CCAMP Working Group Ashok Kunjidhapatham Internet-Draft Rajan Rao Intended status: Proposed Standard Biao Lu Expires: September 15, 2011 Snigdho Bardalai Khuzema Pithewan Infinera Corp John E Drake Juniper Networks Steve Balls Metswitch Networks March 14, 2011 OSPF TE Extensions for Generalized MPLS (GMPLS) Control of G.709 Optical Transport Networks draft-ashok-ccamp-gmpls-ospf-g709-03.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. 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 Copyright and License Notice Copyright (c) 2011 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 Rajan Rao, et al. Expires September 15, 2011 [Page 1] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Abstract As OTN network capabilities continue to evolve, there is an increased need to support GMPLS control for the same. [RFC4328] introduced GMPLS signaling extensions for supporting the early version of G.709 [G.709-v1]. The basic routing considerations from signaling perspective is also specified in [RFC4328]. The recent revision of ITU-T Recommendation G.709 [G.709-v3] and [GSUP.43] have introduced new ODU containers (both fixed and flexible) and additional ODU multiplexing capabilities, enabling support for optimal service aggregation. This document describes OSPF protocol extensions to support Generalized MPLS (GMPLS) control for routing services over the standardized OTU/ODU containers in support of ODU based TDM switching. Routing support for Optical Channel Layer switching (Lambda switching) is not covered in this document. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Conventions used in this document . . . . . . . . . . . . . . . 5 3. OTU/ODU Link Representation . . . . . . . . . . . . . . . . . . 5 3.1. OTUk TE-Link . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. ODUk TE-Link . . . . . . . . . . . . . . . . . . . . . . . 6 3.3. ODUj TE-Link . . . . . . . . . . . . . . . . . . . . . . . 6 3.4. Bundled TE-Link . . . . . . . . . . . . . . . . . . . . . . 7 3.5. OTU/ODU Link Property Agreement . . . . . . . . . . . . . . 7 4. OTU/ODU Link Bandwidth Model . . . . . . . . . . . . . . . . . . 8 5. OSPF TE-LSA Extension . . . . . . . . . . . . . . . . . . . . . 9 5.1. Maximum Bandwidth . . . . . . . . . . . . . . . . . . . . . 9 5.2. Maximum Reservable Bandwidth . . . . . . . . . . . . . . . 9 5.3. Unreserved Bandwidth . . . . . . . . . . . . . . . . . . . 9 5.4. Interface Switch Capability Descriptor . . . . . . . . . . 9 5.4.1 ODU Switching . . . . . . . . . . . . . . . . . . . . 11 5.4.2. ODUk Switch Capability Specific Information . . . . 11 5.4.2.1 Bandwidth sub TLV for fixed ODUj . . . . . . . . 12 5.4.2.2 Bandwidth sub-TLV for ODUflex . . . . . . . . . 13 5.5. Interface Multiplexing Capability Descriptor . . . . . . 13 5.5.1 Multiplex Layers and Hierarchical LSP . . . . . . . . 14 Rajan Rao, et al. Expires September 15, 2011 [Page 2] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 5.5.2 IMCD format . . . . . . . . . . . . . . . . . . . . . 15 5.5.2.1 G-PID . . . . . . . . . . . . . . . . . . . . . 16 5.5.2.2 Available Bandwidth . . . . . . . . . . . . . . 17 5.5.3 Controlling IMCD advertisement . . . . . . . . . . . 17 5.5.4 How to use IMCDs for FA creation . . . . . . . . . . 18 5.5.5 IMCD and non OTN services . . . . . . . . . . . . . . 18 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.1. Network with no IMCD advertisement (no FA support) . . . 19 6.2. Network with IMCD advertisement for FA support . . . . . 20 6.3. Link bundle with similar muxing capabilities . . . . . . 22 6.4. Link bundle with dissimilar muxing capabilities: Layer relation . . . . . . . . . . . . . . . . . . . . . . . . 23 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 10.1. Normative References . . . . . . . . . . . . . . . . . 25 10.2. Informative References . . . . . . . . . . . . . . . . 25 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26 Author's Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 Appendix A: Abbreviations & Terminology . . . . . . . . . . . . 28 A.1 Abbreviations: . . . . . . . . . . . . . . . . . . . . . . 28 A.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . 28 Appendix B : Optimization Techniques . . . . . . . . . . . . . . 30 B.1 Multiple ISCDs Vs. Single ISCD . . . . . . . . . . . . . . 30 B.1 Multiple IMCDs Vs. Single IMCD . . . . . . . . . . . . . . 30 B.1 Eight priorities Vs. restricted number of priorities . . . 30 Appendix C: Relation with MLN & MRN . . . . . . . . . . . . . . . 30 Appendix D : AMP, BMP & GMP Mapping . . . . . . . . . . . . . . . 30 Rajan Rao, et al. Expires September 15, 2011 [Page 3] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 1. Introduction Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945] extends MPLS from supporting Packet Switching Capable (PSC) interfaces and switching to include support of four new classes of interfaces and switching: Layer-2 Switching (L2SC), Time-Division Multiplex (TDM), Lambda Switch (LSC), and Fiber-Switch (FSC) Capable. A functional description of the extensions to MPLS signaling that are needed to support these new classes of interfaces and switching is provided in [RFC3471]. OSPF extensions for supporting GMPLS are defined in [RFC4203]. ITU-T Recommendations G.709 and G.872 provide specifications for OTN interface and network architecture respectively. As OTN network capabilities continue to evolve; there is an increased need to support GMPLS control for the same. GMPLS signaling extensions to support G.709 OTN interfaces are specified in [RFC4328]. The basic routing considerations from signaling perspective is specified. G.709 specifications evolved rapidly over the last few years. Following are the features added in OTN since the first version [G.709-v1]. (a) OTU Containers: Pre-existing Containers: OTU1, OTU2 and OTU3 New Containers introduced in [G.709-v3]: OTU2e and OTU4 New Containers introduced in [GSUP.43]: OTU1e, OTU3e1 and OTU3e2 (b) Fixed ODU Containers: Pre-existing Containers: ODU1, ODU2 and ODU3 New Containers introduced in [G.709-v3]: ODU0, ODU2e and ODU4 New Containers introduced in [GSUP.43]: ODU1e, ODU3e1 and ODU3e2 (c) Flexible ODU Containers: ODUflex for CBR and GFP-F mapped services. ODUflex uses 'n' number of OPU Tributary Slots where 'n' is different from the number of OPU Tributary Slots used by the Fixed ODU Containers. (d) Tributary Slot Granularity: OPU2 and OPU3 support two Tributary Slot Granularities: (i) 1.25Gbps and (ii) 2.5Gbps. (e) Multi-stage ODU Multiplexing: Multi-stage multiplexing of LO-ODUs into HO-ODU is supported. Also, multiplexing could be heterogeneous (meaning LO-ODUs of different rates can be multiplexed into a HO-ODU). OTN networks support switching at two layers: (i) ODU Layer - TDM Rajan Rao, et al. Expires September 15, 2011 [Page 4] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 Switching and (ii) OCH Layer - Lambda (LSC) Switching. The nodes on the network may support one or both the switching types. When multiple switching types are supported MRN/MLN based routing [RFC5212] and [RFC6001] is assumed. This document covers OSPF extensions to support routing over the standardized OTU/ODU containers in support of ODU Layer based TDM switching as outlined in the framework document [G.709-FRAME]. The Interface Switch Capability Descriptor extensions for ODU Layer switching and bandwidth representation for ODU containers are defined in this document. Routing support for Optical Channel Layer switching (LSC) is beyond the scope of this document. Refer to [WSON-FRAME] for further details. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document is to be interpreted as described in RFC-2119 [RFC2119]. In addition, the reader is assumed to be familiar with the terminology used in ITU-T [G.709-v3], [G.872] and [GSUP.43], as well as [RFC4201] and [RFC4203]. Abbreviations used in this document is detailed in Appendix A. 3. OTU/ODU Link Representation G.709 OTU/ODU Links are represented as TE-Links in GMPLS Traffic Engineering Topology for supporting ODU layer switching. These TE-Links can be modeled in multiple ways. Some of the prominent representations are captured below. 3.1. OTUk TE-Link OTUk Link can be modeled as a TE-Link. Switching at ODUk layer and ODUj layer (including multi-stage multiplexing) can be managed on OTUk TE-Link. Figure-1 below provides an illustration of this link type. When a LO-ODU layer being switched on an OTUk interface involves multi-stage multiplexing, all the HO-ODU layer(s) should necessarily terminate between the same pair of nodes as the OTUk layer in this case. For example, if ODU1 layer switching is configured on a OTU3 link via multiplexing hierarchy Rajan Rao, et al. Expires September 15, 2011 [Page 5] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 ODU3<-ODU2<-ODU1, HO-ODUs (namely ODU3 & ODU2) should terminate between the same pair of nodes as OTU3 layer. +-------+ +-------+ +-------+ | OTN | | OTN | | OTN | |Switch |<- OTUk Link ->|Switch |<- OTUk Link ->|Switch | | A | | B | | C | +-------+ +-------+ +-------+ |<-- TE-Link -->| |<-- TE-Link -->| Figure-1: OTUk TE-Link 3.2. ODUk TE-Link When ODUk layer does not terminate on the same pair of nodes as OTUk layer, ODUk link should be modeled as a TE-Link. As bandwidth is directly managed on the ODUk link, associated OTUk links are not significant in this case. Switching at ODUj layer (including multi-stage multiplexing) can be managed on ODUk TE-Link. Figure-2 below provides an illustration of this link type. When a LO-ODU layer being switched on the ODUk interface involves multi-stage multiplexing, all the HO-ODU layer(s) should necessarily terminate between the same pair of nodes as ODUk in this case. For example, if ODU1 layer switching is configured on an ODU3 link via multiplexing hierarchy ODU3<-ODU2<-ODU1, HO-ODU (namely ODU2) should terminate between the same pair of nodes as ODU3. +-------+ +-------+ +-------+ | OTN | | OTN | | OTN | |Switch |<- OTUk Link ->|Switch |<- OTUk Link ->|Switch | | A | | B | | C | +-------+ +-------+ +-------+ ODUk Switched |<------------- ODUk Link ------------->| |<-------------- TE-Link--------------->| Figure-2: ODUk TE-Link 3.3. ODUj TE-Link When a LO-ODUj within a HO-ODUk does not terminate on the same pair of nodes as HO-ODUk layer, Separate TE-Links needs to be modeled for ODUk link and ODUj link. Also, ODUk link shall no longer manage the bandwidth associated with the ODUj link. Switching at sub-ODUj layer (including multi-stage multiplexing) Rajan Rao, et al. Expires September 15, 2011 [Page 6] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 can be supported on this ODUj TE-Link. Figure-3 below provides an illustration of this link type. When a LO-ODU layer being switched on an ODUj interface involves multi-stage multiplexing, all the HO-ODU layer(s) should necessarily terminate between the same pair of nodes as ODUj in this case. For example, if ODU0 layer switching is configured on an ODU2 link via multiplexing hierarchy ODU2<-ODU1<-ODU0, HO-ODU (namely ODU1) should terminate between the same pair of nodes as ODU2. +-----+ +-----+ +-----+ +-----+ | OTN | | OTN | | OTN | | OTN | | SW |<-OTUk Link->| SW |<-OTUk Link->| SW |<-OTUk Link->| SW | | A | | B | | C | | D | +-----+ +-----+ +-----+ +-----+ ODUj Switched ODUk Switched |<--------- ODUk Link ---------->| |<--------- TE-Link #1 --------->| |<-------------------- ODUj Link ------------------->| |<-------------------- TE-Link #2 ------------------>| Figure-3: ODUj TE-Link 3.4. Bundled TE-Link Any mix of OTU and ODU links of dissimilar rates that terminates on same pair of nodes and meets the entire bundling criterion specified in TE-Link Bundling specification [RFC4201] can be pulled together to form a Bundle TE-Link. This is required for better scalability. 3.5. OTU/ODU Link Property Agreement The OTN interfaces (associated with peer nodes) participating in a TE-Link may not be fully compatible in terms of OTN interface properties. The lowest common denominator between the two links endpoints need to be used for forming the TE link. Some of OTN specific link properties that need to be agreed upon between the two link endpoints (on peer nodes) are: (a) OPU Tributary Slot Granularity for OPU2 and OPU3. (b) Multiplexing hierarchies supported - both number of stages and specific LO-ODUs supported in each stage. This includes both Fixed and Flexible ODU containers. Rajan Rao, et al. Expires September 15, 2011 [Page 7] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 These link properties either can be configured or discovered through Link discovery mechanism. The details of such mechanism is beyond the scope of this document. 4. OTU/ODU Link Bandwidth Model Bandwidth allocation/management on OTU/ODU links is done in terms of discrete units called OPU Tributary Slots. OPU Tributary Slots occurs in two granularities (1.25Gbps and 2.5Gbps) and the actual bit-rate of the OPU Tributary Slot slightly varies for different ODU container types (i.e., ODU1, ODU2, ODU3 and ODU4). As a result of this disparity, number of Tributary Slots required to map a LO-ODU on different HO-ODU container types could vary. For example, ODU2e requires 9 OPU TSs on ODU3 and 8 OPU TSs on ODU4. The basic objectives of OTN interface bandwidth model are as follows: (a) Support ODU multi-stage multiplexing hierarchy and yet not require advertisement of complete hierarchy tree. (b) Account for bandwidth fragmentation that can result due to the restricted multiplexing hierarchy supported on an OTN interface. For example, assume that an ODU3 interface supports direct multiplexing of ODU2 only. Here, mapping of ODU1 and ODU0 is possible only through second stage multiplexing underneath ODU2. If two ODU1 are created under two different ODU2, only two ODU2 can be created further on the interface although 28 Tributary Slots (1.25Gbps) are available on the interface (ODU hierarchy). (c) Hide the complexities in Tributary Slot Granularities (1.25Gbps and 2.5Gbps) from bandwidth model and thereby simplify the end-to-end path computation. As explained in the previous section, this needs to be negotiated as a part of link discovery or pre-configured locally on the either ends. (d) Hide the complexities in Tributary Slot Size disparities (among ODU containers) and number of Tributary Slots required to map a LO-ODU. This can be achieved by advertising the number of LO-ODU containers that can be mapped on an OTN interface rather than number of Tributary Slots or absolute bandwidth in bytes/sec. (e) For ODU-Flex service, Absolute bandwidth required (for CBR or GFP mapped service) needs to be mapped to 'n' Tributary Slots of certain bit rate. This needs Tributary Slot bit-rate and number of Tributary slots to be advertised. Rajan Rao, et al. Expires September 15, 2011 [Page 8] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 5. OSPF TE-LSA Extension This section describes the OSPF TE-LSA Extensions to support bandwidth encoding for OTU/ODU TE-Links. 5.1. Maximum Bandwidth The format and interpretation of this attribute must be consistent with OSPF-TE Extension [RFC3630] and TE-Link Bundling Support [RFC4201] specifications. The OPUk payload nominal rate (in bytes per sec) as specified in [G.709-v3] shall be encoded in this attribute. 5.2. Maximum Reservable Bandwidth The format and interpretation of this attribute must be consistent with OSPF-TE Extension [RFC3630] and TE-Link Bundling Support [RFC4201] specifications. 5.3. Unreserved Bandwidth The format and interpretation of this attribute must be consistent with OSPF-TE Extension [RFC3630] and TE-Link Bundling Support [RFC4201] specifications. Unreserved Bandwidth in bytes per second is not of much value for OTU/ODU interfaces. Unreserved Bandwidth per ODU rate is more appropriate and useful in this case. Implementations may choose to ignore this attribute and consider per ODU-rate Unreserved Bandwidth defined in Interface Switch Capability Descriptor for "G.709 ODUk" encoding type. See section 5.4.1 for details. 5.4. Interface Switch Capability Descriptor The Interface Switching Capability Descriptor describes switching capability of an interface [RFC 4202]. This document defines a new Switching Capability value for OTN [G.709-v3] as follows: Value Type ----- ---- 250 OTN-TDM capable (OTN-TDM) Nodes advertising ODUk switching BW for for its links must use Switching Type and Encoding values as follows: Switching Type = OTN-TDM Encoding Type = G.709 ODUk (Digital Path) [as defined in RFC4328] Rajan Rao, et al. Expires September 15, 2011 [Page 9] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 Both fixed ODUk (where k=0,1,2,3,4,1e,2e) and flexible ODUs (ODUflex) use same switching type and encoding values. When Swithcing Type and Encoding fields are set to values as stated above, the Interface Switching Capability Descriptor should be interpreted 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Cap | Encoding | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ODUk - Switch Capability Specific Information | | (variable length) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Maximum LSP Bandwidth This field should be encoded with Nominal Rate of the ODUj (j<= k) for which Bandwidth is advertised. The bandwidth unit is in bytes per second & the encoding is in IEEE floating point format [RFC 3471]. The discrete values for varous ODUj(s) is shown in the table below. For an unbundled link, the Maximum LSP Bandwidth at priority 'p' is set to Nominal rate of the ODUj for which bandwidth is advertised in Switch Capability Specific Information (SCSI). For bundled link too, the Maximum LSP Bandwidth at priority 'p' is set to Nominal rate of the ODUj for which bandwidth is advertised in Switch Capability Specific Information (SCSI). Rajan Rao, et al. Expires September 15, 2011 [Page 10] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 ODU type Nomial Rate(bytes/s) Value in Byes/Sec (IEEE format) ----------- ----------------- ------------------------------ ODU0 15552000 ODU1 312346890.75 ODU2 1254659240.50 ODU2e 1299940664.50 ODU1e ODU3 5039902372.875 ODU4 13099305726.875 ODUflex Any The Maximum LSP bandwidth field is used to identify the ODUj type. 5.4.1 ODU Switching When Switching Capability is set to OTN-TDM, it means the node is capable of - terminating OTUk layer - Switching of HO-ODU (ODUk) - switching of LO-ODU (ODUj) if HO-ODU supports mux/demux (termination of HO-ODU is required for mux/demux operation) Multiple ISCDs would be advertised if an interface supports more than one type of ODUk switching. There would be one ISCD advertisement per ODUj independent of the OTN multiplexing branch it belongs to. For e.g. If an OTU3 interface supports ODU0, ODU1 and ODU2 switching, there would be three ISCDs one for each ODU type. Refer to examples in section 7.0. 5.4.2. ODUk Switch Capability Specific Information This SCSI field contains bandwidth information for fixed ODUj(j=0,1,2,3,4,2e,1e) or ODUflex. The type of ODUj/ODuflex is identified by Maximum LSP bandwidth field and BW sub TLV Type field as follows. If bandwidth advertisement is for fixed size ODUj, then - set BW sub TLV Type = 1 - Encode nominal rate of the ODUj in Max LSP BW field - Encode avaialble number of ODUj(s) as shown below If bandwidth advertisment is for ODUflex, then - set BW sub TLV Type = 2 - Encode available BW in Max LSP BW field Rajan Rao, et al. Expires September 15, 2011 [Page 11] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 - Encode avaialble Bandwidth as shown below The SCSI field must be included when Switching Capability is "OTN-TDM". 5.4.2.1 Bandwidth sub TLV for fixed ODUj The format of Bandwidth sub TLV for fixed size ODUj is shown below; (j=0,1,2,3,4,2e,1e). The TLV Type must be set to 1 for fixed ODUs. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=1 (for fixed ODUj) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUj count at priority 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Available ODUj(s): This field (32 bits) indicates the maximum number of Containers of a given ODUj-Type at priority 'p' available on this TE-Link. The "Available ODUj(s)" of a bundled link at priority p is defined to be the sum of "Available ODUj(s)" at priority p of all of its component links. Rajan Rao, et al. Expires September 15, 2011 [Page 12] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 5.4.2.2 Bandwidth sub-TLV for ODUflex The format of Bandwidth sub TLV for ODUflex is shown below. The TLV Type is set to 2 for flexible ODUs. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=2 (for ODUflex) | length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUflex BW in bytes/sec priority 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Available BW (in bytes/sec) Available BW (in bytes/sec) is represented in IEEE float-point format similar to Max-Lsp-Bandwidth in ISCD. The "Available BW" of a bundled link at priority p is defined to be the sum of "Available BW" at priority p of all of its component links. This information may be used to route LSPs over links which have most bandwidth available. 5.5. Interface Multiplexing Capability Descriptor The OTN multiplexing hierarchy involves one or more ODU layers. The server ODU layer is called the higher order ODU(HO-ODU) and the layer multiplexed into a server ODU layer is called lower order ODU (LO-ODU). Rajan Rao, et al. Expires September 15, 2011 [Page 13] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 A HO-ODU can carry (mux/demux) one or more LO-ODUs as specified in G.709. Termination of HO-ODU is necessary to mux/demux LO-ODUs. For e.g. a) on a OTU2 interface with OTU2-ODU2-ODU0 muxing stack, it is necessary to terminate ODU2(H) in order to mux/demux contained ODU0s. b) on a OTU2 interface with OTU2-ODU2-ODU1-ODU0 muxing stack, it is necessary to terminate ODU2 and ODU1 layers to mux/demux contained ODU0s. An OTN interface supporting multi-stage multiplexing requires termination of more than one HO-ODU to access one or more LO-ODUs for switching purposes. For e.g. on an interface with OTU3-ODU3-ODU2-ODU0 multiplexing stack/hierarchy, ODU3 and ODU2 layers should be terminated to access ODU0s for switching purposes. 5.5.1 Multiplex Layers and Hierarchical LSP It is possible to construct H-LSP(s) using different HO-ODU muxing layer(s). While creation of H-LSP is optional, it becomes necessary in network scenarios where switching restrictions exist for LO-ODUs. Example #1: - Nodes A, B, D & E are ODU0 and ODU2 switching capable; - Nodes C is ODU2 switching capable only. An ODU2-FA between nodes B & D is necessary to support E2E ODU0-LSP(s) A-----B---------C--------D-----E <-----ODU2-FA------> <------------ODU0-LSP --------> Example #2: ODU0-LSP over G.709-v1 capable node (legacy node) - Nodes A, B, D & E are ODU0 & ODU1 switch capable nodes; - Node C is ODU1 switching capable An ODU1-FA between nodes B & D is necessary to support E2E ODU0-LSPs A-----B---------C--------D-----E <-----ODU1-FA------> <------------ODU0-LSP --------> In order to support identification of potential FA boundary points, it is Rajan Rao, et al. Expires September 15, 2011 [Page 14] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 necessary to flood mux/demux information. This includes information about: - the HO-ODU layer which can be terminated - the LO-ODUs available upon HO-ODU termination (muxing hierarchy) The multiplexing hierarchy provides information about specific branch(es) of the OTN muxing hierarchy. This includes - one or more HO-ODU(s) which needs to be terminated and - a LO-ODU layer which can be accessed after termination The HO-ODUs which are terminate-able are potential FA end points. FA becomes necessary when switching bandwidth is not available at all nodes along the path for an LSP (specifically for LSPs at LO-ODU layers). This draft proposes the use of IMCD (Interface Multiplexing Capability Descriptor) to distribute OTN mux/demux information of Te-end points. 5.5.2 IMCD format The Interface Multiplexing Capability Descriptor (IMCD) describes "Multiplexing" capability of an interface. It is a sub-TLV of the Link TLV (Type TBD). The format of value field is as shown below: 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-PID | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available HO-ODUj count at priority 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rajan Rao, et al. Expires September 15, 2011 [Page 15] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 5.5.2.1 G-PID The G-PID field is a 16 bit field as defined in [RFC3471]. New G-PID values are defined in addition to those defined in [RFC3471]. Within OTN context, the new G-PID values identify multiplexing stack supported by the Te-end point. The table below shows newly defined values for G-PID: Value G-PID Meaning ----- ------ ---------------------------- 60 ODU1-ODU0 ODU1 termination required 61 ODU2-ODU0 ODU2 termination required 62 ODU2-ODU1 ODU2 termination required 63 ODU2-ODU1-ODU0 ODU2 & ODU1 termination required 64 ODU2-ODUflex ODU2 termination required 65 ODU3-ODU0 ODU3 termination required 66 ODU3-ODU1 ODU3 termination required 67 ODU3-ODU1-ODU0 ODU3 & ODU1 termination required 68 ODU3-ODU2 ODU3 termination required 69 ODU3-ODU2-ODU0 ODU3 & ODU2 termination required 70 ODU3-ODU2-ODU1 ODU3 & ODU2 termination required 71 ODU3-ODU2-ODU1-ODU0 ODU3 & ODU2 & ODU1 termination required 72 ODU3-ODU2-ODUflex ODU3 & ODU2 termination required 73 ODU3-ODUflex ODU3 termination required 74 ODU3-ODU2e ODU3 termination required 75 ODU4-ODU0 ODU4 termination required 76 ODU4-ODU1 ODU4 termination required 77 ODU4-ODU1-ODU0 ODU4 & ODU1 termination required 78 ODU4-ODU2 ODU4 termination required 79 ODU4-ODU2-ODU0 ODU4 & ODU2 termination required 80 ODU4-ODU2-ODU1 ODU4 & ODU2 termination required 81 ODU4-ODU2-ODU1-ODU0 ODU4 & ODU2 & ODU1 termination required 82 ODU4-ODU2-ODUflex ODU4 & ODU2 termination required 83 ODU4-ODU3 ODU4 termination required 84 ODU4-ODU3-ODU0 ODU4 & ODU3 termination required 85 ODU4-ODU3-ODU1 ODU4 & ODU3 termination required 86 ODU4-ODU3-ODU1-ODU0 ODU4 & ODU3 & ODU1 termination required 87 ODU4-ODU3-ODU2 ODU4 & ODU3 termination required 88 ODU4-ODU3-ODU2-ODU0 ODU4 & ODU3 & ODU2 termination required 89 ODU4-ODU3-ODU2-ODU1 ODU4 & ODU3 & ODU2 termination required 90 ODU4-ODU3-ODU2-ODU1-ODU0 ODU4 & ODU3 & ODU2 & ODU1 termination required 91 ODU4-ODU3-ODU2-ODUflex ODU4 & ODU3 & ODU2 termination required 92 ODU4-ODU3-ODUflex ODU4 & ODU3 termination required 93 ODU4-ODU3-ODU2e ODU4 & ODU3 termination required 94 ODU4-ODUflex ODU4 termination required 95 ODU4-ODU2e ODU4 termination required Rajan Rao, et al. Expires September 15, 2011 [Page 16] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 96 ODU1 ODU1 termination required 97 ODU2 ODU2 termination required 98 ODU3 ODU3 termination required 99 ODU4 ODU4 termination required 100 ODU2-GFP-10GBE ODU2 termination for Ethernet 101 ODU2e-10GBE ODU2e termination for Ethernet 102 ODU2-OC192 ODU2 termination for SONET 5.5.2.2 Available Bandwidth The available bandwidth advertised in "Available HO-ODUj" field indicates the number of "Terminations" possible at HO-ODUj layer. The HO-ODUj layer (Parent ODU) is identified by G-PID field. This field (32 bits) indicates maximum number of Containers of a given HO-ODUj at priority 'p' available on the TE-Link; where {j=1,2,3,4}. The "Available HO-ODUj(s)" of a bundled link at priority 'p' is defined to be the sum of "Available HO-ODUj(s)" at priority 'p' of all of its component links for that specific G-PID. Example#1: Unbundled link with ODU2-ODU0 muxing hierarchy support A ---------- B IMCD advertised would be as follows: o G-PID= ODU2-ODU0 o Available HO-ODUj count = 1 ( refers to ODU2 layer) The ODU2 termination implies ability to mux/demux 8xODU0s. Example#2: Bundled Te-link with ODU2-ODU0 muxing hierarchy support (3 links) A ========== B IMCD advertised would be as follows: o G-PID= ODU2-ODU0 o Available HO-ODUj count = 3 (refers to ODU2 layer) The ODU2 termination implies ability to mux/demux 24xODU0s in total. 5.5.3 Controlling IMCD advertisement The IMCD advertisement is not mandatory and it is required only when FA support is needed. Rajan Rao, et al. Expires September 15, 2011 [Page 17] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 The network operators can selectively enable IMCD advertisement for specific HO-ODU mux layer(s). This can be done on a link by link basis, node basis or network basis. The mechanism to achieve this is outside the scope of this document. 5.5.4 How to use IMCDs for FA creation When computing path for an FA (induced or otherwise), the path computing node should look for matching G-PIDs at the FA boundary nodes. For example, to create ODU1-FA for ODU0 service, the path computation should look for matching G-PID = ODU1-ODU0 at nodes B & D The need for FA is due to Node-C's ability to switch ODU1 only. A-----B---------C--------D-----E <-----ODU1-FA------> <------------ODU0-LSP --------> 5.5.5 IMCD and non OTN services In certain deployments it may be beneficial to advertise ODU termination bandwidth without the LO-ODU information. The intent is to allow signaling to decide non-OTN signal to adapt at the time of path establishment. The G-PID values 96, 97, 98, 99 defined in section 5.5.2.1 are meant for this purpose. The path computation can also be preformed for specific clients over an ODUj using G-PID values 100, 101 & 102 (e.g. 10GBE mapping to ODU2 using GFP). Rajan Rao, et al. Expires September 15, 2011 [Page 18] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 6. Examples This sections presents some use-cases for bandwidth encoding and usage. 6.1. Network with no IMCD advertisement (no FA support) A-------B------C------D-----E Suppose Muxing Hierarchy supported at the end points as shown: Link A-B: Mux hierarchy at A & B ends is as follows: ODU1 ODU0 \ / \ / ODU2 | OTU2 Link B-C: Mux hierarchy at B & C ends is as follows: ODU0 | ODU1 ODU0 \ / \ / ODU2 | OTU2 Link C-D: mux hierarchy at C & D ends is as follows: ODU0 | ODU1 | ODU2 | OTU2 Rajan Rao, et al. Expires September 15, 2011 [Page 19] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 a) The ISCD advertisement by nodes A, B, C & D would be as follows ISCD1: Max LSP BW = ODU2 nominal rate in bytes/sec Available ODU2 count at priority 'p' = 1 ISCD2: Max LSP BW = ODU1 nominal rate in bytes/sec Available ODU1 count at priority 'p' = 4 ISCD3: Max LSP BW = ODU0 nominal rate in bytes/sec Available ODU0 count at priority 'p' = 8 b) BW advertisement after an ODU0-LSP creation from A to D. The bandwidth is no longer available at ODU2 rate. ISCD1: Max LSP BW = ODU1 nominal rate in bytes/sec Available ODU1 count at priority 'p' = 3 ISCD2: Max LSP BW = ODU0 nominal rate in bytes/sec Available ODU0 count at priority 'p' = 7 6.2. Network with IMCD advertisement for FA support A-------B------C------D-----E <---ODU1-FA---> <---------- ODU0-LSP -------> The above network can support FA at ODU2 and ODU1 layers. To support FA origination/termination, the IMCDs would be advertised as follows. This is in addition to ISCD advertisement. The ISCD1, ISCD2 & ISCD3 advertisement by A, B, C & D is same as in section 7.1 The IMCD advertisement by A & B for link A-B: IMCD1: G-PID = ODU2-ODU1 Available HO-ODUj count at Pi = 1 (ODU2) IMCD2: G-PID = ODU2-ODU0 Available HO-ODUj count at Pi = 1 (ODU2) The IMCD advertisement by B & C for link B-C: IMCD1: Rajan Rao, et al. Expires September 15, 2011 [Page 20] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 G-PID = ODU2-ODU1 Available HO-ODUj count at Pi = 1 (ODU2) IMCD2: G-PID = ODU2-ODU0 Available HO-ODUj count at Pi = 1 (ODU2) IMCD3: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 4 (ODU1) The IMCDs advertised by C & D for link C-D would be as follows: IMCD1: G-PID = ODU2-ODU1 Available HO-ODUj count at Pi = 1 (ODU2) IMCD2: G-PID = ODU2-ODU1-ODU0 Available HO-ODUj count at Pi = 1 (ODU2) IMCD3: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 4 (ODU1) The IMCD advertisement by B & C for link B-C after ODU1-FA creation: IMCD1: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 3 (ODU1) The IMCD advertisement by C & D for link C-D after ODU1-FA creation: IMCD1: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 3 (ODU1) Rajan Rao, et al. Expires September 15, 2011 [Page 21] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 6.3. Link bundle with similar muxing capabilities Consider a Bundled Te-link with 2xOTU3 links between Nodes A & B with multiplexing hierarchy as shown: ODU1 ODU0 \ / ODU0 \ / | ODU2 ODU1 ODU0 ODUflex | / / / ---------------- | ODU3 | OTU3 A ===================== B The ISCDs and IMCDs advertised by A & B would be as follows: ISCD1: Max LSP BW = ODU3 nominal rate in bytes/sec Available ODU3 count at priority 'p' = 2 ISCD2: Max LSP BW = ODU2 nominal rate in bytes/sec Available ODU2 count at priority 'p' = 8 ISCD3: Max LSP BW = ODU1 nominal rate in bytes/sec Available ODU1 count at priority 'p' = 32 ISCD4: Max LSP BW = ODU0 nominal rate in bytes/sec Available ODU0 count at priority 'p' = 64 ISCD5: Max LSP BW = ODU3 nominal rate in bytes/sec Available ODUflex BW = 2xODU3 BW in byte/sec To support FAs at ODU3, ODU2 & ODU1 rates, the following IMCDs are advertised IMCD1: G-PID = ODU3-ODU2 Available HO-ODUj count at Pi = 2 (ODU3) Rajan Rao, et al. Expires September 15, 2011 [Page 22] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 IMCD2: G-PID = ODU3-ODU2-ODU1 Available HO-ODUj count at Pi = 2 (ODU3) IMCD3: G-PID = ODU3-ODU2-ODU0 Available HO-ODUj count at Pi = 2 (ODU3) IMCD4: G-PID = ODU3-ODU1 Available HO-ODUj count at Pi = 2 (ODU3) IMCD5: G-PID = ODU3-ODU1-ODU0 Available HO-ODUj count at Pi = 2 (ODU3) IMCD6: G-PID = ODU3-ODU0 Available HO-ODUj count at Pi = 2 (ODU3) IMCD7: G-PID = ODU2-ODU1 Available HO-ODUj count at Pi = 8 (ODU2) IMCD8: G-PID = ODU2-ODU0 Available HO-ODUj count at Pi = 8 (ODU2) IMCD9: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 32 (ODU1) IMCD9: G-PID = ODU3-ODUflex Available HO-ODUj count at Pi = 3 (ODUflex) 6.4. Link bundle with dissimilar muxing capabilities: Layer relation A---------B---------C--------D-------E |------ODU2-FA-----| |------ODU1-FA-------------| |----------------ODU0-LSP------------| Link A-B: Hierarchy at both ends is OTU2-ODU2-ODU0 Link B-C: Is a bundled Te-link with 3 component links with multiplexing hierarchy at both ends as shown: Rajan Rao, et al. Expires September 15, 2011 [Page 23] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 Component link#1: OTU2 link with mux hierarchy: OTU2-ODU2-ODU1-ODU0 Component link#2: OTU2 link with mux hierarchy: OTU2-ODU2-ODU1 Component link#3: OTU1 link with mux hierarchy: OTU1-ODU1-ODU0 Link C-D: - Hierarchy at C end is OTU2-ODU2 - Hierarchy at D end is OTU2-ODU2-ODU1 Link D-E: - Hierarchy at D end is OTU1-ODU1 - Hierarchy at E end is OTU1-ODU1-ODU0 The IMCDs advertised for B-C would include the following: IMCD1: G-PID = ODU2-ODU1 Available HO-ODUj count at Pi = 2 (ODU2) IMCD2: G-PID = ODU1-ODU0 Available HO-ODUj count at Pi = 5 (ODU1) IMCD3: G-PID = ODU2-ODU1-ODU0 Available HO-ODUj count at Pi = 1 (ODU2) In this example, we need two FAs to originate from the same point (at node-B). It is necessary to advertise IMCD3 as we can not conclude full mux relation from IMCD1 & IMCD2. 7. Backward Compatibility If backwards compatibility is required with G.709-v1, then [RFC4328] based ISCDs should be a advertised in addition to ISCDs/IMCDs specified in this document. 8. Security Considerations There are no additional security implications to OSPF routing protocol due to the extensions captured in this document. 9. IANA Considerations The memo introduces two new sub-TLVs of the Interface Switch Capability Descriptor Sub-TLV of TE-LSA. [RFC3630] says that the sub-TLVs of the TE Link TLV in the range 10-32767 must be assigned by Expert Review, and must be registered with IANA. Rajan Rao, et al. Expires September 15, 2011 [Page 24] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels". [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC4201] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in MPLS Traffic Engineering (TE)" [RFC4203] Kompella, K. and Y. Rekhter, "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)" [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, October 2005. [RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, January 2006. [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. [RFC5339] Le Roux, JL. and D. Papadimitriou, "Evaluation of Existing GMPLS Protocols against Multi-Layer and Multi-Region Networks (MLN/MRN)", RFC 5339, September 2008. [RFC6001] D. Papadimitriou, et al, Generalized MPLS (GMPLS) Protocol Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN) [G.709-v3] ITU-T, "Interfaces for the Optical Transport Network (OTN)", G.709 Recommendation, December 2009. [GSUP.43] ITU-T, "Proposed revision of G.sup43 (for agreement)", December 2008. 10.2. Informative References Rajan Rao, et al. Expires September 15, 2011 [Page 25] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [G.709-v1] ITU-T, "Interface for the Optical Transport Network (OTN)," G.709 Recommendation (and Amendment 1), February 2001 (October 2001). [G.872] ITU-T, "Architecture of optical transport networks", November 2001 (11 2001). [G.709-FRAME] F. Zhang, D. Li, H. Li, S. Belotti, "Framework for GMPLS and PCE Control of G.709 Optical Transport Networks", draft-zhang-ccamp-gmpls-g709-framework-02, work in progress. [WSON-FRAME] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks (WSON)", draft-ietf-ccamp-rwa-wson-framework, work in progress. 11. Acknowledgements Special thanks to Daniele Ceccarelli, Lyndon Ong, Sergio Belotti, Pietro Grandi, Jonathan Sadler, Remi Theillaud, Fatai Zhang and Diego Caviglia for discussions on various modeling options. Authors would like to thank Lou Berger,Ping Pan, Radhakrishna Valiveti and Mohit Misra for review comments and suggestions. Author's Addresses Ashok Kunjidhapatham Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: akunjidhapatham@infinera.com Rajan Rao Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: rrao@infinera.com Snigdho Bardalai Infinera Corporation Rajan Rao, et al. Expires September 15, 2011 [Page 26] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 169, Java Drive Sunnyvale, CA-94089 USA Email: sbardalai@infinera.com Khuzema Pithewan Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: kpithewan@infinera.com Biao Lu Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: blu@infinera.com John Drake Juniper Networks USA Email: jdrake@juniper.net Steve Balls Metaswitch Networks 100 Church Street Enfield EN2 6BQ U.K. Email: steve.balls@metaswitch.com Xihua Fu, ZTE China fu.xihua@zte.com.cn Rajan Rao, et al. Expires September 15, 2011 [Page 27] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 Appendix A: Abbreviations & Terminology A.1 Abbreviations: CBR Constant Bit Rate GFP Generic Framing Procedure HO-ODU Higher Order ODU LSC Lambda Switch Capable LSP Label Switched Path LO-ODU Lower Order ODU ISCD Interface Switch Capability Descriptor OCC Optical Channel Carrier OCG Optical Carrier Group OCh Optical Channel (with full functionality) OChr Optical Channel (with reduced functionality) ODTUG Optical Date Tributary Unit Group ODU Optical Channel Data Unit OMS Optical Multiplex Section OMU Optical Multiplex Unit OPS Optical Physical Section OPU Optical Channel Payload Unit OSC Optical Supervisory Channel OTH Optical Transport Hierarchy OTM Optical Transport Module OTN Optical Transport Network OTS Optical Transmission Section OTU Optical Channel Transport Unit OTUkV Functionally Standardized OTUk SCSI Switch Capability Specific Information TDM Time Division Multiplex A.2 Terminology 1. ODUk and ODUj ODUk refers to the ODU container that is directly mapped to an OTU container. ODUj refers to the lower order ODU container that is mapped to an higher order ODU container via multiplexing. 2. LO-ODU and HO-ODU LO-ODU refers to the ODU client layer of lower rate that is mapped to an ODU server layer of higher rate via multiplexing. HO-ODU refers to the ODU server layer of higher rate that supports mapping of one or more ODU client layers of lower rate. In multi-stage multiplexing case, a given ODU layer can be a client for one stage (interpreted as LO-ODU) and at the same Rajan Rao, et al. Expires September 15, 2011 [Page 28] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 time server for another stage (interpreted as HO-ODU). In this case, the notion of LO-ODU and HO-ODU needs to be interpreted in a recursive manner. ODU0 | (LO-ODU) | | | | Stage #1 V | (LO-ODU) | ODU1 | (HO-ODU) | | Stage #2 | | | V (HO-ODU) | ODU2 | (LO-ODU) | | | | Stage #3 V | ODU3 | (HO-ODU) Figure-4 : LO-ODU and HO-ODU Rajan Rao, et al. Expires September 15, 2011 [Page 29] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-03.txt March 14, 2011 Appendix B : Optimization Techniques Optimization techniques can be used to reduce TE-LSA size. The following sub sections describe available options. B.1 Multiple ISCDs Vs. Single ISCD It is possible to encode ISCDs corresponding to different ODU layers into SCSI field of a single ISCD. This options was shown in previous version of this draft (draft-ashok-ccamp-gmpls-ospf-g709-02). Doing so will reduce the LSA size by a factor of: 10 words x (#ODUjs - 1) It is possible to reduce LSA size further by reducing the size of BW field to half word. Doing so will reduce LSA size by a factor of: 4 words x (#ODUjs) B.1 Multiple IMCDs Vs. Single IMCD This optimization doesn't save much. The shrinking of BW field to 1/2 word helps reduce LSA size to some extent. The size reduction depends on the number of ODUs supported. 4 words x (#ODUjs) B.1 Eight priorities Vs. restricted number of priorities It is possible to further optimize by advertising BW only for supported priorities. This can be easily achieved by having a bit vector as described in previous version of this draft. Appendix C: Relation with MLN & MRN The ISCD and IMCDs defined in this draft doesn't repalce IACDs. All three (ISCD, IMCD & IACD) can co-exist in a network and serve different purposes. Appendix D : AMP, BMP & GMP Mapping The G.709 defines various mapping schemes for LO-ODUs into HO-ODUs. From G.709 descriptions, the AMP & GMP mapping appears to be fixed for a given LO-ODU to HO-ODU based on the time slot granularity. Since the mapping is fixed we do not see value in advertising this information in TE-LSAs. Rajan Rao, et al. Expires September 15, 2011 [Page 30]