Transport Module (-N) (SDH).
     STS(-N): Synchronous Transport Signal-Level N (SONET).
     VC-n: Virtual Container-n (SDH).
     VTn: Virtual Tributary-n (SONET).

2. SONET and SDH Traffic Parameters

   This section defines the GMPLS traffic parameters for SONET/SDH.
   The protocol specific formats, for the SONET/SDH-specific RSVP-TE
   objects and CR-LDP TLVs are described in sections 2.2 and 2.3
   respectively.

   These traffic parameters specify indeed a base set of capabilities
   for SONET ANSI [T1.105] and SDH ITU-T [G.707] such as
   concatenation and transparency. Other documents may further
   enhance this set of capabilities in the future. For instance,

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   signaling for SDH over PDH ITU-T G.832 or sub-STM-0 ITU-T G.708
   interfaces could be defined.

   The traffic parameters defined hereafter (see Section 2.1) MUST be
   used when the label is encoded as SUKLM as defined in this memo
   (see Section 3). They MUST also be used when requesting one of
   Section/RS or Line/MS overhead transparent STS-1/STM-0/STS-
   3*N/STM-N (N=1, 4, 16, 64, 256) signals.

   The traffic parameters and label encoding defined in [RFC3471]
   Section 3.2 MUST be used for fully transparent STS-1/STM-0/STS-
   3*N/STM-N (N=1, 4, 16, 64, 256) signal requests. A fully
   transparent signal is one for which all overhead is left
   unmodified by intermediate nodes, i.e., when all defined
   Transparency (T) bits would be set if the traffic parameters
   defined in section 2.1 were used.

2.1. SONET/SDH Traffic Parameters

   The traffic parameters for SONET/SDH are organized 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  |      RCC      |              NCC              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              NVC              |        Multiplier (MT)        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Transparency (T)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Profile (P)                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Annex 1 lists examples of SONET and SDH signal coding.

   Signal Type (ST): 8 bits

     This field indicates the type of Elementary Signal that
     comprises the requested LSP. Several transforms can be applied
     successively on the Elementary Signal to build the Final Signal
     being actually requested for the LSP.

     Each transform application is optional and must be ignored if
     zero, except the Multiplier (MT) that cannot be zero and is
     ignored if equal to one.

     Transforms must be applied strictly in the following order:

      - First, contiguous concatenation (by using the RCC and NCC
        fields) can be optionally applied on the Elementary Signal,
        resulting in a contiguously concatenated signal.
      - Second, virtual concatenation (by using the NVC field) can
        be optionally applied on the Elementary Signal resulting in
        a virtually concatenated signal.

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      - Third, some transparency (by using the Transparency field)
        can be optionally specified when requesting a frame as
        signal rather than an SPE or VC based signal.
      - Fourth, a multiplication (by using the Multiplier field) can be
        optionally applied either directly on the Elementary Signal, or
        on the contiguously concatenated signal obtained from the first
        phase, or on the virtually concatenated signal obtained from
        the second phase, or on these signals combined with some
        transparency.

   Permitted Signal Type values for SONET/SDH are:

       Value  Type (Elementary Signal)
       -----  ------------------------
        1     VT1.5  SPE / VC-11
        2     VT2    SPE / VC-12
        3     VT3    SPE
        4     VT6    SPE / VC-2
        5     STS-1  SPE / VC-3
        6     STS-3c SPE / VC-4
        7     STS-1      / STM-0   (only when requesting transparency)
        8     STS-3      / STM-1   (only when requesting transparency)
        9     STS-12     / STM-4   (only when requesting transparency)
        10    STS-48     / STM-16  (only when requesting transparency)
        11    STS-192    / STM-64  (only when requesting transparency)
        12    STS-768    / STM-256 (only when requesting transparency)

     A dedicated signal type is assigned to a SONET STS-3c SPE instead
     of coding it as a contiguous concatenation of three STS-1 SPEs.
     This is done in order to provide easy interworking between SONET
     and SDH signaling.

     Appendix 1 adds one signal type (optional) to the above values.

   Requested Contiguous Concatenation (RCC): 8 bits

     This field is used to request the optional SONET/SDH contiguous
     concatenation of the Elementary Signal.

     This field is a vector of flags. Each flag indicates the
     support of a particular type of contiguous concatenation.
     Several flags can be set at the same time to indicate a choice.

     These flags allow an upstream node to indicate to a downstream
     node the different types of contiguous concatenation that it
     supports. However, the downstream node decides which one to use
     according to its own rules.

     A downstream node receiving simultaneously more than one flag
     chooses a particular type of contiguous concatenation, if any
     supported, and based on criteria that are out of this document
     scope. A downstream node that doesnÆt support any of the
     concatenation types indicated by the field must refuse the LSP


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     request. In particular, it must refuse the LSP request if it
     doesnÆt support contiguous concatenation at all.

     When several flags have been set, the upstream node retrieves
     the (single) type of contiguous concatenation the downstream
     node has selected by looking at the position indicated by the
     first label and the number of label(s) as returned by the
     downstream node (see also Section 3).

     The entire field is set to zero to indicate that no contiguous
     concatenation is requested at all (default value). A non-zero
     field indicates that some contiguous concatenation is
     requested.

     The following flag is defined:

         Flag 1 (bit 1): Standard contiguous concatenation.

     Flag 1 indicates that the standard SONET/SDH contiguous
     concatenation as defined in [T1.105]/[G.707] is supported. Note
     that bit 1 is the low order bit. Other flags are reserved for
     extensions, if not used they must be set to zero when sent, and
     should be ignored when received.

     See note 1 hereafter in the section on the NCC about the SONET
     contiguous concatenation of STS-1 SPEs when the number of
     components is a multiple of three.

   Number of Contiguous Components (NCC): 16 bits

     This field indicates the number of identical SONET SPEs/SDH VCs
     (i.e. Elementary Signal) that are requested to be concatenated,
     as specified in the RCC field.

     Note 1: when requesting a SONET STS-Nc SPE with N=3*X, the
     Elementary Signal to use must always be an STS-3c_SPE signal
     type and the value of NCC must always be equal to X. This
     allows also facilitating the interworking between SONET and
     SDH. In particular, it means that the contiguous concatenation
     of three STS-1 SPEs can not be requested because according to
     this specification, this type of signal must be coded using the
     STS-3c SPE signal type.

     Note 2: when requesting a transparent STS-N/STM-N signal
     limited to a single contiguously concatenated STS-Nc_SPE/VC-4-
     Nc, the signal type must be STS-N/STM-N, RCC with flag 1 and
     NCC set to 1.

     The NCC value must be consistent with the type of contiguous
     concatenation being requested in the RCC field. In particular,
     this field is irrelevant if no contiguous concatenation is
     requested (RCC = 0), in that case it must be set to zero when
     sent, and should be ignored when received. A RCC value


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     different from 0 must imply a number of contiguous components
     greater than 1.

   Number of Virtual Components (NVC): 16 bits

     This field indicates the number of signals that are requested
     to be virtually concatenated. These signals are all of the same
     type by definition. They are Elementary Signal SPEs/VCs for
     which signal types are defined in this document, i.e.
     VT1.5_SPE/VC-11, VT2_SPE/VC-12, VT3_SPE, VT6_SPE/VC-2, STS-
     1_SPE/VC-3 or STS-3c_SPE/VC-4.

     This field is set to 0 (default value) to indicate that no
     virtual concatenation is requested.

   Multiplier (MT): 16 bits

     This field indicates the number of identical signals that are
     requested for the LSP, i.e. that form the Final Signal. These
     signals can be either identical Elementary Signals, or
     identical contiguously concatenated signals, or identical
     virtually concatenated signals. Note that all these signals
     belong thus to the same LSP.

     The distinction between the components of multiple virtually
     concatenated signals is done via the order of the labels that
     are specified in the signaling. The first set of labels must
     describe the first component (set of individual signals
     belonging to the first virtual concatenated signal), the second
     set must describe the second component (set of individual
     signals belonging to the second virtual concatenated signal)
     and so on.

     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 can not be supported,
     the receiver node MUST generate a PathErr/NOTIFICATION message
     (see Section 2.2/2.3, respectively).

     Zero is an invalid value. If received, the node MUST generate a
     PathErr/NOTIFICATION message (see Section 2.2/2.3, respectively).

     Note 1: when requesting a transparent STS-N/STM-N signal limited
     to a single contiguously concatenated STS-Nc-SPE/VC-4-Nc, the
     multiplier field MUST be equal to 1 (only valid value).

   Transparency (T): 32 bits

     This field is a vector of flags that indicates the type of
     transparency being requested. Several flags can be combined to
     provide different types of transparency. Not all combinations


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     are necessarily valid. The default value for this field is
     zero, i.e. no transparency requested.

     Transparency, as defined from the point of view of this
     signaling specification, is only applicable to the fields in
     the SONET/SDH frame overheads. In the SONET case, these are the
     fields in the Section Overhead (SOH), and the Line Overhead
     (LOH). In the SDH case, these are the fields in the Regenerator
     Section Overhead (RSOH), the Multiplex Section overhead (MSOH),
     and the pointer fields between the two. With SONET, the pointer
     fields are part of the LOH.

     Note as well that transparency is only applicable when using
     the following Signal Types: STS-1/STM-0, STS-3/STM-1, STS-12/
     STM-4, STS-48/STM-16, STS-192/STM-64 and STS-768/STM-256. At
     least one transparency type must be specified when requesting
     such a signal type.

     Transparency indicates precisely which fields in these
     overheads must be delivered unmodified at the other end of the
     LSP. An ingress LSR requesting transparency will pass these
     overhead fields that must be delivered to the egress LSR
     without any change. From the ingress and egress LSRs point of
     views, these fields must be seen as unmodified.

     Transparency is not applied at the interfaces with the
     initiating and terminating LSRs, but is only applied between
     intermediate LSRs.

     The transparency field is used to request an LSP that supports
     the requested transparency type; it may also be used to setup
     the transparency process to be applied at each intermediate
     LSR.

     The different transparency flags are the following:

        Flag 1 (bit 1): Section/Regenerator Section layer.
        Flag 2 (bit 2): Line/Multiplex Section layer.

     Where bit 1 is the low order bit. Other flags are reserved, they
     should be set to zero when sent, and should be ignored when
     received. A flag is set to one to indicate that the corresponding
     transparency is 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 transparency. If the requested flags can not be
     supported, the receiver node MUST generate a PathErr/NOTIFICATION
     message (see Section 2.2/2.3, respectively).

     Section/Regenerator Section layer transparency means that the
     entire frames must be delivered unmodified. This implies that
     pointers cannot be adjusted. When using Section/Regenerator
     Section layer transparency all other flags MUST be ignored.

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     Line/Multiplex Section layer transparency means that the
     LOH/MSOH must be delivered unmodified. This implies that
     pointers cannot be adjusted.

   Profile (P): 32 bits

     This field is intended to indicate particular capabilities that
     must be supported for the LSP, for example monitoring
     capabilities.

     No standard profile is currently defined and this field SHOULD
     be set to zero when transmitted and SHOULD be ignored when
     received.

     In the future TLV based extensions may be created.

2.2. RSVP-TE Details

   For RSVP-TE, the SONET/SDH traffic parameters are carried in the
   SONET/SDH 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 2.1. The
   objects have the following class and type:

    For SONET ANSI T1.105 and SDH ITU-T G.707:

    SONET/SDH SENDER_TSPEC object: Class = 12, C-Type = TBA (by IANA)
    SONET/SDH FLOWSPEC object: Class = 9, C-Type = TBA (by IANA)

   There is no Adspec associated with the SONET/SDH 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, RCC, NCC, NVC and Multiplier (as
   defined in Section 2.1). If the requested value(s) can not 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]).


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   Intermediate nodes MUST also verify that the node itself and the
   interfaces on which the LSP will be established can support the
   requested Transparency (as defined in Section 2.1). If the
   requested value(s) can not be supported, the receiver node MUST
   generate a PathErr message with a "Traffic Control Error/Service
   unsupported" indication (see [RFC2205]).

2.3. CR-LDP Details

   For CR-LDP, the SONET/SDH traffic parameters are carried in the
   SONET/SDH Traffic Parameters TLV.  The content of the TLV is
   defined above in Section 2.1. The header of the 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |U|F|          Type             |      Length                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The type field for the SONET/SDH Traffic Parameters TLV is: TBA
   (by IANA).

   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, RCC, NCC, NVC and Multiplier (as
   defined in Section 2.1). If the requested value(s) can not be
   supported, the receiver node MUST generate a NOTIFICATION message
   with a "Resource Unavailable" status code (see [RFC3212]).

   In addition, if the MT field is received with a zero value, the
   node MUST generate a NOTIFICATION message with a "Resource
   Unavailable" status code (see [RFC3212]).

   Intermediate nodes MUST also verify that the node itself and the
   interfaces on which the LSP will be established can support the
   requested Transparency (as defined in Section 2.1). If the
   requested value(s) can not be supported, the receiver node MUST
   generate a NOTIFICATION message with a "Resource Unavailable"
   status code (see [RFC3212]).

3. SONET and SDH Labels

   SONET and SDH each define a multiplexing structure. Both
   structures are trees whose roots are respectively an STS-N or an
   STM-N; and whose leaves are the signals that can be transported
   via the time-slots and switched between time-slots within an
   ingress port and time-slots within an egress port, i.e. a VTx SPE,
   an STS-x SPE or a VC-x. A SONET/SDH label will identify the exact
   position (i.e. first time-slot) of a particular VTx SPE, STS-x SPE
   or VC-x signal in a multiplexing structure. SONET and SDH labels
   are carried in the Generalized Label per [RFC3473] and [RFC3472].



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   Note that by time-slots we mean the time-slots as they appear
   logically and sequentially in the multiplex, not as they appear
   after any possible interleaving.

   These multiplexing structures will be used as naming trees to
   create unique multiplex entry names or labels. The same format of
   label is used for SONET and SDH. As explained in [RFC3471], a
   label does not identify the "class" to which the label belongs.
   This is implicitly determined by the link on which the label is
   used.

   In case of signal concatenation or multiplication, a list of
   labels can appear in the Label field of a Generalized Label.

   In case of contiguous concatenation, only one label appears in the
   Label field. This label identifies the lowest time-slot occupied
   by the contiguously concatenated signal. By lowest time-slot we
   mean the one having the lowest label (value) when compared as
   integer values, i.e. the time-slot occupied by the first component
   signal of the concatenated signal encountered when descending the
   tree.

   In case of virtual concatenation, the explicit ordered list of all
   labels in the concatenation is given. Each label indicates the
   first time-slot occupied by a component of the virtually
   concatenated signal. The order of the labels must reflect the
   order of the payloads to concatenate (not the physical order of
   time-slots). The above representation limits virtual concatenation
   to remain within a single (component) link; it imposes as such a
   restriction compared to the ANSI [T1.105]/ITU-T [G.707]
   recommendations.

   The standard definition for virtual concatenation allows each
   virtual concatenation components to travel over diverse paths.
   Within GMPLS, virtual concatenation components must travel over
   the same (component) link if they are part of the same LSP. This
   is due to the way that labels are bound to a (component) link.
   Note however, that the routing of components on different paths is
   indeed equivalent to establishing different LSPs, each one having
   its own route. Several LSPs can be initiated and terminated
   between the same nodes and their corresponding components can then
   be associated together (i.e. virtually concatenated).

   In case of multiplication (i.e. using the multiplier transform),
   the explicit ordered list of all labels that take part in the
   Final Signal is given. In case of multiplication of virtually
   concatenated signals, the first set of labels indicates the time-
   slots occupied by the first virtually concatenated signal, the
   second set of labels indicates the time-slots occupied by the
   second virtually concatenated signal, and so on. The above
   representation limits multiplication to remain within a single
   (component) link.

   The format of the label for SONET and/or SDH TDM-LSR link is:

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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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               S               |   U   |   K   |   L   |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   This is an extension of the numbering scheme defined in [G.707]
   sections 7.3.7 to 7.3.13, i.e. the (K, L, M) numbering.  Note that
   the higher order numbering scheme defined in [G.707] sections
   7.3.1 to 7.3.6 is not used here.

   Each letter indicates a possible branch number starting at the
   parent node in the multiplex structure. Branches are considered as
   numbered in increasing order, starting from the top of the
   multiplexing structure. The numbering starts at 1, zero is used to
   indicate a non-significant or ignored field.

   When a field is not significant or ignored in a particular context
   it MUST be set to zero when transmitted, and MUST be ignored when
   received.

   When a hierarchy of SONET/SDH LSPs is used, a higher order LSP
   with a given bandwidth can be used to carry lower order LSPs.
   Remember here that a higher order LSP is established through a
   SONET/SDH higher order path layer network and a lower order LSP,
   through a SONET/SDH lower order path layer network (see also ITU-T
   G.803, Section 3 for the corresponding definitions). In this
   context, the higher order SONET/SDH LSP behaves as a "virtual
   link" with a given bandwidth (e.g. VC-3), it may also be used as a
   Forwarding Adjacency. A lower order SONET/SDH LSP can be
   established through that higher order LSP. Since a label is local
   to a (virtual) link, the highest part of that label (i.e. the S, U
   and K fields) is non-significant and is set to zero, i.e. the
   label is "0,0,0,L,M". Similarly, if the structure of the lower
   order LSP is unknown or not relevant, the lowest part of that
   label (i.e. the L and M fields) is non-significant and is set to
   zero, i.e. the label is "S,U,K,0,0".

   For instance, a VC-3 LSP can be used to carry lower order LSPs. In
   that case the labels allocated between the two ends of the VC-3
   LSP for the lower order LSPs will have S, U and K set to zero,
   i.e., non-significant, while L and M will be used to indicate the
   signal allocated in that VC-3.

   In case of tunneling such as VC-4 containing VC-3 containing VC-
   12/VC-11 where the SUKLM structure is not adequate to represent
   the full signal structure, a hierarchical approach must be used,
   i.e. per layer network signaling.

   The possible values of S, U, K, L and M are defined as follows:

     1. S=1->N is the index of a particular STS-3/AUG-1 inside an
     STS-N/STM-N multiplex. S is only significant for SONET STS-N

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     (N>1) and SDH STM-N (N>0). S must be 0 and ignored for STS-1 and
     STM-0.

     2. U=1->3 is the index of a particular STS-1_SPE/VC-3 within an
     STS-3/AUG-1. U is only significant for SONET STS-N (N>1) and SDH
     STM-N (N>0). U must be 0 and ignored for STS-1 and STM-0.

     3. K=1->3 is the index of a particular TUG-3 within a VC-4. K is
     only significant for an SDH VC-4 structured in TUG-3s. K must be
     0 and ignored in all other cases.

     4. L=1->7 is the index of a particular VT_Group/TUG-2 within an
     STS-1_SPE/TUG-3 or VC-3. L must be 0 and ignored in all other
     cases.

     5. M is the index of a particular VT1.5_SPE/VC-11, VT2_SPE/VC-12
     or VT3_SPE within a VT_Group/TUG-2. M=1->2 indicates a specific
     VT3 SPE inside the corresponding VT Group, these values MUST NOT
     be used for SDH since there is no equivalent of VT3 with SDH.
     M=3->5 indicates a specific VT2_SPE/VC-12 inside the
     corresponding VT_Group/TUG-2. M=6->9 indicates a specific
     VT1.5_SPE/VC-11 inside the corresponding VT_Group/TUG-2.

   Note that a label always has to be interpreted according the
   SONET/SDH traffic parameters, i.e. a label by itself does not
   allow knowing which signal is being requested (a label is context
   sensitive).

   The label format defined in this section, referred to as SUKLM,
   MUST be used for any SONET/SDH signal requests that are not
   transparent i.e. when all Transparency (T) bits defined in section
   2.1 are set to zero. Any transparent STS-1/STM-0/STS-3*N/STM-N
   (N=1, 4, 16, 64, 256) signal request MUST use a label format as
   defined in [RFC3471].

     The S encoding is summarized in the following table:

          S    SDH                     SONET
         ------------------------------------------------
          0    other                   other
          1    1st AUG-1               1st STS-3
          2    2nd AUG-1               2nd STS-3
          3    3rd AUG-1               3rd STS-3
          4    4rd AUG-1               4rd STS-3
          :    :                       :
          N    Nth AUG-1               Nth STS-3

     The U encoding is summarized in the following table:

          U    SDH AUG-1               SONET STS-3
         -------------------------------------------------
          0    other                   other
          1    1st VC-3                1st STS-1 SPE
          2    2nd VC-3                2nd STS-1 SPE

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draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

          3    3rd VC-3                3rd STS-1 SPE

      The K encoding is summarized in the following table:

          K    SDH VC-4
         ---------------
          0    other
          1    1st TUG-3
          2    2nd TUG-3
          3    3rd TUG-3

      The L encoding is summarized in the following table:

          L    SDH TUG-3    SDH VC-3    SONET STS-1 SPE
         -------------------------------------------------
          0    other        other       other
          1    1st TUG-2    1st TUG-2   1st VTG
          2    2nd TUG-2    2nd TUG-2   2nd VTG
          3    3rd TUG-2    3rd TUG-2   3rd VTG
          4    4th TUG-2    4th TUG-2   4th VTG
          5    5th TUG-2    5th TUG-2   5th VTG
          6    6th TUG-2    6th TUG-2   6th VTG
          7    7th TUG-2    7th TUG-2   7th VTG

      The M encoding is summarized in the following table:

          M    SDH TUG-2                 SONET VTG
         -------------------------------------------------
          0    other                     other
          1    -                         1st VT3 SPE
          2    -                         2nd VT3 SPE
          3    1st VC-12                 1st VT2 SPE
          4    2nd VC-12                 2nd VT2 SPE
          5    3rd VC-12                 3rd VT2 SPE
          6    1st VC-11                 1st VT1.5 SPE
          7    2nd VC-11                 2nd VT1.5 SPE
          8    3rd VC-11                 3rd VT1.5 SPE
          9    4th VC-11                 4th VT1.5 SPE

   Examples of labels:

   Example 1: the label for the STS-3c_SPE/VC-4 in the Sth STS-3/AUG-
   1 is: S>0, U=0, K=0, L=0, M=0.

   Example 2: the label for the VC-3 within the Kth-1 TUG-3 within
   the VC-4 in the Sth AUG-1 is: S>0, U=0, K>0, L=0, M=0.

   Example 3: the label for the Uth-1 STS-1_SPE/VC-3 within the Sth
   STS-3/AUG-1 is: S>0, U>0, K=0, L=0, M=0.

   Example 4: the label for the VT6/VC-2 in the Lth-1 VT Group/TUG-2
   in the Uth-1 STS-1_SPE/VC-3 within the Sth STS-3/AUG-1 is: S>0,
   U>0, K=0, L>0, M=0.


E.Mannie & D.Papadimitriou (Editors)                                13

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

   Example 5: the label for the 3rd VT1.5_SPE/VC-11 in the Lth-1 VT
   Group/TUG-2 within the Uth-1 STS-1_SPE/VC-3 within the Sth STS-
   3/AUG-1 is: S>0, U>0, K=0, L>0, M=8.

   Example 6: the label for the STS-12c/VC-4-4c which uses the 9th
   STS-3/AUG-1 as its first timeslot is: S=9, U=0, K=0, L=0, M=0.

   In case of contiguous concatenation, the label that is used is the
   lowest label (value) of the contiguously concatenated signal as
   explained before. The higher part of the label indicates where the
   signal starts and the lowest part is not significant.

   In case of STM-0/STS-1, the values of S, U and K must be equal to
   zero according to the field coding rules. For instance, when
   requesting a VC-3 in an STM-0 the label is S=0, U=0, K=0, L=0,
   M=0. When requesting a VC-11 in a VC-3 in an STM-0 the label is
   S=0, U=0, K=0, L>0, M=6..9.

   Note: when a Section/RS or Line/MS transparent STS-1/STM-0/STS-
   3*N/STM-N (N=1, 4, 16, 64, 256) signal is requested, the SUKLM
   label format and encoding is not applicable and the label encoding
   MUST follow the rules defined in [RFC3471] Section 3.2.

4. Acknowledgments

   Valuable comments and input were received from the CCAMP mailing
   list where outstanding discussions took place.

5. Security Considerations

   This draft introduces no new security considerations to either
   [RFC3473] or [RFC3472]. GMPLS security is described in section 11
   of [RFC3471] and refers to [RFC3209] for RSVP-TE and to [RFC3212]
   for CR-LDP.

6. IANA Considerations

   Three values have to be defined by IANA for this document:

   Two RSVP C-Types in registry:
          http://www.iana.org/assignments/rsvp-parameters

          - A SONET/SDH SENDER_TSPEC object: Class = 12, C-Type = TBA
            (see section 2.2).

          - A SONET/SDH FLOWSPEC object: Class = 9, C-Type = TBA (see
            section 2.2).

   One LDP TLV Type in registry:
          http://www.iana.org/assignments/ldp-namespaces

          - A type field for the SONET/SDH Traffic Parameters TLV
            (see section 2.3).


E.Mannie & D.Papadimitriou (Editors)                                14

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

7. Intellectual Property Notice

   The IETF takes no position regarding the validity or scope of any
   intellectual property 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; neither does it represent that it
   has made any effort to identify any such rights. Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11. Copies of
   claims of rights made available for publication 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 implementors or users of this specification
   can be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard. Please address the information to the IETF Executive
   Director.

8. References

8.1 Normative References

   [G.707]      ITU-T Recommendation G.707, "Network Node Interface
                for the Synchronous Digital Hierarchy", October 2000.

   [GMPLS-ARCH] Mannie, E., Papadimitriou D., et al., "Generalized
                Multiprotocol Label Switching Architecture", Internet
                Draft, Work in progress, draft-ietf-ccamp-gmpls-
                architecture-03.txt, August 2002.

   [RFC2119]    Bradner, S., "Key words for use in RFCs to Indicate
                Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2205]    Braden, R., et al., "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.

   [RFC3209]    Awduche, D., et al., "RSVP-TE: Extensions to RSVP for
                LSP Tunnels", RFC 3209, December 2001.

   [RFC3212]    Jamoussi, B., et al., "Constraint-Based LSP Setup using
                LDP", RFC 3212, January 2002.

   [RFC3471]    Berger, L. (Editor), et al., "Generalized MPLS û
                Signaling Functional Description", RFC 3471, January
                2003.


E.Mannie & D.Papadimitriou (Editors)                                15

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

   [RFC3472]    Berger, L. (Editor), et al., "Generalized MPLS
                Signaling - CR-LDP Extensions", RFC 3472, January
                2003.

   [RFC3473]    Berger, L. (Editor), et al., "Generalized MPLS
                Signaling - RSVP-TE Extensions", RFC 3473, January
                2003.

   [T1.105]     "Synchronous Optical Network (SONET): Basic
                Description Including Multiplex Structure, Rates, and
                Formats", ANSI T1.105, October 2000.

9. Authors Addresses

   Eric Mannie (Consulting)
   Phone:  +32 2 648-5023
   Mobile: +32 (0)495-221775
   Email:  eric_mannie@hotmail.com

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

10. Contributors

   Contributors are listed by alphabetical order:

   Stefan Ansorge (Alcatel)           Peter Ashwood-Smith (Nortel)
   Lorenzstrasse 10                   PO. Box 3511 Station C,
   70435 Stuttgart, Germany           Ottawa, ON K1Y 4H7, Canada
   Email: stefan.ansorge@alcatel.de   Email:petera@nortelnetworks.com

   Ayan Banerjee (Calient)            Lou Berger (Movaz)
   5853 Rue Ferrari                   7926 Jones Branch Drive
   San Jose, CA 95138, USA            McLean, VA 22102, USA
   Email: abanerjee@calient.net       Email: lberger@movaz.com

   Greg Bernstein (Ciena)             Angela Chiu (Celion)
   10480 Ridgeview Court              One Sheila Drive, Suite 2
   Cupertino, CA 94014, USA           Tinton Falls, NJ 07724-2658
   Email: greg@ciena.com              Email: angela.chiu@celion.com

   John Drake (Calient)               Yanhe Fan (Axiowave)
   5853 Rue Ferrari                   100 Nickerson Road
   San Jose, CA 95138, USA            Marlborough, MA 01752, USA
   Email: jdrake@calient.net          Email: yfan@axiowave.com

   Michele Fontana (Alcatel)          Gert Grammel (Alcatel)
   Via Trento 30,                     Lorenzstrasse, 10
   I-20059 Vimercate, Italy           70435 Stuttgart, Germany
   Email: michele.fontana@alcatel.it  Email: gert.grammel@alcatel.de


E.Mannie & D.Papadimitriou (Editors)                                16

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

   Juergen Heiles (Siemens)           Suresh Katukam (Cisco)
   Hofmannstr. 51                     1450 N. McDowell Blvd,
   D-81379 Munich, Germany            Petaluma, CA 94954-6515, USA
   Email: juergen.heiles@siemens.com  Email: suresh.katukam@cisco.com

   Kireeti Kompella (Juniper)         Jonathan P. Lang (Calient)
   1194 N. Mathilda Ave.              25 Castilian
   Sunnyvale, CA 94089, USA           Goleta, CA 93117, USA
   Email: kireeti@juniper.net         Email: jplang@calient.net

   Fong Liaw (Solas Research)         Zhi-Wei Lin (Lucent)
   Email: fongliaw@yahoo.com          101 Crawfords Corner Rd
                                      Holmdel, NJ  07733-3030, USA
                                      Email: zwlin@lucent.com

   Ben Mack-Crane (Tellabs)           Dimitrios Pendarakis (Tellium)
   Email: ben.mack-crane@tellabs.com  2 Crescent Place, P.O. Box 901
                                      Oceanport, NJ 07757-0901, USA
                                      Email: dpendarakis@tellium.com

   Mike Raftelis (White Rock)         Bala Rajagopalan (Tellium)
   18111 Preston Road                 2 Crescent Place, P.O. Box 901
   Dallas, TX 75252, USA              Oceanport, NJ 07757-0901, USA
                                      Email: braja@tellium.com

   Yakov Rekhter (Juniper)            Debanjan Saha (Tellium)
   1194 N. Mathilda Ave.              2 Crescent Place, P.O. Box 901
   Sunnyvale, CA 94089, USA           Oceanport, NJ 07757-0901, USA
   Email: yakov@juniper.net           Email: dsaha@tellium.com

   Vishal Sharma (Metanoia)           George Swallow (Cisco)
   335 Elan Village Lane              250 Apollo Drive
   San Jose, CA 95134, USA            Chelmsford, MA 01824, USA
   Email: vsharma87@yahoo.com         Email: swallow@cisco.com

   Z. Bo Tang (Tellium)               Eve Varma (Lucent)
   2 Crescent Place, P.O. Box 901     101 Crawfords Corner Rd
   Oceanport, NJ 07757-0901, USA      Holmdel, NJ  07733-3030, USA
   Email: btang@tellium.com           Email: evarma@lucent.com

   Yangguang Xu (Lucent)
   21-2A41, 1600 Osgood Street
   North Andover, MA 01845, USA
   Email: xuyg@lucent.com











E.Mannie & D.Papadimitriou (Editors)                                17

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

11. Full Copyright Statement

   "Copyright (C) The Internet Society (date). All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph
   are included on all such copies and derivative works. However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS 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."




























E.Mannie & D.Papadimitriou (Editors)                                18

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

Appendix 1 - Signal Type Values Extension for VC-3

   This appendix defines the following optional additional Signal
   Type value for the Signal Type field of section 2.1:

       Value         Type
       -----  ---------------------
        20     "VC-3 via AU-3 at the end"

   According to the ITU-T [G.707] recommendation a VC-3 in the TU-
   3/TUG-3/VC-4/AU-4 branch of the SDH multiplex cannot be structured
   in TUG-2s, however a VC-3 in the AU-3 branch can be. In addition,
   a VC-3 could be switched between the two branches if required.

   A VC-3 circuit could be terminated on an ingress interface of an
   LSR (e.g. forming a VC-3 forwarding adjacency). This LSR could
   then want to demultiplex this VC-3 and switch internal low order
   LSPs. For implementation reasons, this could be only possible if
   the LSR receives the VC-3 in the AU-3 branch. E.g. for an LSR not
   able to switch internally from a TU-3 branch to an AU-3 branch on
   its incoming interface before demultiplexing and then switching
   the content with its switch fabric.

   In that case it is useful to indicate that the VC-3 LSP must be
   terminated at the end in the AU-3 branch instead of the TU-3
   branch.

   This is achieved by using the "VC-3 via AU-3 at the end" signal
   type. This information can be used, for instance, by the
   penultimate LSR to switch an incoming VC-3 received in any branch
   to the AU-3 branch on the outgoing interface to the destination
   LSR.

   The "VC-3 via AU-3 at the end" signal type does not imply that the
   VC-3 must be switched via the AU-3 branch at some other places in
   the network. The VC-3 signal type just indicates that a VC-3 in
   any branch is suitable.


















E.Mannie & D.Papadimitriou (Editors)                                19

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Annex 1 - Examples

   This annex defines examples of SONET and SDH signal coding. Their
   objective is to help the reader to understand how works the traffic
   parameter coding and not to give examples of typical SONET or SDH
   signals.

   As stated above, signal types are Elementary Signals to which
   successive concatenation, multiplication and transparency
   transforms can be applied to obtain Final Signals.

   1. A VC-4 signal is formed by the application of RCC with value 0,
   NCC with value 0, NVC with value 0, MT with value 1 and T with
   value 0 to a VC-4 Elementary Signal.

   2. A VC-4-7v signal is formed by the application of RCC with value
   0, NCC with value 0, NVC with value 7 (virtual concatenation of 7
   components), MT with value 1 and T with value 0 to a VC-4
   Elementary Signal.

   3. A VC-4-16c signal is formed by the application of RCC with flag
   1 (standard contiguous concatenation), NCC with value 16, NVC with
   value 0, MT with value 1 and T with value 0 to a VC-4 Elementary
   Signal.

   4. An STM-16 signal with Multiplex Section layer transparency is
   formed by the application of RCC with value 0, NCC with value 0,
   NVC with value 0, MT with value 1 and T with flag 2 to an STM-16
   Elementary Signal.

   5. An STM-4 signal with Multiplex Section layer transparency is
   formed by the application of RCC with flag 0, NCC with value 0,
   NVC with value 0, MT with value 1 and T with flag 2 applied to an
   STM-4 Elementary Signal.

   6. An STM-256 signal with Multiplex Section layer transparency is
   formed by the application of RCC with flag 0, NCC with value 0,
   NVC with value 0, MT with value 1 and T with flag 2 applied to an
   STM-256 Elementary Signal.

   7. An STS-1 SPE signal is formed by the application of RCC with
   value 0, NCC with value 0, NVC with value 0, MT with value 1 and T
   with value 0 to an STS-1 SPE Elementary Signal.

   8. An STS-3c SPE signal is formed by the application of RCC with
   value 1 (standard contiguous concatenation), NCC with value 1, NVC
   with value 0, MT with value 1 and T with value 0 to an STS-3c SPE
   Elementary Signal.

   9. An STS-48c SPE signal is formed by the application of RCC with
   flag 1 (standard contiguous concatenation), NCC with value 16, NVC
   with value 0, MT with value 1 and T with value 0 to an STS-3c SPE
   Elementary Signal.


E.Mannie & D.Papadimitriou (Editors)                                20

draft-ietf-ccamp-gmpls-sonet-sdh-08.txt                  February 2003

   10. An STS-1-3v SPE signal is formed by the application of RCC
   with value 0, NVC with value 3 (virtual concatenation of 3
   components), MT with value 1 and T with value 0 to an STS-1 SPE
   Elementary Signal.

   11. An STS-3c-9v SPE signal is formed by the application of RCC
   with value 1, NCC with value 1, NVC with value 9 (virtual
   concatenation of 9 STS-3c), MT with value 1 and T with value 0 to
   an STS-3c SPE Elementary Signal.

   12. An STS-12 signal with Section layer (full) transparency is
   formed by the application of RCC with value 0, NVC with value 0,
   MT with value 1 and T with flag 1 to an STS-12 Elementary Signal.

   13. 3 x STS-768c SPE signal is formed by the application of RCC
   with flag 1, NCC with value 256, NVC with value 0, MT with value
   3, and T with value 0 to an STS-3c SPE Elementary Signal.

   14. 5 x VC-4-13v composed signal is formed by the application of
   RCC with value 0, NVC with value 13, MT with value 5 and T with
   value 0 to a VC-4 Elementary Signal.

   The encoding of these examples is summarized in the following
   table:

   Signal                     ST   RCC   NCC   NVC   MT   T
   --------------------------------------------------------
   VC-4                        6     0     0     0    1   0
   VC-4-7v                     6     0     0     7    1   0
   VC-4-16c                    6     1    16     0    1   0
   STM-16 MS transparent      10     0     0     0    1   2
   STM-4 MS transparent        9     0     0     0    1   2
   STM-256 MS transparent     12     0     0     0    1   2
   STS-1 SPE                   5     0     0     0    1   0
   STS-3c SPE                  6     1     1     0    1   0
   STS-48c SPE                 6     1    16     0    1   0
   STS-1-3v SPE                5     0     0     3    1   0
   STS-3c-9v SPE               6     1     1     9    1   0
   STS-12 Section transparent  9     0     0     0    1   1
   3 x STS-768c SPE            6     1   256     0    3   0
   5 x VC-4-13v                6     0     0    13    5   0














E.Mannie & D.Papadimitriou (Editors)                                21


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