DOTS M. Boucadair Internet-Draft Orange Intended status: Standards Track J. Shallow Expires: 15 August 2022 11 February 2022 Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Configuration Attributes for Robust Block Transmission draft-ietf-dots-robust-blocks-03 Abstract This document specifies new DOTS signal channel configuration parameters that are negotiated between DOTS peers to enable the use of Q-Block1 and Q-Block2 CoAP Options. These options enable robust and faster transmission rates for large amounts of data with less packet interchanges as well as supporting faster recovery should any of the blocks get lost in transmission. This document defines a YANG data model for representing these new DOTS signal channel configuration parameters. 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 15 August 2022. Copyright Notice Copyright (c) 2022 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 Boucadair & Shallow Expires 15 August 2022 [Page 1] Internet-Draft DOTS Robust Block Transmission February 2022 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. DOTS Attributes for Robust Block Transmission . . . . . . . . 4 4. YANG/JSON Mapping Parameters to CBOR . . . . . . . . . . . . 10 5. DOTS Robust Block Transmission YANG Module . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 6.1. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 18 6.2. DOTS Robust Block Transmission YANG Module . . . . . . . 19 7. Security Considerations . . . . . . . . . . . . . . . . . . . 19 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 9.1. Normative References . . . . . . . . . . . . . . . . . . 20 9.2. Informative References . . . . . . . . . . . . . . . . . 21 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction The Constrained Application Protocol (CoAP) [RFC7252], although inspired by HTTP, was designed to use UDP instead of TCP. The message layer of CoAP over UDP includes support for reliable delivery, simple congestion control, and flow control. The block- wise transfer [RFC7959] introduced the CoAP Block1 and Block2 Options to handle data records that cannot fit in a single IP packet, so not having to rely on IP fragmentation. The block-wise transfer was further updated by [RFC8323] for use over TCP, TLS, and WebSockets. The CoAP Block1 and Block2 Options work well in environments where there are no or minimal packet losses. These options operate synchronously where each individual block has to be requested and can only ask for (or send) the next block when the request for the previous block has completed. Packet, and hence block transmission rate, is controlled by Round Trip Times (RTTs). Boucadair & Shallow Expires 15 August 2022 [Page 2] Internet-Draft DOTS Robust Block Transmission February 2022 There is a requirement for these blocks of data to be transmitted at higher rates under network conditions where there may be asymmetrical transient packet loss (i.e., responses may get dropped). An example is when a network is subject to a Distributed Denial of Service (DDoS) attack and there is a need for DDoS mitigation agents relying upon CoAP to communicate with each other (e.g., [I-D.ietf-dots-telemetry]). As a reminder, [RFC7959] recommends the use of Confirmable (CON) responses to handle potential packet loss. However, such a recommendation does not work with a flooded pipe DDoS situation because the returning ACK packets may not get through. The block-wise transfer specified in [RFC7959] covers the general case, but falls short in situations where packet loss is highly asymmetrical. The mechanism specified in [I-D.ietf-core-new-block] provides roughly similar features to the Block1/Block2 Options, but provides additional properties that are tailored towards the intended DOTS transmission. Concretely, [I-D.ietf-core-new-block] primarily targets applications such as DDoS Open Threat Signaling (DOTS) that can't use Confirmable responses to handle potential packet loss and that support application-specific mechanisms to assess whether the remote peer is able to handle the messages sent by a CoAP endpoint (e.g., DOTS heartbeats in Section 4.7 of [RFC9132]). [I-D.ietf-core-new-block] includes guards to prevent a CoAP agent from overloading the network by adopting an aggressive sending rate. These guards are followed in addition to the existing CoAP congestion control as specified in Section 4.7 of [RFC7252] (mainly, PROBING_RATE). Table 1 lists the additional CoAP attributes that are used for the guards (Section 7.2 of [I-D.ietf-core-new-block]). +---------------------+-------------------+ | Parameter Name | Default Value | +=====================+===================+ | MAX_PAYLOADS | 10 | | NON_MAX_RETRANSMIT | 4 | | NON_TIMEOUT | 2 s | | NON_RECEIVE_TIMEOUT | 4 s | | NON_PROBING_WAIT | between 247-248 s | | NON_PARTIAL_TIMEOUT | 247 s | +---------------------+-------------------+ Table 1: Congestion Control Parameters PROBING_RATE and other transmission parameters are negotiated between DOTS peers as discussed in Section 4.5.2 of [RFC9132]. Nevertheless, the attributes listed in Table 1 are not supported. This document defines new DOTS signal channel attributes that are used to customize the configuration of robust block transmission in a DOTS context. Boucadair & Shallow Expires 15 August 2022 [Page 3] Internet-Draft DOTS Robust Block Transmission February 2022 2. Terminology 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. Readers should be familiar with the terms and concepts defined in [RFC7252] and [RFC8612]. The terms "payload" and "body" are defined in [RFC7959]. The term "payload" is thus used for the content of a single CoAP message (i.e., a single block being transferred), while the term "body" is used for the entire resource representation that is being transferred in a block-wise fashion. The meaning of the symbols in YANG tree diagrams are defined in [RFC8340] and [RFC8791]. 3. DOTS Attributes for Robust Block Transmission Section 7.2 of [I-D.ietf-core-new-block] defines the following attributes that are used for congestion control purposes: MAX_PAYLOADS: is the maximum number of payloads that can be transmitted at any one time. NON_MAX_RETRANSMIT: is the maximum number of times a request for the retransmission of missing payloads can occur without a response from the remote peer. By default, NON_MAX_RETRANSMIT has the same value as MAX_RETRANSMIT (Section 4.8 of [RFC7252]). NON_TIMEOUT: is the maximum period of delay between sending sets of MAX_PAYLOADS payloads for the same body. NON_TIMEOUT has the same value as ACK_TIMEOUT (Section 4.8 of [RFC7252]). NON_RECEIVE_TIMEOUT: is the maximum time to wait for a missing payload before requesting retransmission. By default, NON_RECEIVE_TIMEOUT has a value of twice NON_TIMEOUT. NON_PROBING_WAIT: is used to limit the potential wait needed calculated when using PROBING_WAIT. NON_PARTIAL_TIMEOUT: is used for expiring partially received bodies. Boucadair & Shallow Expires 15 August 2022 [Page 4] Internet-Draft DOTS Robust Block Transmission February 2022 These attributes are used together with PROBING_RATE parameter which in CoAP indicates the average data rate that must not be exceeded by a CoAP endpoint in sending to a peer endpoint that does not respond. The single body of blocks will be subjected to PROBING_RATE (Section 4.7 of [RFC7252]), not the individual packets. If the wait time between sending bodies that are not being responded to calculated using on PROBING_RATE exceeds NON_PROBING_WAIT, then the gap time is limited to NON_PROBING_WAIT. This document augments the "ietf-dots-signal-channel" DOTS signal YANG module defined in Section 5.3 of [RFC9132] with the following additional attributes that can be negotiated between DOTS peers to enable robust and faster transmission: max-payloads: This attribute echoes the MAX_PAYLOADS parameter in [I-D.ietf-core-new-block]. This is an optional attribute. non-max-retransmit: This attribute echoes the NON_MAX_RETRANSMIT parameter in [I-D.ietf-core-new-block]. The default value of this attribute is 'max-retransmit'. Note that DOTS uses a default value of '3' instead of '4' used for the generic CoAP use (Section 4.5.2 of [RFC9132]) for max-transmit. This is an optional attribute. non-timeout: This attribute echoes the NON_TIMEOUT parameter in [I-D.ietf-core-new-block]. The default value of this attribute is 'ack-timeout'. This is an optional attribute. non-receive-timeout: This attribute echoes the NON_RECEIVE_TIMEOUT parameter in [I-D.ietf-core-new-block]. The default value of this attribute is twice 'non-timeout'. This is an optional attribute. non-probing-wait: This attribute echoes the NON_PROBING_WAIT parameter in [I-D.ietf-core-new-block]. The default value of this attribute is 247s. This is an optional attribute. non-partial-timeout: This attribute echoes the NON_PARTIAL_TIMEOUT parameter in [I-D.ietf-core-new-block]. The default value of this attribute is 274s. Boucadair & Shallow Expires 15 August 2022 [Page 5] Internet-Draft DOTS Robust Block Transmission February 2022 This is an optional attribute. The tree structure of the "ietf-dots-robust-trans" module (Section 5) is shown in Figure 1. module: ietf-dots-robust-trans augment-structure /dots-signal:dots-signal/dots-signal:message-type /dots-signal:signal-config /dots-signal:mitigating-config: +-- max-payloads | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value? uint16 | | +-- min-value? uint16 | +-- current-value? uint16 +-- non-max-retransmit | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value? uint16 | | +-- min-value? uint16 | +-- current-value? uint16 +-- non-timeout | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-receive-timeout | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-probing-wait | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-partial-wait: +-- (direction)? | +--:(server-to-client-only) | +-- max-value-decimal? decimal64 | +-- min-value-decimal? decimal64 +-- current-value-decimal? decimal64 augment-structure /dots-signal:dots-signal/dots-signal:message-type Boucadair & Shallow Expires 15 August 2022 [Page 6] Internet-Draft DOTS Robust Block Transmission February 2022 /dots-signal:signal-config/dots-signal:idle-config: +-- max-payloads | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value? uint16 | | +-- min-value? uint16 | +-- current-value? uint16 +-- non-max-retransmit | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value? uint16 | | +-- min-value? uint16 | +-- current-value? uint16 +-- non-timeout | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-receive-timeout | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-probing-wait | +-- (direction)? | | +--:(server-to-client-only) | | +-- max-value-decimal? decimal64 | | +-- min-value-decimal? decimal64 | +-- current-value-decimal? decimal64 +-- non-partial-wait: +-- (direction)? | +--:(server-to-client-only) | +-- max-value-decimal? decimal64 | +-- min-value-decimal? decimal64 +-- current-value-decimal? decimal64 Figure 1: DOTS Fast Block Transmission Tree Structure These attributes are mapped to CBOR types as specified in Section 4 and Section 6 of [RFC9132]. DOTS clients follow the procedure specified in Section 4.5 of [RFC9132] to negotiate, configure, and retrieve the DOTS signal channel session behavior (including Q-Block parameters) with DOTS peers. Boucadair & Shallow Expires 15 August 2022 [Page 7] Internet-Draft DOTS Robust Block Transmission February 2022 Implementation Note 1: 'non-probing-wait' ideally should be left having some jitter and so should not be hard-coded with an explicit value. It is suggested to use a base value (using NON_TIMEOUT instead of NON_TIMEOUT_RANDOM) and, then, the jitter (ACK_RANDOM_FACTOR - 1) is added to each time the value is checked. Implementation Note 2: If any of the signal channel session configuration parameters is updated, the 'non-probing-wait' and 'non-partial-timeout' values should be recalculated according to the definition algorithms in Section 7.2 of [I-D.ietf-core-new-block]. An example of PUT message to configure Q-Block parameters is depicted in Figure 2. In this example, the 'max-payloads' attribute is set to '15' when no mitigation is active, while it is set to '10' when a mitigation is active. The same value is used for 'non-max- retransmit', 'non-timeout', 'non-receive-timeout', 'non-probing- wait', and "non-partial-wait" in both idle and mitigation times. The meaning of other attributes is detailed in Section 4.5 of [RFC9132]. Header: PUT (Code=0.03) Uri-Path: ".well-known" Uri-Path: "dots" Uri-Path: "config" Uri-Path: "sid=123" Content-Format: "application/dots+cbor" { "ietf-dots-signal-channel:signal-config": { "mitigating-config": { "heartbeat-interval": { "current-value": 30 }, "missing-hb-allowed": { "current-value": 15 }, "probing-rate": { "current-value": 15 }, "max-retransmit": { "current-value": 3 }, "ack-timeout": { "current-value-decimal": "2.00" }, "ack-random-factor": { "current-value-decimal": "1.50" Boucadair & Shallow Expires 15 August 2022 [Page 8] Internet-Draft DOTS Robust Block Transmission February 2022 }, "ietf-dots-robust-trans:max-payloads": { "current-value": 10 }, "ietf-dots-robust-trans:non-max-retransmit": { "current-value": 3 }, "ietf-dots-robust-trans:non-timeout": { "current-value-decimal": "2.00" }, "ietf-dots-robust-trans:non-receive-timeout": { "current-value-decimal": "4.00" }, "ietf-dots-robust-trans:non-probing-wait": { "current-value-decimal": "247.00" }, "ietf-dots-robust-trans:non-partial-wait": { "current-value-decimal": "247.00" } }, "idle-config": { "heartbeat-interval": { "current-value": 0 }, "max-retransmit": { "current-value": 3 }, "ack-timeout": { "current-value-decimal": "2.00" }, "ack-random-factor": { "current-value-decimal": "1.50" }, "ietf-dots-robust-trans:max-payloads": { "current-value": 15 }, "ietf-dots-robust-trans:non-max-retransmit": { "current-value": 3 }, "ietf-dots-robust-trans:non-timeout": { "current-value-decimal": "2.00" }, "ietf-dots-robust-trans:non-receive-timeout": { "current-value-decimal": "4.00" }, "ietf-dots-robust-trans:non-probing-wait": { "current-value-decimal": "247.00" }, Boucadair & Shallow Expires 15 August 2022 [Page 9] Internet-Draft DOTS Robust Block Transmission February 2022 "ietf-dots-robust-trans:non-partial-wait": { "current-value-decimal": "247.00" } } } } Figure 2: Example of PUT to Convey the Configuration Parameters The payload of the message depicted in Figure 2 is CBOR-encoded as indicated by the Content-Format set to "application/dots+cbor" (Section 10.3 of [RFC9132]). However, and for the sake of better readability, the example uses JSON encoding of YANG-modeled data following the mapping table in Section 4 and Section 6 of [RFC9132]: use the JSON names and types defined in Section 4. These conventions are inherited from [RFC9132]. 4. YANG/JSON Mapping Parameters to CBOR The YANG/JSON mapping parameters to CBOR are listed in Table 2. * Note: Implementers must check that the mapping output provided by their YANG-to-CBOR encoding schemes is aligned with the content of Table 2. Boucadair & Shallow Expires 15 August 2022 [Page 10] Internet-Draft DOTS Robust Block Transmission February 2022 +----------------------+------------+------+---------------+--------+ | Parameter Name | YANG | CBOR | CBOR Major | JSON | | | Type | Key | Type & | Type | | | | | Information | | +======================+============+======+===============+========+ | ietf-dots-robust- | container | TBA1 | 5 map | Object | | trans:max-payloads | | | | | +----------------------+------------+------+---------------+--------+ | ietf-dots-robust- | container | TBA2 | 5 map | Object | | trans:non-max- | | | | | | retransmit | | | | | +----------------------+------------+------+---------------+--------+ | ietf-dots-robust- | container | TBA3 | 5 map | Object | | trans:non-timeout | | | | | +----------------------+------------+------+---------------+--------+ | ietf-dots-robust- | container | TBA4 | 5 map | Object | | trans:non-receive- | | | | | | timeout | | | | | +----------------------+------------+------+---------------+--------+ | ietf-dots-robust- | container | TBA5 | 5 map | Object | | trans:non-probing- | | | | | | wait | | | | | +----------------------+------------+------+---------------+--------+ | ietf-dots-robust- | container | TBA6 | 5 map | Object | | trans:non-partial- | | | | | | wait | | | | | +----------------------+------------+------+---------------+--------+ Table 2: YANG/JSON Mapping Parameters to CBOR 5. DOTS Robust Block Transmission YANG Module The "ietf-dots-robust-trans" module is not intended to be used via NETCONF/RESTCONF; it serves only to provide abstract data structures. This module uses the data structure extension defined in [RFC8791]. file "ietf-dots-robust-trans@2022-01-04.yang" module ietf-dots-robust-trans { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-dots-robust-trans"; prefix dots-robust; import ietf-dots-signal-channel { prefix dots-signal; reference "RFC 9132: Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Specification"; Boucadair & Shallow Expires 15 August 2022 [Page 11] Internet-Draft DOTS Robust Block Transmission February 2022 } import ietf-yang-structure-ext { prefix sx; reference "RFC 8791: YANG Data Structure Extensions"; } organization "IETF DDoS Open Threat Signaling (DOTS) Working Group"; contact "WG Web: WG List: Author: Mohamed Boucadair ; Author: Jon Shallow "; description "This module contains YANG definitions for the configuration of parameters that can be negotiated between a DOTS client and a DOTS server for robust block transmission. Copyright (c) 2022 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2022-01-04 { description "Initial revision."; reference "RFC XXXX: Distributed Denial-of-Service Open Threat Signaling (DOTS) Configuration Attributes for Robust Block Transmission"; } grouping robust-transmission-attributes { description "A set of DOTS signal channel session configuration Boucadair & Shallow Expires 15 August 2022 [Page 12] Internet-Draft DOTS Robust Block Transmission February 2022 that are negotiated between DOTS agents when making use of Q-Block1 and Q-Block2 Options."; container max-payloads { description "Indicates the maximum number of payloads that can be transmitted at any one time."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description "These data nodes appear only in a message sent from the server to the client."; leaf max-value { type uint16; description "Maximum acceptable max-payloads value."; } leaf min-value { type uint16; description "Minimum acceptable max-payloads value."; } } } leaf current-value { type uint16; default "10"; description "Current max-payloads value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } container non-max-retransmit { description "Indicates the maximum number of times a request for the retransmission of missings payloads can occur without a response from the remote peer."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description Boucadair & Shallow Expires 15 August 2022 [Page 13] Internet-Draft DOTS Robust Block Transmission February 2022 "These data nodes appear only in a message sent from the server to the client."; leaf max-value { type uint16; description "Maximum acceptable non-max-retransmit value."; } leaf min-value { type uint16; description "Minimum acceptable non-max-retransmit value."; } } } leaf current-value { type uint16; default "3"; description "Current non-max-retransmit value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } container non-timeout { description "Indicates the maximum period of delay between sending sets of MAX_PAYLOADS payloads for the same body."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description "These data nodes appear only in a message sent from the server to the client."; leaf max-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Maximum ack-timeout value."; } leaf min-value-decimal { type decimal64 { Boucadair & Shallow Expires 15 August 2022 [Page 14] Internet-Draft DOTS Robust Block Transmission February 2022 fraction-digits 2; } units "seconds"; description "Minimum ack-timeout value."; } } } leaf current-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; default "2.00"; description "Current ack-timeout value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } container non-receive-timeout { description "Indicates the time to wait for a missing payload before requesting retransmission."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description "These data nodes appear only in a message sent from the server to the client."; leaf max-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Maximum non-receive-timeout value."; } leaf min-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description Boucadair & Shallow Expires 15 August 2022 [Page 15] Internet-Draft DOTS Robust Block Transmission February 2022 "Minimum non-receive-timeout value."; } } } leaf current-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; default "4.00"; description "Current non-receive-timeout value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } container non-probing-wait { description "Is used to limit the potential wait needed calculated when using probing-rate."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description "These data nodes appear only in a message sent from the server to the client."; leaf max-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Maximum non-probing-wait value."; } leaf min-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Minimum non-probing-wait value."; } } } Boucadair & Shallow Expires 15 August 2022 [Page 16] Internet-Draft DOTS Robust Block Transmission February 2022 leaf current-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; default "247.00"; description "Current non-probing-wait value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } container non-partial-wait { description "Is used for expiring partially received bodies."; choice direction { description "Indicates the communication direction in which the data nodes can be included."; case server-to-client-only { description "These data nodes appear only in a message sent from the server to the client."; leaf max-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Maximum non-partial-wait value."; } leaf min-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; description "Minimum non-partial-wait value."; } } } leaf current-value-decimal { type decimal64 { fraction-digits 2; } units "seconds"; Boucadair & Shallow Expires 15 August 2022 [Page 17] Internet-Draft DOTS Robust Block Transmission February 2022 default "247.00"; description "Current non-partial-wait value."; reference "RFC NNNN: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission, Section 7.2"; } } } sx:augment-structure "/dots-signal:dots-signal" + "/dots-signal:message-type" + "/dots-signal:signal-config" + "/dots-signal:mitigating-config" { description "Indicates DOTS configuration parameters to use for robust transmission when a mitigation is active."; uses robust-transmission-attributes; } sx:augment-structure "/dots-signal:dots-signal" + "/dots-signal:message-type" + "/dots-signal:signal-config" + "/dots-signal:idle-config" { description "Indicates DOTS configuration parameters to use for robust transmission when no mitigation is active."; uses robust-transmission-attributes; } } Note to the RFC Editor: Please replace RFC NNNN with the RFC number assignd to [I-D.ietf-core-new-block]. 6. IANA Considerations 6.1. DOTS Signal Channel CBOR Mappings Registry This specification registers the following parameters in the IANA "DOTS Signal Channel CBOR Key Values" registry [Key-Map]. * Note to the RFC Editor: Please replace TBA1-TBA6 with the CBOR keys that are assigned from the 32768-49151 range. Please update Table 2 accordingly. Boucadair & Shallow Expires 15 August 2022 [Page 18] Internet-Draft DOTS Robust Block Transmission February 2022 +------------------------+-------+-------+------------+---------------+ | Parameter Name | CBOR | CBOR | Change | Specification | | | Key | Major | Controller | Document(s) | | | Value | Type | | | +========================+=======+=======+============+===============+ | ietf-dots-robust-trans:| TBA1 | 5 | IESG | [RFCXXXX] | | max-payloads | | | | | +------------------------+-------+-------+------------+---------------+ | ietf-dots-robust-trans:| TBA2 | 5 | IESG | [RFCXXXX] | | non-max-retransmit | | | | | +------------------------+-------+-------+------------+---------------+ | ietf-dots-robust-trans:| TBA3 | 5 | IESG | [RFCXXXX] | | non-timeout | | | | | +------------------------+-------+-------+------------+---------------+ | ietf-dots-robust-trans:| TBA4 | 5 | IESG | [RFCXXXX] | | non-receive-timeout | | | | | +------------------------+-------+-------+------------+---------------+ | ietf-dots-robust-trans:| TBA5 | 5 | IESG | [RFCXXXX] | | non-probing-wait | | | | | +------------------------+-------+-------+------------+---------------+ | ietf-dots-robust-trans:| TBA6 | 5 | IESG | [RFCXXXX] | | non-partial-wait | | | | | +------------------------+-------+-------+------------+---------------+ 6.2. DOTS Robust Block Transmission YANG Module This document requests IANA to register the following URI in the "ns" subregistry within the "IETF XML Registry" [RFC3688]: URI: urn:ietf:params:xml:ns:yang:ietf-dots-robust-trans Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. This document requests IANA to register the following YANG module in the "YANG Module Names" subregistry [RFC6020] within the "YANG Parameters" registry. Name: ietf-dots-robust-trans Namespace: urn:ietf:params:xml:ns:yang:ietf-dots-robust-trans Maintained by IANA? N Prefix: dots-robust Reference: RFC XXXX 7. Security Considerations The security considerations for the DOTS signal channel protocol are discussed in Section 11 of [RFC9132]. Boucadair & Shallow Expires 15 August 2022 [Page 19] Internet-Draft DOTS Robust Block Transmission February 2022 CoAP-specific security considerations are discussed in Section 11 of [I-D.ietf-core-new-block]. This document defines YANG data structures that are meant to be used as an abstract representation in DOTS signal channel messages. As such, the "ietf-dots-robust-trans" module (Section 5) does not introduce any new vulnerabilities beyond those specified above. 8. Acknowledgements Thanks to Tiru Reddy, Meiling Chen, and kaname nishizuka for the review. Thanks to Michal Vasko for the yangdoctors review. Thanks to Valery Smyslov for shepherding the document. 9. References 9.1. Normative References [I-D.ietf-core-new-block] Boucadair, M. and J. Shallow, "Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission", Work in Progress, Internet-Draft, draft-ietf-core-new-block-14, 26 May 2021, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, June 2014, . Boucadair & Shallow Expires 15 August 2022 [Page 20] Internet-Draft DOTS Robust Block Transmission February 2022 [RFC7959] Bormann, C. and Z. Shelby, Ed., "Block-Wise Transfers in the Constrained Application Protocol (CoAP)", RFC 7959, DOI 10.17487/RFC7959, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8323] Bormann, C., Lemay, S., Tschofenig, H., Hartke, K., Silverajan, B., and B. Raymor, Ed., "CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets", RFC 8323, DOI 10.17487/RFC8323, February 2018, . [RFC8791] Bierman, A., Björklund, M., and K. Watsen, "YANG Data Structure Extensions", RFC 8791, DOI 10.17487/RFC8791, June 2020, . [RFC9132] Boucadair, M., Ed., Shallow, J., and T. Reddy.K, "Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Specification", RFC 9132, DOI 10.17487/RFC9132, September 2021, . 9.2. Informative References [I-D.ietf-dots-telemetry] Boucadair, M., Reddy.K, T., Doron, E., Chen, M., and J. Shallow, "Distributed Denial-of-Service Open Threat Signaling (DOTS) Telemetry", Work in Progress, Internet- Draft, draft-ietf-dots-telemetry-23, 4 February 2022, . [Key-Map] IANA, "DOTS Signal Channel CBOR Key Values", . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8612] Mortensen, A., Reddy, T., and R. Moskowitz, "DDoS Open Threat Signaling (DOTS) Requirements", RFC 8612, DOI 10.17487/RFC8612, May 2019, . Boucadair & Shallow Expires 15 August 2022 [Page 21] Internet-Draft DOTS Robust Block Transmission February 2022 Authors' Addresses Mohamed Boucadair Orange 35000 Rennes France Email: mohamed.boucadair@orange.com Jon Shallow United Kingdom Email: supjps-ietf@jpshallow.com Boucadair & Shallow Expires 15 August 2022 [Page 22]