PCE Working Group Z. Ali Internet-Draft S. Sivabalan Intended status: Standards Track C. Filsfils Expires: August 27, 2019 Cisco Systems R. Varga Pantheon Technologies V. Lopez O. Gonzalez de Dios Telefonica H. Zheng X. Zhang Huawei Technologies February 23, 2019 Path Computation Element Communication Protocol (PCEP) Extensions for remote-initiated GMPLS LSP Setup draft-ietf-pce-remote-initiated-gmpls-lsp-06.txt Abstract [RFC8281] specifies procedures that can be used for creation and deletion of PCE-initiated LSPs in the active stateful PCE model. However, this specification focuses on MPLS networks, and does not cover remote instantiation of paths in GMPLS-controlled networks. This document complements [RFC8281] by addressing the requirements for remote-initiated GMPLS LSPs. Requirements Language 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]. 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 https://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." Ali, et al. Expires August 27, 2019 [Page 1] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 This Internet-Draft will expire on August 27, 2019. Copyright Notice Copyright (c) 2019 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 (https://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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements for Remote-Initiated GMPLS LSPs . . . . . . . . 3 3. PCEP Extensions for Remote-Initiated GMPLS LSPs . . . . . . . 4 3.1. Generalized Endpoint in LSP Initiate Message . . . . . . . 4 3.2. GENERALIZED-BANDWIDTH object in LSP Initiate Message . . . 4 3.3. Protection Attributes in LSP Initiate Message . . . . . . . 5 3.4. ERO in LSP Initiate Object . . . . . . . . . . . . . . . . 5 3.4.1. ERO with explicit label control . . . . . . . . . . . . . 5 3.4.2. ERO with Path Keys . . . . . . . . . . . . . . . . . . . 6 3.4.3. Switch Layer Object . . . . . . . . . . . . . . . . . . . 6 3.5. LSP delegation and cleanup . . . . . . . . . . . . . . . . 6 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 5.1. PCEP-Error Object . . . . . . . . . . . . . . . . . . . . . 7 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.2. Informational References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction The Path Computation Element communication Protocol (PCEP) provides mechanisms for Path Computation Elements (PCEs) to perform route computations in response to Path Computation Clients (PCCs) requests. PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model draft [RFC8231] describes a set of extensions to PCEP to enable active control of MPLS-TE and GMPLS network. Ali, et al. Expires August 27, 2019 [Page 2] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 [RFC8281] describes the setup and teardown of PCE-initiated LSPs under the active stateful PCE model, without the need for local configuration on the PCC. This enables realization of a dynamic network that is centrally controlled and deployed. However, this specification is focused on MPLS networks, and does not cover the GMPLS networks (e.g., WSON, OTN, SONET/ SDH, etc. technologies). This document complements [RFC8281] by addressing the requirements for remote-initiated GMPLS LSPs. These requirements are covered in Section 2 of this draft. The PCEP extensions for remote initiated GMPLS LSPs are specified in Section 3. 2. Requirements for Remote-Initiated GMPLS LSPs [RFC8281] specifies procedures that can be used for creation and deletion of PCE-initiated LSPs under the active stateful PCE model. However, this specification does not address GMPLS requirements outlined in the following: o GMPLS support multiple switching capabilities on per TE link basis. GMPLS LSP creation requires knowledge of LSP switching capability (e.g., TDM, L2SC, OTN-TDM, LSC, etc.) to be used [RFC3471] , [RFC3473] . o GMPLS LSP creation requires knowledge of the encoding type (e.g., lambda photonic, Ethernet, SONET/ SDH, G709 OTN, etc.) to be used by the LSP [RFC3471] , [RFC3473]. o GMPLS LSP creation requires information of the generalized payload (G-PID) to be carried by the LSP [RFC3471] , [RFC3473]. o GMPLS LSP creation requires specification of data flow specific traffic parameters (also known as Tspec), which are technology specific. o GMPLS also specifics support for asymmetric bandwidth requests [RFC6387] . o GMPLS extends the addressing to include unnumbered interface identifiers, as defined in [RFC3477] . o In some technologies path calculation is tightly coupled with label selection along the route. For example, path calculation in a WDM network may include lambda continuity and/ or lambda feasibility constraints and hence a path computed by the PCE is associated with a specific lambda (label). Hence, in such networks, the label information needs to be provided to a PCC in order for a PCE to initiate GMPLS LSPs under the active stateful PCE model. I.e., explicit label control may be required. Ali, et al. Expires August 27, 2019 [Page 3] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 o GMPLS specifics protection context for the LSP, as defined in [RFC4872] , [RFC4873]. 3. PCEP Extensions for Remote-Initiated GMPLS LSPs LSP initiate (PCInitiate) message defined in [RFC8281] needs to be extended to include GMPLS specific PCEP objects as follows: 3.1. Generalized Endpoint in LSP Initiate Message This document does not modify the usage of END-POINTS object for PCE initiated LSPs as specified in [RFC8281] . It augments the usage as specified below. END-POINTS object has been extended by [I-D.ietf-pce-gmpls-pcep-extensions] to include a new object type called "Generalized Endpoint". PCInitiate message sent by a PCE to a PCC to trigger a GMPLS LSP instantiation SHOULD include the END- POINTS with Generalized Endpoint object type. Furthermore, the END- POINTS object MUST contain "label request" TLV. The label request TLV is used to specify the switching type, encoding type and GPID of the LSP being instantiated by the PCE. If the END-POINTS Object of type Generalized Endpoint is missing the label request TLV, the PCC MUST send a PCErr message with Error- type=6 (Mandatory Object missing) and Error-value= TBA (label request TLV missing). If the PCC does not support the END-POINTS Object of type Generalized Endpoint, the PCC MUST send a PCErr message with Error-type = 3 (Unknown Object), Error-value = 2(unknown object type). The unnumbered endpoint TLV can be used to specify unnumbered endpoint addresses for the LSP being instantiated by the PCE. The END-POINTS MAY contain other TLVs defined in [I-D.ietf-pce-gmpls-pcep-extensions]. 3.2. GENERALIZED-BANDWIDTH object in LSP Initiate Message LSP initiate message defined in [RFC8281] can optionally include the BANDWIDTH object. However, the following possibilities cannot be represented in the BANDWIDTH object: o Asymmetric bandwidth (different bandwidth in forward and reverse direction), as described in [RFC6387] . o Technology specific GMPLS parameters (e.g., Tspec for SDH/SONET, G.709, ATM, MEF, etc.) are not supported. Ali, et al. Expires August 27, 2019 [Page 4] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 GENERALIZED-BANDWIDTH object has been defined in [I-D.ietf-pce-gmpls-pcep-extensions] to address the above-mentioned limitation of the BANDWIDTH object. This document specifies the use of GENERALIZED-BANDWIDTH object in PCInitiate message. Specifically, GENERALIZED-BANDWIDTHobject MAY be included in the PCInitiate message. The GENERALIZED-BANDWIDTH object in PCInitiate message is used to specify technology specific Tspec and asymmetrical bandwidth values for the LSP being instantiated by the PCE. 3.3. Protection Attributes in LSP Initiate Message This document does not modify the usage of LSPA object for PCE initiated LSPs as specified in [RFC8281] . It augments the usage of LSPA object in LSP Initiate Message to carry the end-to-end protection context this also includes the protection state information. The LSP Protection Information TLV of LSPA in the PCInitiate message can be used to specify protection attributes of the LSP being instantiated by the PCE. 3.4. ERO in LSP Initiate Object This document does not modify the usage of ERO object for PCE initiated LSPs as specified in [RFC8281]. It augments the usage as specified in the following sections. 3.4.1. ERO with explicit label control As mentioned earlier, there are technologies and scenarios where active stateful PCE requires explicit label control in order to instantiate an LSP. Explicit label control (ELC) is a procedure supported by RSVP-TE, where the outgoing label(s) is (are) encoded in the ERO. [I-D.ietf-pce-gmpls-pcep-extensions] extends the ERO object of PCEP to include explicit label control. The ELC procedure enables the PCE to provide such label(s) directly in the path ERO. The extended ERO object in PCInitiate message can be used to specify label along with ERO to PCC for the LSP being instantiated by the active stateful PCE. Ali, et al. Expires August 27, 2019 [Page 5] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 3.4.2. ERO with Path Keys There are many scenarios in packet and optical networks where the route information of an LSP may not be provided to the PCC for confidentiality reasons. A multi-domain or multi-layer network is an example of such networks. Similarly, a GMPLS User- Network Interface (UNI) [RFC4208] is also an example of such networks. In such scenarios, ERO containing the entire route cannot be provided to PCC (by PCE). Instead, PCE provides an ERO with Path Keys to the PCC. For example, in the case UNI interface between the router and the optical nodes, the ERO in the LSP Initiate Message may be constructed as follows: o The first hop is a strict hop that provides the egress interface information at PCC. This interface information is used to get to a network node that can extend the rest of the ERO. (Please note that in the cases where the network node is not directly connected with the PCC, this part of ERO may consist of multiple hops and may be loose). o The following(s) hop in the ERO may provide the network node with the path key [RFC5520] that can be resolved to get the contents of the route towards the destination. o There may be further hops but these hops may also be encoded with the path keys (if needed). This document does not change encoding or processing roles for the path keys, which are defined in [RFC5520]. 3.4.3. Switch Layer Object [I-D.ietf-pce-inter-layer-ext] specifies the SWITCH-LAYER object which defines and specifies the switching layer (or layers) in which a path MUST or MUST NOT be established. A switching layer is expressed as a switching type and encoding type. [I-D.ietf-pce-gmpls-pcep-extensions], which defines the GMPLS extensions for PCEP, suggests using the SWITCH-LAYER object. Thus, SWITCH-LAYER object can be used in the PCInitiate message to specify the switching layer (or layers) of the LSP being remotely initiated. 3.5. LSP delegation and cleanup LSP delegation and cleanup procedure specified in [I-D.ietf-pce-gmpls-pcep-extensions] are equally applicable to GMPLS LSPs and this document does not modify the associated usage. Ali, et al. Expires August 27, 2019 [Page 6] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 4. Security Considerations The security considerations described in [RFC8281] apply to the extensions described in this document. 5. IANA Considerations 5.1. PCEP-Error Object This document defines the following new Error-Value: Error-type Error Value Reference 6 Error-value = TBA: Label Request TLV Missing this document 6. Contributors Sajal Agarwal Cisco Systems Email: sajaagar@cisco.com 7. Acknowledgements The authors would like to thank George Swallow and Jan Medved for their comments. 8. References 8.1. Normative References [I-D.ietf-pce-gmpls-pcep-extensions] Margaria, C., Dios, O., and F. Zhang, "PCEP extensions for GMPLS", draft-ietf-pce-gmpls-pcep-extensions-13 (work in progress), January 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, . Ali, et al. Expires August 27, 2019 [Page 7] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 [RFC5623] Oki, E., Takeda, T., Le Roux, JL., and A. Farrel, "Framework for PCE-Based Inter-Layer MPLS and GMPLS Traffic Engineering", RFC 5623, DOI 10.17487/RFC5623, September 2009, . [RFC6107] Shiomoto, K., Ed. and A. Farrel, Ed., "Procedures for Dynamically Signaled Hierarchical Label Switched Paths", RFC 6107, DOI 10.17487/RFC6107, February 2011, . [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE", RFC 8231, DOI 10.17487/RFC8231, September 2017, . [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for PCE-Initiated LSP Setup in a Stateful PCE Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, . 8.2. Informational References [I-D.ietf-pce-inter-layer-ext] Oki, E., Takeda, T., Farrel, A., and F. Zhang, "Extensions to the Path Computation Element communication Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic Engineering", draft-ietf-pce-inter-layer-ext-12 (work in progress), January 2017. [RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, DOI 10.17487/RFC3471, 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, . [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links in Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003, . Ali, et al. Expires August 27, 2019 [Page 8] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 [RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter, "Generalized Multiprotocol Label Switching (GMPLS) User- Network Interface (UNI): Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Support for the Overlay Model", RFC 4208, DOI 10.17487/RFC4208, October 2005, . [RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou, Ed., "RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007, . [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, "GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873, May 2007, . [RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel, "Preserving Topology Confidentiality in Inter-Domain Path Computation Using a Path-Key-Based Mechanism", RFC 5520, DOI 10.17487/RFC5520, April 2009, . [RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J. Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label Switched Paths (LSPs)", RFC 6387, DOI 10.17487/RFC6387, September 2011, . Authors' Addresses Zafar Ali Cisco Systems Email: zali@cisco.com Siva Sivabalan Cisco Systems Email: msiva@cisco.com Clarence Filsfils Cisco Systems Email: cfilsfil@cisco.com Ali, et al. Expires August 27, 2019 [Page 9] Internet-DraftExtensions to PCEP for GMPLS Remote InitiatioFebruary 2019 Robert Varga Pantheon Technologies Email: nite@hq.sk Victor Lopez Telefonica Email: victor.lopezalvarez@telefonica.com Oscar Gonzalez de Dios Telefonica Email: oscar.gonzalezdedios@telefonica.com Haomian Zheng (Editor) Huawei Technologies H1-1-A043S Huawei Industrial Base, Songshanhu Dongguan, Guangdong 523808 P.R.China Email: zhenghaomian@huawei.com Xian Zhang Huawei Technologies G1-2, Huawei Industrial Base, Bantian, Longgang District Shenzhen, Guangdong 518129 P.R.China Email: zhang.xian@huawei.com Ali, et al. Expires August 27, 2019 [Page 10]