Application-Layer Traffic Optimization H. Hong Internet-Draft Huawei Intended status: Informational C. Zhou Expires: December 26, 2021 China Mobile C. Xie China Telecom Q. Ma Huawei June 24, 2021 Network Topology data retrieval using ALTO protocol draft-hzx-alto-network-topo-00 Abstract RFC8345 introduces an abstract YANG data model to represent network topologies. This document uses ALTO protocol to provide access to network Topology data such as L3 topology data , data center network topology data, flexible enough to enable querying of specific and possibly aggregated data. 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 December 26, 2021. Copyright Notice Copyright (c) 2021 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 Hong, et al. Expires December 26, 2021 [Page 1] Internet-Draft ALTO for Network Topo Data June 2021 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 Language . . . . . . . . . . . . . . . . . . . . 3 3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 3 4. Translation of Structure of L3 Topo data to ALTO data format 4 5. Translation of Structure of L2 Topo data to ALTO data format 5 6. Translation of Structure of Data Fabric Topo data to ALTO data format . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Translation of Structure of VPN Performance Monitoring Data to ALTO data format . . . . . . . . . . . . . . . . . . . . . 8 8. Proposed ALTO protocol extension . . . . . . . . . . . . . . 10 9. Security Considerations . . . . . . . . . . . . . . . . . . . 10 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 12.1. Informative References . . . . . . . . . . . . . . . . . 10 12.2. Normative References . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction This document uses ALTO protocol to provide access to network Topology data such as L3 topology data , Data Center Network Topology data, flexible enough to enable querying of specific and possibly aggregated data. In addition, this document introduces a topology data translation mechanism which allow translation of structure of network topology data modeled in YANG to ALTO data format, which can be seen as a typical example of functional model of reference architecture of Digital Twin Network defined in [I-D.zhou-nmrg- digitaltwin-network-concepts]. The concept of digital twin was proposed by Grieves in [Grieves2014]. It is defined as a virtual representation that serves as the real- time digital counterpart of a physical entity and reflects the whole life-cycle device management. A digital twin network graph is designed by digital twin platform and formulated by applying digital twin techniques to physical networks: it creates a virtual image of a physical network by using network data model technology. The data model defined in [RFC8345] can be seen as basic model defined in [I- D.zhou-nmrg-digitaltwin-network-concepts] and is divided into two parts: The first part of the data model defines a network data model Hong, et al. Expires December 26, 2021 [Page 2] Internet-Draft ALTO for Network Topo Data June 2021 that enables the definition of network hierarchies, or network stacks (i.e., networks that are layered on top of each other) and maintenance of an inventory of nodes contained in a network. The second part of the data model augments the basic network data model with information to describe topology information. Specifically, it adds the concepts of "links" and "termination points" to describe how nodes in a network are connected to each other. Moreover, the data model introduces vertical layering relationships between networks that can be augmented to cover both network inventories and network/ service topologies. Note that functional model is a derived model from basic models defined in [I-D.zhou-nmrg-digitaltwin-network- concepts] and can be used to provide network analysis, simulation, diagnosis, prediction, assurance, etc. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119][RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Solution Overview This document addresses how to retrieve potentially aggregated network topology data from topology manager using ALTO protocol for a certain network,e.g., Data Fabric network, layer 3 network, layer 2 network. These network topology data are collected by NETCONF client using NETCONF protocol [RFC6241] and Layer 3 topology YANG data model [RFC8345], Layer 2 topology YANG data model [RFC8944], data fabric topology YANG data model [RFC8542] and stored in the topo database within the Topolgy manager. The Topology manager is comprised of four components: NETCONF client, Topology database, Topology data translation and ALTO server. The topology data translation component is used to translate structure of Topology data modeled in YANG into ALTO data object format. ALTO server provides a query interface for topology data retrieval. NETCONF client retrieves the network topology related data or network element related data from each Network Elements using NETCONF protocols or via other telemetry interface. And the Topology database is fed by the NETCONF client with its retrieved data, as shown in below figure. Hong, et al. Expires December 26, 2021 [Page 3] Internet-Draft ALTO for Network Topo Data June 2021 +-----------------------------------+ | Topology Manager | +-------+ |+-----------++---------+ +-------+| | | || Topo || Topo | |ALTO || | ALTO | ||translation||database | |Server ++-------+-Client| |+-----------++---------+ +-------+| +-------+ | +---------+ | | |NC Client| | | +-+----+--+ | +------------+----+-----------------+ | | +----| +---------+ | | +------+---------+ +--+-------------+ | +----+----+ | | ++--------+ | | |NC Server| | | |NC Server| | | +---------+ | | +---------+ | |Network Element1| |Network Element2| +----------------+ +----------------+ 4. Translation of Structure of L3 Topo data to ALTO data format The following table lists the ALTO data objects with corresponding objects in the L3 Topo YANG data model [RFC8345]. Note that the network topology data described in L3 Topo YANG data model represents aggregated topology information,i.e., overlay network topology information. Hong, et al. Expires December 26, 2021 [Page 4] Internet-Draft ALTO for Network Topo Data June 2021 +----------------------------------+--------------------------------+ | YANG data node in | ALTO data object | | /nw:networks/nw:network/ | | +----------------------------------+--------------------------------+ |l3t:l3-topology-attributes/l3t:name network-map/resource-id | | | | |nw:node/l3t:l3-node-attributes | | | /l3t:name | network-map/PIDName | | | | |/nw:node/l3t:l3-node-attributes | | | /l3t:flag | network-map/PIDName.flag | | | | |/nw:node/l3t:l3-node-attributes | network-map/PIDName | | /l3t:router-id | /EndpointAddrGroup | | | | |/nw:node/l3t:l3-node-attributes | network-map/PIDName | | /l3t:prefix/l3t:prefix | /EndpointAddrGroup | | | | |/nw:node/l3t:l3-node-attributes | network-map/PIDName | | /l3t:prefix/l3t:metric | /EndpointAddrGroup.metric | | | | |/nw:node/l3t:l3-node-attributes | network-map/PIDName | | /l3t:prefix/l3t:flag | /EndpointAddrGroup.flag | | | | |/nw:link/l3t:l3-link-attributes | network-map/PIDName | | /l3t:name | /PIDName | | | | |/nw:link/l3t:l3-link-attributes | network-map/PIDName | | /l3t:metric1 | /PIDName/DstCost | | | | |/nw:link/l3t:l3-link-attributes | network-map/PIDName | | /l3t:metric2 | /PIDName/DstCost | | | | |/nw:link/l3t:l3-link-attributes | network-map/PIDName | | /l3t:flag | /PIDName.flag | +----------------------------------+--------------------------------+ 5. Translation of Structure of L2 Topo data to ALTO data format The following table lists the ALTO data objects with corresponding objects in the L2 Topo YANG data model [RFC8944]. Note that the network topology data described in L2 Topo YANG data model represents aggregated topology information,i.e., overlay network topology information. Hong, et al. Expires December 26, 2021 [Page 5] Internet-Draft ALTO for Network Topo Data June 2021 +----------------------------------+--------------------------------+ | YANG data node in | ALTO data object | | /nw:networks/nw:network/ | | +----------------------------------+--------------------------------+ |l2t:l2-topology-attributes/l2t:name network-map/resource-id | | | |nw:node/l2t:l2-node-attributes | | | /l2t:name | network-map/PIDName | | | |/nw:node/l2t:l2-node-attributes | | | /l2t:flag | network-map/PIDName.flag | | | |/nw:node/l2t:l2-node-attributes | network-map/PIDName | | /l2t:bridge-id | /EndpointAddrGroup(Not support)| | | |/nw:node/l2t:l2-node-attributes | network-map/PIDName | | /l2t:management-address | /EndpointAddrGroup | | | .management-address | | | |/nw:node/l2t:l2-node-attributes | network-map/PIDName | | /l2t:management-mac | /EndpointAddrGroup | | | .management-mac | | | |/nw:node/l2t:l2-node-attributes | network-map/PIDName | | /l2t:management-vlan | /EndpointAddrGroup | | | .management-vlan | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName | | /l2t:name | /PIDName | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName | | /l2t:rate | /PIDName/DstCost | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName | | /l2t:rate | /PIDName/DstCost | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName | | /l2t:flag | /PIDName.flag | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName/ | | /l2t:auto-nego | PIDName.auto-nego | | | |/nw:link/l2t:l2-link-attributes | network-map/PIDName | | /l2t:duplex | /PIDName.duplex | +----------------------------------+--------------------------------+ Hong, et al. Expires December 26, 2021 [Page 6] Internet-Draft ALTO for Network Topo Data June 2021 6. Translation of Structure of Data Fabric Topo data to ALTO data format The following table lists the ALTO data objects with corresponding objects in the Data Fabric Topo YANG data model [RFC8542]. Note that the network topology data described in Data Fabric Topo YANG data model represents aggregated topology information,i.e., overlay network topology information. +----------------------------------+--------------------------------+ | YANG data node in | ALTO data object | | /nw:networks/nw:network/ | | +----------------------------------+--------------------------------+ |/nw:node/fabric:fabric-attributes | network-map/PIDName | | /fabric:name | | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.type | | /fabric:type | | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.fabric-id | | /fabric:fabric-id | | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.description| | /fabric:description | | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.options | |/fabric:options/fabric:gateway-mode .gateway-mode | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.options | |/fabric:options/fabric: | .traffic-behavior | | traffic-behavior | | | | | |/nw:node/fabric:fabric-attributes | network-map/PIDName.options | |/fabric:options/fabric: | .capability-support | | capability-support | | | | | |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-nodes| |/fabric:device-nodes/fabric: | .device-ref | | device-ref | | | | | |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-nodes| | /fabric:device-nodes | .role | | /fabric:role | | | | | |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-links| | /fabric:device-links | .link-ref | | /fabric:link-ref | | | | | Hong, et al. Expires December 26, 2021 [Page 7] Internet-Draft ALTO for Network Topo Data June 2021 |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports| | /fabric:device-ports | .port-ref | | /fabric:port-ref | | | | | |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports| |/fabric:device-ports | .port-type | |/fabric:port-type | | | | | |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports| |/fabric:device-ports | .bandwidth | |/fabric:bandwidth | | +----------------------------------+--------------------------------+ 7. Translation of Structure of VPN Performance Monitoring Data to ALTO data format The following table lists the ALTO data objects with corresponding objects in the VPN performance monitoring YANG data model [I-D.ietf- opsawg-yang-vpn-service-pm]. Note that the network topology data described in VPN performance monitoring model represents aggregated topology information,i.e., overlay network topology information.When VPN performance data gets changed, the translation function defined in this document should be triggered to fetch the updated network topology data and translate them into ALTO map data. This can be realized by using I2RS Pub/Sub Retrieval. +----------------------------------+--------------------------------+ | YANG data node in | ALTO data object | | /nw:networks/nw:network/nw:link | | +----------------------------------+--------------------------------+ |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:loss-statistics | /PIDName/DstCost | |/nvp:packet-loss-count | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:loss-statistics | /PIDName/DstCost | |/nvp:packet-reorder-count | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:loss-statistics | /PIDName/DstCost | |/nvp:packet-out-of-seq-count | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:loss-statistics | /PIDName/DstCost | |/nvp:packet-dup-count | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:loss-statistics | /PIDName/DstCost | Hong, et al. Expires December 26, 2021 [Page 8] Internet-Draft ALTO for Network Topo Data June 2021 |/nvp:loss-ratio | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:direction | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:unit-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:min-delay-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:max-delay-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:low-delay-percentile | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:middle-delay-percentile | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:delay-statistics | /PIDName/DstCost | |/nvp:high-delay-percentile | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | |/nvp:unit-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | |/nvp:min-jitter-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | |/nvp:max-jitter-value | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | |/nvp:low-jitter-percentile | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | Hong, et al. Expires December 26, 2021 [Page 9] Internet-Draft ALTO for Network Topo Data June 2021 |/nvp:middle-jitter-percentile | | | | | |/nvp:link-telemetry/attributes | network-map/PIDName | |/nvp:jitter-statistics | /PIDName/DstCost | |/nvp:high-jitter-percentile | | +----------------------------------+--------------------------------+ 8. Proposed ALTO protocol extension ALTO is designed on two abstractions that are useful here. First is the abstraction of the physical network topology into an aggregated but logical topology. The second abstraction that is useful for LMAP (Large Scale Measurement of Broadband Performance) [RFC7594] is the notion of a "cost map". To support network topology data exposure using ALTO protocol, two ALTO protocol extensions are required: o Additional address types such as MAC address, VLAN ID need to be defined to represent layer 2 endpoint address. o Additional entity property type such as termination points needs to be introduced to express how two endpoints or network element are connected to each other. In addition, path vector needs to be investigated to see how a set of service flows are steered in the different network path. 9. Security Considerations TBD 10. Acknowledgements TBD 11. IANA Considerations TBD 12. References 12.1. Informative References [Grieves2014] Grieves, M., "Digital twin: Manufacturing excellence through virtual factory replication", 2003. Hong, et al. Expires December 26, 2021 [Page 10] Internet-Draft ALTO for Network Topo Data June 2021 12.2. Normative References [I-D.ietf-opsawg-yang-vpn-service-pm] Wu, B., Wu, Q., Boucadair, M., Dios, O. G. D., Wen, B., Liu, C., and H. Xu, "A YANG Model for Network and VPN Service Performance Monitoring", draft-ietf-opsawg-yang- vpn-service-pm-00 (work in progress), February 2021. [I-D.zhou-nmrg-digitaltwin-network-concepts] Zhou, C., Yang, H., Duan, X., Lopez, D., Pastor, A., Wu, Q., Boucadair, M., and C. Jacquenet, "Concepts of Digital Twin Network", draft-zhou-nmrg-digitaltwin-network- concepts-03 (work in progress), February 2021. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC7594] Eardley, P., Morton, A., Bagnulo, M., Burbridge, T., Aitken, P., and A. Akhter, "A Framework for Large-Scale Measurement of Broadband Performance (LMAP)", RFC 7594, DOI 10.17487/RFC7594, September 2015, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N., Ananthakrishnan, H., and X. Liu, "A YANG Data Model for Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March 2018, . [RFC8542] Zhuang, Y., Shi, D., Gu, R., and H. Ananthakrishnan, "A YANG Data Model for Fabric Topology in Data-Center Networks", RFC 8542, DOI 10.17487/RFC8542, March 2019, . [RFC8944] Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A YANG Data Model for Layer 2 Network Topologies", RFC 8944, DOI 10.17487/RFC8944, November 2020, . Hong, et al. Expires December 26, 2021 [Page 11] Internet-Draft ALTO for Network Topo Data June 2021 Authors' Addresses Hanshu Hong Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: honghanshu@huawei.com Cheng Zhou China Mobile Beijing 100053 China Email: zhouchengyjy@chinamobile.com Chongfeng Xie China Telecom Beijing China Email: xiechf@chinatelecom.cn Qiufang Ma Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: maqiufang1@huawei.com Hong, et al. Expires December 26, 2021 [Page 12]