Internet Engineering Task Force (IETF) F. Zhang, Ed. Request for Comments: 7062 D. Li Category: Informational Huawei ISSN: 2070-1721 H. Li CMCC S. Belotti Alcatel-Lucent D. Ceccarelli Ericsson November 2013 Framework for GMPLS and PCE Control of G.709 Optical Transport Networks Abstract This document provides a framework to allow the development of protocol extensions to support Generalized Multi-Protocol Label Switching (GMPLS) and Path Computation Element (PCE) control of Optical Transport Networks (OTNs) as specified in ITU-T Recommendation G.709 as published in 2012. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7062. Zhang, et al. Informational [Page 1] RFC 7062 OTN Framework November 2013 Copyright Notice Copyright (c) 2013 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. Table of Contents 1. Introduction ....................................................3 2. Terminology .....................................................3 3. G.709 Optical Transport Network .................................4 3.1. OTN Layer Network ..........................................5 3.1.1. Client Signal Mapping ...............................6 3.1.2. Multiplexing ODUj onto Links ........................7 3.1.2.1. Structure of MSI Information ...............9 4. Connection Management in OTN ...................................10 4.1. Connection Management of the ODU ..........................11 5. GMPLS/PCE Implications .........................................13 5.1. Implications for Label Switched Path (LSP) Hierarchy ......13 5.2. Implications for GMPLS Signaling ..........................14 5.3. Implications for GMPLS Routing ............................16 5.4. Implications for Link Management Protocol .................18 5.5. Implications for Control-Plane Backward Compatibility .....19 5.6. Implications for Path Computation Elements ................20 5.7. Implications for Management of GMPLS Networks .............20 6. Data-Plane Backward Compatibility Considerations ...............21 7. Security Considerations ........................................21 8. Acknowledgments ................................................22 9. Contributors ...................................................22 10. References ....................................................23 10.1. Normative References .....................................23 10.2. Informative References ...................................24 Zhang, et al. Informational [Page 2] RFC 7062 OTN Framework November 2013 1. Introduction Optical Transport Networks (OTNs) have become a mainstream layer 1 technology for the transport network. Operators want to introduce control-plane capabilities based on GMPLS to OTN to realize the benefits associated with a high-function control plane (e.g., improved network resiliency, resource usage efficiency, etc.). GMPLS extends Multi-Protocol Label Switching (MPLS) to encompass Time Division Multiplexing (TDM) networks (e.g., Synchronous Optical NETwork (SONET) / Synchronous Digital Hierarchy (SDH), Plesiochronous Digital Hierarchy (PDH), and G.709 sub-lambda), lambda switching optical networks, and spatial switching (e.g., incoming port or fiber to outgoing port or fiber). The GMPLS architecture is provided in [RFC3945], signaling function and Resource Reservation Protocol - Traffic Engineering (RSVP-TE) extensions are described in [RFC3471] and [RFC3473], routing and Open Shortest Path First (OSPF) extensions are described in [RFC4202] and [RFC4203], and the Link Management Protocol (LMP) is described in [RFC4204]. The GMPLS signaling extensions defined in [RFC4328] provide the mechanisms for basic GMPLS control of OTN based on the 2001 revision of the G.709 specification. The 2012 revision of the G.709 specification, [G709-2012], includes new features, for example, various multiplexing structures, two types of Tributary Slots (TSs) (i.e., 1.25 Gbps and 2.5G bps), and extension of the Optical channel Data Unit-j (ODUj) definition to include the ODUflex function. This document reviews relevant aspects of OTN technology evolution that affect the GMPLS control-plane protocols and examines why and how to update the mechanisms described in [RFC4328]. This document additionally provides a framework for GMPLS control of OTN and includes a discussion of the implications for the use of the PCE [RFC4655]. For the purposes of the control plane, the OTN can be considered to be comprised of ODU and wavelength (Optical Channel (OCh)) layers. This document focuses on the control of the ODU layer, with control of the wavelength layer considered out of the scope. Please refer to [RFC6163] for further information about the wavelength layer. 2. Terminology OTN: Optical Transport Network OPU: Optical Channel Payload Unit ODU: Optical Channel Data Unit Zhang, et al. Informational [Page 3] RFC 7062 OTN Framework November 2013 OTU: Optical Channel Transport Unit OMS: Optical Multiplex Section MSI: Multiplex Structure Identifier TPN: Tributary Port Number LO ODU: Lower Order ODU. The LO ODUj (j can be 0, 1, 2, 2e, 3, 4, or flex) represents the container transporting a client of the OTN that is either directly mapped into an OTUk (k = j) or multiplexed into a server HO ODUk (k > j) container. HO ODU: Higher Order ODU. The HO ODUk (k can be 1, 2, 2e, 3, or 4) represents the entity transporting a multiplex of LO ODUj tributary signals in its OPUk area. ODUflex: Flexible ODU. A flexible ODUk can have any bit rate and a bit rate tolerance of +/-100 ppm (parts per million). In general, throughout this document, "ODUj" is used to refer to ODU entities acting as an LO ODU, and "ODUk" is used to refer to ODU entities being used as an HO ODU. 3. G.709 Optical Transport Network This section provides an informative overview of the aspects of the OTN impacting control-plane protocols. This overview is based on the ITU-T Recommendations that contain the normative definition of the OTN. Technical details regarding OTN architecture and interfaces are provided in the relevant ITU-T Recommendations. Specifically, [G872-2012] describes the functional architecture of optical transport networks providing optical signal transmission, multiplexing, routing, supervision, performance assessment, and network survivability. The legacy OTN referenced by [RFC4328] defines the interfaces of the optical transport network to be used within and between subnetworks of the optical network. With the evolution and deployment of OTN technology, many new features have been specified in ITU-T recommendations, including, for example, new ODU0, ODU2e, ODU4, and ODUflex containers as described in [G709-2012]. Zhang, et al. Informational [Page 4] RFC 7062 OTN Framework November 2013 3.1. OTN Layer Network The simplified signal hierarchy of OTN is shown in Figure 1, which illustrates the layers that are of interest to the control plane. Other layers below OCh (e.g., Optical Transmission Section (OTS)) are not included in this figure. The full signal hierarchy is provided in [G709-2012]. Client signal | ODUj | OTU/OCh OMS Figure 1: Basic OTN Signal Hierarchy Client signals are mapped into ODUj containers. These ODUj containers are multiplexed onto the OTU/OCh. The individual OTU/OCh signals are combined in the OMS using Wavelength Division Multiplexing (WDM), and this aggregated signal provides the link between the nodes. Zhang, et al. Informational [Page 5] RFC 7062 OTN Framework November 2013 3.1.1. Client Signal Mapping The client signals are mapped into an LO ODUj. The current values of j defined in [G709-2012] are: 0, 1, 2, 2e, 3, 4, and flex. The approximate bit rates of these signals are defined in [G709-2012] and are reproduced in Tables 1 and 2. +-----------------------+-----------------------------------+ | ODU Type | ODU nominal bit rate | +-----------------------+-----------------------------------+ | ODU0 | 1,244,160 Kbps | | ODU1 | 239/238 x 2,488,320 Kbps | | ODU2 | 239/237 x 9,953,280 Kbps | | ODU3 | 239/236 x 39,813,120 Kbps | | ODU4 | 239/227 x 99,532,800 Kbps | | ODU2e | 239/237 x 10,312,500 Kbps | | | | | ODUflex for | | |Constant Bit Rate (CBR)| 239/238 x client signal bit rate | | Client signals | | | | | | ODUflex for Generic | | | Framing Procedure | Configured bit rate | | - Framed (GFP-F) | | | Mapped client signal | | +-----------------------+-----------------------------------+ Table 1: ODU Types and Bit Rates NOTE: The nominal ODUk rates are approximately: 2,498,775.126 Kbps (ODU1), 10,037,273.924 Kbps (ODU2), 40,319,218.983 Kbps (ODU3), 104,794,445.815 Kbps (ODU4), and 10,399,525.316 Kbps (ODU2e). Zhang, et al. Informational [Page 6] RFC 7062 OTN Framework November 2013 +-----------------------+-----------------------------------+ | ODU Type | ODU bit rate tolerance | +-----------------------+-----------------------------------+ | ODU0 | +/-20 ppm | | ODU1 | +/-20 ppm | | ODU2 | +/-20 ppm | | ODU3 | +/-20 ppm | | ODU4 | +/-20 ppm | | ODU2e | +/-100 ppm | | | | | ODUflex for CBR | | | Client signals | +/-100 ppm | | | | | ODUflex for GFP-F | | | Mapped client signal | +/-100 ppm | +-----------------------+-----------------------------------+ Table 2: ODU Types and Tolerance One of two options is for mapping client signals into ODUflex depending on the client signal type: - Circuit clients are proportionally wrapped. Thus, the bit rate is defined by the client signal, and the tolerance is fixed to +/-100 ppm. - Packet clients are mapped using the Generic Framing Procedure (GFP). [G709-2012] recommends that the ODUflex(GFP) will fill an integral number of tributary slots of the smallest HO ODUk path over which the ODUflex(GFP) may be carried, and the tolerance should be +/-100 ppm. Note that additional information on G.709 client mapping can be found in [G7041]. 3.1.2. Multiplexing ODUj onto Links The links between the switching nodes are provided by one or more wavelengths. Each wavelength carries one OCh, which carries one OTU, which carries one ODU. Since all of these signals have a 1:1:1 relationship, we only refer to the OTU for clarity. The ODUjs are mapped into the TSs (Tributary Slots) of the OPUk. Note that in the case where j=k, the ODUj is mapped into the OTU/OCh without multiplexing. Zhang, et al. Informational [Page 7] RFC 7062 OTN Framework November 2013 The initial versions of G.709 referenced by [RFC4328] only provided a single TS granularity, nominally 2.5 Gbps. [G709-2012] added an additional TS granularity, nominally 1.25 Gbps. The number and type of TS provided by each of the currently identified OTUk are provided below: Tributary Slot Granularity 2.5 Gbps 1.25 Gbps Nominal Bit Rate OTU1 1 2 2.5 Gbps OTU2 4 8 10 Gbps OTU3 16 32 40 Gbps OTU4 -- 80 100 Gbps To maintain backward compatibility while providing the ability to interconnect nodes that support a 1.25 Gbps TS at one end of a link and a 2.5 Gbps TS at the other, [G709-2012] requires 'new' equipment to fall back to the use of a 2.5 Gbps TS when connected to legacy equipment. This information is carried in band by the payload type. The actual bit rate of the TS in an OTUk depends on the value of k. Thus, the number of TSs occupied by an ODUj may vary depending on the values of j and k. For example, an ODU2e uses 9 TSs in an OTU3 but only 8 in an OTU4. Examples of the number of TSs used for various cases are provided below (referring to Tables 7-9 of [G709-2012]): - ODU0 into ODU1, ODU2, ODU3, or ODU4 multiplexing with 1.25 Gbps TS granularity o ODU0 occupies 1 of the 2, 8, 32, or 80 TSs for ODU1, ODU2, ODU3, or ODU4 - ODU1 into ODU2, ODU3, or ODU4 multiplexing with 1.25 Gbps TS granularity o ODU1 occupies 2 of the 8, 32, or 80 TSs for ODU2, ODU3, or ODU4 - ODU1 into ODU2 or ODU3 multiplexing with 2.5 Gbps TS granularity o ODU1 occupies 1 of the 4 or 16 TSs for ODU2 or ODU3 - ODU2 into ODU3 or ODU4 multiplexing with 1.25 Gbps TS granularity o ODU2 occupies 8 of the 32 or 80 TSs for ODU3 or ODU4 - ODU2 into ODU3 multiplexing with 2.5 Gbps TS granularity o ODU2 occupies 4 of the 16 TSs for ODU3 - ODU3 into ODU4 multiplexing with 1.25 Gbps TS granularity o ODU3 occupies 31 of the 80 TSs for ODU4 Zhang, et al. Informational [Page 8] RFC 7062 OTN Framework November 2013 - ODUflex into ODU2, ODU3, or ODU4 multiplexing with 1.25 Gbps TS granularity o ODUflex occupies n of the 8, 32, or 80 TSs for ODU2, ODU3, or ODU4 (n <= Total TS number of ODUk) - ODU2e into ODU3 or ODU4 multiplexing with 1.25 Gbps TS granularity o ODU2e occupies 9 of the 32 TSs for ODU3 or 8 of the 80 TSs for ODU4 In general, the mapping of an ODUj (including ODUflex) into a specific OTUk TS is determined locally, and it can also be explicitly controlled by a specific entity (e.g., head end or Network Management System (NMS)) through Explicit Label Control [RFC3473]. 3.1.2.1. Structure of MSI Information When multiplexing an ODUj into an HO ODUk (k>j), G.709 specifies the information that has to be transported in-band in order to allow for correct demultiplexing. This information, known as MSI, is transported in the OPUk overhead and is local to each link. In case of bidirectional paths, the association between the TPN and TS must be the same in both directions. The MSI information is organized as a set of entries, with one entry for each HO ODUj TS. The information carried by each entry is: - Payload Type: the type of the transported payload. - TPN: the port number of the ODUj transported by the HO ODUk. The TPN is the same for all the TSs assigned to the transport of the same ODUj instance. For example, an ODU2 carried by an HO ODU3 is described by 4 entries in the OPU3 overhead when the TS granularity is 2.5 Gbps, and by 8 entries when the TS granularity is 1.25 Gbps. On each node and on every link, two MSI values have to be provisioned (referring to [G798]): - The Transmitted MSI (TxMSI) information inserted in OPU (e.g., OPU3) overhead by the source of the HO ODUk trail. - The Expected MSI (ExMSI) information that is used to check the Accepted MSI (AcMSI) information. The AcMSI information is the MSI valued received in-band, after a three-frame integration. Zhang, et al. Informational [Page 9] RFC 7062 OTN Framework November 2013 As described in [G798], the sink of the HO ODU trail checks the complete content of the AcMSI information against the ExMSI. If the AcMSI is different from the ExMSI, then the traffic is dropped, and a payload mismatch alarm is generated. Provisioning of TPN can be performed by either a network management system or control plane. In the last case, the control plane is also responsible for negotiating the provisioned values on a link-by-link basis. 4. Connection Management in OTN OTN-based connection management is concerned with controlling the connectivity of ODU paths and OCh. This document focuses on the connection management of ODU paths. The management of OCh paths is described in [RFC6163]. While [G872-2001] considered the ODU to be a set of layers in the same way as SDH has been modeled, recent ITU-T OTN architecture progress [G872-2012] includes an agreement to model the ODU as a single-layer network with the bit rate as a parameter of links and connections. This allows the links and nodes to be viewed in a single topology as a common set of resources that are available to provide ODUj connections independent of the value of j. Note that when the bit rate of ODUj is less than the server bit rate, ODUj connections are supported by HO ODU (which has a one-to-one relationship with the OTU). From an ITU-T perspective, the ODU connection topology is represented by that of the OTU link layer, which has the same topology as that of the OCh layer (independent of whether the OTU supports an HO ODU, where multiplexing is utilized, or an LO ODU in the case of direct mapping). Thus, the OTU and OCh layers should be visible in a single topological representation of the network, and from a logical perspective, the OTU and OCh may be considered as the same logical, switchable entity. Note that the OTU link-layer topology may be provided via various infrastructure alternatives, including point-to-point optical connections, optical connections fully in the optical domain, and optical connections involving hybrid sub-lambda/lambda nodes involving 3R, etc. See [RFC6163] for additional information. Zhang, et al. Informational [Page 10] RFC 7062 OTN Framework November 2013 4.1. Connection Management of the ODU An LO ODUj can be either mapped into the OTUk signal (j = k) or multiplexed with other LO ODUjs into an OTUk (j < k), and the OTUk is mapped into an OCh. From the perspective of the control plane, there are two kinds of network topology to be considered. (1) ODU layer In this case, the ODU links are presented between adjacent OTN nodes, as illustrated in Figure 2. In this layer, there are ODU links with a variety of TSs available, and nodes that are Optical Digital Cross Connects (ODXCs). LO ODU connections can be set up based on the network topology. Link #5 +--+---+--+ Link #4 +--------------------------| |--------------------------+ | | ODXC | | | +---------+ | | Node E | | | +-++---+--+ +--+---+--+ +--+---+--+ +--+---+-++ | |Link #1 | |Link #2 | |Link #3 | | | |--------| |--------| |--------| | | ODXC | | ODXC | | ODXC | | ODXC | +---------+ +---------+ +---------+ +---------+ Node A Node B Node C Node D Figure 2: Example Topology for LO ODU Connection Management If an ODUj connection is requested between Node C and Node E, routing/path computation must select a path that has the required number of TSs available and that offers the lowest cost. Signaling is then invoked to set up the path and to provide the information (e.g., selected TSs) required by each transit node to allow the configuration of the ODUj-to-OTUk mapping (j = k) or multiplexing (j < k) and demapping (j = k) or demultiplexing (j < k). (2) ODU layer with OCh switching capability In this case, the OTN nodes interconnect with wavelength switched nodes (e.g., Reconfiguration Optical Add/Drop Multiplexer (ROADM) or Optical Cross-Connect (OXC)) that are capable of OCh switching; this is illustrated in Figures 3 and 4. There are the ODU layer and the OCh layer, so it is simply a Multi-Layer Network (MLN) (see Zhang, et al. Informational [Page 11] RFC 7062 OTN Framework November 2013 [RFC6001]). OCh connections may be created on demand, which is described in Section 5.1. In this case, an operator may choose to allow the underlying OCh layer to be visible to the ODU routing/path computation process, in which case the topology would be as shown in Figure 4. In Figure 3, however, a cloud representing OCh-capable switching nodes is represented. In Figure 3, the operator choice is to hide the real OCh-layer network topology. Node E Link #5 +--------+ Link #4 +------------------------| |------------------------+ | ------ | | // \\ | | || || | | | OCh domain | | +-+-----+ +------ || || ------+ +-----+-+ | | | \\ // | | | | |Link #1 | -------- |Link #3 | | | +--------+ | | +--------+ + | ODXC | | ODXC +--------+ ODXC | | ODXC | +-------+ +---------+Link #2 +---------+ +-------+ Node A Node B Node C Node D Figure 3: OCh Hidden Topology for LO ODU Connection Management Link #5 +---------+ Link #4 +------------------------| |-----------------------+ | +----| ODXC |----+ | | +-++ +---------+ ++-+ | | Node f | | Node E | | Node g | | +-++ ++-+ | | | +--+ | | +-+-----+ +----+----+--| |--+-----+---+ +-----+-+ | |Link #1 | | +--+ | |Link #3 | | | +--------+ | Node h | +--------+ | | ODXC | | ODXC +--------+ ODXC | | ODXC | +-------+ +---------+ Link #2+---------+ +-------+ Node A Node B Node C Node D Figure 4: OCh Visible Topology for LO ODUj Connection Management Zhang, et al. Informational [Page 12] RFC 7062 OTN Framework November 2013 In Figure 4, the cloud in the previous figure is substituted by the real topology. The nodes f, g, and h are nodes with OCh switching capability. In the examples (i.e., Figures 3 and 4), we have considered the case in which LO ODUj connections are supported by an OCh connection and the case in which the supporting underlying connection can also be made by a combination of HO ODU/OCh connections. In this case, the ODU routing/path selection process will request an HO ODU/OCh connection between node C and node E from the OCh domain. The connection will appear at the ODU level as a Forwarding Adjacency, which will be used to create the ODU connection. 5. GMPLS/PCE Implications The purpose of this section is to provide a set of requirements to be evaluated for extensions of the current GMPLS protocol suite and the PCE applications and protocols to encompass OTN enhancements and connection management. 5.1. Implications for Label Switched Path (LSP) Hierarchy The path computation for an ODU connection request is based on the topology of the ODU layer. The OTN path computation can be divided into two layers. One layer is OCh/OTUk; the other is ODUj. [RFC4206] and [RFC6107] define the mechanisms to accomplish creating the hierarchy of LSPs. The LSP management of multiple layers in OTN can follow the procedures defined in [RFC4206], [RFC6001], and [RFC6107]. As discussed in Section 4, the route path computation for OCh is in the scope of the Wavelength Switched Optical Network (WSON) [RFC6163]. Therefore, this document only considers the ODU layer for an ODU connection request. The LSP hierarchy can also be applied within the ODU layers. One of the typical scenarios for ODU layer hierarchy is to maintain compatibility with introducing new [G709-2012] services (e.g., ODU0 and ODUflex) into a legacy network configuration (i.e., the legacy OTN referenced by [RFC4328]). In this scenario, it may be necessary to consider introducing hierarchical multiplexing capability in specific network transition scenarios. One method for enabling multiplexing hierarchy is by introducing dedicated boards in a few specific places in the network and tunneling these new services through the legacy containers (ODU1, ODU2, ODU3), thus postponing the need to upgrade every network element to [G709-2012] capabilities. Zhang, et al. Informational [Page 13] RFC 7062 OTN Framework November 2013 In such cases, one ODUj connection can be nested into another ODUk (j +----------+ | TS1==|===========\--------+--TS1 | | TS2==|=========\--\-------+--TS2 | | TS3==|=======\--\--\------+--TS3 | | TS4==|=====\--\--\--\-----+--TS4 | | | \ \ \ \----+--TS5 | | | \ \ \------+--TS6 | | | \ \--------+--TS7 | | | \----------+--TS8 | +----------+ <------------ +----------+ node A Resv node B Figure 5: Interworking between 1.25 Gbps TS and 2.5 Gbps TS Take Figure 5 as an example. Assume that there is an ODU2 link between node A and B, where node A only supports the 2.5 Gbps TS while node B supports the 1.25 Gbps 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 1.25 Gbps. But in the label sent from B to A, it is indicated that the TS#i with the granularity of 2.5 Gbps is reserved. In the opposite direction, when receiving a label from node A indicating that the TS#i with the granularity of 2.5 Gbps is reserved, node B will reserve the TS#i and TS#i+4 with the granularity of 1.25 Gbps in its data plane. 7. Security Considerations The use of control-plane protocols for signaling, routing, and path computation opens an OTN to security threats through attacks on those protocols. However, this is not greater than the risks presented by the existing OTN control plane as defined by [RFC4203] and [RFC4328]. Meanwhile, the Data Communication Network (DCN) for OTN GMPLS control-plane protocols is likely to be in the in-fiber overhead, which, together with access lists at the network edges, provides a significant security feature. For further details of specific security measures, refer to the documents that define the protocols Zhang, et al. Informational [Page 21] RFC 7062 OTN Framework November 2013 ([RFC3473], [RFC4203], [RFC5307], [RFC4204], and [RFC5440]). [RFC5920] provides an overview of security vulnerabilities and protection mechanisms for the GMPLS control plane. 8. Acknowledgments We would like to thank Maarten Vissers and Lou Berger for their reviews and useful comments. 9. Contributors Jianrui Han Huawei Technologies Co., Ltd. F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R. China Phone: +86-755-28972913 EMail: hanjianrui@huawei.com Malcolm Betts EMail: malcolm.betts@rogers.com Pietro Grandi Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy Phone: +39 039 6864930 EMail: pietro_vittorio.grandi@alcatel-lucent.it Eve Varma Alcatel-Lucent 1A-261, 600-700 Mountain Av PO Box 636 Murray Hill, NJ 07974-0636 USA EMail: eve.varma@alcatel-lucent.com Zhang, et al. Informational [Page 22] RFC 7062 OTN Framework November 2013 10. References 10.1. Normative References [G709-2012] ITU-T, "Interface for the Optical Transport Network (OTN)", G.709/Y.1331 Recommendation, February 2012. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC4201] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in MPLS Traffic Engineering (TE)", RFC 4201, October 2005. [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, October 2005. [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005. [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, October 2005. [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. [RFC4328] Papadimitriou, D., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, January 2006. [RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 5307, October 2008. Zhang, et al. Informational [Page 23] RFC 7062 OTN Framework November 2013 [RFC5440] Vasseur, JP., Ed., and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, March 2009. [RFC6001] Papadimitriou, D., Vigoureux, M., Shiomoto, K., Brungard, D., and JL. Le Roux, "Generalized MPLS (GMPLS) Protocol Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN)", RFC 6001, October 2010. [RFC6107] Shiomoto, K., Ed., and A. Farrel, Ed., "Procedures for Dynamically Signaled Hierarchical Label Switched Paths", RFC 6107, February 2011. [RFC6344] Bernstein, G., Ed., Caviglia, D., Rabbat, R., and H. van Helvoort, "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label Switching (GMPLS)", RFC 6344, August 2011. 10.2. Informative References [G798] ITU-T, "Characteristics of optical transport network hierarchy equipment functional blocks", G.798 Recommendation, December 2012. [G872-2001] ITU-T, "Architecture of optical transport networks", G.872 Recommendation, November 2001. [G872-2012] ITU-T, "Architecture of optical transport networks", G.872 Recommendation, October 2012. [G7041] ITU-T, "Generic framing procedure", G.7041/Y.1303, April 2011. [G7042] ITU-T, "Link capacity adjustment scheme (LCAS) for virtual concatenated signals", G.7042/Y.1305, March 2006. [G7044] ITU-T, "Hitless adjustment of ODUflex (HAO)", G.7044/Y.1347, October 2011. [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, August 2006. Zhang, et al. Informational [Page 24] RFC 7062 OTN Framework November 2013 [RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, April 2011. [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010. [RFC7025] Otani, T., Ogaki, K., Caviglia, D., Zhang, F., and C. Margaria, "Requirements for GMPLS Applications of PCE", RFC 7025, September 2013. [TDM-OAM] Kern, A., and A. Takacs, "GMPLS RSVP-TE Extensions for SONET/SDH and OTN OAM Configuration", Work in Progress, November 2013. Zhang, et al. Informational [Page 25] RFC 7062 OTN Framework November 2013 Authors' Addresses Fatai Zhang (editor) 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 Dan Li Huawei Technologies F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R. China Phone: +86-755-28973237 EMail: huawei.danli@huawei.com Han Li China Mobile Communications Corporation 53 A Xibianmennei Ave. Xuanwu District Beijing 100053 P.R. China Phone: +86-10-66006688 EMail: lihan@chinamobile.com Sergio Belotti Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy Phone: +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 Zhang, et al. Informational [Page 26]