--- 1/draft-ietf-ccamp-flexi-grid-fwk-05.txt 2015-08-25 03:14:59.620792966 -0700 +++ 2/draft-ietf-ccamp-flexi-grid-fwk-06.txt 2015-08-25 03:14:59.704794972 -0700 @@ -1,53 +1,57 @@ CCAMP Working Group O. Gonzalez de Dios, Ed. Internet-Draft Telefonica I+D Intended status: Informational R. Casellas, Ed. -Expires: November 26, 2015 CTTC - May 25, 2015 +Expires: February 26, 2016 CTTC + August 25, 2015 Framework and Requirements for GMPLS-based control of Flexi-grid DWDM networks - draft-ietf-ccamp-flexi-grid-fwk-05 + draft-ietf-ccamp-flexi-grid-fwk-06 Abstract To allow efficient allocation of optical spectral bandwidth for high bit-rate systems, the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) has extended its Recommendations G.694.1 and G.872 to include a new dense wavelength division multiplexing (DWDM) grid by defining a set of nominal central frequencies, channel spacings and the concept of "frequency slot". In such an environment, a data plane connection is switched based on allocated, variable-sized frequency ranges within the optical spectrum creating what is known as a flexible grid (flexi- grid). - This document defines a framework and the associated control plane - requirements for the GMPLS-based control of flexi-grid DWDM networks. + Given the specific characteristics of flexi-grid optical networks and + their associated technology, this document defines a framework and + the associated control plane requirements for the application of the + existing GMPLS architecture and control plane protocols to the + control of flexi-grid DWDM networks. The actual extensions to the + GMPLS protocols will be defined in companion documents. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on November 26, 2015. + This Internet-Draft will expire on February 26, 2016. Copyright Notice Copyright (c) 2015 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 @@ -80,41 +84,41 @@ 4.3. Consideration of LSPs in Flexi-grid . . . . . . . . . . . 15 4.4. Control Plane Modeling of Network Elements . . . . . . . 20 4.5. Media Layer Resource Allocation Considerations . . . . . 20 4.6. Neighbor Discovery and Link Property Correlation . . . . 24 4.7. Path Computation / Routing and Spectrum Assignment (RSA) 25 4.7.1. Architectural Approaches to RSA . . . . . . . . . . . 25 4.8. Routing and Topology Dissemination . . . . . . . . . . . 26 4.8.1. Available Frequency Ranges/Slots of DWDM Links . . . 27 4.8.2. Available Slot Width Ranges of DWDM Links . . . . . . 27 4.8.3. Spectrum Management . . . . . . . . . . . . . . . . . 27 - 4.8.4. Information Model . . . . . . . . . . . . . . . . . . 27 + 4.8.4. Information Model . . . . . . . . . . . . . . . . . . 28 5. Control Plane Requirements . . . . . . . . . . . . . . . . . 29 5.1. Support for Media Channels . . . . . . . . . . . . . . . 29 5.1.1. Signaling . . . . . . . . . . . . . . . . . . . . . . 30 5.1.2. Routing . . . . . . . . . . . . . . . . . . . . . . . 30 5.2. Support for Media Channel Resizing . . . . . . . . . . . 31 5.3. Support for Logical Associations of Multiple Media Channels . . . . . . . . . . . . . . . . . . . . . . . . 31 5.4. Support for Composite Media Channels . . . . . . . . . . 31 5.5. Support for Neighbor Discovery and Link Property Correlation . . . . . . . . . . . . . . . . . . . . . . . 32 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 7. Security Considerations . . . . . . . . . . . . . . . . . . . 32 8. Manageability Considerations . . . . . . . . . . . . . . . . 33 9. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 10. Contributing Authors . . . . . . . . . . . . . . . . . . . . 34 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 37 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 37 12.1. Normative References . . . . . . . . . . . . . . . . . . 37 12.2. Informative References . . . . . . . . . . . . . . . . . 38 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 1. Introduction The term "Flexible grid" (flexi-grid for short) as defined by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Study Group 15 in the latest version of [G.694.1], refers to the updated set of nominal central frequencies (a frequency grid), channel spacing and optical spectrum management/allocation considerations that have been defined in order to allow an efficient and flexible allocation and configuration of @@ -166,35 +170,33 @@ 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]. While [RFC2119] describes interpretations of these key words in terms of protocol specifications and implementations, they are used in this document to describe design requirements for protocol extensions. 2.2. Abbreviations - EFS: Effective Frequency Slot - FS: Frequency Slot FSC: Fiber-Switch Capable LSR: Label Switching Router NCF: Nominal Central Frequency OCh: Optical Channel OCh-P: Optical Channel Payload - OTN: Optical Transport Network + OTN: Optical Transport Network OTSi: Optical Tributary Signal OTSiG: OTSi Group is a set of OTSi OCC: Optical Channel Carrier PCE: Path Computation Element ROADM: Reconfigurable Optical Add-Drop Multiplexer @@ -280,44 +282,50 @@ axis. A slot width is constrained to be m x SWG (that is, m x 12.5 GHz), where m is an integer greater than or equal to 1. Frequency Slot 1 Frequency Slot 2 ------------- ------------------- | | | | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 ...--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--... ------------- ------------------- ^ ^ - Central F = 193.1THz Central F = 193.14375 THz + Slot NCF = 193.1THz Slot NCF = 193.14375 THz Slot width = 25 GHz Slot width = 37.5 GHz + n=0, m=2 n=7, m=3 Figure 3: Example Frequency Slots * The symbol '+' represents the allowed nominal central frequencies * The '--' represents the nominal central frequency granularity + in units of 6.25 GHz * The '^' represents the slot nominal central frequency * The number on the top of the '+' symbol represents the 'n' in the frequency calculation formula. * The nominal central frequency is 193.1 THz when n equals to zero. o Effective Frequency Slot [G.870]: The effective frequency slot of a media channel is that part of the frequency slots of the filters along the media channel that is common to all of the filters' frequency slots. Note that both the Frequency Slot and Effective Frequency Slot are local terms. + o Figure 4 shows the effect of combining two filters along a + channel. The combination of frequency slot 1 and frequency slot 2 + applied to the media channel is effective frequency slot shown. + Frequency Slot 1 ------------- | | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 ..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... Frequency Slot 2 ------------------- | | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 @@ -393,23 +401,24 @@ (i.e., there is no spectrum between them that can be used for other media channels) or non-contiguous. o It is not currently envisaged that such composite media channels may be constructed from slots carried on different fibers whether those fibers traverse the same hop-by-hop path through the network or not. o Furthermore, it is not considered likely that a media channel may be constructed from a different variation of slot composition on - each hop. That is, the slot composition must be the same from one - end to the other of the media channel even if the specific slots - and their spacing may vary hop by hop. + each hop. That is, the slot composition (i.e., the group of OTSi + carried by the composite media channel) must be the same from one + end to the other of the media channel even if the specific slot + for each OTSi and the spacing among slots may vary hop by hop. o How the signal is carried across such groups of network media channels is out of scope for this document. 3.3. Hierarchy in the Media Layer In summary, the concept of frequency slot is a logical abstraction that represents a frequency range, while the media layer represents the underlying media support. Media Channels are media associations, characterized by their (effective) frequency slot, respectively; and @@ -417,21 +426,21 @@ control and management perspective, a media channel can be logically split into network media channels. In Figure 5, a media channel has been configured and dimensioned to support two network media channels, each of them carrying one OTSi. Media Channel Frequency Slot +-------------------------------X------------------------------+ | | | Frequency Slot Frequency Slot | - | +------------X----------+ +----------X-----------+ | + | +-----------X-----------+ +----------X-----------+ | | | OTSi | | OTSi | | | | o | | o | | | | | | | | | | -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 --+---+---+---+---+---+---+---+---+---+---+---+--+---+---+---+---+-- <- Network Media Channel-> <- Network Media Channel-> <------------------------ Media Channel -----------------------> @@ -518,21 +527,22 @@ networks are covered in Section 5. This framework is aimed at controlling the media layer within the OTN hierarchy, and controlling the required adaptations of the signal layer. This document also defines the term Spectrum-Switched Optical Network (SSON) to refer to a Flexi-grid enabled DWDM network that is controlled by a GMPLS/PCE control plane. This section provides a mapping of the ITU-T G.872 architectural aspects to GMPLS/Control plane terms, and considers the relationship between the architectural concept/construct of media channel and its - control plane representations (e.g., as a TE link). + control plane representations (e.g., as a TE link, as defined in + [RFC3945]). 4.1. General Considerations The GMPLS control of the media layer deals with the establishment of media channels that are switched in media channel matrices. GMPLS labels are used to locally represent the media channel and its associated frequency slot. Network media channels are considered a particular case of media channels when the end points are transceivers (that is, source and destination of an OTSi). @@ -688,22 +698,22 @@ |------------------| |----------------| LSR | TE link | LSR | TE link | LSR |------------------| |----------------| -----+ +---------------+ +----- Figure 11: Flex-grid LSP Representing a Media Channel that Starts at the Filter of the Outgoing Interface of the Ingress LSR and ends at the Filter of the Incoming Interface of the Egress LSR In Figure 12 a Network Media Channel is represented as terminated at - the network side of the trnaponders. This is commonly names as OTSi- - trail connection. + the network side of the transceivers. This is commonly named an + OTSi-trail connection. |--------------------- Network Media Channel ----------------------| +----------------------+ +----------------------+ | | | +------+ +------+ +------+ +------+ | | +----+ | | | | +----+ | |OTSi OTSi| o-| |-o | +-----+ | o-| |-o |sink src | | | | | ===+-+ +-+==| | | | | O---|R T|***o******o******************************************************** @@ -860,36 +870,37 @@ perspective of network control and management, this effective slot is seen as the "usable" end-to-end frequency slot. The establishment of an LSP is related to the establishment of the media channel and the configuration of the effective frequency slot. A "service request" is characterized (at a minimum) by its required effective frequency slot width. This does not preclude that the request may add additional constraints such as also imposing the nominal central frequency. A given effective frequency slot may be requested for the media channel in the control plane LSP setup - messages, and a specific frequency slot can be requeste on any + messages, and a specific frequency slot can be requested on any specific hop of the LSP setup. Regardless of the actual encoding, - the LSP setup message specifies a minimum frequency slot width that - needs to be fulfilled in order to successful establish the requsted - LSP. + the LSP setup message specifies a minimum effective frequency slot + width that needs to be fulfilled in order to successful establish the + requsted LSP. An effective frequency slot must equally be described in terms of a central nominal frequency and its slot width (in terms of usable spectrum of the effective frequency slot). That is, it must be possible to determine the end-to-end values of the n and m parameters. We refer to this by saying that the "effective frequency slot of the media channel/LSP must be valid". In GMPLS the requested effective frequency slot is represented to the - TSpec present in the Path message, and the effective frequency slot - is mapped to the FlowSpec carried in the Resv message. + TSpec present in the RSVP-TE Path message, and the effective + frequency slot is mapped to the FlowSpec carried in the RSVP-TE Resv + message. In GMPLS-controlled systems, the switched element corresponds to the 'label'. In flexi-grid where the switched element is a frequency slot, the label represents a frequency slot. In consequence, the label in flexi-grid conveys the necessary information to obtain the frequency slot characteristics (i.e, central frequency and slot width: the n and m parameters). The frequency slot is locally identified by the label. The local frequency slot may change at each hop, given hardware @@ -975,80 +985,87 @@ have assigned different frequency slots. For Figure 15 the effective slot is made valid by ensuring that the minimum m is greater than the requested m. The effective slot (intersection) is the lowest m (bottleneck). For Figure 16 the effective slot is made valid by ensuring that it is valid at each hop in the upstream direction. The intersection needs to be computed because invalid slots could result otherwise. + C B A |Path(m_req) | ^ | |---------> | # | | | # ^ -^--------------^----------------#----------------#-- Effective # # # # FS n, m # . . . . . . .#. . . . . . . . # . . . . . . . .# <-fixed # # # # n -v--------------v----------------#----------------#--- | | # v | | # Resv | | | v <------ | | | |FlowSpec(n, m_a)| | | <--------| | | | FlowSpec (n, | <--------| min(m_a, m_b)) FlowSpec (n, | min(m_a, m_b, m_c)) + m_a, m_b, m_c: Selected frequency slot widths + Figure 15: Distributed Allocation with Different m and Same n - |Path(m_req) ^ | + C B A + |Path(m_req) ^ | | |---------> # | | | # ^ ^ -^-------------#----------------#-----------------#-------- Effective # # # # FS n, m # # # # # # # # -v-------------v----------------#-----------------#-------- | | # v | | # Resv | | | v <------ | | | |FlowSpec(n_a, m_a) | | <--------| | | | FlowSpec (FSb [intersect] FSa) <--------| FlowSpec ([intersect] FSa,FSb,FSc) + n_a: Selected nominal central frequencyfr by node A + m_a: Selected frequency slot widths by node A + FSa, FSb, FSc: Frequency slot at each hop A, B, C + Figure 16: Distributed Allocation with Different m and Different n Note, when a media channel is bound to one OTSi (i.e., is a network - media channel), the EFS must be the one of the OTSi. The media - channel setup by the LSP may contains the EFS of the network media - channel EFS. This is an endpoint property: the egress and ingress - have to constrain the EFS to be the OTSi EFS. + media channel), the effective FS must be the one of the OTSi. The + media channel setup by the LSP may contain the effective FS of the + network media channel effective FS. This is an endpoint property: + the egress and ingress have to constrain the Effective FS to be the + OTSi Effective FS. 4.6. Neighbor Discovery and Link Property Correlation There are potential interworking problems between fixed-grid DWDM and flexi-grid DWDM nodes. Additionally, even two flexi-grid nodes may have different grid properties, leading to link property conflict with resulting limited interworking. Devices or applications that make use of the flexi-grid might not be able to support every possible slot width. In other words, different applications may be defined where each supports a different grid - granularity. Consider a node with an application where the nominal - central frequency granularity is 12.5 GHz and where slot widths are - multiples of 25 GHz. In this case the link between two optical nodes - with different grid granularities must be configured to align with - the larger of both granularities. Furthermore, different nodes may - have different slot-width tuning ranges. + granularity. In this case the link between two optical nodes with + different grid granularities must be configured to align with the + larger of both granularities. Furthermore, different nodes may have + different slot-width tuning ranges. In summary, in a DWDM Link between two nodes, at least the following properties need to be negotiated: o Grid capability (channel spacing) - Between fixed-grid and flexi- grid nodes. o Grid granularity - Between two flexi-grid nodes. o Slot width tuning range - Between two flexi-grid nodes. @@ -1265,28 +1282,31 @@ 5.1.1. Signaling The signaling procedure SHALL be able to configure the nominal central frequency (n) of a flexi-grid LSP. The signaling procedure SHALL allow a flexible range of values for the frequency slot width (m) parameter. Specifically, the control plane SHALL allow setting up a media channel with frequency slot width (m) ranging from a minimum of m=1 (12.5GHz) to a maximum of the - entire C-band with a slot width granularity of 12.5GHz. + entire C-band (the wavelength range 1530 nm to 1565 nm, which + corresponds to the amplification range of erbium doped fiber + amplifiers) with a slot width granularity of 12.5GHz. The signaling procedure SHALL be able to configure the minimum width (m) of a flexi-grid LSP. In addition, the signaling procedure SHALL be able to configure local frequency slots. The control plane architecture SHOULD allow for the support of L-band - and S-band. + (the wavelength range 1565 nm to 1625 nm) and S-band (the wavelength + range 1460 nm to 1530 nm). The signalling process SHALL be able to collect the local frequency slot assigned at each link along the path. The signaling procedures SHALL support all of the RSA architectural models (R&SA, R+SA, and R+DSA) within a single set of protocol objects although some objects may only be applicable within one of the models. 5.1.2. Routing @@ -1350,21 +1370,22 @@ media channels to be added to or removed from the whole. The routing protocols MUST provide sufficient information for the computation of paths and slots for composite media channels using any of the three RSA architectural models (R&SA, R+SA, and R+DSA). 5.5. Support for Neighbor Discovery and Link Property Correlation The control plane MAY include support for neighbor discovery such that an flexi-grid network can be constructed in a "plug-and-play" - manner. + manner. Note, however, that in common operational practice + validation processes are used rather than automatic discovery. The control plane SHOULD allow the nodes at opposite ends of a link to correlate the properties that they will apply to the link. Such correlation SHOULD include at least the identities of the node and the identities they apply to the link. Other properties such as the link characteristics described for the routing information model in Figure 17 SHOULD also be correlated. Such neighbor discovery and link property correlation, if provided, MUST be able to operate in both an out-of-band and an out-of-fiber @@ -1599,87 +1620,114 @@ [G.872] International Telecomunications Union, "ITU-T Recommendation G.872, Architecture of optical transport networks, draft v0.16 2012/09 (for discussion)", 2012. [G.959.1-2013] International Telecomunications Union, "Update of ITU-T Recommendation G.959.1, Optical transport network physical layer interfaces", 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate - Requirement Levels", BCP 14, RFC 2119, March 1997. + Requirement Levels", BCP 14, RFC 2119, + DOI 10.17487/RFC2119, March 1997, + . - [RFC4202] Kompella, K. and Y. Rekhter, "Routing Extensions in - Support of Generalized Multi-Protocol Label Switching - (GMPLS)", RFC 4202, October 2005. + [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label + Switching (GMPLS) Architecture", RFC 3945, + DOI 10.17487/RFC3945, October 2004, + . + + [RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions + in Support of Generalized Multi-Protocol Label Switching + (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, 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. + (GMPLS) Traffic Engineering (TE)", RFC 4206, + DOI 10.17487/RFC4206, October 2005, + . [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol - Specifications", RFC 5511, April 2009. + Specifications", RFC 5511, DOI 10.17487/RFC5511, April + 2009, . 12.2. Informative References - [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching - (GMPLS) Signaling Resource ReserVation Protocol-Traffic - Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. + [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label + Switching (GMPLS) Signaling Resource ReserVation Protocol- + Traffic Engineering (RSVP-TE) Extensions", RFC 3473, + DOI 10.17487/RFC3473, January 2003, + . - [RFC4204] Lang, J., "Link Management Protocol (LMP)", RFC 4204, - October 2005. + [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, + DOI 10.17487/RFC4204, October 2005, + . [RFC4397] Bryskin, I. and A. Farrel, "A Lexicography for the Interpretation of Generalized Multiprotocol Label Switching (GMPLS) Terminology within the Context of the ITU-T's Automatically Switched Optical Network (ASON) - Architecture", RFC 4397, February 2006. + Architecture", RFC 4397, DOI 10.17487/RFC4397, February + 2006, . [RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi- Protocol Label Switching (GMPLS) Extensions for Synchronous Optical Network (SONET) and Synchronous - Digital Hierarchy (SDH) Control", RFC 4606, August 2006. + Digital Hierarchy (SDH) Control", RFC 4606, + DOI 10.17487/RFC4606, August 2006, + . - [RFC4783] Berger, L., "GMPLS - Communication of Alarm Information", - RFC 4783, December 2006. + [RFC4783] Berger, L., Ed., "GMPLS - Communication of Alarm + Information", RFC 4783, DOI 10.17487/RFC4783, December + 2006, . - [RFC4802] Nadeau, T. and A. Farrel, "Generalized Multiprotocol Label - Switching (GMPLS) Traffic Engineering Management - Information Base", RFC 4802, February 2007. + [RFC4802] Nadeau, T., Ed., Farrel, A., and , "Generalized + Multiprotocol Label Switching (GMPLS) Traffic Engineering + Management Information Base", RFC 4802, + DOI 10.17487/RFC4802, February 2007, + . - [RFC4803] Nadeau, T. and A. Farrel, "Generalized Multiprotocol Label - Switching (GMPLS) Label Switching Router (LSR) Management - Information Base", RFC 4803, February 2007. + [RFC4803] Nadeau, T., Ed. and A. Farrel, Ed., "Generalized + Multiprotocol Label Switching (GMPLS) Label Switching + Router (LSR) Management Information Base", RFC 4803, + DOI 10.17487/RFC4803, February 2007, + . - [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS - Networks", RFC 5920, July 2010. + [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS + Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010, + . - [RFC6163] Lee, Y., Bernstein, G., and W. Imajuku, "Framework for - GMPLS and Path Computation Element (PCE) Control of - Wavelength Switched Optical Networks (WSONs)", RFC 6163, - April 2011. + [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, DOI 10.17487/RFC6163, April 2011, + . - [RFC6344] Bernstein, G., Caviglia, D., Rabbat, R., and H. van + [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. + Multi-Protocol Label Switching (GMPLS)", RFC 6344, + DOI 10.17487/RFC6344, August 2011, + . - [RFC7139] Zhang, F., Zhang, G., Belotti, S., Ceccarelli, D., and K. - Pithewan, "GMPLS Signaling Extensions for Control of - Evolving G.709 Optical Transport Networks", RFC 7139, - March 2014. + [RFC7139] Zhang, F., Ed., Zhang, G., Belotti, S., Ceccarelli, D., + and K. Pithewan, "GMPLS Signaling Extensions for Control + of Evolving G.709 Optical Transport Networks", RFC 7139, + DOI 10.17487/RFC7139, March 2014, + . [RFC7260] Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE Extensions for Operations, Administration, and Maintenance - (OAM) Configuration", RFC 7260, June 2014. + (OAM) Configuration", RFC 7260, DOI 10.17487/RFC7260, June + 2014, . Authors' Addresses Oscar Gonzalez de Dios (editor) Telefonica I+D Don Ramon de la Cruz 82-84 Madrid 28045 Spain Phone: +34913128832