tvr J. Wang Internet-Draft P. Liu Intended status: Informational China Mobile Expires: 29 March 2024 26 September 2023 Consideration for TVR (Time-Variant Routing) Requirements draft-wang-tvr-requirements-consideration-01 Abstract This document makes some supplements to TVR's requirements, including advertisement, identification, classification of node attributes, and appropriate system settings. 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 29 March 2024. 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 (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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Wang & Liu Expires 29 March 2024 [Page 1] Internet-Draft tvr-requirements September 2023 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Support the Identification and Advertisement of Node Attribute Changes . . . . . . . . . . . . . . . . . . . . 3 3.2. Support Agent Node Advertisement . . . . . . . . . . . . 3 3.3. Support Identification and Classification of Node Attributes . . . . . . . . . . . . . . . . . . . . . . . 4 3.4. Support System Schedule and Time Interval Changes . . . . 4 3.5. Support Appropriate Time Accuracy . . . . . . . . . . . . 4 4. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Informative References . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction Existing routing protocols are expected to maintain end-to-end connected paths across a network. There are cases where the end-to- end path can not be maintained, such as the loss of an adjacent peer. In these cases, corrections could be applied prior to the resumption of data transmission. Corrections may include attempting to re- establish lost adjacencies and recalculating or rediscovering a functional topology. There were three use cases had been defined in the TVR's use case document [I-D.ietf-tvr-use-cases]. The first is resource preservation; one example of a network where nodes must perform resource preservation is an energy-harvesting, wireless sensor network. The second is operating efficiency; one example of a network where nodes might seek to optimize operating cost is a set of nodes operating over cellular connections that charge both On-Peak and Off-Peak data rates. The third is mobile devices; some examples of this use case are vehicle-to-vehicle communications, Low Earth Orbit (LEO) networked constellation (LEO-NC), and so on. Recently, the document [I-D.ietf-tvr-requirements] gave some TVR's requirements about general temporality , and this document makes some supplements for TVR's requirements. Wang & Liu Expires 29 March 2024 [Page 2] Internet-Draft tvr-requirements September 2023 2. Conventions 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. Requirements Considering requirements for TVR (Time-Variant Routing) in the following aspects 3.1. Support the Identification and Advertisement of Node Attribute Changes In Time-Variant Routing, scheduling of the system are as expected. In practical situations, however, the attributes of nodes can be converted back and forth between Time-Variant and Non-Time-Variant nodes. For example, a mobile phone can be considered a Non-Time- Variant node in the network when charging. After unplugging the power cord, it can be considered a Time-Variant-Node because it starts to be powered by batteries. o MUST support the identification and advertisement of node attribute changes. Besides, If there are abnormal changes in the system, it is necessary to advertise them through the existing routing protocols in time to achieve the stability of Time-Variant Routing and avoid redundant advertisements. For example, a node in the system is suddenly damaged due to external factors. Therefore, o Should provide a advertisement methodology for responding to abnormal changes in the system. 3.2. Support Agent Node Advertisement Agent nodes can help to improve the efficiency of the network. There are some nodes in the network that do not have routing functions. When their attributes change, they are unable to notify other nodes in the network. Agent nodes can help nodes without routing functions to advertise information, thus improving the efficiency of the network. Therefore, o MUST support agent nodes to help non-routing nodes implement information advertisement. Wang & Liu Expires 29 March 2024 [Page 3] Internet-Draft tvr-requirements September 2023 3.3. Support Identification and Classification of Node Attributes The node attributes of the network may change as described in 3.1. If the system cannot timely identify and classify in a processing manner after the node attributes change, it will lead to suboptimal routing decisions. Therefore, o MUST provide a discovery and resolving methodology for the identification and classification of node attributes. 3.4. Support System Schedule and Time Interval Changes The system's schedule may change, requiring of to be reconfigured instead it being set once and not being able to be modified. Additionally, time-variant intervals in the system may also vary. Therefore, o MUST support system schedule changes. o MUST support time interval changes. 3.5. Support Appropriate Time Accuracy The accuracy of the time cannot be too large or too small; otherwise, convergence may not be possible. Therefore, o MUST support appropriate time accuracy. 4. Conclusion This document makes some supplements to TVR's requirements. 5. Security Considerations TBD. 6. IANA Considerations TBD. 7. Informative References [I-D.ietf-tvr-use-cases] Birrane, E. J., Kuhn, N., and Y. Qu, "TVR (Time-Variant Routing) Use Cases", Work in Progress, Internet-Draft, draft-ietf-tvr-use-cases-01, 3 July 2023, . Wang & Liu Expires 29 March 2024 [Page 4] Internet-Draft tvr-requirements September 2023 [I-D.ietf-tvr-requirements] King, D., Contreras, L. M., and B. Sipos, "TVR (Time- Variant Routing) Requirements", Work in Progress, Internet-Draft, draft-ietf-tvr-requirements-00, 6 September 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Authors' Addresses Jing Wang China Mobile No.32 XuanWuMen West Street Beijing 100053 China Email: wangjingjc@chinamobile.com Peng Liu China Mobile No.32 XuanWuMen West Street Beijing 100053 China Email: liupengyjy@chinamobile.com Wang & Liu Expires 29 March 2024 [Page 5]