CATS H. Yao Internet Draft China Mobile Intended status: Informational X. Wang Expires: April 23, 2024 Ruijie Networks Z. Li China Mobile D.H. Daniel ZTE Corporation C. Lin New H3C Technologies October 23, 2023 Computing and Network Information Awareness (CNIA) system architecture for CATS draft-yao-cats-awareness-architecture-02 Abstract This document describes a Computing and Network Information Awareness (CNIA)system architecture for Computing-Aware Traffic Steering (CATS). Based on the CATS framework, this document further describes a proposal detailed awareness architecture about the network information and computing information. It includes a new component and the corresponding interfaces and workflows in the CATS control plane. 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 April 23, 2024. yao, et al. Expires April, 2024 [Page 1] Internet-Draft CNIA October 2023 Copyright Notice Copyright (c) 2023 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. Architecture Components and Interfaces.........................3 3. Architecture Workflow..........................................5 3.1. Awareness Information Classification......................5 3.2. Workflow..................................................6 3.2.1. A centralized model..................................6 3.2.2. A hybrid model.......................................8 3.2.3. A distributed model..................................9 4. IANA Considerations...........................................10 5. Security Considerations.......................................10 6. References....................................................10 6.1. Normative References.....................................10 6.2. Informative References...................................10 Authors' Addresses...............................................12 yao, et al. Expires April, 2024 [Page 2] Internet-Draft CNIA October 2023 1. Introduction Computing-Aware Traffic Steering (CATS)[I-D.ldbc-cats-framework]aims to solve the problem of how the network edge can steer traffic between clients of a service and sites offering the service. To enable the computing- and network-aware traffic steering decisions, awareness of computing information and network information is the foundation. Currently there are some work being done on the classification and awareness of computing and network information. As described in[I- D.du-cats-computing-modeling-description], there could be two models of computing information: one is some detailed computing parameters, and another is a comprehensive computing level parameter. Further, the former includes some static information such as service ability, and some dynamic information such as service status. This modeling document could be a solid foundation of CATS. For the awareness solution of computing and network information, the current recommended methods are generally BGP[I-D.ietf-idr-5g-edge-service- metadata], BGP-LS[I-D.ls-idr-bgp-ls-service-metadata], and BGP-FS[I- D.yi-idr-bgp-fs-edge-service-metadata]. CATS Service Metric Agent(C-SMA) and CATS Path Selector (C-PS) components defined in [I- D.ldbc-cats-framework] could be deployed in different locations. Overall, the current awareness technology is some sporadic solutions. This document hopes to comprehensively sort out the computing and network awareness method and defines a comprehensive awareness architecture to support the different types of computing and network information, to facilitate the deployment of CATS. This awareness architecture acts as the control plane of CATS. 2. Architecture Components and Interfaces To consider various kinds of computing and network information, a control center component is additionally introduced on the basis of CATS framework. That is, CATS framework includes a control center and CAT routers. A control center performs computing management and control functions, including computing information awareness function, service scheduling function, etc., A control center collects computing and network information, and schedules service based on computing and network information. CATS Router collects omputing and network information, and schedules service based on computing and network information, then forwarding data packets based on service scheduling. As a comprehensive awareness architecture CNIA supports both distributed,centralized,hybrid awareness models. yao, et al. Expires April, 2024 [Page 3] Internet-Draft CNIA October 2023 For some coarse-grained and relatively static information with low update frequency, it is recommended to be aware in a distributed way. The distributed way has better robustness and high scalability. For some fine-grained dynamic information with a high update frequency, it is recommended to aware it in a centralized way. Frequent information updates will greatly increase the burden on network devices and are not conducive to information convergence. The centralized way is more suitable for the management of fine- grained dynamic information. This comprehensive-aware model is consistent with the design philosophy of segment routing architecture[RFC8402]. The services that require planning for dynamic resources, such as TE(Traffic Engineering), are implemented by a centralized controller. The BE(best-effort) service is still preserved on the devices and implemented in a distributed manner, which could take advantage of distributed robustness and reduce the burden of interfacing between the controller and devices, facilitating deployment. CATS-control center | +----------------------------------+ | +----------+ | Management Plane | | API |cloud | +----------------------------------+ |<=========>|management| | Control Plane | | |platform | +----------------------------------+ | +---+------+ /\ CATS-SBI | | || | | CATS-Forwarder \/ | | +----------------------------------+ | +--------+ | Data Plane | | API | +--------+ +----------------------------------+ |<=========>| |service | | +-|instance| | +--------+ Figure 1: CNIA System Arhicteture To realize the scheduling of fine-grained computing information, the control center introduces several components and interface: CATS Computing information Base(C-CIB): Maintain fine-grained computing information, such as service connections,CPU performance,which may be obtained from the CATS-Forwarders or from the cloud management platform. CATS Network Metric information Base(C-NIB): Maintain fine-grained network information, such as remaining bandwidth,delay, which could be obtained from the routers. CATS Path Calculation Unit(C-PCE): Calculate optimal computing resource and network path based on C-CIB and C-NIB, and generate path policy and deliver to the CATS-Forwarders. yao, et al. Expires April, 2024 [Page 4] Internet-Draft CNIA October 2023 CATS-SBI interface: An extended interface based on the traditional controller southbound interface between the CATS-Forwarders and the CATS-control center, could be used to report network and computing information from CATS routers to the CATS-control center, and also could be used to send path and service policy information or compute information to CATS-Forwarders. C-SMA API: An extended interface based on the traditional controller southbound interface between the CATS-Forwarders and the cloud management or between CATS-Forwarders and service-instance, used to report network and computing information to the CATS-control center or to CATS-Forwarders. Given the comprehensive architecture described above, this document proposes a comprehensive awareness system of the deployment location, real-time resource and service status, load information and requirements of computing resources and services. On the one hand, the network aggregates the computing and network metrics reported by multiple nodes to build a globally unified computing and network status view. On the other hand, the network completes the unified analysis of service, computing and network requirements, realizes the comprehensive perception and provides guarantee for computing-aware scheduling based on service requirement. 3. Architecture Workflow 3.1. Awareness Information Classification Currently the detailed network and computing parameters used by CATS have not yet reached a consensus in the industry, in order to avoid introducing too much signaling overhead into the whole network advertisement, this document proposes to classify the content of the computing advertisement according to the characteristics of the content and frequency of information announcement, and adopt different information awareness methods and information announcement protocols. As shown in Table 1, the computing and network information could be classified into capability information and status information. Capability information contains the deployment location and identifier information, and so on. Status information tends to be some real-time status parameters of the network and computing, such as remaining bandwidth,delay,service connections,CPU performance. This type of information is mainly used for some services that are sensitive to network and computing status, such as AR/VR services. yao, et al. Expires April, 2024 [Page 5] Internet-Draft CNIA October 2023 +=============+=========================+=========================+ | Awareness | Network information | Computing information | | information | | | +=============+=========================+=========================+ | Capability | Device location; Device | Service ID; Service- | | parameters | type; Topology | domain name; Computing | | | information | energy consumption; | | | | Computing cost; Peak | | | | value of available | | | | computing | +-------------+-------------------------+-------------------------+ | Status | Service policy | Number of available | | parameters | information; Traffic | service connections; | | | information | Available resources; | | | (bandwidth,delay,packet | CPU/GPU/NPU | | | loss rate,delay jitter) | performance; Storage | | | | capacity; Service delay | +-------------+-------------------------+-------------------------+ Table 1: Awareness information content examples Table 1 provides some detailed parameters examples about the two kinds of awareness information. 3.2. Workflow 3.2.1. A centralized model In centralized mode, the collection of computing information and the selection of paths are implemented by the controller, which is then sent to the CATS-Forwarder via the CATS-SBI interface. yao, et al. Expires April, 2024 [Page 6] Internet-Draft CNIA October 2023 CATS-control center +----------------------------------+ +----------+ | Management | API |cloud | | Plane +------+----------+ |<=========>|management| | | | | | |platform | | | +--v---+ +--v---+ | +---+------+ | | |C-CIB | |C-NIB | | | | | +---^--+ +--^---+ | | | | | | | | +---------|-------|---------|------+ | | Control | +---v--+ +--v---+ | | | Plane | |C-SMA | |C-NMA | | | | | +------+ +------+ | | | | | | | | +-------+ | | | +-->| C-PCE | | | | +-------+ | | +----------------------------------+ | /\ CATS-SBI | || | CATS-Forwarder \/ | +----------------------------------+ | | Data +------+ | +--------+ | Plane |C-TC | | ...........| +--------+ | +------+ | ...........| |service | +----------------------------------+ +-|instance| +--------+ Figure 2: centralized model For some services that are sensitive to computing and network status, especially latency, such as AV/VR services, the network needs to be able to perceive detailed computing information and network information to meet the strict requirements of the service. This kind of computing information could be aware by the CATS- control center by restful interface from cloud management platform. The network information could be aware by the BGP-LS or telemetry interface to get the status parameters such as remaining bandwidth and the delay. Further, CATS-control center performs service scheduling according to the computing information and network information, then generates routing policy and sends to CATS ingress router . When CATS ingress router receives the service demand from the client, it selects the optimal service instance and network policy, and maintains the instance affinity subsequently. yao, et al. Expires April, 2024 [Page 7] Internet-Draft CNIA October 2023 3.2.2. A hybrid model In hybrid mode, both the controller and the CATS-Forwarder with routing capabilities can perform the collection of computing information and the selection of paths. The CATS-Forwarder with routing capabilities can perform more precise path selection operations based on instructions from the controller. CATS- Forwarders without routing capabilities, on the other hand, directly forward data based on the results provided by the controller. CATS-control center +----------------------------------+ +----------+ | Management | API |cloud | | Plane +------+----------+ |<============>|management| | | | | | |platform | | | +--v---+ +--v---+ | +---+------+ | | |C-CIB | |C-NIB | | | | | +---^--+ +--^---+ | | | | | | | | +---------|-------|---------|------+ | | Control | +---v--+ +--v---+ | | | Plane | |C-SMA | |C-NMA | | | | | +------+ +------+ | | | | | | | | +-------+ | | | +-->| C-PCE | | | | +-------+ | | +----------------------------------+ | /\ CATS-SBI /\ CATS-SBI | || || | CATS-Forwarder1 \/ CATS-Forwarder2 \/ | +-------------------+ +--------------------------------+ | | Data +------+ | | Data +-----+-------+ | +--------+ | Plane |C-TC | | | Plane |C-TC |C-PS | |...... | +--------+ | +------+ | | +-----+---+---+ |...... | |service | +-------------------+ | | | +-|instance| | +------+---+ | +--------+ | | | | | +--+---+ +-+----+ | | |C-SMA | |C-NMA | | | +------+ +------+ | +--------------------------------+ Figure 4: hybrid model yao, et al. Expires April, 2024 [Page 8] Internet-Draft CNIA October 2023 For some high-value customers, hybrid awareness can be deployed to accurately match customer requirements. After the CATS-control center obtains computing and network information through SBI or restful interfaces, the details of this information are directly transmitted to the CATS ingress routers. The device performs accurate resource matching and continuous experience detection after receiving service traffic. 3.2.3. A distributed model In distributed mode, these operations are performed by the CATS- Forwarder itself, while the controller is responsible for monitoring the information. CATS-control center +----------------------------------+ | Management +------+ +------+ | | Plane |C-CIB | |C-NIB | | | +------+ +------+ | +----------+ | | |cloud | +----------------------------------+ |management| | Control | |platform | | Plane | +---+------+ +----------------------------------+ | /\ CATS-SBI | || | CATS-Forwarder \/ | +--------------------------------+ | | Data +-----+-------+ | API +--------+ | Plane |C-TC |C-PS | |<========= | +--------+ | +-----+---+---+ | | |service | | | | +-|instance| | +------+---+ | +--------+ | | | | | +--+---+ +-+----+ | | |C-SMA | |C-NMA | | | +------+ +------+ | +--------------------------------+ Figure 3: distributed model For distributed mode, the ingress CATS router responsibles for collecting computing and network information and scheduling service. When the ingress CATS router receives the service demand from the client it makes decision of the service instance to access independently according to the service instances status and network status and maintains instance affinity. The detailed workflow can be seen in[I-D.ldbc-cats-framework]. yao, et al. Expires April, 2024 [Page 9] Internet-Draft CNIA October 2023 4. IANA Considerations TBD 5. Security Considerations TBD 6. References 6.1. Normative References [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018, . 6.2. Informative References [I-D.ietf-idr-5g-edge-service-metadata] Dunbar, L., Majumdar, K., Wang, H., Mishra, G. S., and Z. Du, "BGP Extension for 5G Edge Service Metadata", Work in Progress, Internet-Draft, draft-ietf-idr-5g-edge-service- metadata-04, 6 July 2023, . [I-D.ls-idr-bgp-ls-service-metadata] Li, C., Shi, H., He, T., Pang, R., and G. Qian, "Distribution of Service Metadata in BGP- LS", Work in Progress, Internet-Draft, draft-ls-idr-bgp- ls-service-metadata-01, 24 February 2023, . [I-D.yi-idr-bgp-fs-edge-service-metadata] yixinxin, He, T., Shi, H., Ding, X., and H. Wang, "Distribution of Service Metadata in BGP FlowSpec", Work in Progress, Internet-Draft, draft- yi-idr-bgp-fs-edge-service-metadata-00, 23 February 2023, . yao, et al. Expires April, 2024 [Page 10] Internet-Draft CNIA October 2023 [I-D.ldbc-cats-framework] Li, C., Du, Z., Boucadair, M., Contreras, L. M., Drake, J., Huang, D., and G. S. Mishra, "A Framework for Computing-Aware Traffic Steering (CATS)", Work in Progress, Internet-Draft, draft-ldbc-cats- framework-02, 22 June 2023, . [I-D.du-cats-computing-modeling-description] Du, Z., Fu, Y., Li, C., Huang, D., and Z. Fu, "Computing Information Description in Computing-Aware Traffic Steering", Work in Progress, Internet-Draft, draft-du- cats-computing-modeling- description-01, 4 July 2023, . yao, et al. Expires April, 2024 [Page 11] Internet-Draft CNIA October 2023 Authors' Addresses Huijuan Yao China Mobile No.32 XuanWuMen West Street Beijing 100053 China Email: yaohuijuan@chinamobile.com Xuewei Wang Ruijie Networks Beijing China Email: wangxuewei1@ruijie.com.cn Zhiqiang Li China Mobile No.32 XuanWuMen West Street Beijing 100053 China Email: lizhiqiangyjy@chinamobile.com Daniel Huang ZTE Corporation Nanjing Phone: +86 13770311052 Email: huang.guangping@zte.com.cn Changwang Lin New H3C Technologies Beijing China Email: linchangwang.04414@h3c.com yao, et al. Expires April, 2024 [Page 12]