CCAMP Working Group Snigdho Bardalai Internet-Draft Rajan Rao Intended status: Proposed Standard Ashok Kunjidhapatham Expires: April 15, 2011 Khuzema Pithewan Infinera Corp October 12, 2010 OSPF TE Extensions for Generalized MPLS (GMPLS) Control of G.709 Optical Transport Networks draft-ashok-ccamp-gmpls-ospf-g709-01.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) 2010 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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Ashok, et al. Expires April 15, 2011 [Page 1] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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 . . . . . . . . . . . . . . . . . . . . . 8 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. TDM - Switch Capability Specific Information . . . . 11 5.4.2. ODUk Switch Capability Specific Information . . . . 11 5.4.2.1. Signal Type . . . . . . . . . . . . . . . . . . 12 5.4.2.2. Bandwidth Type . . . . . . . . . . . . . . . . 13 5.4.2.3. Flags . . . . . . . . . . . . . . . . . . . . . 13 5.4.2.4. Available ODUs . . . . . . . . . . . . . . . . 14 6. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.1. Links supporting line rate service only . . . . . . . . . 14 6.2. Multi-stage multiplexing . . . . . . . . . . . . . . . . 14 6.3. Link bundle with dissimilar OTU/ODU interfaces . . . . . 15 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16 Ashok, et al. Expires April 15, 2011 [Page 2] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . 16 9.2. Informative References . . . . . . . . . . . . . . . . . 17 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 Author's Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Ashok, et al. Expires April 15, 2011 [Page 3] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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). Ashok, et al. Expires April 15, 2011 [Page 4] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 OTN networks support switching at two layers: (i) ODU Layer - TDM 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 MLN based routing [RFC5339] 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 Ashok, et al. Expires April 15, 2011 [Page 5] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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) can be supported on this ODUj TE-Link. Figure-3 below provides an illustration of this link type. Ashok, et al. Expires April 15, 2011 [Page 6] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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. 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. Ashok, et al. Expires April 15, 2011 [Page 7] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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. 5. OSPF TE-LSA Extension This section describes the OSPF TE-LSA Extensions to support Ashok, et al. Expires April 15, 2011 [Page 8] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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 5.4.2. 5.4. Interface Switch Capability Descriptor As specified in GMPLS Signaling Extensions for OTN [RFC4238], following are the Switching and Encoding Types that needs to be used for OTU/ODU interface supporting ODU switching. Switching Type = TDM [defined in RFC3471] Encoding Type = G.709 ODUk (Digital Path) [defined in RFC4328] Interface Switching Capability Descriptor for TDM is defined in [RFC4203]. The current definition needs to be extended to cover the bandwidth specification for ODU layer(s). When Encoding Type is "G.709 ODUk", Interface switching Capability Descriptor should be interpreted as follows: Ashok, et al. Expires April 15, 2011 [Page 9] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TDM - Switch Capability Specific Information | | (8 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ODUk - Switch Capability Specific Information | | (variable length) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Max LSP Bandwidth Format and interpretation of this attribute must be consistent with specification in GMPLS Routing Extension [RFC4202] and TE-Link Bundling Support [RFC4201]. For ODU Encoding type, this should be coded with maximum bandwidth (in bytes per second) available on a single ODU container for ODUflex service. If OTU/ODU interface is composed of multiple ODU containers (through multi-stage multiplexing), the ODU container with highest capacity available for ODUflex shall be chosen for encoding this attribute. If the interface does not support ODU-flex service, this value should be coded as zero. Encoding of Max LSP Bandwidth is as follows: Max LSP Bandwidth = Unreserved-TS-Count x TS-Nominal-Rate where, Unreserved-TS-Count: Number OPU Tributary Slots available on the Ashok, et al. Expires April 15, 2011 [Page 10] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 ODU Container TS-Nominal-Rate: Nominal rate of an OPU Trib Slot on the ODU Container in Bytes per second. When link bundling is involved, the interpretation of this attribute must be consistent with TE-Link Bundling Support [RFC4201]. 5.4.1. TDM - Switch Capability Specific Information The format and interpretation of TDM - Switch Capability Specific Information must be as per OSPF GMPLS Extension [RFC4203]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Minimum LSP Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Indication | Reserved (not Padding!) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Minimum LSP Bandwidth This attribute needs to be used in conjunction with Max LSP Bandwidth. Nominal rate of OPU Tributary Slot in bytes per second should be coded in this attribute such that following relationship holds good. Max LSP Bandwidth Number of OPU TSs = ------------------------- Min LSP Bandwidth Indication This attribute is not applicable for this encoding type. It is important to note that Padding bytes defined in [RFC4203] should be interpreted as "Reserved". That means - TLV length of Interface Switch Capability Descriptor includes these bytes as well. 5.4.2. ODUk Switch Capability Specific Information This is the new sub-TLV added for supporting ODUk switching. This must be included when encoding type is "G.709 ODUk". TLV type of ODUk-SCSI-TLV shall be coded as 1. This Sub-TLV should contain one or more PER-SIGNALTYPE-BW-TLV sub-TLV(s). Ashok, et al. Expires April 15, 2011 [Page 11] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PER-SIGNALTYPE-BW-TLV #1 | | (24 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | .... | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PER-SIGNALTYPE-BW-TLV #n | | (24 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ PER-SIGNALTYPE-BW-TLV shall be included for each Signal Type that can be switched on the TE-Link. The TLV type of PER-SIGNALTYPE-BW-TLV shall be coded as 1. The format of this sub-TLV is 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type (1) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type |Bw Type| Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUs at Prio 0 | Available ODUs at Prio 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUs at Prio 2 | Available ODUs at Prio 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUs at Prio 4 | Available ODUs at Prio 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available ODUs at Prio 6 | Available ODUs at Prio 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Optimization Note: It is possible to optimize this bandwidth information by including the available bandwidth for the supported priority levels only. A bitmap (8 bits) can be added in place of reserved bytes to indicate the priority values(8) for which available bandwidth is advertised. 5.4.2.1. Signal Type This field (8 bits) must be coded as specified in OTN Signaling Extension [RFC4238]. The values defined in [RFC4238] pertains to [G.709-v1]. This needs to be extended to support additional ODU Ashok, et al. Expires April 15, 2011 [Page 12] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 containers defined in more recent G.709 specifications [G.709-v3]. Value Type ----- ---- 4 ODU4 (100Gbps) 5 ODU0 (1.25Gbps) 10 ODUflex 11 ODU1e (10Gbps Ethernet [GSUP.43]) 12 ODU2e (10Gbps Ethernet) 13 ODU3e1 (40Gbps Ethernet [GSUP.43]) 14 ODU3e2 (40Gbps Ethernet [GSUP.43]) 15-39 Reserved (for future) 40 ODU0_ANY (ODU0 and future 1.25Gbps ODU variants) 41 ODU1_ANY (ODU1 and future 2.5Gbps ODU variants ) 42 ODU2_ANY (ODU2, ODU1e, ODU2e and future 10Gbps ODU variants) 43 ODU3_ANY (ODU3, ODU3e1, ODU3e2 and future 40Gbps ODU variants) 44 ODU4_ANY (ODU4 and future 100Gbps ODU variants) 45-255 Reserved (for future) Signal Types 40 to 44 can be used for further optimizing the bandwidth encoding by advertising a single bandwidth entry for all the ODU types (of almost same rate) switchable on a given interface. For instance, assume an OTU interface that can be configured as OTU2 or OTU2e or OTU1e. Though the interface can potentially switch ODU2 or ODU2e or ODU1e, it is wasteful to advertise separate PER-SIGNALTYPE-BW-TLV for each ODU2 variants namely ODU1e, ODU2e and ODU2. In such cases, ODU2_ANY can be used. It is important to note that when ODUj_ANY bandwidth entry is included, no separate bandwidth entry for individual ODUj variants must be present. The route computation engine should treat ODUj_ANY as a wildcard entry for all the ODUj variants of the same rate. 5.4.2.2. Bandwidth Type This field (4 bits) indicates the bandwidth (BW) type pertaining to "Available ODUs" field. The values supported are as follows: Value Type ----- ---- 0 Max LSP Bandwidth 1 Unreserved Bandwidth 2-15 Reserved (for future) 5.4.2.3. Flags This field (4 bits) should be interpreted as a bitmap. The bits are reserved for future use. This should be coded as 0x0. The receiving node should discard this field. Ashok, et al. Expires April 15, 2011 [Page 13] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 5.4.2.4. Available ODUs This field (16 bits) indicates the maximum number of ODU Containers of a given Signal-Type available on this TE-Link. When Bw-Type (=0) is "Max-Lsp-Bandwidth", The "Available ODUs" of a bundled link at priority p is defined to be the maximum of the "Available ODUs" at priority p of all of its component links. When Bw-Type (=1) is "Unreserved-Bandwidth", The "Available ODUs" of a bundled link at priority p is defined to be the sum of the "Available ODUs" at priority p of all of its component links. Bw-Type of 1 (Unreserved Bandwidth) is not applicable when there is no link bundling. 6. Use Cases This sections presents some use-cases for bandwidth encoding and usage. 6.1. Links supporting line rate service only Assume OTU2 interface that supports ODU2 switching only. Interface Switching Capability Descriptor should be coded as follows: Max Lsp Bw = 0 // ODUflex is not supported. Min Lsp Bw = (1,249,409 / 8) // Nominal rate of OPU2 TS in bytes // per second. ODUk Switching Capability Specific Information: +===============+================+===========================+ | Signal Type | Bandwidth Type | Available ODUs at Prio P | +===============+================+===========================+ | 2 (ODU2) | 0 (Max-Lsp-Bw) | 1 | +---------------+----------------+---------------------------+ 6.2. Multi-stage multiplexing Assume OTU3 interface that supports switching at line rate ODU3 and lower rates - ODU0, ODU1, ODU2, ODU2e & ODUflex via multiplexing. Max Lsp Bw = (32 * Min Lsp Bw) // BW for ODUflex (on ODU3) Min Lsp Bw = (1,254,703 / 8) // Nominal rate of OPU3 TS in // bytes per second. ODUk Switching Capability Specific Information: +===============+================+===========================+ | Signal Type | Bandwidth Type | Available ODUs at Prio P | +===============+================+===========================+ Ashok, et al. Expires April 15, 2011 [Page 14] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 | 3 (ODU3) | 0 (Max-Lsp-Bw) | 1 | +---------------+----------------+---------------------------+ | 5 (ODU0) | 0 (Max-Lsp-Bw) | 32 | +---------------+----------------+---------------------------+ | 1 (ODU1) | 0 (Max-Lsp-Bw | 16 | +---------------+----------------+---------------------------+ | 2 (ODU2) | 0 (Max-Lsp-Bw) | 4 | +---------------+----------------+---------------------------+ | 12 (ODU2e) | 0 (Max-Lsp-Bw) | 3 | +---------------+----------------+---------------------------+ Note that ODUflex bandwidth is encoded in ISCD itself, so it is not advertised in "ODUk Switching Capability Specific Information". 6.3. Link bundle with dissimilar OTU/ODU interfaces Assume a link bundle involving OTU3, OTU2 and OTU2e interfaces that support switching at all standard LO-ODUs. Max Lsp Bw = (32 * Min Lsp Bw) // BW for ODUflex (on ODU3) Min Lsp Bw = (1,254,703 / 8) // OPU3 TS Size in bytes per // second. ODUk Switching Capability Specific Information: +===============+================+===========================+ | Signal Type | Bandwidth Type | Available ODUs at Prio P | +===============+================+===========================+ | 3 (ODU3) | 0 (Max-Lsp-Bw) | 1 | +---------------+----------------+---------------------------+ | 5 (ODU0) | 0 (Max-Lsp-Bw) | 32 (i.e. Max of 32 and 8) | +---------------+----------------+---------------------------+ | 1 (ODU1) | 0 (Max-Lsp-Bw | 16 (i.e. Max of 16 and 4) | +---------------+----------------+---------------------------+ | 2 (ODU2) | 0 (Max-Lsp-Bw) | 4 (i.e. Max of 4 and 1) | +---------------+----------------+---------------------------+ | 12 (ODU2e) | 0 (Max-Lsp-Bw) | 3 (i.e. Max of 3 and 1) | +---------------+----------------+---------------------------+ | 3 (ODU3) | 1 (Unres-Bw) | 1 | +---------------+----------------+---------------------------+ | 5 (ODU0) | 1 (Unres-Bw) | 40 (i.e. 32 + 8) | +---------------+----------------+---------------------------+ | 1 (ODU1) | 1 (Unres-Bw) | 20 (i.e. 16 + 4) | +---------------+----------------+---------------------------+ | 2 (ODU2) | 1 (Unres-Bw) | 5 (i.e. 4 + 1) | +---------------+----------------+---------------------------+ | 12 (ODU2e) | 1 (Unres-Bw) | 4 (i.e. 3 + 1) | Ashok, et al. Expires April 15, 2011 [Page 15] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 +---------------+----------------+---------------------------+ Note that ODUflex bandwidth is encoded in ISCD itself, so it is not advertised in "ODUk Switching Capability Specific Information". 7. Security Considerations There are no additional security implications to OSPF routing protocol due to the extensions captured in this document. 8. 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. The memo has two suggested values for the two sub-TLVs of the Interface Switch Capability Descriptor Sub-TLV; it is strongly recommended that the suggested values be granted, as there are interoperable implementations using these values. 9. References 9.1. 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)" Ashok, et al. Expires April 15, 2011 [Page 16] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 [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. [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. [G.709-v3] ITU-T, "Interfaces for the Optical Transport Network (OTN)", G.709 Recommendation, December 2009. 9.2. Informative References [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. 10. Acknowledgements Authors would like to thank Lou Berger, Biao Lu, Ping Pan, Radhakrishna Valiveti, & Mohit Misra for review comments and suggestions. Author's Addresses Ashok, et al. Expires April 15, 2011 [Page 17] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 Snigdho Bardalai Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: sbardalai@infinera.com Rajan Rao Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: rrao@infinera.com Ashok Kunjidhapatham Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: akunjidhapatham@infinera.com Khuzema Pithewan Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: kpithewan@infinera.com Appendix A A. 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) Ashok, et al. Expires April 15, 2011 [Page 18] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 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 B. 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 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 Ashok, et al. Expires April 15, 2011 [Page 19] Internet-Draft draft-ashok-ccamp-gmpls-ospf-g709-01.txtOctober 12, 2010 V | ODU3 | (HO-ODU) Figure-4 : LO-ODU and HO-ODU Ashok, et al. Expires April 15, 2011 [Page 20]