[Search] [txt|pdfized|bibtex] [Tracker] [Email] [Diff1] [Diff2] [Nits]
Versions: 00 01 02 03 04                                                
CCAMP Working Group                                   D. Ceccarelli, Ed.
Internet-Draft                                               F. Fondelli
Intended status: Informational                                  Ericsson
Expires: April 25, 2013                                       S. Belotti
                                                   D. Papadimitriou, Ed.
                                                          Alcatel-Lucent
                                                        October 22, 2012


         Multi layer implications in GMPLS controlled networks
                draft-bcg-ccamp-gmpls-ml-implications-03

Abstract

   This document defines requirements and uses cases for the extension
   of the OTN MLN work to MRNs.  It also provides an evaluation of
   already existing solutions againts new requirements.


Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on April 25, 2013.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of



Ceccarelli, et al.       Expires April 25, 2013                 [Page 1]


Internet-Draft          Multi layer implications            October 2012


   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  MLN and MRN networks: relationship and rationale . . . . . . .  3
   3.  Applicability Scenarios  . . . . . . . . . . . . . . . . . . .  5
   4.  Requirements . . . . . . . . . . . . . . . . . . . . . . . . .  7
   5.  Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . .  8
   6.  Missing information  . . . . . . . . . . . . . . . . . . . . . 13
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
   8.  Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 14
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 14
     10.2. Informative References . . . . . . . . . . . . . . . . . . 15
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15































Ceccarelli, et al.       Expires April 25, 2013                 [Page 2]


Internet-Draft          Multi layer implications            October 2012


1.  Introduction

   Generalized MPLS (GMPLS) supports the control of multiple switching
   technologies: packet switching, Layer-2 switching, TDM (Time-Division
   Multiplexing) switching, wavelength switching, and fiber switching
   ([RFC3945]).

   The Interface Switching Capability concept has been defined for the
   advertisement of the Switching Capabilities of the different
   interfaces of a node [RFC4202], while in the context of Multi Region
   Networks (MRN) the Interface Adjustment Capabiltiy concept has been
   introduced [RFC5339] for the advertisement of adjustment capacity
   within an hybrid node.

   With the introduction of G709v3 networks, a new Switching Capability
   (OTN-TDM) has been defined [OSPF-OTN] and the ISCD updated in order
   to cope with the OTN specific multi stage multiplexing capabilities.
   The new Switching Capability Specific Information (SCSI) field
   provides information about the bandwidth availability at each layer
   of the OTN hierarchy and about the operations that can be performed
   on the different layers, in terms of termination and switching
   capabilities.

   These issues have been addressed in the OTN documents within the OTN
   multi layer scope but need to be extended to MRNs, where the
   termination of a hierarchical LSP leads to the need of properly
   managing different switching capabilities and different adaptation
   functions.

   Scope of this document is describing new requirements derived from
   the extension of OTN MLN hierarchies to MRNs and evaluating impacts
   on existing solutions.

1.1.  Terminology

   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].


2.  MLN and MRN networks: relationship and rationale

   As per [RFC5212], the definition of MLNs and MRNs is as follows:

      - MLN: "a Traffic Engineering (TE) domain comprising multiple data
      plane switching layers either of the same ISC (e.g., TDM) or
      different ISC (e.g., TDM and PSC) and controlled by a single GMPLS
      control plane instance"



Ceccarelli, et al.       Expires April 25, 2013                 [Page 3]


Internet-Draft          Multi layer implications            October 2012


      - MRN: "is defined as a TE domain supporting at least two
      different switching types (e.g., PSC and TDM), either hosted on
      the same device or on different ones, and under the control of a
      single GMPLS control plane instance"

   A network which is an MLN but not an MRN (i.e. multiple layers but a
   single switching capability), like for example an OTN domain, can be
   advertised via the utilization of the Interface Switching Capability
   Descriptor (ISCD).  The ISCD is defined in [RFC4202] and its
   technology specific extensions (SCSI) are defined in different memos
   depending on the technology, e.g. the OTN ones in [OSPF-OTN] and the
   SDH ones in [RFC4203].

   On the other side MRNs (i.e. multiple layers with multiple switching
   capabilities), like for example an OTN data plane (with one or more
   layers) over a WDM data plane (with one or more layers) controlled by
   a single GMPLS instance, need the utilization of an ISCD for each
   technology and an Interface Adjustment Capability Descriptor (IACD)
   [RFC6001] for the advertisement of the internal links providing
   adjustment between the switching capabilities.  A node able to
   terminate data links (over the same interface) with different
   switching capabilities is called hybrid node.  [RFC5212].  For more
   details please see Section 5.

   Hybrid nodes have been introduced not only to address the case of
   nodes able to switch/terminate LSPs from different switching
   capability but also to perform for instance:

      - Traffic-grooming: base GMPLS doesn't enable insertion of traffic
      at an intermediate point along an established LSP, i.e., the
      control plane limits the flexibility of nesting LSP only at the
      head-end of the underlying LSP.  MRN extensions enable to
      multiplex and demultiplex e.g.  PSC LSP into LSC LSP even if the
      LSC LSP does not originate or end at the nodes where the PSC LSP
      are multiplexed or demultiplexed.

      - Transparent regeneration: enables certain nodes equipped with
      PSC + LSC capability to regenerate the photonic signal without
      interrupting the LSC LSP.  This functionality enables to setup
      end-to-end LSC even if certain intermediate nodes are being used
      to regenerate the signal at the PSC level.

   This means that MRN extends the node functionality beyond "terminate
   or switch".

   The central notion in MRN is "adjustment capability".  Adjustment
   capability assumes the availability of adjustment capacity.  An
   adjustment capability is the mean by mean which LSP can be adapted



Ceccarelli, et al.       Expires April 25, 2013                 [Page 4]


Internet-Draft          Multi layer implications            October 2012


   from one SC = X to SC = Y or inserted (e.g. multiplexed or
   demultiplexed) from SC = X to SC = Y .  Advertisement of adjustment
   capacity by a given node assumes the functionality of adjustment is
   locally supported.


3.  Applicability Scenarios

   When moving from OTN MLNs to general MRNs, the multiplexing tree
   concept introduced in [OSPF-OTN] needs to be extended so to take into
   account both different switching capabilities within the same muxing
   tree and adaptations between client hierarchies and server
   hierarchies.

   In the following figure an example of muxing tree supporting TDM,
   PSC, OTN-TDM and LSC hierarchies mixed together is shown.


                      VC-4
                       |
              ODU1   STM-16    PSC   L2SC
                |      |        |     |
                |      |        |     |
              ODU2    ODU2     ODU1   |
                 \     \        /    /
                  \     \      /    /
                   \     \    /    /
                    \     \  /    /
                     \     \/    /
                      \_ _ODU3__/
                           |
                          OCh


                           Figure 1: Muxing tree

   As it is possible to understand from the figure above, an MRN
   equipment can host a variety of client-server relationships.  Four
   different scenarios can be identified:

      - A signal type X is a client to a Signal type Y (1:1) - e.g.
      Ethernet over WDM

      - A signal type X is a client to a Intra switching technology
      Hierarchy Y (1:N) - e.g.  Ethernet over OTN

      - An Intra switching technology Hierarchy X is a client to a
      Signal Type Y (M:1) - e.g.  ODU over WDM



Ceccarelli, et al.       Expires April 25, 2013                 [Page 5]


Internet-Draft          Multi layer implications            October 2012


      - An Intra switching technology Hierarchy X is a client to an
      Intra switching technology Hierarchy Y (M:N) - e.g.  SDH over OTN

   Being the first three scenarios a particular case of the fourth one,
   in the following only the general case of M:N relationship will be
   addressed.

   This kind of client-server hierarchy can be achieved, depending on
   the impelemntation, via single board or a cascade of them.  In the
   latter case boards are connected via internal links, which can be
   either intra or inter switching capaility (e.g.  ODU2->ODU3 or
   PSC->LSC).  Those links should not be modeled as external TE links,
   but there is the need to advertise their characteristics and
   availability in terms of bandwidth and optical parameters.


        +--------------------------------------------------------+
        |        +------------+    Eth   +------------+          |
        |        |            |     |    |            |          |
        |  OTU-1 +----+       |     |    +----+       |          |
        |   +----+    |       |     +--> +    |       |          |
        |        | 8  |       |          | 4  |       |          |
        |  OTU-1 |ODU1+------+|          |ODU2+------+| OTU-3    |
        |   +----+    |ODU-2 |..........>+    |ODU-3 |+----------|-->
        |        |    +------+|Internal  |    +------+|          |
        |   OTU-1|    |       |Physical  |    |       |          |
        |   +----+    |       |  Link    +    |       |          |
        |        +----+       | (OTU-2)  +----+       |          |
        |        |            |          |            |          |
        |        +------------+          +------------+          |
        +--------------------------------------------------------+



                       Figure 2: Cascaded muxponder

   Moreover, as described in [RFC5212], in a hybrid node there is the
   need to take into account also the node's internal adjustment
   capabilities between the switching technologies supported.  An
   example of hybrid node with different switching matrices is shown in
   the following figure, where both an SDH and OTN matrix are available
   and the two switching elements are internally interconnected so that
   it is possible to terminate some resources (e.g.  OTN interface Y1)
   or provide adjustment for the SDH traffic (e.g.  OTN interface Y2
   toward the SDH matrix).  In addition to the internal links between
   matrices it is possible to have internal links between matrices and
   cascaded cards for the creation of the muxing hierarchy.  In the
   example below both the SDH and OTN matrices are client to an



Ceccarelli, et al.       Expires April 25, 2013                 [Page 6]


Internet-Draft          Multi layer implications            October 2012


   ODU2->ODU3 muxponder (through interfaces Y4 and Y5), which in turn is
   client to an OCh WSS.



                                       | 10GbE
         +-------------------------+-------------+
         |                         |             |
         |                         |             |
    +-+  |          +---------+    |             |
    |X|  |      X1  |         |    |             |
  __+-+__|__________|   \  /  |    |             |
         |          `    \/   | X3 |             |
         |      X2  |    /\   '''| |    ODU2     |
         |     |'''''   /  \  |  | | Y6+---+     |          +---------+
         |     |    |  +---+  |  | +---+   |     |          |         |
         |     |    |  |SDH|  +  |  Y5 |   | ODU3|          |         |
         |     |    |__+---+__|  +-----+   +----+|          |         |
         |     |                       |   |    ||  OTU3/OCH|  +---+  |
         |     |                       |   |    ++----------+  |WSS|  +---
         |     |                    Y4 |   |    || Y7       |  +---+  |Y8
         |     |    +----------+  ......   +----+|          |         |
    +-+  |     |    |   \  /   |  | ___|   |+--+ |          |         |
    |Y|  |     |Y2  |    \/    |  | |  +---+|OT| |          |         |
    +-+  |     .....|    /\    |Y3| |       +--+ |          +---------+
  -------+----------+   /  \   |  | |            |
         |      Y1  |          .... |            |
         |          |  +---+   |    |    +       |
         |          |  |OTN|   |    | ODU2       |
         |          |__+---+___|                 |
         +---------------------------------------+


   Figure 3: Hybrid node with optical muxponder and different switching
                                 matrices


4.  Requirements

   In order to deal with all the scenarios depiscted in the previous
   sections, protocol extensions need to take into account the following
   set of requirements.

      1.  It must be possible to identify from which branch of X to
      which branch of Y the mapping is performed.  Due to a restricted
      connectivity to a given switching layer, not all the indicated
      branches are really available.  An example of such limitations can
      be seen in figure Figure 3, where for example the SDH client can



Ceccarelli, et al.       Expires April 25, 2013                 [Page 7]


Internet-Draft          Multi layer implications            October 2012


      be mapped only on itnerface Y5 of the muxponder board or the
      10GbEth on interface Y6.  In figure Figure 1 it is also possible
      to see that the OTN has a hierarchy with 3 branches (i.e.
      ODU1->ODU2->ODU3, ODU2->ODU3 and ODU1->ODU3) and an SDH signal can
      be mapped only over the ODU2->ODU3 branch while an Ethernet one
      can be mapped only on the ODU1->ODU3).  So it is not eough to say
      that SDH can be mapped over ODU or Eth over ODU as further info is
      needed.  Moreover it is also not enough to say that Eth is mapped
      over ODU1 because in the same example 2 different branches have
      the ODU1 as the top most layer (i.e.  ODU1->ODU2->ODU3 and
      ODU1->ODU3) and not both of them can support Eth mapping.

      2.  Adaptation information from X to Y to be used both in case of
      Y being switched and X mapped over it or in case of both X and Y
      being switched.  Please note that more than one type of adaptation
      might be availble.

      3.  Amount of available bandwidth in the mapping between X and Y
      (as per actual IACD definition)

      4.  It must be possible to advertise intra-switching capability
      associated to internal links.  A typical case is a hierarchy
      gained through the cascade of multiple cards (e.g. trasnponders,
      muxponders) and the link from one board to the other one has a
      given bandwidth.

      5.  It must be possible to advertise inter-switching capability
      associated to internal links.  A typical case is a M:N client-
      layer hierarchy gained through the cascade of multiple cards (e.g.
      SDH client to a muxponder card) and the link from one board to the
      other one has a given bandwidth.


5.  Evaluation

   [RFC6001] defined the Interface Adjustment Capability Descriptor
   (IACD) for the advertisement of internal adjustment capability of
   hybrid nodes [RFC5212].

   A common adjustment pool is a pool of reservable and sharable
   resources that are i) allocated on demand/dynamically and ii) either
   assigned to a single SC (single adjustment pool model) or multiple SC
   (multiple adjustment pool model) or possibly their combination.

   In the former case (single pool model), the "lower SC" value of the
   IACD sub-TLV (associated to the adjustment pool) is set to the SC
   value of ISCD sub-TLV of the interface that interfaces with the
   adjustment pool.  The "upper" SC value of the IACD (associated to the



Ceccarelli, et al.       Expires April 25, 2013                 [Page 8]


Internet-Draft          Multi layer implications            October 2012


   adjustment pool) determines the SC capability of the resource pool
   itself.  In this case the (upper) encoding is set to 0xFF.  In other
   terms, the capacity of the adjustment pool is not directly accessible
   - over the wire - by other nodes belonging to the same TE domain
   (assuming homogeneous LSP encoding type along the LSP path).  This
   model (see Example 1) is typically used when the node matrix
   switching capability is not terminating/initiating any LSP (the node
   only exposes the capability associated to its I/O) but nodes part of
   the same TE domain can still take into account the adjustment
   capacity usage on that node.

   In the latter case (multiple pool model), the "lower SC" value of the
   IACD sub-TLV (associated to the adjustment pool) is set to the SC
   value of ISCD sub-TLV of the interface(s) that interfaces with the
   adjustment pool.  The "upper" SC value of the IACD sub-TLV
   (associated to the adjustment pool) determines the SC capability of
   the adjustment pool itself.  However, the (upper) SC value of the
   IACD sub-TLV shall correspond to at least one of the SC values
   associated to one of the ISCD sub-TLVs, i.e., the adjustment pool SC
   value shall be covered by at least one of the SC values associated to
   the ISCD sub-TLVs.  In other terms, the capacity of the adjustment
   pool is directly accessible compared to the single pool model.  This
   model (see Example 2) is typically used when nodes expose their full
   (multi-level) grooming and initiation/ termination capacity.

   Example of single pool model: in the IACD sub-TLV the "upper" SC type
   = TDM/HO-SDH, and the "lower" SC type being respectively "L2SC" and
   "OTH/TDM".  In this example, the capacity associated to the IACD
   represents the "interconnection capacity" between the interface X
   (L2SC or OTH) to Y = (HO-SDH/TDM).  The encoding type associated to
   the upper SC is set to 0xFF.




















Ceccarelli, et al.       Expires April 25, 2013                 [Page 9]


Internet-Draft          Multi layer implications            October 2012


                                 ^ ^     ^
                                 | |     |
                  +-------------------------------------+
                  | Network      | | ... |              |
                  | element      | |     |              |
                  |             +---------+             |
                  |      +------|  L2SC   |<----+       |
                  |      |      |         |     |       |
                  |      |      +---------+     |       |
                  |      |                      |       |
                  |      |      +---------+     |       |
                  |      +----->| HO-SDH  |-----+       |
                  |      +------|         |<----+       |
                  |      |      +---------+     |       |
                  |      |                      |       |
                  |      |      +---------+     |       |
                  |      +----->|         |-----+       |
                  |      _      |         |      _      |
                  |     / |     |         |     | \     |
        Fiber 1   |    /  |-----|   OTH   |-----|  \    | Fiber 1
             -----|---|   |-----|         |-----|   |---|----
              ... |   |   |-----|         |-----|   |...|
             -----|---|   |-----|         |-----|   |---|----
        Fiber N   |    \  |-----|         |-----|  /    | Fiber N
                  |     \_|     +---------+     |_/     |
                  +-------------------------------------+



                  Figure 4: Example of single pool model

   The advertisement for the node interfaces will be:

      + L2SC interfaces

         - ISCD sub_TLV 1 for L2SC interface

         - IACD sub_TLV 1 for L2SC to HO-SDH (1) in figure above

      + OTH inferfaces

         - ISCD sub_TLV 1 for OTH interface

         - IACD sub_TLV 1 for OTH to HO-SDH (2) in figure above

   Example of multiple pool model: In this case we will show two
   examples, the first of which does not foresee any interconnection
   between the L2SC and the HO-SDH matrices, while the second one does.



Ceccarelli, et al.       Expires April 25, 2013                [Page 10]


Internet-Draft          Multi layer implications            October 2012


   In the former case there is at least one ISCD sub-TLV of SC = X
   corresponding to the lower SC value (HO-SDH/TDM) of the IACD sub-TLV
   associated to the first adjustment pool (HO-SDH/TDM), and one ISCD
   sub-TLV of type SC = Y corresponding to the lower SC value (L2SC) of
   the IACD sub-TLV associated to the second adjustment pool Y (L2SC).
   In this example, the capacity associated to the IACD represents the
   "interconnection capacity" between the pool of SC = X (HO-SDH/TDM) to
   Y (L2SC).  Each TE Link 1...N is able to get access to this
   adjustment capacity.


              +------------------------------------------------+
              | Network                                        |
              | element                                        |
              |                  +---------+                   |
              |        +---------|  L2SC   |<---------+        |
              |        |       **|         |**        |        |
              |        |       * +---------+ *        |        |
              |        |       *             *        |        |
              |        |       * +---------+ *        |        |
              |        |       **|         |**        |        |
              |        | +-------| HO-SDH  |<-------+ |        |
              |        | |       |         |        | |        |
              |        | |       +---------+        | |        |
              |        | |                          | |        |
              |        | |       +---------+        | |        |
              |        | |       |         |        | |        |
              |     _  | |       |         |        | | _      |
              |    / |<- |       |         |        | +| \     |
    Fiber 1   |   /  |<--+       |   OTH   |        +--|  \    | Fiber 1
         -----|--|   |-----------|         |-----------|   |---|----
          ... |  |   |-----------|         |-----------|   |...|
         -----|--|   |-----------|         |-----------|   |---|----
    Fiber N   |   \  |-----------|         |-----------|  /    | Fiber N
              |    \_|           +---------+           |_/     |
              +------------------------------------------------+


   Figure 5: Example of multiple pool model - No interconnection between
                              OTH and HO-SDH

   In this case the advertisement, which is the same for each of the N
   TE Link is:

      - ISCD sub_TLV for LSC

      - ISCD sub_TLV for HO-SDH




Ceccarelli, et al.       Expires April 25, 2013                [Page 11]


Internet-Draft          Multi layer implications            October 2012


      - ISCD sub_TLV for OTH

      - IACD sub_TLV for LSC to HO-SDH (starred link)

   On the other side, if we consider the same scenario including the
   inteconnection between the OTH and HO-SDH matrices, as shown in
   figure below, the advertisement changes as follows.


              +------------------------------------------------+
              | Network                                        |
              | element                                        |
              |                  +---------+                   |
              |        +---------|  L2SC   |<---------+        |
              |        |       **|         |**        |        |
              |        |       * +---------+ *        |        |
              |        |       *             *        |        |
              |        |       * +---------+ *        |        |
              |        |       **|         |**        |        |
              |        | +-------| HO-SDH  |<-------+ |        |
              |        | |     ..|         |..      | |        |
              |        | |     : +---------+ .      | |        |
              |        | |     :             :      | |        |
              |        | |     : +---------+ :      | |        |
              |        | |     : |         | :      | |        |
              |     _  | |     :.|         |.:      | | _      |
              |    / |<- |       |         |        | +| \     |
    Fiber 1   |   /  |<--+       |   OTH   |        +--|  \    | Fiber 1
         -----|--|   |-----------|         |-----------|   |---|----
          ... |  |   |-----------|         |-----------|   |...|
         -----|--|   |-----------|         |-----------|   |---|----
    Fiber N   |   \  |-----------|         |-----------|  /    | Fiber N
              |    \_|           +---------+           |_/     |
              +------------------------------------------------+


      Figure 6: Example of multiple pool model - With interconnection
                          between OTH and HO-SDH

   This time the advertisement is modified as follows:

      - ISCD sub_TLV 1 for LSC

      - ISCD sub_TLV 2 for HO-SDH

      - ISCD sub_TLV 3 for OTH





Ceccarelli, et al.       Expires April 25, 2013                [Page 12]


Internet-Draft          Multi layer implications            October 2012


      - IACD sub_TLV 1 for LSC to HO-SDH (starred link)

      - IACD sub_TLV 2 for HO-SDH to OTH (dotted link)

   The IACD is the only object defined in routing for the management of
   hybrid nodes.  It provides the information for the forwarding/
   switching capability and is used in addition to the ISCD.



       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Lower SC      | Lower Encoding| Upper SC      | Upper Encoding|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 0              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 1              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 2              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 3              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 4              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 5              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 6              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Max LSP Bandwidth at priority 7              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            Adjustment Capability-specific information         |
      |                           (variable)                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                           Figure 7: IACD format


6.  Missing information

   The pieces of information needed for addressing the requirements
   listed in Section 4 are:

      - Mapping information from a client to a server layer.  E.g. an
      ethernet client could be mapped over and OTN hierarchy using a
      GFP-F or GFP-T adaptation.




Ceccarelli, et al.       Expires April 25, 2013                [Page 13]


Internet-Draft          Multi layer implications            October 2012


      - Connectivity constraints: need to describe optical transponder
      muxing scheme with positioning and restricted connectivity in
      order to provide end to end connectivity.  In the example shown in
      picture Figure 1, the capability of muxing an SDH hierarchy is
      shown, but the SDH cannot be injected in any branch of the OTN
      hierarchy.  There is the need to specify that the SDH hierarchy
      can be only muxed into the ODU->ODU3 branch of the OTN hierarchy
      and not in all of them.

      - Multistage interswitching capability: The IACD already allows
      advertising the multiplexing of single and multi-stage muxing
      scenarios like the one in the reference muxing tree, where an SDH
      hierarchy is muxed over an OTN hierarchy, which is againg muxed
      over an OCh (two levels of muxing).


7.  IANA Considerations

   TBD


8.  Contributors

   TBD


9.  Acknowledgements

   TBD


10.  References

10.1.  Normative References

   [OSPF-OTN]
              D.Ceccarelli, D.Caviglia, F.Zhang, D.Li, S.Belotti,
              P.Grandi, R.Rao, K.Pithewan, J.Drake, "Traffic Engineering
              Extensions to OSPF for Generalized MPLS (GMPLS) Control of
              Evolving G.709 OTN Networks, work in progress
              draft-ietf-ccamp-gmpls-ospf-g709v3-03", August 2012.

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

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



Ceccarelli, et al.       Expires April 25, 2013                [Page 14]


Internet-Draft          Multi layer implications            October 2012


   [RFC4203]  Kompella, K. and Y. Rekhter, "OSPF Extensions in Support
              of Generalized Multi-Protocol Label Switching (GMPLS)",
              RFC 4203, October 2005.

   [RFC5212]  Shiomoto, K., Papadimitriou, D., Le Roux, JL., Vigoureux,
              M., and D. Brungard, "Requirements for GMPLS-Based Multi-
              Region and Multi-Layer Networks (MRN/MLN)", RFC 5212,
              July 2008.

   [RFC6001]  Papadimitriou, D., Vigoureux, M., Shiomoto, K., Brungard,
              D., and JL. Le Roux, "Generalized MPLS (GMPLS) Protocol
              Extensions for Multi-Layer and Multi-Region Networks (MLN/
              MRN)", RFC 6001, October 2010.

10.2.  Informative References

   [G.709]    ITU-T, "Interface for the Optical Transport Network
              (OTN)", G.709 Recommendation (and Amendment 1),
              February 2001.

   [G.709-v3]
              ITU-T, "Draft revised G.709, version 3", consented
              by ITU-T on Oct 2009.


Authors' Addresses

   Daniele Ceccarelli (editor)
   Ericsson
   Via Melen 77
   Genova - Sestri Ponente
   Italy

   Email: daniele.ceccarelli@ericsson.com


   Francesco Fondelli
   Ericsson
   Via Moruzzi 1
   Pisa
   Italy

   Email: francesco.fondelli@ericsson.com








Ceccarelli, et al.       Expires April 25, 2013                [Page 15]


Internet-Draft          Multi layer implications            October 2012


   Sergio Belotti
   Alcatel-Lucent
   Via Trento, 30
   Vimercate
   Italy

   Email: sergio.belotti@alcatel-lucent.com


   Dimitri Papadimitriou (editor)
   Alcatel-Lucent
   Copernicuslaan 50
   Antwerpen  B-2018
   Belgium

   Email: dimitri.papadimitriou@alcatel-lucent.be



































Ceccarelli, et al.       Expires April 25, 2013                [Page 16]