Network Working Group
Internet Draft
Expiration Date: September 2001                   Maarten Visses
                                                     Zhi-Wei Lin
                                                    Yangguang Xu
                                           Siva Sankaranarayanan

                                        Lucent Technologies, Inc.



                Common Label and Label Request Specification
                 for Automatic Switched Transport Network

             draft-lin-ccamp-ipo-common-label-request-00.txt



1. 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/ietf/1id-abstracts.txt

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



2. Abstract

   This draft completes the [GMPLS-REORG] draft and details technology
   specific issues. It proposes different approach and enhancement to
   [GMPLS-SIG] and [GMPLS-SIGEN]. Changes are:

   -- New set of Signal Type structures of ETSI-PDH, ANSI-PDH, SONET, SDH and
      OTN for Generalized Label Request [GMPLS-SIG].
   -- G-PIDs associated each signal type for G-Label Request.
   -- Label Channel ID [GMPLS-REORG] field structure.



Z. Lin et. al.                                                     Page [1]

Internet Draft      G-Label and G-Label Request Specification      March 2001


3. G-Label Request Specification

     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | LSP Enc. Type |                Signal Type                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Service Type |  Dir  | Rserved |           G-PID             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    LSP Encoding Type and Signal Type together identify the unique signal
    type of the LSP.


3.1 LSP Encoding

    LSP Encoding Type: 8 bit

    Indicates the encoding technology of the LSP being requested.

                 Value        Type
                 -----        --------
                 3            ANSI PDH
                 4            ETSI PDH
                 5            SDH
                 6            SONET
                 7            OTN
                 8            Analog


3.2 Signaling Type and Associated G-PID

    Signaling Type: 24 bits

    Indicates the specific signal type of the LSP being requested. This
    field is interpreted according to the technology specified by LSP
    Encoding Type. The Signal Type provides transit switches with the
    information required to determine which link connection can support
    the LSP.


    G-PID: 16 bits

    Indicates the payload carried by an LSP, i.e. an identifier of the
    client layer of the LSP.  It's the same as Payload Types in G.709,
    Signal Label in G.707 and L3PID in RSVP-TE. Each of signal type may
    only allow certain types of client signals. The G-PID is mainly used by
    the adaptation layer function at the LSP terminating points. G-PID is
    associated with each signal type.



Z. Lin et. al.                                                     Page [2]

Internet Draft      G-Label and G-Label Request Specification      March 2001


3.2.1 ANSI PDH Signaling Type

   Permitted values and their meaning for LSP Encoding Type ANSI-PDH:

                 Value       Type
                 -----       ----
                 1           DS1 SF
                 2           DS1 ESF
                 3           DS2
                 4           DS3 M23
                 5           DS3 C-bit Parity
                 6           DS4

   When the technology encoding type is ANSI-PDH, GPID can take the
   following values:

                 Value       Client Type
                 -----       -----------
                 0           Unknown


3.2.2 ETSI PDH Signaling Type

   Permitted values and their meaning for LSP Encoding Type ETSI-PDH:

                 Value        Type
                 -----        ----
                 1            E1 P12x
                 2            E1 P12s
                 3            E2 P22x
                 4            E2 P22e
                 5            E3 P31x
                 6            E3 P31e
                 7            E3 P31s
                 8            E4 P4x
                 9            E4 P4e
                 10           E4 P4s


3.2.3 SDH Signaling Type

    For SONET/SDH, the 24-bit Signal Type SHALL be encoded in 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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | LSP Enc. Type |     Type      |              X                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



Z. Lin et. al.                                                     Page [3]

Internet Draft      G-Label and G-Label Request Specification      March 2001


    Type: 8 bits

    Indicates specific signal type of a LSP encoding type


    X : 16 bits

    Indicates concatenation value.


    Permitted type values and their meaning for LSP Encoding Type SDH
    are:

                 Value        Type
                 -----        --------
                 1            VC-11
                 2            VC-12
                 3            VC-2
                 4            VC-2-Xc (1<=x<=7)
                 5            VC-3
                 6            VC-4
                 7            VC-4-Xc (X=4,16,64,256)
                 8            MS-X (STM-X MS) (X=1,4,16,64,256)
                 9            STM-X (X=1,4,16,64,256)
                 10           VC-11-Xv (1<=X<=64)
                 11           VC-12-Xv (1<=X<=64)
                 12           VC-2-Xv (1<=X<=64)
                 13           VC-3-Xv (1<=X<=256)
                 14           VC-4-Xv (1<=X<=256)
                 15           VC-11-Xv LCAS
                 16           VC-12-Xv LCAS
                 17           VC-2-Xv LCAS
                 18           VC-3-Xv LCAS
                 19           VC-4-Xv LCAS
                 20           VC-11-X **
                 21           VC-12-X
                 22           VC-2-X
                 23           VC-3-X
                 24           VC-4-X
                 128          TUG-2
                 129          TUG-3
                 130          AUG-X (X=1,4,16,64,256)
                 131          VC-4-Xa (1<=X<=256)
                 132          STM-Xst
                 133-143        Reserved for vendor specific SDH signal type

   ** This is used at intermediate nodes to support the LCAS when a subset
      of the link connections are co-routed.




Z. Lin et. al.                                                     Page [4]

Internet Draft      G-Label and G-Label Request Specification      March 2001


   The "MS-X" and "STM-X" Signal types represent transparent STM Multiplex
   Section and Regenerator Section LSPs respectively. Note that the "STM-X"
   signal type represents the complete STM-N signal, including all its SOH.

   The "VC-n-Xc" Signal Type represents a contiguous standard concatenated
   VC-n signal (ITU-T Rec. G.707), which is transported via the AU and TU
   timeslots according to the (E,D,C,B,A) and (K,L,M) structures.

   The "VC-n-Xv" Signal type represents a virtual concatenated VC-n signal.

   The "VC-n-Xv LCAS" Signal type represents a VC-n-Xv signal with Link
   Capacity Adjustment Scheme (LCAS) capability. The "VC-n-X" Signal type
   represents a group of VC-n signals that are to be co-routed.

   Besides the set of signal types derived from the SDH standards, a number of
   additional signal types are defined. These additional signal types are
   vendor specific extensions of the SDH standards.

   The "AUG-X" Signal type represents an AUG-X bandwidth, of which the
   specific AU structure is not predefined. This AUG-X link will autonomously
   adapt to the incoming AU structure. Idem for TUG-2 and TUG-3.

   The "VC-4-Xa" Signal type represents a contiguous arbitrary concatenated
   VC-4 signal.

   The "STM-Xst" Signal type represents a "semi transparent" STM-X signal. The
   AUG-X and some of the SOH (vendor specific selection) is transported
   through the link connection. Interworking between equipment of different
   vendors is not to be expected.

   To support other vendor specific SDH signal types a set of 13 code points
   (133-143) is reserved. Within its subnetwork a vendor may assign these code
   points to its specific signals.

   The G-PIDs associated with each Signal Type are (based on G.707):
      VC-11:     (1) async 1.544 Mbps, (2) bit sync 1.544 Mbps, (3) byte sync
                     1.544 Mbps, (4) byte sync 384 kbps, (5) ATM, (6) HDLC
                     framed, (7) GFP framed
      VC-12:     (1) async 2.048 Mbps - transparent, (2) async 2.048 Mbps -
                     terminated, (3) byte sync 2.048 Mbps - transparent, (4)
                     byte sync 2.048 Mbps - terminated, (3) 31x64 kbps, (4)
                     ATM, (5) HDLC framed, (7) GFP framed
      VC-2:      (1) async 6.312 Mbps, (2) bit sync 6.312 Mbps, (3) ATM, (4)
                     HDLC framed, (5) GFP framed
      VC-2-Xc:   (1) ATM, (2) HDLC framed w/ scrambling
      VC-3:      (1) 44.736 Mbps - transparent, (2) 44.736 Mbps - terminated,
                     (3) 34.368 Mbps - transparent, (4) 34.368 Mbps -
                     terminated G.751 frame, (5) 34.368 Mbps - terminated
                     G.832 frame, (3) TUG (4) ATM, (5) HDLC framed w/
                     scrambling, (6) GFP framed


Z. Lin et. al.                                                     Page [5]

Internet Draft      G-Label and G-Label Request Specification      March 2001


      TUG-2:     (1) one TU-2, (2) three TU-12, (3) four TU-11
      TUG-3:     (1) one TU-3, (2) seven TUG-2
      VC-4:      (1) 139.264 Mbps - transparent, (2) 139.264 Mbps - terminated
                     G.751 frame, (3) 139.264 Mbps - terminated G.832 frame,
                     (4) TUG, (5) ATM, (6) HDLC framed w/ scrambling, (7)
                     DQDB, (8) async FDDI, (9) GFP framed
      VC-4-4c:   (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-4-16c:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-4-64c:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-4-256c: (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      AUG-1:     (1) one AU-4,   (2) three AU-3
      AUG-4:     (1) four AUG-1, (2) one AU-4-4c
      AUG-16:    (1) four AUG-4, (2) one AU-4-16c
      AUG-64:    (1) four AUG-16, (2) one AU-4-64c
      AUG-256:   (1) four AUG-64, (2) one AU-4-256c
      MS-X:      (1) AUG-X
      STM-X:
      VC-11-Xv:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-12-Xv:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-2-Xv:   (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-3-Xv:   (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-4-Xv:   (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-11-Xv LCAS: (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-12-Xv LCAS: (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-2-Xv LCAS:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-3-Xv LCAS:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-4-Xv LCAS:  (1) ATM, (2) HDLC framed w/ scrambling, (3) GFP framed
      VC-11-X group that is co-routed: (0) unknown
      VC-12-X group that is co-routed: (0) unknown
      VC-2-X group that is co-routed:  (0) unknown
      VC-3-X group that is co-routed:  (0) unknown
      VC-4-X group that is co-routed:  (0) unknown


3.2.4 SONET Signaling Type

    Permitted type values and their meaning for LSP Encoding Type SONET
    are:

                 Value        Type
                 -----        --------
                 1            VT1.5
                 2            VT2
                 3            VT3
                 4            VT6
                 5            STS-1 SPE
                 6            STS-Xc SPE      (X=3,12,48,192,768)
                 7            STS-X SPE       (X=1,3,12,48,192,768)
                 8            STS-X Line      (X=1,3,12,48,192,768)



Z. Lin et. al.                                                     Page [6]

Internet Draft      G-Label and G-Label Request Specification      March 2001


                 9            STS-X           (X=1,3,12,48,192,768)
                 10           VT1.5-Xv        (1<=X<=64)
                 11           VT2-Xv          (1<=X<=64)
                 12           VT3-Xv          (1<=X<=64)
                 13           VT6-Xv          (1<=X<=64)
                 14           STS-1-Xv        (1<=X<=256)
                 15           STS-3c-Xv       (1<=X<=256)
                 16           VT1.5-Xv LCAS
                 17           VT2-Xv LCAS
                 18           VT3-Xv LCAS
                 19           VT6-Xv LCAS
                 20           STS-1-Xv LCAS
                 21           STS-3c-Xv LCAS
                 22           VT1.5-X **
                 23           VT2-X
                 24           VT3-X
                 25           VT6-X
                 26           STS-1-X
                 27           STS-3c-X
                 128          VTG
                 129          STS Group-X (X=3,12,48,192,768)
                 130          STS-3c-Xa (1<=X<=256)
                 131          STS-Xst
                 132-143      Reserved for vendor specific SONET signal type

   ** This is used at intermediate nodes to support the LCAS when a subset
   of the link connections are co-routed.

   The "STS-X Line" and "STS-X" Signal types represent transparent STS Line
   and STS Section LSPs respectively. Note that the "STS-X" signal type
   represents the complete STS-N signal, including all its TOH.

   The "STS-Xc" Signal Type represents a contiguous standard concatenated STS
   signal (ANSI T1.105), which is transported via the STS timeslots according
   to the (E,D,C,B,A) structures.

   The "VTn-Xv" and "STS-n-Xv" Signal types represent virtual concatenated VT
   and STS signals. The "VTn-Xv LCAS" and "STS-n-Xv LCAS" Signal type
   represent VTn-Xv and STS-n-Xv signal with Link Capacity Adjustment Scheme
   (LCAS) capability. The "VTn-X" and "STS-n-X" Signal types represent a group
   of VTn and STS-n signals that are to be co-routed.

   Besides the set of signal types derived from the SONET standards, a number
   of additional signal types are defined. These additional signal types are
   vendor specific extensions of the SONET standards.

   The "STS Group-X" Signal type represents an STS Group bandwidth, of which
   the specific STS structure is not predefined. This STS Group-X link will
   autonomously adapt to the incoming STS structure. Idem VTG.



Z. Lin et. al.                                                     Page [7]

Internet Draft      G-Label and G-Label Request Specification      March 2001


   The "STS-3c-Xa" Signal type represents a contiguous arbitrary concatenated
   STS-3c signal.

   The "STS-Xst" Signal type represents a "semi transparent" STS-X signal. The
   STS-X SPE and some of the TOH (vendor specific selection) is transported
   through the link connection. Inter-working between equipment of different
   vendors is not to be expected.

   To support other vendor specific SONET signal types a set of 13 code points
   (132-143) is reserved. Within its subnetwork a vendor may assign these code
   points to its specific signals.

   The G-PIDs associated with each Signal Type are (based on T1.105):
      VT1.5:       (1) async DS1 (1.544 Mbps), (2) bit sync DS1, byte sync
                       DS1, (3) GFP framed
      VT2:         (1) async 2.048 Mbps, (2) bit sync 2.048 Mbps, (3) byte
                       sync 2.048 Mbps, (4) GFP framed
      VT3:         (1) async DS1C (3.152 Mbps)
      VT6:         (1) async DS2 (6.312 Mbps), (2) GFP framed
      STS Group-X: (1) STS-X SPE
      STS-1 SPE:   (1) async DS3 (44.736 Mbps), (2) VTG, (3) GFP framed
      STS-3c SPE:  (1) ATM, (2) HDLC framed, (3) GFP framed, (4) SDL w/
                       scrambler
      STS-12c SPE: (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      STS-48c SPE: (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      STS-192c SPE:(1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler,
                       10 Gbps Ethernet
      STS-768c SPE:(1)ATM,  (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      STS-1 Line:
      STS-3 Line:
      STS-12 Line:
      STS-48 Line:
      STS-192 Line:
      STS-768 Line:
      STS-1:
      STS-3:
      STS-12:
      STS-48:
      STS-192:
      STS-768:
      VT1.5-Xv:    (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      VT2-Xv:      (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      VT3-Xv:      (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      VT6-Xv:      (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      STS-1-Xv:    (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      STS-3c-Xv:   (1) ATM, (2) HDLC framed, (3) GFP framed, SDL w/ scrambler
      VT1.5-Xv LCAS:
      VT2-Xv LCAS:
      VT3-Xv LCAS:



Z. Lin et. al.                                                     Page [8]

Internet Draft      G-Label and G-Label Request Specification      March 2001


      VT6-Xv LCAS:
      STS-1-Xv LCAS:
      STS-3c-Xv LCAS:


3.2.5 OTN Signaling Type

   For OTN, the permitted signal types are

          Value        Type
          -----        --------
          1            ODU1
          2            ODU2
          3            ODU3

          10           OCh  - further typing will be added to OCh

   G-PIDs for ODU1 include:

          Value        Type
          -----        --------
          1            CBR2G5a  (asynchronous constant bit rate of 2.5 Gbps
                                 such as STM-16 or OC-48)
          2            CBR2G5b  (bit synchronous constant bit rate of 2.5 Gbps
                                 such as STM-16 or OC-48)
          3            ATM2G5
          4            GFP2G5   (used for transporting data, e.g., IP @ 2.5
                                 Gbps)
          5            BSOT2G5  (mapping of non-specific client bit stream w/
                                 octet timing)
          6            BSNT2G5  (mapping of non-specific client bit stream w/o
                                 octet timing)

    G-PIDs for ODU2 include:

          Value        Type
          -----        --------
          1            CBR10Ga
          2            CBR10Gb
          3            ATM10G
          4            GFP10G
          5            BSOT10G
          6            BSNT10G

    G-PIDs for ODU3 include:

          Value        Type
          -----        --------
          1            CBR40Ga



Z. Lin et. al.                                                     Page [9]

Internet Draft      G-Label and G-Label Request Specification      March 2001


          2            CBR40Gb
          3            ATM40G
          4            GFP40G
          5            BSOT40G
          6            BSNT40G

    G-PIDs for OCh include:

          Value        Type
          -----        --------
           1           OTU1
           2           OTU1V
           3           OTU2
           4           OTU2V
           5           OTU3
           6           OTU3V
           7           STM-16/OC-48
           8           STM-64/OC-192
           9           STM-256/OC-256
           10          1 GbE

3.3 Directionality and Service Type are defined in [GMPLS-REORG].


4. G-label Channel ID Specification

4.1 G-Label Specification

   [GMPLS-REORG] introduces two type of Label format for automatically
   switched transport network.

   Basic 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  G-Label     (Port ID)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | D |              G-Label     (Channel ID)                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Hierarchical 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   //                 G-Label     (Connection ID)                  //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | D |              G-Label     (Channel ID)                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


Z. Lin et. al.                                                     Page [10]

Internet Draft      G-Label and G-Label Request Specification      March 2001


4.2 G-Label Channel ID for SONET/SDH

    For SDH/SONET, the label identifies both a timeslot in the SDH/SONET frame
    as well as a Connection Termination Point (CTP) in the equipment.

    The Channel ID of the G-label represents for SDH/SONET either the AU/STS
    timeslots or the TU/VT timeslots.

    SDH/SONET are technologies encompassing multiple independent layer
    networks. Trails and connections in layer networks are set up and torn
    down independent of trails and connections in their server layer networks.
    Trails and connections in layer networks are modified independent of
    trails and connections in their server and client layer networks.

    Typically, server layer trails must have been set up before client layer
    connections and trails can be set up. Server layer trails provide the
    client layer link connections (label switched hops). As such, STM-N/OC-N
    (i.e. multiplex section/line) trails must have been established before
    HOVC connections and trails can be set up. Similarly, VC-4/STS-1 trails
    must have been established before LOVC/VT connections and trails can be
    set up.

    There is a multiplicity of ports (physical and logical) in SDH/SONET
    equipment; STM-N/OC-N physical ports, HOVC/STS logical ports, LOVC/VT
    logical ports. In future hybrid OTN/SDH/SONET equipment STM-N/OC-N ports
    might also be logical ports.

    HOVC/STS signals can be transported over STM-N/OC-N signals. LOVC/VT
    signals can be transported over either VC-4/VC-3/STS-1 signals, or sub-
    STM-0/sub-STS-1 signals (e.g. sSTM-1k [k=1,2,4,8,16], sSTM-2n [n=1,2,4]),
    or 34 376 and 139 264 kbit/s signals with G.832 framing.

    STM-N/OC-N signals aggregate HOVC/STS signals. The associated multiplex
    structure may be adapted during the lifetime of the STM-N/OC-N trail to
    accommodate the requested mix of HOVC/STS signal types. VC-4/VC-3/STS-1
    signals aggregate LOVC/VT signals. The associated multiplex structure may
    be adapted during the lifetime of the VC-4/VC-3/STS-1 trail to accommodate
    the requested mix of LOVC/VT signal types. At any moment in time, the
    complete aggregation bandwidth's multiplex structure must be defined to
    prevent alarms to be raised.

    SDH/SONET equipment may have either no switch fabric, or a HOVC/STS switch
    fabric, or a LOVC/VT switch fabric, or a HOVC/STS and a LOVC/VT switch
    fabric. SDH/SONET interfaces on none-SDH/SONET equipment typically have no
    switch fabric. Hybrid equipment may have SDH/SONET type switch fabrics in
    addition to client layer (e.g. ATM VP, ATM, VC, IP, Ethernet) switch
    fabrics and/or server layer (e.g. OTN OCh, OTN ODUk) switch fabrics.

    Installing fibers between equipment will establish physical layer trails,



Z. Lin et. al.                                                     Page [11]

Internet Draft      G-Label and G-Label Request Specification      March 2001


    but most likely no HOVC/STS or LOVC/VT trails, despite that there might be
    some SDH/SONET interfaces without switch fabrics connected at the edge of
    the (sub)network.

    Therefore, HOVC/STS labels are independent of LOVC/VT labels. Each one
    will have a dedicated Channel ID.


4.2.1. HOVC/STS specific Channel ID in STM-N/OC-N

    The latest version of G.707 (10/00) has defined a naming structure for
    the AU's, similar to that for the TU's. AUs are now named according the
    (E,D,C,B,A) structure (TUs are named according the (K,L,M) structure).
    This (E,D,C,B,A) structure identifies the AU type, the location in the
    STM-N/OC-N frame and at the same time implies a restriction on the AU-4-
    Xc/STS-Xc types and the timeslots these signals can be transported over.
    Vendor specific extensions exist that have fewer restrictions. To
    accommodate both cases in a single channel ID structure, HOVC/STS channel
    IDs are represented by means of the "SU" structure. A conversion between
    (E,D,C,B,A) and SU is included.

    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   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   1. S is the index of a particular AUG-X/STS-X, AU/STS, STM-Xst signal.
      S=1->N indicates the first timeslot of a specific AUG-X/STS-X,

      AU/STS, STM-Xst inside an STM-N/STS-N multiplex. For example, S=1
      indicates the first AUG-1/STS-3, and S=N indicates the last AUG-1/STS-3 of
      this multiplex.  S=0 is invalid.

  2. U indicates if the AUG-1/STS-3 is subdivided. U=1 indicates that
     the AUG-1/STS-3 is not further subdivided and contains an
     AU-4/STS-3c. U=2->4 indicates a specific AU-3/STS-1 inside the
     given AUG-1/STS-3. For the other signals, U is not-applicable
     and is fixed to 0.


4.2.2. TU/VT specific Channel ID portion in VC-4 and STS-1

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                       |   K   |   L   |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   For SDH VC-4 and VC-3, this is an extension of the numbering scheme defined


Z. Lin et. al.                                                     Page [12]

Internet Draft      G-Label and G-Label Request Specification      March 2001


   in G.707 section 7.3, i.e. the (K, L, M) and (L,M) numbering. For
   SONET and SDH VC-3 the K field is not significant and must be set to zero.

   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 field.

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

   1. K is only significant for SDH VC-4 and must be ignored for SONET and SDH
      VC-3. It indicates a specific branch of a VC-4. K=1 indicates that the
      VC-4 is not further sub-divided and contains a C-4. K=2->4 indicates a
      specific TUG-3 inside the VC-4.

   2. L indicates a specific branch of a TUG-3, VC-3 or STS-1 SPE. It
      is not significant for an unstructured VC-4, and must be 0 in this case.
      L=1 indicates that the TUG-3/VC-3/STS-1 SPE is not further sub-divided
      and contains a TU-3 in SDH; It is not applicable for SONET. L=2->8
      indicates a specific TUG-2/VT Group inside the corresponding
      higher order signal.
      L=9 indicates that the TUG3 structure is not predefined;
      instead it is determined by the incoming signal and autonomously
      adapts to the TU structure of the incoming signal. This signal
      is referred to as a TUG-3.

   3. M indicates a specific branch of a TUG-2/VT Group. It is not
      significant for an unstructured VC-4, TUG-3, VC-3 or STS-1
      SPE and must be 0 in this case. M=1 indicates that the TUG-2/VT Group is
      not further sub-divided and contains a TU-2/VT-6. M=2->3 indicates a
      specific VT-3 inside the corresponding VT Group, these values
      MUST NOT be used for SDH since there is no equivalent of VT-3
      with SDH. M=4->6 indicates a specific TU-12/VT-2 inside the
      corresponding TUG-2/VT Group. M=7->10 indicates a specific
      TU-11/VT-1.5 inside the corresponding TUG-2/VT Group.
      M=11 indicates that the TUG2/VTG structure is not predefined;
      instead it is determined by the incoming signal and autonomously
      adapts to the TU/VT structure of the incoming signal. This signal
      is referred to as a TUG-2/VTG.


4.2.3   TU/VT specific channel portion in sSTM-1k and sSTM-2n

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                               |   L   |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


Z. Lin et. al.                                                     Page [13]

Internet Draft      G-Label and G-Label Request Specification      March 2001


   For SDH sSTM-2n, this is an extension of the numbering scheme defined in
   G.708, i.e. the (L,M) numbering.

   1. L=1->n indicates a specific TUG-2/VT Group inside the sSTM-2n (n=1,2,4).
      L=5 indicates that the TUG2 structure is not predefined;
      instead it is determined by the incoming signal and autonomously
      adapts to the TU structure of the incoming signal. This signal
      is referred to as a TUG-2.

   2. M indicates a specific branch of a TUG-2/VT Group. M=1 indicates that
      the TUG-2/VT Group is not further sub-divided and contains a TU-2/VT-6.
      M=2->4 indicates a specific TU-12/VT-2 inside the corresponding TUG-2/VT
      Group. M=5->8 indicates a specific TU-11/VT-1.5 inside the corresponding
      TUG-2/VT Group.
      M=9 indicates that the TUG2/VTG structure is not predefined;
      instead it is determined by the incoming signal and autonomously
      adapts to the TU/VT structure of the incoming signal. This signal
      is referred to as a TUG-2/VTG.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                       |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   For SDH sSTM-1k, this is an extension of the numbering scheme defined in
   G.708, i.e. the (M) numbering.

   1. M=1->k indicates a specific TU-12 inside the sSTM-1k (k=1,2,4,8,16).


4.2.4   TU/VT specific channel portion in P31s and P4s

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                       |   K   |   L   |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   For the 139 264 kbit/s G.832 framed signal (P4s) option II, this is an
   extension of the numbering scheme defined in ETSI EN 300 417-5-1, i.e. the
   (K, L, M) numbering.

   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 field.




Z. Lin et. al.                                                     Page [14]

Internet Draft      G-Label and G-Label Request Specification      March 2001

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

   1. K indicates a specific branch of a P4s. K=1->3 indicates a specific TUG-
      3 (A, B, C) inside the P4s.

   2. L indicates a specific branch of a TUG-3. L=1 indicates that
      the TUG-3 is not further sub-divided and contains a TU-3. L=2->8 (for
      K=3, L is limited to 2->6) indicates a specific TUG-2.

   3. M indicates a specific branch of a TUG-2. It is not significant for an
      unstructured TUG-3 and must be 0 in this case. M=1 indicates that the
      TUG-2 is not further sub-divided and contains a TU-2. M=2->4 indicates a
      specific TU-12 inside the corresponding TUG-2.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                               |   L   |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   For the 139 264 kbit/s G.832 framed signal (P4s) option I, this is an
   extension of the numbering scheme defined in ETSI EN 300 417-5-1, i.e. the
   (L, M) numbering.

   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 field.

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

   1. L indicates a specific branch of a P4s. L=1->20
      indicates a specific TUG-2.

   2. M indicates a specific branch of a TUG-2. M=1 indicates that the TUG-2
      is not further sub-divided and contains a TU-2. M=2->4 indicates a
      specific TU-12 inside the corresponding TUG-2.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                       |   M   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   For the 34 368 kbit/s G.832 framed signal (P4s) option I, this is an
   extension of the numbering scheme defined in ETSI EN 300 417-5-1, i.e. the
   (L, M) numbering. For sSTM-1k, this is an extension of the numbering scheme



Z. Lin et. al.                                                     Page [15]

Internet Draft      G-Label and G-Label Request Specification      March 2001


   defined in G.708, i.e. the (M) numbering.

   1. M=1->k indicates a specific TU-12 inside the sSTM-1k (k=1,2,4,8,16).


4.3 OTN Label

    TBD

5. Security Considerations

   This document raises no new security concerns.

6. References

[GMPLS-REORG]   Y. Xu, et. al., "GMPLS Signaling Functional Spec.
Modification and Reorganization", Work in Progress, March 2001.

[GMPLS-SIG]       P. Ashwood-Smith, et. al., "Generalized MPLS - Signaling
Functional Description", Work in Progress, Nov. 2000.

[GMPLS-ARCH]      Y. Xu, et. al.,  "GMPLS Control Plane Architecture for ASTN",
Work in Progress, Nov. 2000.

[GMPLS-SIGEN]     B. Mack-Crane, et. al., "Enhancements to GMPLS Signaling for
Optical Technologies", Work in Progress, Nov. 2000.


7. Author Information

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

   Zhi-Wei Lin
   101 Crawfords Corner Rd
   Holmdel, NJ  07733-3030
   Email: zwlin@lucent.com

   Siva Sankaranarayanan
   101 Crawfords Corner Rd
   Holmdel, NJ  07733-3030
   Email: siva@hotair.hobl.lucent.com

   Maarten Visses
   Botterstraat 45
   Postbus 18
   1270 AA Huizen, Netherlands
   Email: mvissers@lucent.com


Z. Lin et. al.                                                     Page [16]