TEAS LM. Contreras Internet-Draft Telefonica Intended status: Informational R. Rokui Expires: May 6, 2021 Nokia J. Tantsura Apstra B. Wu Huawei X. Liu Volta D. Dhody Huawei S. Belloti Nokia November 2, 2020 IETF Network Slice Controller and its associated data models draft-contreras-teas-slice-controller-models-00 Abstract This document describes the major functional components of an IETF Network Slice Controller (NSC) as well as references the data models required for supporting the requests of IETF network slices and their realization. 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." This Internet-Draft will expire on May 6, 2021. Contreras , et al. Expires May 6, 2021 [Page 1] Internet-Draft Slice Controller and its data models November 2020 Copyright Notice Copyright (c) 2020 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. IETF Network Slice data models . . . . . . . . . . . . . . . 3 3. Structure of the IETF Network Slice Controller (NSC) . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction Editor's Note: the terminology in this draft will be aligned with the final terminology selected for describing the notion of IETF Network Slice when applied to IETF technologies, which is currently under discussion. By now same terminology as used in [I-D.nsdt-teas-ietf-network-slice-definition] and [I-D.nsdt-teas-ns-framework] is primarily used here. Consensus to use "IETF Network Slice" term has been reached. The generic idea of network slicing intends to provide tailored end- to-end network capabilities to customers in the way that they could be perceived as a dedicated network, despite the fact that it makes use of shared physical infrastructure facilities. Among the capabilities mentioned, connectivity of different parts of a network slice with particular characteristics play a central role. Thus, the concept of IETF Network Slice, realized by any of the IETF technologies, emerges as complementary but essential part of an end- to-end network slice. In order to facilitate the request, realization and lifecycle control and management of a transport slice, a new element named IETF Network Contreras , et al. Expires May 6, 2021 [Page 2] Internet-Draft Slice Controller and its data models November 2020 Slice Controller (NSC) is being proposed in [I-D.nsdt-teas-ietf-network-slice-definition] and [I-D.nsdt-teas-ns-framework]. The NSC from its North Bound Interface (NBI) exposes set of APIs that allow a higher level system to request an end-to-end transport slice. It receives the request of enablement of an IETF Network Slice by a customer (i.e. creation, modification or deletion). Upon receiving a request from its NBI, NSC finds the resources needed for realization of the IETF Network Slice and in turn interfaces from its South Bound Interface (SBI) with one or more Network Controllers for the realization of the requested IETF Network Slice request and the management of its lifecycle. Figure 1 presents a high-level view of the TSC. +------------------------------------------+ | A higher level system | | (e.g E2E network slice orchestrator) | +------------------------------------------+ A | NSC NBI V +------------------------------------------+ | IETF Network Slice Controller (NSC) | +------------------------------------------+ A | NSC SBI V +------------------------------------------+ | Network Controller(s) | +------------------------------------------+ Figure 1: Interface of Transport Slice Controller This memo describes the characteristics of the NSC as well as a detailed structure of the NSC and its major components. In addition, it describes the characteristics of the data models to identify the IETF Network Slice and its realization. Then the data models referred are mapped to the interfaces among components. 2. IETF Network Slice data models At the time of provisioning and operating IETF Network Slices different views can be identified as necessary: Contreras , et al. Expires May 6, 2021 [Page 3] Internet-Draft Slice Controller and its data models November 2020 o Customer's view, mostly focused on the individual IETF Network Slice request process, reflecting the needs of each particular customer, including SLOs and other characteristics of the slice relevant for it. This view is technology agnostics and describes the characteristics of the IETF Network Slice from a customer's point of view. It can include the slice topology, performance parameters, endpoints of the slice, traffic characteristics of the slice, and the KPIs to monitor the slice. o Provider's view, mostly focused on the provisioning and operation of the IETF Network Slices in the transport network, considering how a particular IETF Network Slice interplays with other IETF Network Slices maintained by the provider on a shared infrastructure. In other words, operator's view shows how an IETF Network Slice is realized in operator's network along with all the resources used during the its realization. Both views are complementary, each of them specialized for a given purpose. In consequence, it should be consistency between both in order to ensure alignment. Currently there are two different models proposed, on for each of the categories above. The model in [I-D.wd-teas-ietf-network-slice-nbi-yang] fits into the customer view, while the model defined in [I-D.liu-teas-transport-network-slice-yang] fits in to the provider view. It should be noted that for the realization of a transport slice, the NSC interacts with one or more Network Controllers. In that case, the data models to be used are particular for each Network Controller (e.g., technology dependent), as well as the mapping function from its NBI to SBI and the details of this mapping function are both out of the scope of this document. 3. Structure of the IETF Network Slice Controller (NSC) The NSC should work with both data models. The NSC takes first the customer's view by analyzing the needs of the customer, processing such requests taking into account the overall view of the network and the IETF Network Slices already instantiated, normalizing its instantiation across different technologies, and finally generates the provider view. Once the new request is processed and declared as feasible, the NSC triggers its realization by interacting with the Network Controllers and communicates back to the higher level controller to start the billing cycle. Contreras , et al. Expires May 6, 2021 [Page 4] Internet-Draft Slice Controller and its data models November 2020 In order to accommodate these procedures, the internal structure of the NSC can be divided into: o IETF Network Slice Mapper: this high-level component processes the customer request, putting it into the context of the overall IETF Network Slices in the network. o IETF Network Slice Realizer: this high-level component processes the complete view of transport slices including the one requested by the customer, decides the proper technologies for realizing the IETF Network Slice and triggers its realization. Figure 2 illustrates the components described and the associated models, as follows o (a) -> customer's view, e.g. [I-D.wd-teas-ietf-network-slice-nbi-yang]. o (b) -> provider's view, e.g. [I-D.liu-teas-transport-network-slice-yang]. o (c) -> models per network controller, out of scope of this document Contreras , et al. Expires May 6, 2021 [Page 5] Internet-Draft Slice Controller and its data models November 2020 Higher Level System | | --------------------------- | NSC | (a) | | v | | ------------------- | | | | | | | NS Mapper | | | | | | | ------------------- | | | (b) | | v | | ------------------- | | | | | | | NS Realizer | | | | | | | ------------------- | | | (c) | --------------------------- | v Network Controllers Figure 2: IETF Network Slice Controller structure and asspociated data models TODO item #1 - Breakdown "NS mapper" and "NS Realizer" to their logical components. TODO item #2- Add complementarity of the models for satisfying Type 1 and Type 2 Services as per [RFC8453]. Discussion: equivalent to the Virtual Network (VN) described in [RFC8453], there are two views of an IETF network slices as well: o The IETF network slice can be abstracted as a set of edge-to-edge links (Type 1). o The IETF network slice can be abstracted as a topology of virtual nodes and virtual links (Type 2) which represent the partitioning of underlay network resources for use by network slice connectivity. The use cases of these two types of networks are further described by [RFC8453]. [I-D.wd-teas-ietf-network-slice-nbi-yang] models the Type 1 service, while [I-D.liu-teas-transport-network-slice-yang] models the Type 2 service. When a customer intends to request a Type 2 service, [I-D.liu-teas-transport-network-slice-yang] can also be used Contreras , et al. Expires May 6, 2021 [Page 6] Internet-Draft Slice Controller and its data models November 2020 at the point (a) in Figure 2. As an example, when ACTN is used to realize an IETF network slice, model mappings are described in more details in [I-D.ietf-teas-actn-yang]. 4. Security Considerations To be done. 5. IANA Considerations This draft does not include any IANA considerations 6. References [I-D.ietf-teas-actn-yang] Lee, Y., Zheng, H., Ceccarelli, D., Yoon, B., Dios, O., Shin, J., and S. Belotti, "Applicability of YANG models for Abstraction and Control of Traffic Engineered Networks", draft-ietf-teas-actn-yang-06 (work in progress), August 2020. [I-D.liu-teas-transport-network-slice-yang] Liu, X., Tantsura, J., Bryskin, I., Contreras, L., WU, Q., Belotti, S., and R. Rokui, "Transport Network Slice YANG Data Model", draft-liu-teas-transport-network-slice- yang-01 (work in progress), July 2020. [I-D.nsdt-teas-ietf-network-slice-definition] Rokui, R., Homma, S., Makhijani, K., Contreras, L., and J. Tantsura, "Definition of IETF Network Slices", draft-nsdt- teas-ietf-network-slice-definition-00 (work in progress), October 2020. [I-D.nsdt-teas-ns-framework] Gray, E. and J. Drake, "Framework for Transport Network Slices", draft-nsdt-teas-ns-framework-04 (work in progress), July 2020. [I-D.wd-teas-ietf-network-slice-nbi-yang] Bo, W., Dhody, D., Han, L., and R. Rokui, "A Yang Data Model for IETF Network Slice NBI", draft-wd-teas-ietf- network-slice-nbi-yang-00 (work in progress), October 2020. [RFC8453] Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for Abstraction and Control of TE Networks (ACTN)", RFC 8453, DOI 10.17487/RFC8453, August 2018, . Contreras , et al. Expires May 6, 2021 [Page 7] Internet-Draft Slice Controller and its data models November 2020 Authors' Addresses Luis M. Contreras Telefonica Ronda de la Comunicacion, s/n Sur-3 building, 3rd floor Madrid 28050 Spain Email: luismiguel.contrerasmurillo@telefonica.com URI: http://lmcontreras.com/ Reza Rokui Nokia Canada Email: reza.rokui@nokia.com Jeff Tantsura Apstra USA Email: jefftant.ietf@gmail.com Bo Wu Huawei Technologies 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: lana.wubo@huawei.com Xufeng Liu Volta Networks Email: xufeng.liu.ietf@gmail.com Contreras , et al. Expires May 6, 2021 [Page 8] Internet-Draft Slice Controller and its data models November 2020 Dhruv Dhody Huawei Technologies Divyashree Techno Park Bangalore, Karnataka 560066 India Email: dhruv.ietf@gmail.com Sergio Belloti Nokia Email: sergio.belotti@nokia.com Contreras , et al. Expires May 6, 2021 [Page 9]