Network Working Group Fatai Zhang Internet Draft Huawei Category: Standards Track Guoying Zhang CATR Sergio Belotti Alcatel-Lucent D. Ceccarelli Ericsson Expires: August 2010 February 27, 2010 Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for the evolving G.709 Optical Transport Networks Control draft-zhang-ccamp-gmpls-evolving-g709-04.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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 26, 2010. Abstract Recent progress in ITU-T Recommendation G.709 standardization has introduced new ODU containers (ODU0, ODU4, ODU2e and ODUflex) and enhanced Optical Transport Networking (OTN) flexibility. Several Expires August 2010 [Page 1] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 recent documents have proposed ways to modify GMPLS signaling protocols to support these new OTN features. It is important that a single solution is developed for use in GMPLS signaling and routing protocols. This solution must support ODUk multiplexing capabilities, address all of the new features, be acceptable to all equipment vendors, and be extensible considering continued OTN evolution. This document describes the extensions to the Generalized Multi- Protocol Label Switching (GMPLS) signaling to control the evolutive Optical Transport Networks (OTN) addressing ODUk multiplexing and new features including ODU0, ODU4, ODU2e and ODUflex. 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 are to be interpreted as described in [RFC2119]. Table of Contents 1. Introduction..................................................3 2. Terminology...................................................4 3. GMPLS Extensions for the Evolutive G.709 - Overview...........4 4. Extensions for Traffic Parameters for the Evolutive G.709.....5 4.1. Usage of ODUflex traffic parameter.......................7 4.2. Example of ODUflex traffic parameter.....................8 5. Generalized Label.............................................9 5.1. New definition of ODUk label.............................9 5.2. Examples................................................11 5.3. Label Distribution Procedure............................12 5.4. Backward Compatibility Considerations...................13 5.4.1. Control Plane Backward Compatibility Considerations13 5.4.2. Data Plane Backward Compatibility Considerations...14 5.5. Collision management....................................15 6. Security Considerations......................................15 7. IANA Considerations..........................................15 8. References...................................................15 8.1. Normative References....................................15 8.2. Informative References..................................16 9. Authors' Addresses...........................................17 Acknowledgment..................................................18 Zhang Expires August 2010 [Page 2] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 1. Introduction Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945] extends MPLS to include Layer-2 Switching (L2SC), Time-Division Multiplex (e.g., SONET/SDH, PDH, and ODU), Wavelength (OCh, Lambdas) Switching, and Spatial Switching (e.g., incoming port or fiber to outgoing port or fiber). [RFC3471] presents a functional description of the extensions to Multi-Protocol Label Switching (MPLS) signaling required to support Generalized MPLS. RSVP-TE-specific formats and mechanisms and technology specific details are defined in [RFC3473]. With the evolution and deployment of G.709 technology, it is necessary that appropriate enhanced control technology support be provided for G.709. [RFC4328] describes the control technology details that are specific to foundation G.709 Optical Transport Networks (OTN), as specified in the ITU-T G.709 recommendation [ITUT- G709], for ODUk deployments without multiplexing. In addition to increasing need to support ODUk multiplexing, the evolution of OTN has introduced additional containers and new flexibility. For example, ODU0, ODU2e, ODU4 containers as described in [G709-Amd3], and ODUflex being developed in [G709-v3]. In addition, the following issues require consideration: - Support for ODUflex resizing capabilities, potentially hitless (similar to LCAS, as defined in [VCAT-LCAS]), which is under discussion in ITU-T. - Support for Tributary Port Number. The Tributary Port Number has to be negotiated on each link for flexible assignment of tributary ports to tributary slots in case of LO-ODU over HO- ODU (e.g., ODU2 into ODU3). Alternatively, the nodes of the network are supposed to run AutoMSI mode. Therefore, it is clear that [RFC4328] has to be updated or replaced in order to support ODUk multiplexing, as well as other ODU enhancements introduced by evolution of OTN standards. This document updates RFC4328 extending the G.709 ODUk traffic parameters and also presents a new OTN label format which is very flexible and scalable. Zhang Expires August 2010 [Page 3] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 2. 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]. 3. GMPLS Extensions for the Evolutive G.709 - Overview The new features for the evolutive OTN are described in the separate ITU-T documents, for example, ODU0, ODU2e,ODU4 are described in [G709-Amd3] and ODUflex is being developed in [G709-v3]. The new signal types of digital wrapper layer for the evolutive OTN are listed as follows: - Optical Channel Transport Unit (OTUk): . OTU4 - Optical Channel Data Unit (ODUk): . ODU0 . ODU2e . ODU4 . ODUflex A new Tributary Slot (TS) granularity (i.e., 1.25 Gbps) is introduced in [G709-Amd3]. At this point there are two TS granularities for the original ODU1, ODU2, ODU3. The TS granularity at 2.5 Gbps is used on legacy interfaces while the new 1.25 Gbps will be used for the new interfaces. New ITU-T documents not only introduce new signal types but also define the new multiplexing hierarchy for the evolutive OTN. In addition to the support of ODUk mapping into OTUk (k = 1, 2, 3, 4), G.709 and its amendments, support ODUk multiplexing. For the evolutive OTN, the multiplexing of ODUj (j = 0, 1, 2, 2e, 3, flex) into an ODUk (k > j) signal can be depicted as follows: - ODU0 into ODU1 multiplexing (with 1,25Gbps TS granularity) - ODU0, ODU1, ODUflex into ODU2 multiplexing (with 1.25Gbps TS granularity) - ODU1 into ODU2 multiplexing (with 2.5Gbps TS granularity) - ODU0, ODU1, ODU2, ODU2e and ODUflex into ODU3 multiplexing (with 1.25Gbps TS granularity) Zhang Expires August 2010 [Page 4] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 - ODU1, ODU2 into ODU3 multiplexing (with 2.5Gbps TS granularity) - ODU0, ODU1, ODU2, ODU2e, ODU3 and ODUflex into ODU4 multiplexing (with 1.25Gbps TS granularity) [RFC4328] describes GMPLS signaling extensions to support the control for G.709 Optical Transport Networks (OTN) [ITUT-G709]. However, [RFC4328] need to be updated because it does not provide the means to signal all the new signal types and related mapping and multiplexing functionalities. Moreover, it supports only the optional auto-MSI mode which assumes that the Tributary Port Number is automatically assigned in the transmit direction and not checked in the receive direction. This document extends the G.709 traffic parameters described in [RFC4328] and also presents a new OTN label format which is very flexible and scalable. [Editors note] There are several possibilities to include the Tributary Port Number information in the signaling. Note that ITU-T has not yet given a clear interpretation of the Tributary Port number information in case of bidirectional paths, so the adoption of any solution should be kept on hold until ITU-T provides an approved definition. 4. Extensions for Traffic Parameters for the Evolutive G.709 The traffic parameters for G.709 are defined as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Tolerance | NMC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NVC | Multiplier (MT) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Bit_Rate | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ [Editors note] NMC field in RFC4328 had the meaning to indicate how many labels have to be expected. This information allows the protocol to operate without specific knowledge of the signal type. The same effect could be obtained either indicating the bit map length or indicating the number of labels. Zhang Expires August 2010 [Page 5] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 The Signal Type should be extended to cover the new Signal Type introduced by the evolutive OTN. The new Signal Type is extended as follows: Value Type ----- ---- 0 Not significant 1 ODU1 (i.e., 2.5 Gbps) 2 ODU2 (i.e., 10 Gbps) 3 ODU3 (i.e., 40 Gbps) 4 ODU4 (i.e., 100 Gbps) 5 Reserved (for future use) 6 OCh at 2.5 Gbps 7 OCh at 10 Gbps 8 OCh at 40 Gbps 9 OCh at 100 Gbps 10~19 Reserved (for future use) 20 ODU0 (i.e., 1.25 Gbps) 21~30 Reserved (for future use) 31 ODU2e (i.e., 10Gbps for FC1200 and GE LAN) 32 ODUflex (i.e., 1.25*N Gbps) 33~255 Reserved (for future use) In case of ODUflex(CBR), the Bit_Rate and Tolerance fields are used together to represent the actual bandwidth of ODUflex, where: - The Bit_Rate field indicates the nominal bit rate of ODUflex(CBR) encoded as a 32-bit IEEE single-precision floating-point number (referring to [RFC4506] and [IEEE]). - The Tolerance field indicates the bit rate tolerance (part per million, ppm) of the ODUflex(CBR) encoded as an unsigned integer. For example, for an ODUflex(CBR) service with Bit_Rate = 2.5Gbps and Tolerance = 50ppm, the actual bandwidth of the ODUflex is: 2.5Gbps * (1 - 50ppm) ~ 2.5Gbps * (1 + 50ppm) In case of other ODUk signal types, the Bit_Rate and Tolerance fields are not necessary and MUST be filled with 0. Zhang Expires August 2010 [Page 6] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 4.1. Usage of ODUflex traffic parameter In case of ODUflex(CBR), the information of Bit_Rate and Tolerance in the ODUflex traffic parameter is used to determine the total number of tributary slots N in the HO ODUk link to be reserved. Here: N = Ceiling of ODUflex(CBR) nominal bit rate * (1 + ODUflex(CBR) bit rate tolerance) --------------------------------------------------------------------- ODTUk.ts nominal bit rate * (1 - HO OPUk bit rate tolerance) Therefore, a node receiving a Path message containing ODUflex(CBR) traffic parameter can allocate precise number of tributary slots and set up the cross-connection for the ODUflex service. The table below shows the actual bandwidth of the tributary slot of ODUk (in Gbps), referring to [G709-v3]. ODUk Minimum Nominal Maximum ------------------------------------------------------- ODU2 1.249 384 632 1.249 409 620 1.249 434 608 ODU3 1.254 678 635 1.254 703 729 1.254 728 823 ODU4 1.301 683 217 1.301 709 251 1.301 735 285 Note that: Minimum bandwidth of ODUTk.ts = ODTUk.ts nominal bit rate * (1 - HO OPUk bit rate tolerance) Maximum bandwidth of ODTUk.ts = ODTUk.ts nominal bit rate * (1 + HO OPUk bit rate tolerance) Where: HO OPUk bit rate tolerance = 20ppm For different ODUk, the bandwidths of the tributary slot are different, and so the total number of tributary slots to be reserved for the ODUflex(CBR) may not be the same on different HO ODUk links. This is why the traffic parameter should bring the actual bandwidth information other than the NMC field. In case of ODUflex(GFP), the total number of tributary slots to be reserved for one ODUflex service MUST keep the same in different HO ODUk links. So the NMC field can be used to indicate the total number of TS, instead of using the Bit_Rate and Tolerance fields. Therefore, when Signal Type = ODUflex(32), the zero value of NMC field and Zhang Expires August 2010 [Page 7] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 nonzero values of Bit_Rate and Tolerance fields imply an ODUflex(CBR) traffic parameter, and the nonzero value of NMC field and zero values of Bit_Rate and Tolerance fields imply an ODUflex(GFP) traffic parameter. 4.2. Example of ODUflex traffic parameter This section gives an example to illustrate the usage of ODUflex(CBR) traffic parameter. Assume there is an ODUflex(CBR) service requesting a bandwidth of (2.5Gbps, +/-20ppm) from node A to node C. In other words, the ODUflex traffic parameter indicates that Signal Type is 32 (ODUflex), Bit_Rate is 2.5Gbps and Tolerance is 20ppm. +-----+ +---------+ +-----+ | +-------------+ +-----+ +-------------+ | | ===============\| ODU |/=============== | | ===============/| flex+-=============== | | +-------------+ | |\=============== | | +-------------+ +-----+ +-------------+ | | | | | | | | | ....... | | ....... | | | A +-------------+ B +-------------+ C | +-----+ HO ODU4 +---------+ HO ODU2 +-----+ =========: TS occupied by ODUflex ---------: free TS - On the HO ODU4 link between node A and B: The maximum bandwidth of the ODUflex equals 2.5Gbps * (1 + 20ppm), and the minimum bandwidth of the tributary slot of ODU4 equals 1.301 683 217Gbps, so the total number of tributary slots N1 to be reserved on this link is: N1 = ceiling (2.5Gbps * (1 + 20ppm) / 1.301 683 217) = 2 - On the HO ODU2 link between node B and C: The maximum bandwidth of the ODUflex equals 2.5Gbps * (1 + 20ppm), and the minimum bandwidth of the tributary slot of ODU2 equals 1.249 384 632Gbps, so the total number of tributary slots N2 to be reserved on this link is: N2 = ceiling (2.5Gbps * (1 + 20ppm) / 1.249 384 632) = 3 Zhang Expires August 2010 [Page 8] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 5. Generalized Label [RFC3471] has defined the Generalized Label which extends the traditional label by allowing the representation of not only labels which travel in-band with associated data packets, but also labels which identify time-slots, wavelengths, or space division multiplexed positions. The format of the corresponding RSVP-TE Generalized Label object is defined in the Section 2.3 of [RFC3473]. However, for different technologies, we usually need use specific label rather than the Generalized Label. For example, the label format described in [RFC4606] could be used for SDH/SONET, the label format in [RFC4328] for G.709. According to the ODUk label format defined in [RFC4328], it could be updated to support new signal types defined in G.709 amendment 3 but would hardly be further enhanced to support possible new signal types. Furthermore such label format can face big problems related to scalability matters due to the high number of labels needed. For example, when ODU3 is mapped into ODU4 with 1.25G tributary slots, it will need thirty-one labels (31*4*8=992 bits) to be allocated for one ODU3 connection. If ODUflex into ODU4, it may need up to eighty labels (80*4*8=2560 bits) to be allocated for one ODUflex connection. In this document, a new ODUk label format is defined. The new ODUk label format is very flexible and scalable. 5.1. New definition of ODUk label In order to be compatible with new types of ODU signal and new types of tributary slot, the following new ODUk label format is defined: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ODUj |OD(T)Uk| T | Reserved | Bit Map | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ......... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ODUj and OD(T)Uk (4 bits respectively): indicate that LO ODUj is multiplexed into HO ODUk(k>j), or LO ODUj is mapped into OTUk (j=k). Zhang Expires August 2010 [Page 9] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 ODUj field Signal type ---------- ----------- 0 LO ODU0 1 LO ODU1 2 LO ODU2 3 LO ODU3 4 LO ODU4 5 LO ODU2e 6 LO ODUflex 7-15 Reserved (for future use) OD(T)Uk field Signal type ------------- ----------- 0 Reserved (for future use) 1 HO ODU1 / OTU1 2 HO ODU2 / OTU2 3 HO ODU3 / OTU3 4 HO ODU4 / OTU4 5-15 Reserved (for future use) T (2 bits): indicates the type of tributary slot of HO ODUk. Currently, two types of tributary slot are defined in [G.709], the 1.25Gbps tributary slot and the 2.5Gbps tributary slot. T field TS type ------- ------- 0 1.25Gbps TS granularity 1 2.5Gbps TS granularity 2-3 Reserved (for future use) Bit Map (variable): indicates which tributary slots in HO ODUk that the LO ODUj will be multiplexed into. The sequence of the Bit Map is consistent with the sequence of the tributary slots in HO ODUk. Each bit in the bit map represents the corresponding tributary slot in HO ODUk with a value of 1 or 0 indicating whether the tributary slot will be used by LO ODUj or not. The size of the bit map equals to the total number of the tributary slots of HO ODUk. Zhang Expires August 2010 [Page 10] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 In case of an ODUk mapped into OTUk, it's no need to indicate which tributary slots will be used, so the size of Bit Map is 0. Padded bits are added behind the Bit Map to make the whole label a multiple of four bytes if necessary. Padded bit MUST be set to 0 and MUST be ignored. [Editors note] Tributary Port Number information to be inserted as soon as clarification from ITU has been provided. 5.2. Examples The following examples are given in order to illustrate the label format described in the previous sections of this document. (1) ODUk into OTUk mapping: In such conditions, the downstream node along an LSP returns a label indicating that the ODU1 (ODU2 or ODU3 or ODU4) is directly mapped into the corresponding OTU1 (OTU2 or OTU3 or ODU4). The following example label indicates an ODU1 mapped into OTU1. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|0 0 0 1|0 1| Reserved | Padded Bits (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (2) ODUj into ODUk multiplexing: In such conditions, this label indicates that an ODUj is multiplexed into several tributary slots of OPUk and then mapped into OTUk. Some instances are shown as follow: - ODU0 into ODU2 Multiplexing: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 0|0 0 1 0|0 0| Reserved |0 1 0 0 0 0 0 0|Padded Bits (0)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU0 multiplexed into the second tributary slot of ODU2, wherein the type of the tributary slot is 1.25Gbps. Zhang Expires August 2010 [Page 11] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 - ODU1 into ODU2 Multiplexing with 1.25Gbps TS granularity: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|0 0 1 0|0 0| Reserved |0 1 0 1 0 0 0 0|Padded Bits (0)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU1 multiplexed into the 2nd and the 4th tributary slot of ODU2, wherein the type of the tributary slot is 1.25Gbps. - ODU2 into ODU3 Multiplexing with 2.5Gbps TS granularity: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 1 0|0 0 1 1|0 1| Reserved |0 1 1 0 1 0 1 0 0 0 0 0 0 0 0 0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU2 multiplexed into the 2nd, 3rd, 5th and 7th tributary slot of ODU3, wherein the type of the tributary slot is 2.5Gbps. 5.3. Label Distribution Procedure This document does not change the existing label distribution procedures [RFC4328] for GMPLS except that the new ODUk label should be processed as follows. When a node receives a generalized label request for setting up an ODUj LSP from its upstream node, the node should generate an ODU label according to the signal type of the requested LSP and the free resources (i.e., free tributary slots of ODUk) that will be reserved for the LSP, and send the label to its upstream node. Note that these labels can also be specified by the source node of the connection. In case of ODUj to ODUk multiplexing, the node should firstly determine the size of the Bit Map field according to the signal type and the tributary slot type of ODUk, and then set the bits to 1 in the Bit Map field corresponding to the reserved tributary slots. In case of ODUk to OTUk mapping, the node only needs to fill the ODUj and the ODUk fields with corresponding values in the label. Other bits are reserved and MUST be set to 0. Zhang Expires August 2010 [Page 12] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 When receiving an ODU label from its downstream node, the node should learn which ODU signal type is multiplexed or mapped into which ODU signal type by analyzing the ODUj and the ODUk fields. In case of ODUj to ODUk multiplexing, the node should firstly determine the size of the Bit Map field according to the signal type and the tributary slot type of ODUk, and then obtain which tributary slots in ODUk are reserved by its downstream node according to the position of the bits that are set to 1 in the Bit Map field, so that the node can multiplex the ODUj into the reserved tributary slots of ODUk after the LSP is established. In case of ODUk to OTUk mapping, the size of Bit Map field is 0 and no additional procedure is needed. 5.4. Backward Compatibility Considerations 5.4.1. Control Plane Backward Compatibility Considerations Since the [RFC4328] has been deployed in the network for the nodes which support the [ITUT-G709] (herein we call them "old nodes"), the backward compatibility SHOULD be take into consideration when the new nodes (i.e., nodes that support the [G709-Amd3] or [G709-v3]) and the old nodes are interworking. For backward compatibility consideration, the new node SHOULD have the ability to generate and parse old labels. o For the old node, it always generates and sends old label to its upstream node, no matter the upstream node is new or old, as described in [RFC4328]. o For the new node, it will generate and send old label if its upstream node is an old one, and generate and send new label if its upstream node is a new one. One backward compatibility example is shown below: Path Path Path Path +-----+ ----> +-----+ ----> +-----+ ----> +-----+ ----> +-----+ | | | | | | | | | | | A +-------+ B +-------+ C +-------+ D +-------+ E | |(new)| |(new)| |(old)| |(old)| |(new)| +-----+ <---- +-----+ <---- +-----+ <---- +-----+ <---- +-----+ Resv Resv Resv Resv (new label) (old label) (old label) (old label) Zhang Expires August 2010 [Page 13] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 As described above, for backward compatibility considerations, it is necessary for a new node to know whether the neighbor node is new or old. One optional method is manual configuration. But it is recommended to use LMP to discover the capability of the neighbor node automatically, as described in [OTN-LMP]. When performing the HO ODU link capability negotiation: o If the neighbor node only support the 2.5Gbps TS and only support ODU1/ODU2/ODU3, the neighbor node should be treated as an old node. o If the neighbor node can support the 1.25Gbps TS, or can support other LO ODU types defined in [G709-Amd3] or [G709-v3]), the neighbor node should be treated as new node. o If the neighbor node returns a LinkSummaryNack message including an ERROR_CODE indicating nonsupport of HO ODU link capability negotiation, the neighbor node should be treated as an old node. 5.4.2. Data Plane Backward Compatibility Considerations As described in chapter 3.1 and 4.1 of [OTN-LMP], the node supporting 1.25Gbps TS can interwork with the other nodes that supporting 2.5Gbps TS by combining Specific TSs together in data plane. The control plane MUST support this TS combination. Take the following figure as an example. Assume that there is an ODU2 link between node A and B, where node A only supports the 2.5Gbps TS while node B supports the 1.25Gbps TS. In this case, the TS#i and TS#i+4 (where i<=4) of node B are combined together. When creating an ODU1 service in this ODU2 link, node B reserves the TS#i and TS#i+4 with the granularity of 1.25Gbps. But in the label sent from B to A, it is indicated that the TS#i with the granularity of 2.5Gbps is reserved. Zhang Expires August 2010 [Page 14] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 Path +----------+ ------------> +----------+ | TS1==|===========\--------+--TS1 | | TS2==|=========\--\-------+--TS2 | | TS3==|=======\--\--\------+--TS3 | | TS4==|=====\--\--\--\-----+--TS4 | | | \ \ \ \----+--TS5 | | | \ \ \------+--TS6 | | | \ \--------+--TS7 | | | \----------+--TS8 | +----------+ <------------ +----------+ node A Resv node B In the contrary direction, when receiving a label from node A indicating that the TS#i with the granularity of 2.5Gbps is reserved, node B will reserved the TS#i and TS#i+4 with the granularity of 1.25Gbps in its control plane. 5.5. Collision management [Editors note] This chapter should indicate the procedure in case of collision between Tributary Port Numbers and/or Tributary Slots e.g. two different LSP setups may choose a disjoint set of Tributary Slots but they may request the same Tributary Port Number value (same MSI in G.709 OPUk field). In this case the first signaling should be successful and the second one must fail. 6. Security Considerations TBD. 7. IANA Considerations TBD. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Zhang Expires August 2010 [Page 15] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 [RFC4328] D. Papadimitriou, Ed. "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, Jan 2006. [RFC3471] Berger, L., Editor, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] L. Berger, Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [VCAT-LCAS] G. Bernstein, Ed., "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label Switching (GMPLS)", draft- bernstein-ccamp-gmpls-vcat-lcas, July 29, 2009. [OTN-LMP] Fatai Zhang, Ed., "Link Management Protocol (LMP) extensions for G.709 Optical Transport Networks", draft- zhang-ccamp-gmpls-g.709-lmp-discovery-02.txt, Oct 21, 2009. 8.2. Informative References [ITUT-G709] ITU-T, "Interface for the Optical Transport Network (OTN)," G.709 Recommendation (and Amendment 1), February 2001 (October 2001). [G709-Amd3] ITU-T, "Interface for the Optical Transport Network (OTN)," G.709 Recommendation Amendment3), December 2008. [G709-v3] ITU-T, "Interfaces for the Optical Transport Network (OTN) ", G.709/Y.1331, December 2009. [RFC4506] M. Eisler, Ed., "XDR: External Data Representation Standard", RFC 4506, May 2006. [IEEE] "IEEE Standard for Binary Floating-Point Arithmetic", ANSI/IEEE Standard 754-1985, Institute of Electrical and Electronics Engineers, August 1985. Zhang Expires August 2010 [Page 16] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 9. Authors' Addresses Fatai Zhang Huawei Technologies F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R.China Phone: +86-755-28972912 Email: zhangfatai@huawei.com Guoying Zhang China Academy of Telecommunication Research of MII 11 Yue Tan Nan Jie Beijing, P.R.China Phone: +86-10-68094272 Email: zhangguoying@mail.ritt.com.cn Sergio Belotti Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy +39 039 6863033 Email: sergio.belotti@alcatel-lucent.it Daniele Ceccarelli Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: daniele.ceccarelli@ericsson.com Yi Lin Huawei Technologies F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R.China Phone: +86-755-28972914 Email: linyi_hw@huawei.com Zhang Expires August 2010 [Page 17] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 Yunbin Xu China Academy of Telecommunication Research of MII 11 Yue Tan Nan Jie Beijing, P.R.China Phone: +86-10-68094134 Email: xuyunbin@mail.ritt.com.cn Pietro Grandi Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy +39 039 6864930 Email: pietro_vittorio.grandi@alcatel-lucent.it Diego Caviglia Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: diego.caviglia@ericsson.com Acknowledgment TBD. Intellectual Property The IETF Trust takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in any IETF Document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Copies of Intellectual Property disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or Zhang Expires August 2010 [Page 18] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement any standard or specification contained in an IETF Document. Please address the information to the IETF at ietf-ipr@ietf.org. The definitive version of an IETF Document is that published by, or under the auspices of, the IETF. Versions of IETF Documents that are published by third parties, including those that are translated into other languages, should not be considered to be definitive versions of IETF Documents. The definitive version of these Legal Provisions is that published by, or under the auspices of, the IETF. Versions of these Legal Provisions that are published by third parties, including those that are translated into other languages, should not be considered to be definitive versions of these Legal Provisions. For the avoidance of doubt, each Contributor to the IETF Standards Process licenses each Contribution that he or she makes as part of the IETF Standards Process to the IETF Trust pursuant to the provisions of RFC 5378. No language to the contrary, or terms, conditions or rights that differ from or are inconsistent with the rights and licenses granted under RFC 5378, shall have any effect and shall be null and void, whether published or posted by such Contributor, or included with or in such Contribution. Disclaimer of Validity All IETF Documents and the information contained therein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Zhang Expires August 2010 [Page 19] draft-zhang-ccamp-gmpls-evolving-g709-04.txt February 2010 Copyright 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. Zhang Expires August 2010 [Page 20]