Manet H.R. Rogge Internet-Draft Fraunhofer FKIE Intended status: Standards Track 23 July 2023 Expires: 24 January 2024 DLEP Radio Channel Utilization Extension draft-rogge-manet-dlep-channel-utilization-03 Abstract This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) to provide the utilization of a radio channel. 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 24 January 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. Rogge Expires 24 January 2024 [Page 1] Internet-Draft DLEP Channel Utilization July 2023 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. Extension Usage and Identification . . . . . . . . . . . . . 3 3. Data Items . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. Radio Channel Active Data Item . . . . . . . . . . . . . 4 3.2. Radio Channel Busy Data Item . . . . . . . . . . . . . . 5 3.3. Radio Channel Rx Data Item . . . . . . . . . . . . . . . 5 3.4. Radio Channel Tx Data Item . . . . . . . . . . . . . . . 6 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 5.1. Extension Type Value . . . . . . . . . . . . . . . . . . 7 5.2. Data Item Value . . . . . . . . . . . . . . . . . . . . . 7 6. Normative References . . . . . . . . . . . . . . . . . . . . 7 7. Informative References . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175]. It provides the exchange of link-related control information between DLEP peers. DLEP peers are comprised of a modem and a router. DLEP defines a base set of mechanisms as well as support for possible extensions. This document defines one such extension. Radio channel utilization provides a packet/frame independent measurement how a radio channel is used and how much resources are still available. While incoming and outgoing traffic can be easily measured on the router, the amount of airtime used by management traffic of the radio is invisible to the router, as is unicast traffic between two adjecant radios (unless the radio supports promiscous mode). This could present the a fully utilized radio channel to the router as totally empty. Getting a direct radio level information how much time on the radio channel has been used up by incoming or outgoing data or control frames allows a router to calculate a better routing metric or allows management agents to detect a channel being unusable for communication because of external jamming. 1.1. Requirements Language In many IETF documents, several words, when they are in all capitals as shown below, are used to signify the requirements in the specification. These capitalized words can bring significant clarity and consistency to documents because their meanings are well defined. This document defines how those words are interpreted in IETF documents when the words are in all capitals. Rogge Expires 24 January 2024 [Page 2] Internet-Draft DLEP Channel Utilization July 2023 * These words can be used as defined here, but using them is not required. Specifically, normative text does not require the use of these key words. They are used for clarity and consistency when that is what's wanted, but a lot of normative text does not use them and is still normative. * The words have the meanings specified herein only when they are in all capitals. * When these words are not capitalized, they have their normal English meanings and are not affected by this document. Authors who follow these guidelines should incorporate this phrase near the beginning of their document: 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. 2. Extension Usage and Identification The use of the Channel Utilization Extension SHOULD be configurable. To indicate that the Channel Utilization Extension is to be used, an implementation MUST include the Radio Channel Utilization Extension ID in the Extensions Supported Data Item. The Extensions Supported Data Item is sent and processed according to [RFC8175]. The Channel Utilization TLVs can be used by the router to improve the tracking of channel usage by different radios and give a more exact estimate how much free capacity the channel has currently. This information can be used for adjusting timing intervals between automatically generated data, e.g. HELLO messages of the local routing protocol. All four Data Items are time measurements in nanoseconds since an arbitrary starting point, e.g. the radio bootup. They are never reseted and will just increase monotonic. The first Data Item (Radio Channel Active) announces the channels livetime of the radio channel while the other three provide the amount of time the channel has been used in different ways. Radio Channel Rx provides the time the radio is receiving data, Radio Channel Tx the time the radio is sending data and Radio Channel Busy the time the radio channel is blocked for any unknown reason. Rogge Expires 24 January 2024 [Page 3] Internet-Draft DLEP Channel Utilization July 2023 A radio that doesn't track the time for receiving and transmitting data explicitly can just add all times the radio channel is not free into the Radio Channel Busy Data Item. The time the radio channel has been free can be calculated by substracting the values of Busy, Rx and Tx from the value provided by the Radio Active Channel Data Item. By tracking these values over time The router can calculate statistics on the channel usage for routing metrics or report the received value to a management layer. 3. Data Items All four Data Items of this extension can be used both as Session specific and Destination specific metrics. If the radio is only tracking channel usage on interface level, the Data Items are used in SessionInitResponse and SessionUpdate messages. If the radio also is tracking channel usage for each Destination, they are also used in DestinationUp, DestinationUpdate and DestinationAnnounceResponse messages. 3.1. Radio Channel Active Data Item Radio Channel Active Item contains information how long the radio channel has been active. This provides the router with a reference to interpret the values provided by the other three Data Items. Because of this the value in this item must be larger than the values in the other three Data Items this extensions defines together. This Data Item is mandatory for SessionInitResponse messages. The format of the Radio Channel Active Data Item is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Active Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Active Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 Data Item Type: TBD Length: 8 Rogge Expires 24 January 2024 [Page 4] Internet-Draft DLEP Channel Utilization July 2023 Active Time: Time in nanoseconds since the channel has been active. 3.2. Radio Channel Busy Data Item Radio Channel Busy Item contains information how much time the radio channel has been busy, not including the time provided in the Channel Rx and Chanel Tx Data Item. The format of the Radio Channel Busy Data Item is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Busy Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Busy Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 Data Item Type: TBD Length: 8 Busy Time: Time in nanoseconds the channel was busy during its active time. 3.3. Radio Channel Rx Data Item Radio Channel Rx Item contains information how much time the local radio has been receiving data from other radios. The format of the Radio Channel Rx Data Item is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Rx Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Rx Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3 Rogge Expires 24 January 2024 [Page 5] Internet-Draft DLEP Channel Utilization July 2023 Data Item Type: TBD Length: 8 Rx Time: Time in nanoseconds the local radio was receiving data from other radios during its active time. 3.4. Radio Channel Tx Data Item Radio Channel Tx Item contains information how much time the local radio has been transmitting data to other radios. The format of the Radio Channel Tx Data Item is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tx Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tx Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4 Data Item Type: TBD Length: 8 Tx Time: Time in nanoseconds the local radio was transmitting data to other radios during its active time. 4. Security Considerations The extension introduces a new Data Item for DLEP. The extension does not inherently introduce any additional vulnerabilities above those documented in [RFC8175]. The approach taken to security in that document applies equally when running the extension defined in this document. 5. IANA Considerations As described below, IANA has assigned two values per this document. Both assignments are to registries defined by [RFC8175]. Rogge Expires 24 January 2024 [Page 6] Internet-Draft DLEP Channel Utilization July 2023 5.1. Extension Type Value IANA has assigned the following value in the "Extension Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy: +------+---------------------------+ | Code | Description | +------+---------------------------+ | TBD | Radio Channel Utilization | +------+---------------------------+ Table 1: New Extension Type Value 5.2. Data Item Value IANA has assigned the following value in the "Data Item Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy: +-----------+----------------------+ | Type Code | Description | +-----------+----------------------+ | TBD | Radio Channel Active | +-----------+----------------------+ | TBD | Radio Channel Busy | +-----------+----------------------+ | TBD | Radio Channel Rx | +-----------+----------------------+ | TBD | Radio Channel Tx | +-----------+----------------------+ Table 2: New Data Item Value 6. Normative References [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, . Rogge Expires 24 January 2024 [Page 7] Internet-Draft DLEP Channel Utilization July 2023 [RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, DOI 10.17487/RFC8175, June 2017, . 7. Informative References [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . Author's Address Henning Rogge Fraunhofer FKIE Fraunhofer Strasse 20 53343 Wachtberg Germany Email: henning.rogge@fkie.fraunhofer.de Rogge Expires 24 January 2024 [Page 8]