Internet Engineering Task Force (IETF)                      A. Mortensen
Request for Comments: 8612                                Arbor Networks
Category: Informational                                         T. Reddy
ISSN: 2070-1721                                                   McAfee
                                                            R. Moskowitz
                                                                May 2019

DDoS Open Threat Signaling (DOTS) Requirements

DDoS Open Threat Signaling(DOTS)の要件



This document defines the requirements for the Distributed Denial-of-Service (DDoS) Open Threat Signaling (DOTS) protocols enabling coordinated response to DDoS attacks.


Status of This Memo


This document is not an Internet Standards Track specification; it is published for informational purposes.

このドキュメントはInternet Standards Trackの仕様ではありません。情報提供を目的として公開されています。

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841.

このドキュメントは、IETF(Internet Engineering Task Force)の製品です。これは、IETFコミュニティのコンセンサスを表しています。公開レビューを受け、インターネットエンジニアリングステアリンググループ(IESG)による公開が承認されました。 IESGによって承認されたすべてのドキュメントが、あらゆるレベルのインターネット標準の候補であるとは限りません。 RFC 7841のセクション2をご覧ください。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.

Copyright(c)2019 IETF Trustおよびドキュメントの作成者として識別された人物。全著作権所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( 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.

この文書は、BCP 78およびIETF文書に関するIETFトラストの法的規定(の対象であり、この文書の発行日に有効です。これらのドキュメントは、このドキュメントに関するあなたの権利と制限を説明しているため、注意深く確認してください。このドキュメントから抽出されたコードコンポーネントには、Trust Legal Provisionsのセクション4.eに記載されているSimplified BSD Licenseテキストが含まれている必要があり、Simplified BSD Licenseに記載されているように保証なしで提供されます。

Table of Contents


   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Context and Motivation  . . . . . . . . . . . . . . . . .   2
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  General Requirements  . . . . . . . . . . . . . . . . . .   7
     2.2.  Signal Channel Requirements . . . . . . . . . . . . . . .   8
     2.3.  Data Channel Requirements . . . . . . . . . . . . . . . .  13
     2.4.  Security Requirements . . . . . . . . . . . . . . . . . .  14
     2.5.  Data Model Requirements . . . . . . . . . . . . . . . . .  16
   3.  Congestion Control Considerations . . . . . . . . . . . . . .  17
     3.1.  Signal Channel  . . . . . . . . . . . . . . . . . . . . .  17
     3.2.  Data Channel  . . . . . . . . . . . . . . . . . . . . . .  17
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  18
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  18
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  20
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  21
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  21
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  21
1. Introduction
1. はじめに
1.1. Context and Motivation
1.1. コンテキストと動機

Distributed Denial-of-Service (DDoS) attacks afflict networks connected to the Internet, plaguing network operators at service providers and enterprises around the world. High-volume attacks saturating inbound links are now common as attack scale and frequency continue to increase.


The prevalence and impact of these DDoS attacks has led to an increased focus on coordinated attack response. However, many enterprises lack the resources or expertise to operate on-premise attack mitigation solutions themselves, or are constrained by local bandwidth limitations. To address such gaps, service providers have begun to offer on-demand traffic scrubbing services, which are designed to separate the DDoS attack traffic from legitimate traffic and forward only the latter.


Today, these services offer proprietary interfaces for subscribers to request attack mitigation. Such proprietary interfaces tie a subscriber to a service and limit the abilities of network elements that would otherwise be capable of participating in attack mitigation. As a result of signaling interface incompatibility, attack responses may be fragmented or otherwise incomplete, leaving operators in the attack path unable to assist in the defense.


A standardized method to coordinate a real-time response among involved operators will increase the speed and effectiveness of DDoS attack mitigation and reduce the impact of these attacks. This document describes the required characteristics of protocols that enable attack response coordination and mitigation of DDoS attacks.


DDoS Open Threat Signaling (DOTS) communicates the need for defensive action in anticipation of or in response to an attack, but it does not dictate the implementation of these actions. The DOTS use cases are discussed in [DOTS-USE], and the DOTS architecture is discussed in [DOTS-ARCH].

DDoS Open Threat Signaling(DOTS)は、攻撃を見越して、または攻撃に応じて防御アクションの必要性を伝えますが、これらのアクションの実装を指示するものではありません。 DOTSの使用例は[DOTS-USE]で説明されており、DOTSアーキテクチャは[DOTS-ARCH]で説明されています。

1.2. Terminology
1.2. 用語

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.


These capitalized words are used to signify the requirements for the DOTS protocols design.


This document adopts the following terms:


DDoS: A distributed denial-of-service attack in which traffic originating from multiple sources is directed at a target on a network. DDoS attacks are intended to cause a negative impact on the availability and/or functionality of an attack target. Denial-of-service considerations are discussed in detail in [RFC4732].

DDoS:複数のソースから発信されたトラフィックがネットワーク上のターゲットに向けられる分散型サービス拒否攻撃。 DDoS攻撃は、攻撃対象の可用性や機能に悪影響を与えることを目的としています。サービス拒否の考慮事項は、[RFC4732]で詳細に説明されています。

DDoS attack target: A network-connected entity that is the target of a DDoS attack. Potential targets include (but are not limited to) network elements, network links, servers, and services.


DDoS attack telemetry: Collected measurements and behavioral characteristics defining the nature of a DDoS attack.


Countermeasure: An action or set of actions focused on recognizing and filtering out specific types of DDoS attack traffic while passing legitimate traffic to the attack target. Distinct countermeasures can be layered to defend against attacks combining multiple DDoS attack types.


Mitigation: A set of countermeasures enforced against traffic destined for the target or targets of a detected or reported DDoS attack, where countermeasure enforcement is managed by an entity in the network path between attack sources and the attack target. Mitigation methodology is out of scope for this document.


Mitigator: An entity, typically a network element, capable of performing mitigation of a detected or reported DDoS attack. The means by which this entity performs these mitigations and how they are requested of it are out of scope for this document. The mitigator and DOTS server receiving a mitigation request are assumed to belong to the same administrative entity.


DOTS client: A DOTS-aware software module responsible for requesting attack response coordination with other DOTS-aware elements.


DOTS server: A DOTS-aware software module handling and responding to messages from DOTS clients. The DOTS server enables mitigation on behalf of the DOTS client, if requested, by communicating the DOTS client's request to the mitigator and returning selected mitigator feedback to the requesting DOTS client.

DOTSサーバー:DOTSクライアントからのメッセージを処理および応答するDOTS対応のソフトウェアモジュール。 DOTSサーバーは、DOTSクライアントの要求を軽減機能に伝達し、選択された軽減機能のフィードバックを要求元のDOTSクライアントに返すことにより、DOTSクライアントに代わって軽減を可能にします。

DOTS agent: Any DOTS-aware software module capable of participating in a DOTS signal or data channel. It can be a DOTS client, DOTS server, or, as a logical agent, a DOTS gateway.


DOTS gateway: A DOTS-aware software module resulting from the logical concatenation of the functionality of a DOTS server and a DOTS client into a single DOTS agent. This functionality is analogous to a Session Initiation Protocol (SIP) [RFC3261] Back-to-Back User Agent (B2BUA) [RFC7092]. A DOTS gateway has a client-facing side, which behaves as a DOTS server for downstream clients, and a server-facing side, which performs the role of a DOTS client for upstream DOTS servers. Client-domain DOTS gateways are DOTS gateways that are in the DOTS client's domain, while server-domain DOTS gateways denote DOTS gateways that are in the DOTS server's domain. A DOTS gateway may terminate multiple discrete DOTS client connections and may aggregate these into one or more connections. DOTS gateways are described further in [DOTS-ARCH].

DOTSゲートウェイ:DOTSサーバーとDOTSクライアントの機能を単一のDOTSエージェントに論理的に連結した結果のDOTS対応ソフトウェアモジュール。この機能は、セッション開始プロトコル(SIP)[RFC3261]バックツーバックユーザーエージェント(B2BUA)[RFC7092]に類似しています。 DOTSゲートウェイには、ダウンストリームクライアントのDOTSサーバーとして動作するクライアント側と、アップストリームDOTSサーバーのDOTSクライアントの役割を果たすサーバー側があります。クライアントドメインのDOTSゲートウェイは、DOTSクライアントのドメインにあるDOTSゲートウェイであり、サーバードメインのDOTSゲートウェイは、DOTSサーバーのドメインにあるDOTSゲートウェイを表します。 DOTSゲートウェイは、複数の個別のDOTSクライアント接続を終了し、これらを1つ以上の接続に集約する場合があります。 DOTSゲートウェイについては、[DOTS-ARCH]で詳しく説明しています。

Signal channel: A bidirectional, mutually authenticated communication channel between DOTS agents that is resilient even in conditions leading to severe packet loss such as a volumetric DDoS attack causing network congestion.


DOTS signal: A status/control message transmitted over the authenticated signal channel between DOTS agents, used to indicate the client's need for mitigation or to convey the status of any requested mitigation.


Heartbeat: A message transmitted between DOTS agents over the signal channel, used as a keep-alive and to measure peer health.


Data channel: A bidirectional, mutually authenticated communication channel between two DOTS agents used for infrequent but reliable bulk exchange of data not easily or appropriately communicated through the signal channel. Reliable bulk data exchange may not function well or at all during attacks causing network congestion. The data channel is not expected to operate in such conditions.


Filter: A specification of a matching network traffic flow or set of flows. The filter will typically have a policy associated with it, e.g., rate-limiting or discarding matching traffic [RFC4949].


Drop-list: A list of filters indicating sources from which traffic should be blocked regardless of traffic content.


Accept-list: A list of filters indicating sources from which traffic should always be allowed regardless of contradictory data gleaned in a detected attack.


Multihomed DOTS client: A DOTS client exchanging messages with multiple DOTS servers, each in a separate administrative domain.


2. Requirements
2. 必要条件

The expected layout and interactions amongst DOTS entities is described in the DOTS Architecture [DOTS-ARCH].


The goal of the DOTS requirements specification is to specify the requirements for DOTS signal channel and data channel protocols that have different application and transport-layer requirements. This section describes the required features and characteristics of the DOTS protocols.


The goal of DOTS protocols is to enable and manage mitigation on behalf of a network domain or resource that is or may become the focus of a DDoS attack. An active DDoS attack against the entity controlling the DOTS client need not be present before establishing a communication channel between DOTS agents. Indeed, establishing a relationship with peer DOTS agents during normal network conditions provides the foundation for a more rapid attack response against future attacks, as all interactions setting up DOTS, including any business or service-level agreements, are already complete. Reachability information of peer DOTS agents is provisioned to a DOTS client using a variety of manual or dynamic methods. Once a relationship between DOTS agents is established, regular communication between DOTS clients and servers enables a common understanding of the DOTS agents' health and activity.

DOTSプロトコルの目標は、DDoS攻撃の焦点となる、またはDDoS攻撃の焦点になる可能性のあるネットワークドメインまたはリソースに代わって緩和策を有効にして管理することです。 DOTSエージェント間の通信チャネルを確立する前に、DOTSクライアントを制御するエンティティに対するアクティブなDDoS攻撃が存在する必要はありません。実際、通常のネットワーク状態でピアDOTSエージェントとの関係を確立すると、ビジネスやサービスレベルの合意を含め、DOTSを設定するすべての対話がすでに完了しているため、将来の攻撃に対するより迅速な攻撃応答の基盤が提供されます。ピアDOTSエージェントの到達可能性情報は、さまざまな手動または動的な方法を使用してDOTSクライアントにプロビジョニングされます。 DOTSエージェント間の関係が確立されると、DOTSクライアントとサーバー間の定期的な通信により、DOTSエージェントの正常性とアクティビティの共通理解が可能になります。

The DOTS protocol must, at a minimum, make it possible for a DOTS client to request aid mounting a defense against a suspected attack. This defense could be coordinated by a DOTS server and include signaling within or between domains as requested by local operators. DOTS clients should similarly be able to withdraw aid requests. DOTS requires no justification from DOTS clients for requests for help, nor do DOTS clients need to justify withdrawing help requests; the decision is local to the DOTS clients' domain. Multihomed DOTS clients must be able to select the appropriate DOTS server(s) to which a mitigation request is to be sent. The method for selecting the appropriate DOTS server in a multihomed environment is out of scope for this document.

DOTSプロトコルは、少なくとも、DOTSクライアントが疑わしい攻撃に対する防御の実装を要求できるようにする必要があります。この防御は、DOTSサーバーによって調整され、ローカルオペレーターの要求に応じてドメイン内またはドメイン間のシグナリングを含めることができます。 DOTSクライアントは、同様に援助要請を撤回できる必要があります。 DOTSは、DOTSクライアントからのヘルプ要求の正当化を必要とせず、DOTSクライアントがヘルプ要求の撤回を正当化する必要もありません。決定はDOTSクライアントのドメインに対してローカルです。マルチホームDOTSクライアントは、軽減要求の送信先となる適切なDOTSサーバーを選択できる必要があります。マルチホーム環境で適切なDOTSサーバーを選択する方法は、このドキュメントの範囲外です。

DOTS protocol implementations face competing operational goals when maintaining this bidirectional communication stream. On the one hand, DOTS must include measures to ensure message confidentiality, integrity, authenticity, and replay protection to keep the protocols from becoming additional vectors for the very attacks it is meant to help fight off. On the other hand, the protocol must be resilient under extremely hostile network conditions, providing continued contact between DOTS agents even as attack traffic saturates the link. Such resiliency may be developed several ways, but characteristics such as small message size, asynchronous notifications, redundant message delivery, and minimal connection overhead (when possible, given local network policy) will tend to contribute to the robustness demanded by a viable DOTS protocol. Operators of peer DOTS-enabled domains may enable either quality-of-service or class-of-service traffic tagging to increase the probability of successful DOTS signal delivery, but DOTS does not require such policies be in place and should be viable in their absence.

DOTSプロトコルの実装は、この双方向通信ストリームを維持するときに、競合する運用目標に直面します。一方で、DOTSには、メッセージの機密性、完全性、信頼性、およびリプレイ保護を確実にして、プロトコルが攻撃を阻止するための追加のベクターになるのを防ぐための対策を含める必要があります。一方、攻撃的なトラフィックがリンクを飽和させたとしても、プロトコルは非常に悪意のあるネットワーク条件下で回復力があり、DOTSエージェント間の継続的な接続を提供する必要があります。このような復元力はいくつかの方法で開発できますが、メッセージサイズが小さい、非同期通知、冗長なメッセージ配信、最小限の接続オーバーヘッド(可能な場合はローカルネットワークポリシーを考慮)などの特性が、実行可能なDOTSプロトコルで要求される堅牢性に寄与する傾向があります。ピアDOTS対応ドメインのオペレーターは、サービス品質またはサービスクラスのトラフィックタグ付けを有効にして、DOTS信号が正常に配信される確率を高めることができますが、DOTSでは、そのようなポリシーを設定する必要はなく、不在でも実行可能である必要があります。 。

The DOTS server and client must also have some standardized method of defining the scope of any mitigation, as well as managing other mitigation-related configurations.


Finally, DOTS should be sufficiently extensible to meet future needs in coordinated attack defense, although this consideration is necessarily superseded by the other operational requirements.


2.1. General Requirements
2.1. 一般的な要件

GEN-001 Extensibility: Protocols and data models developed as part of DOTS MUST be extensible in order to keep DOTS adaptable to proprietary DDoS defenses. Future extensions MUST be backward compatible. Implementations of older protocol versions MUST ignore optional information added to DOTS messages as part of newer protocol versions. Implementations of older protocol versions MUST reject DOTS messages carrying mandatory information as part of newer protocol versions.


GEN-002 Resilience and Robustness: The signaling protocol MUST be designed to maximize the probability of signal delivery even under the severely constrained network conditions caused by attack traffic. Additional means to enhance the resilience of DOTS protocols, including when multiple DOTS servers are provisioned to the DOTS clients, SHOULD be considered. The protocol MUST be resilient, that is, continue operating despite message loss and out-of-order or redundant message delivery. In support of signaling protocol robustness, DOTS signals SHOULD be conveyed over transport and application protocols not susceptible to head-of-line blocking. These requirements are at SHOULD strength to handle middle-boxes and firewall traversal.


GEN-003 Bulk Data Exchange: Infrequent bulk data exchange between DOTS agents can also significantly augment attack response coordination, permitting such tasks as population of drop- or accept-listed source addresses, address or prefix group aliasing, exchange of incident reports, and other hinting or configuration supplementing attack responses.


As the resilience requirements for the DOTS signal channel mandate a small signal message size, a separate, secure data channel utilizing a reliable transport protocol MUST be used for bulk data exchange. However, reliable bulk data exchange may not be possible during attacks causing network congestion.


GEN-004 Mitigation Hinting: DOTS clients may have access to attack details that can be used to inform mitigation techniques. Example attack details might include locally collected fingerprints for an on-going attack, or anticipated or active attack focal points based on other threat intelligence. DOTS clients MAY send mitigation hints derived from attack details to DOTS servers, with the full understanding that the DOTS server MAY ignore mitigation hints. Mitigation hints MUST be transmitted across the signal channel, as the data channel may not be functional during an attack. DOTS-server handling of mitigation hints is implementation-specific.

GEN-004軽減ヒント:DOTSクライアントは、軽減技術に通知するために使用できる攻撃の詳細にアクセスできます。攻撃の詳細の例には、進行中の攻撃のためにローカルに収集されたフィンガープリント、または他の脅威インテリジェンスに基づいて予想されるまたはアクティブな攻撃の焦点が含まれる場合があります。 DOTSクライアントは、DOTSサーバーが緩和ヒントを無視してもよいことを完全に理解した上で、攻撃の詳細から導出された緩和ヒントをDOTSサーバーに送信してもよい(MAY)。攻撃中にデータチャネルが機能しない可能性があるため、軽減のヒントを信号チャネルを介して送信する必要があります。緩和のヒントのDOTSサーバー処理は実装固有です。

GEN-005 Loop Handling: In certain scenarios, typically involving misconfiguration of DNS or routing policy, it may be possible for communication between DOTS agents to loop. Signal and data channel implementations should be prepared to detect and terminate such loops to prevent service disruption.


2.2. Signal Channel Requirements
2.2. 信号チャネルの要件

SIG-001 Use of Common Transport Protocols: DOTS MUST operate over common, widely deployed and standardized transport protocols. While connectionless transport such as the User Datagram Protocol (UDP) [RFC768] SHOULD be used for the signal channel, the Transmission Control Protocol (TCP) [RFC793] MAY be used if necessary due to network policy or middlebox capabilities or configurations.


SIG-002 Sub-MTU Message Size: To avoid message fragmentation and the consequently decreased probability of message delivery over a congested link, signaling protocol message size MUST be kept under the signaling Path Maximum Transmission Unit (PMTU), including the byte overhead of any encapsulation, transport headers, and transport- or message-level security. If the total message size exceeds the PMTU, the DOTS agent MUST split the message into separate messages; for example, the list of mitigation scope types could be split into multiple lists and each list conveyed in a new message.


DOTS agents can attempt to learn PMTU using the procedures discussed in [IP-FRAG-FRAGILE]. If the PMTU cannot be discovered, DOTS agents MUST assume a PMTU of 1280 bytes, as IPv6 requires that every link in the Internet have an MTU of 1280 octets or greater as specified in [RFC8200]. If IPv4 support on legacy or otherwise unusual networks is a consideration and the PMTU is unknown, DOTS implementations MAY assume a PMTU of 576 bytes for IPv4 datagrams, as every IPv4 host must be capable of receiving a packet whose length is equal to 576 bytes as discussed in [RFC791] and [RFC1122].

DOTSエージェントは、[IP-FRAG-FRAGILE]で説明されている手順を使用してPMTUの学習を試みることができます。 PMTUが発見できない場合、IPv6ではインターネットのすべてのリンクに[RFC8200]で指定されている1280オクテット以上のMTUが必要であるため、DOTSエージェントは1280バイトのPMTUを想定する必要があります。レガシーネットワークまたは通常とは異なるネットワークでのIPv4サポートが考慮され、PMTUが不明である場合、すべてのIPv4ホストは長さが576バイトのパケットを受信できる必要があるため、DOTS実装はIPv4データグラムに対して576バイトのPMTUを想定できます。 [RFC791]と[RFC1122]で議論されています。

SIG-003 Bidirectionality: To support peer health detection, to maintain an active signal channel, and to increase the probability of signal delivery during an attack, the signal channel MUST be bidirectional, with client and server transmitting signals to each other at regular intervals regardless of any client request for mitigation. The bidirectional signal channel MUST support unidirectional messaging to enable notifications between DOTS agents.


SIG-004 Channel Health Monitoring: DOTS agents MUST support exchange of heartbeat messages over the signal channel to monitor channel health. These keep-alives serve to maintain any on-path NAT or Firewall bindings to avoid cryptographic handshake for new mitigation requests. The heartbeat interval during active mitigation could be negotiable based on NAT/Firewall characteristics. Absent information about the NAT/Firewall characteristics, DOTS agents need to ensure its on-path NAT or Firewall bindings do not expire, by using the keep-alive frequency discussed in Section 3.5 of [RFC8085].

SIG-004チャネルヘルスモニタリング:DOTSエージェントは、チャネルヘルスをモニタリングするために、シグナルチャネルを介したハートビートメッセージの交換をサポートする必要があります。これらのキープアライブは、新しい緩和要求に対する暗号化ハンドシェイクを回避するために、パス上のNATまたはファイアウォールバインディングを維持するのに役立ちます。アクティブな軽減中のハートビート間隔は、NAT /ファイアウォールの特性に基づいて交渉可能です。 NAT /ファイアウォールの特性に関する情報がない場合、DOTSエージェントは、[RFC8085]のセクション3.5で説明されているキープアライブ頻度を使用して、オンパスNATまたはファイアウォールバインディングが期限切れにならないようにする必要があります。

To support scenarios in which loss of heartbeat is used to trigger mitigation, and to keep the channel active, DOTS servers MUST solicit heartbeat exchanges after successful mutual authentication. When DOTS agents are exchanging heartbeats and no mitigation request is active, either agent MAY request changes to the heartbeat rate. For example, a DOTS server might want to reduce heartbeat frequency or cease heartbeat exchanges when an active DOTS client has not requested mitigation, in order to control load.

ハートビートの損失を使用して緩和をトリガーするシナリオをサポートし、チャネルをアクティブに保つために、DOTSサーバーは、相互認証が成功した後にハートビート交換を要求する必要があります。 DOTSエージェントがハートビートを交換していて、軽減リクエストがアクティブでない場合、どちらのエージェントもハートビートレートの変更をリクエストできます(MAY)。たとえば、負荷を制御するために、アクティブなDOTSクライアントが軽減を要求していない場合、DOTSサーバーはハートビートの頻度を減らしたり、ハートビートの交換を停止したりできます。

Following mutual authentication, a signal channel MUST be considered active until a DOTS agent explicitly ends the session. When no attack traffic is present, the signal channel MUST be considered active until either DOTS agent fails to receive heartbeats from the other peer after a mutually agreed upon retransmission procedure has been exhausted. Peer DOTS agents MUST regularly send heartbeats to each other while a mitigation request is active. Because heartbeat loss is much more likely during volumetric attack, DOTS agents SHOULD avoid signal channel termination when mitigation is active and heartbeats are not received by either DOTS agent for an extended period. The exception circumstances to terminating the signal channel session during active mitigation are discussed below:


* To handle a possible DOTS server restart or crash, the DOTS clients MAY attempt to establish a new signal channel session but MUST continue to send heartbeats on the current session so that the DOTS server knows the session is still alive. If the new session is successfully established, the DOTS client can terminate the current session.

* 可能なDOTSサーバーの再起動またはクラッシュを処理するために、DOTSクライアントは新しい信号チャネルセッションの確立を試みてもかまいませんが、現在のセッションでハートビートを送信し続けて、DOTSサーバーがセッションがまだ存続していることを認識している必要があります。新しいセッションが正常に確立されると、DOTSクライアントは現在のセッションを終了できます。

* DOTS servers are assumed to have the ability to monitor the attack, using feedback from the mitigator and other available sources, and MAY use the absence of attack traffic and lack of client heartbeats as an indication the signal channel is defunct.

* DOTSサーバーは、緩和策やその他の利用可能なソースからのフィードバックを使用して、攻撃を監視する機能を持っていると想定され、信号チャネルが機能していないことを示すものとして、攻撃トラフィックの欠如とクライアントハートビートの欠如を使用してもよい(MAY)。

SIG-005 Channel Redirection: In order to increase DOTS operational flexibility and scalability, DOTS servers SHOULD be able to redirect DOTS clients to another DOTS server at any time. DOTS clients MUST NOT assume the redirection target DOTS server shares security state with the redirecting DOTS server. DOTS clients are free to attempt abbreviated security negotiation methods supported by the protocol, such as DTLS session resumption, but MUST be prepared to negotiate new security state with the redirection target DOTS server. The redirection DOTS server and redirecting DOTS server MUST belong to the same administrative domain.

SIG-005チャネルリダイレクト:DOTS操作の柔軟性とスケーラビリティを向上させるために、DOTSサーバーはいつでもDOTSクライアントを別のDOTSサーバーにリダイレクトできる必要があります(SHOULD)。 DOTSクライアントは、リダイレクト先のDOTSサーバーがリダイレクトするDOTSサーバーとセキュリティ状態を共有していると想定してはなりません(MUST NOT)。 DOTSクライアントは、DTLSセッションの再開など、プロトコルでサポートされている省略されたセキュリティネゴシエーションメソッドを自由に試行できますが、リダイレクト先のDOTSサーバーと新しいセキュリティ状態をネゴシエートする準備をしておく必要があります。リダイレクトDOTSサーバーとリダイレクトDOTSサーバーは、同じ管理ドメインに属している必要があります。

Due to the increased likelihood of packet loss caused by link congestion during an attack, DOTS servers SHOULD NOT redirect while mitigation is enabled during an active attack against a target in the DOTS client's domain.


SIG-006 Mitigation Requests and Status: Authorized DOTS clients MUST be able to request scoped mitigation from DOTS servers. DOTS servers MUST send status to the DOTS clients about mitigation requests. If a DOTS server rejects an authorized request for mitigation, the DOTS server MUST include a reason for the rejection in the status message sent to the client.

SIG-006軽減要求とステータス:承認されたDOTSクライアントは、DOTSサーバーからスコープされた軽減を要求できなければなりません(MUST)。 DOTSサーバーは、緩和要求に関するステータスをDOTSクライアントに送信する必要があります。 DOTSサーバーが緩和のための承認された要求を拒否する場合、DOTSサーバーは拒否の理由をクライアントに送信されるステータスメッセージに含める必要があります。

DOTS servers MUST regularly send mitigation status updates to authorized DOTS clients that have requested and been granted mitigation. If unreliable transport is used for the signal channel protocol, due to the higher likelihood of packet loss during a DDoS attack, DOTS servers need to send the mitigation status multiple times at regular intervals following the data transmission guidelines discussed in Section 3.1.3 of [RFC8085].

DOTSサーバーは、軽減を要求して承認された承認済みのDOTSクライアントに、軽減ステータスの更新を定期的に送信する必要があります。信号チャネルプロトコルに信頼性の低いトランスポートが使用されている場合、DDoS攻撃中にパケットが失われる可能性が高いため、DOTSサーバーは、[3.1.3のセクション3.1.3で説明されているデータ送信ガイドラインに従って、定期的に複数の緩和ステータスを送信する必要があります。 RFC8085]。

When DOTS client-requested mitigation is active, DOTS server status messages MUST include the following mitigation metrics:


* Total number of packets blocked by the mitigation

* 緩和策によってブロックされたパケットの総数

* Current number of packets per second blocked

* 現在ブロックされている1秒あたりのパケット数

* Total number of bytes blocked

* ブロックされた合計バイト数

* Current number of bytes per second blocked

* 現在ブロックされている1秒あたりのバイト数

DOTS clients MAY take these metrics into account when determining whether to ask the DOTS server to cease mitigation.


A DOTS client MAY withdraw a mitigation request at any time regardless of whether mitigation is currently active. The DOTS server MUST immediately acknowledge a DOTS client's request to stop mitigation.

DOTSクライアントは、緩和が現在アクティブであるかどうかに関係なく、いつでも緩和要求を取り消す場合があります。 DOTSサーバーは、緩和を停止するというDOTSクライアントの要求をただちに確認する必要があります。

To protect against route or DNS flapping caused by a client rapidly toggling mitigation, and to dampen the effect of oscillating attacks, DOTS servers MAY allow mitigation to continue for a limited period after acknowledging a DOTS client's withdrawal of a mitigation request. During this period, DOTS server status messages SHOULD indicate that mitigation is active but terminating. DOTS clients MAY reverse the mitigation termination during this active-but-terminating period with a new mitigation request for the same scope. The DOTS server MUST treat this request as a mitigation lifetime extension (see SIG-007).

クライアントが緩和を迅速に切り替えることによって引き起こされるルートまたはDNSフラッピングから保護し、振動攻撃の影響を弱めるために、DOTSサーバーは、緩和要求の撤回をDOTSクライアントが確認した後、緩和が限られた期間継続することを許可する場合があります。この期間中、DOTSサーバーステータスメッセージは、軽減がアクティブであるが終了中であることを示す必要があります(SHOULD)。 DOTSクライアントは、同じスコープに対する新しい緩和要求を使用して、このアクティブであるが終了する期間中に緩和の終了を元に戻すことができます。 DOTSサーバーは、この要求を緩和存続期間延長として扱う必要があります(SIG-007を参照)。

The initial active-but-terminating period is both implementation-and deployment-specific, but SHOULD be sufficiently long enough to absorb latency incurred by route propagation. If a DOTS client refreshes the mitigation before the active-but-terminating period elapses, the DOTS server MAY increase the active-but-terminating period up to a maximum of 300 seconds (5 minutes). After the active-but-terminating period elapses, the DOTS server MUST treat the mitigation as terminated, as the DOTS client is no longer responsible for the mitigation.

最初のアクティブですが終了する期間は、実装と展開の両方に固有ですが、ルートの伝播によって発生するレイテンシを吸収するのに十分な長さにする必要があります。 DOTSクライアントがアクティブであるが終了する期間が経過する前に緩和策を更新する場合、DOTSサーバーはアクティブであるが終了する期間を最大300秒(5分)まで延長してもよい(MAY)。アクティブであるが終了する期間が経過した後、DOTSクライアントは緩和の責任を負わないため、DOTSサーバーは緩和を終了したものとして扱う必要があります。

SIG-007 Mitigation Lifetime: DOTS servers MUST support mitigations for a negotiated time interval and MUST terminate a mitigation when the lifetime elapses. DOTS servers also MUST support renewal of mitigation lifetimes in mitigation requests from DOTS clients, allowing clients to extend mitigation as necessary for the duration of an attack.

SIG-007緩和ライフタイム:DOTSサーバーは、ネゴシエートされた時間間隔の緩和をサポートしなければならず、ライフタイムが経過したときに緩和を終了しなければなりません(MUST)。 DOTSサーバーは、DOTSクライアントからの軽減リクエストの軽減ライフタイムの更新もサポートする必要があります。これにより、クライアントは攻撃の持続期間中、必要に応じて軽減を延長できます。

DOTS servers MUST treat a mitigation terminated due to lifetime expiration exactly as if the DOTS client originating the mitigation had asked to end the mitigation, including the active-but-terminating period, as described above in SIG-005.


DOTS clients MUST include a mitigation lifetime in all mitigation requests.


DOTS servers SHOULD support indefinite mitigation lifetimes, enabling architectures in which the mitigator is always in the traffic path to the resources for which the DOTS client is requesting protection. DOTS clients MUST be prepared to not be granted mitigations with indefinite lifetimes. DOTS servers MAY refuse mitigations with indefinite lifetimes for policy reasons. The reasons themselves are out of scope for this document. If the DOTS server does not grant a mitigation request with an indefinite mitigation lifetime, it MUST set the lifetime to a value that is configured locally. That value MUST be returned in a reply to the requesting DOTS client.

DOTSサーバーは無期限の軽減ライフタイムをサポートする必要があり(SHOULD)、軽減者が常にDOTSクライアントが保護を要求しているリソースへのトラフィックパスにあるアーキテクチャを有効にします。 DOTSクライアントは、ライフタイムが無期限の緩和策が許可されないように準備する必要があります。 DOTSサーバーは、ポリシー上の理由により、ライフタイムが無期限の緩和策を拒否する場合があります。理由自体は、このドキュメントの範囲外です。 DOTSサーバーが無期限の緩和の有効期間を含む緩和要求を許可しない場合、サーバーは有効期間をローカルに構成されている値に設定する必要があります。その値は、要求しているDOTSクライアントへの応答で返されなければなりません。

SIG-008 Mitigation Scope: DOTS clients MUST indicate desired mitigation scope. The scope type will vary depending on the resources requiring mitigation. All DOTS agent implementations MUST support the following required scope types:


* IPv4 prefixes [RFC4632]

* IPv4プレフィックス[RFC4632]

* IPv6 prefixes [RFC4291] [RFC5952]

* IPv6プレフィックス[RFC4291] [RFC5952]

* Domain names [RFC1035]

* ドメイン名[RFC1035]

The following mitigation scope type is OPTIONAL:


* Uniform Resource Identifiers [RFC3986]

* Uniform Resource Identifiers [RFC3986]

DOTS servers MUST be able to resolve domain names and (when supported) URIs. How name resolution is managed on the DOTS server is implementation-specific.

DOTSサーバーは、ドメイン名と(サポートされている場合)URIを解決できる必要があります。 DOTSサーバーでの名前解決の管理方法は、実装によって異なります。

DOTS agents MUST support mitigation scope aliases, allowing DOTS clients and servers to refer to collections of protected resources by an opaque identifier created through the data channel, direct configuration, or other means. Domain name and URI mitigation scopes may be thought of as a form of scope alias in which the addresses to which the domain name or URI resolve represent the full scope of the mitigation.


If there is additional information available narrowing the scope of any requested attack response, such as targeted port range, protocol, or service, DOTS clients SHOULD include that information in client mitigation requests. DOTS clients MAY also include additional attack details. DOTS servers MAY ignore such supplemental information when enabling countermeasures on the mitigator.

対象となるポート範囲、プロトコル、サービスなど、要求された攻撃応答の範囲を狭める追加情報がある場合、DOTSクライアントはその情報をクライアントの緩和要求に含める必要があります(SHOULD)。 DOTSクライアントには、追加の攻撃の詳細も含まれる場合があります。 DOTSサーバーは、緩和策で対策を有効にするときに、そのような補足情報を無視する場合があります。

As an active attack evolves, DOTS clients MUST be able to adjust as necessary the scope of requested mitigation by refining the scope of resources requiring mitigation.


A DOTS client may obtain the mitigation scope through direct provisioning or through implementation-specific methods of discovery. DOTS clients MUST support at least one mechanism to obtain mitigation scope.

DOTSクライアントは、直接プロビジョニングを通じて、または実装固有の検出方法を通じて、軽減範囲を取得できます。 DOTSクライアントは、軽減範囲を取得するために少なくとも1つのメカニズムをサポートする必要があります。

SIG-009 Mitigation Efficacy: When a mitigation request is active, DOTS clients MUST be able to transmit a metric of perceived mitigation efficacy to the DOTS server. DOTS servers MAY use the efficacy metric to adjust countermeasures activated on a mitigator on behalf of a DOTS client.

SIG-009緩和効果:緩和要求がアクティブな場合、DOTSクライアントは、認識された緩和効果のメトリックをDOTSサーバーに送信できなければなりません(MUST)。 DOTSサーバーは、有効性メトリックを使用して、DOTSクライアントに代わって緩和策でアクティブ化された対策を調整できます。

SIG-010 Conflict Detection and Notification: Multiple DOTS clients controlled by a single administrative entity may send conflicting mitigation requests as a result of misconfiguration, operator error, or compromised DOTS clients. DOTS servers in the same administrative domain attempting to honor conflicting requests may flap network route or DNS information, degrading the networks attempting to participate in attack response with the DOTS clients. DOTS servers in a single administrative domain SHALL detect such conflicting requests and SHALL notify the DOTS clients in conflict. The notification MUST indicate the nature and scope of the conflict, for example, the overlapping prefix range in a conflicting mitigation request.


SIG-011 Network Address Translator Traversal: DOTS clients may be deployed behind a Network Address Translator (NAT) and need to communicate with DOTS servers through the NAT. DOTS protocols MUST therefore be capable of traversing NATs.


If UDP is used as the transport for the DOTS signal channel, all considerations in "Middlebox Traversal Guidelines" in [RFC8085] apply to DOTS. Regardless of transport, DOTS protocols MUST follow established best common practices established in BCP 127 for NAT traversal [RFC4787] [RFC6888] [RFC7857].

UDPがDOTS信号チャネルのトランスポートとして使用される場合、[RFC8085]の「ミドルボックストラバーサルガイドライン」のすべての考慮事項がDOTSに適用されます。トランスポートに関係なく、DOTSプロトコルは、NATトラバーサル[RFC4787] [RFC6888] [RFC7857]のためにBCP 127で確立された確立されたベストコモンプラクティスに従う必要があります。

2.3. Data Channel Requirements
2.3. データチャネルの要件

The data channel is intended to be used for bulk data exchanges between DOTS agents. Unlike the signal channel, the data channel is not expected to be constructed to deal with attack conditions. As the primary function of the data channel is data exchange, a reliable transport is required in order for DOTS agents to detect data delivery success or failure.


The data channel provides a protocol for DOTS configuration and management. For example, a DOTS client may submit to a DOTS server a collection of prefixes it wants to refer to by alias when requesting mitigation, to which the server would respond with a success status and the new prefix group alias, or an error status and message in the event the DOTS client's data channel request failed.

データチャネルは、DOTSの構成と管理のためのプロトコルを提供します。たとえば、DOTSクライアントは、軽減を要求するときにエイリアスで参照したいプレフィックスのコレクションをDOTSサーバーに送信し、サーバーは、成功ステータスと新しいプレフィックスグループエイリアス、またはエラーステータスとメッセージで応答します。 DOTSクライアントのデータチャネル要求が失敗した場合。

DATA-001 Reliable transport: Messages sent over the data channel MUST be delivered reliably in the order sent.


DATA-003 Resource Configuration: To help meet the general and signal channel requirements in Sections 2.1 and 2.2, DOTS server implementations MUST provide an interface to configure resource identifiers, as described in SIG-008. DOTS server implementations MAY expose additional configurability. Additional configurability is implementation-specific.

DATA-003リソース構成:セクション2.1および2.2の一般および信号チャネル要件を満たすために、SIG-008で説明されているように、DOTSサーバー実装はリソース識別子を構成するためのインターフェースを提供する必要があります。 DOTSサーバーの実装は、追加の構成可能性を公開する場合があります。追加の構成可能性は実装固有です。

DATA-004 Policy Management: DOTS servers MUST provide methods for DOTS clients to manage drop- and accept-lists of traffic destined for resources belonging to a client.


For example, a DOTS client should be able to create a drop- or accept-list entry, retrieve a list of current entries from either list, update the content of either list, and delete entries as necessary.


How a DOTS server authorizes DOTS client management of drop- and accept-list entries is implementation-specific.


2.4. Security Requirements
2.4. セキュリティ要件

DOTS must operate within a particularly strict security context, as an insufficiently protected signal or data channel may be subject to abuse, enabling or supplementing the very attacks DOTS purports to mitigate.


SEC-001 Peer Mutual Authentication: DOTS agents MUST authenticate each other before a DOTS signal or data channel is considered valid. The method of authentication is not specified in this document but should follow current IETF best practices [RFC7525] with respect to any cryptographic mechanisms to authenticate the remote peer.


SEC-002 Message Confidentiality, Integrity, and Authenticity: DOTS protocols MUST take steps to protect the confidentiality, integrity, and authenticity of messages sent between client and server. While specific transport- and message-level security options are not specified, the protocols MUST follow current IETF best practices [RFC7525] for encryption and message authentication. Client-domain DOTS gateways are more trusted than DOTS clients, while server-domain DOTS gateways and DOTS servers share the same level of trust. A security mechanism at the transport layer (TLS or DTLS) is thus adequate to provide security between peer DOTS agents.


In order for DOTS protocols to remain secure despite advancements in cryptanalysis and traffic analysis, DOTS agents MUST support secure negotiation of the terms and mechanisms of protocol security, subject to the interoperability and signal message size requirements in Section 2.2.


While the interfaces between downstream DOTS server and upstream DOTS client within a DOTS gateway are implementation-specific, those interfaces nevertheless MUST provide security equivalent to that of the signal channels bridged by gateways in the signaling path. For example, when a DOTS gateway consisting of a DOTS server and DOTS client is running on the same logical device, the two DOTS agents could be implemented within the same process security boundary.


SEC-003 Data Privacy and Integrity: Transmissions over the DOTS protocols are likely to contain operationally or privacy-sensitive information or instructions from the remote DOTS agent. Theft, modification, or replay of message transmissions could lead to information leaks or malicious transactions on behalf of the sending agent (see Section 4). Consequently, data sent over the DOTS protocols MUST be encrypted using secure transports (TLS or DTLS). DOTS servers MUST enable means to prevent leaking operationally or privacy-sensitive data. Although administrative entities participating in DOTS may detail what data may be revealed to third-party DOTS agents, such considerations are not in scope for this document.

SEC-003データのプライバシーと整合性:DOTSプロトコルを介した送信には、リモートのDOTSエージェントからの操作上またはプライバシー上の機密情報や指示が含まれている可能性があります。メッセージ送信の盗難、変更、または再生は、送信エージェントに代わって情報漏洩または悪意のあるトランザクションにつながる可能性があります(セクション4を参照)。したがって、DOTSプロトコルを介して送信されるデータは、セキュアなトランスポート(TLSまたはDTLS)を使用して暗号化する必要があります。 DOTSサーバーは、運用上またはプライバシーに敏感なデータの漏洩を防ぐ手段を有効にする必要があります。 DOTSに参加している管理エンティティは、サードパーティのDOTSエージェントに公開される可能性のあるデータについて詳しく説明している場合がありますが、そのような考慮事項はこのドキュメントの範囲外です。

SEC-004 Message Replay Protection: To prevent a passive attacker from capturing and replaying old messages, and thereby potentially disrupting or influencing the network policy of the receiving DOTS agent's domain, DOTS protocols MUST provide a method for replay detection and prevention.


Within the signal channel, messages MUST be uniquely identified such that replayed or duplicated messages can be detected and discarded. Unique mitigation requests MUST be processed at most once.


SEC-005 Authorization: DOTS servers MUST authorize all messages from DOTS clients that pertain to mitigation, configuration, filtering, or status.


DOTS servers MUST reject mitigation requests with scopes that the DOTS client is not authorized to manage.


Likewise, DOTS servers MUST refuse to allow creation, modification, or deletion of scope aliases and drop- or accept-lists when the DOTS client is unauthorized.


The modes of authorization are implementation-specific.


2.5. Data Model Requirements
2.5. データモデルの要件

A well-structured DOTS data model is critical to the development of successful DOTS protocols.


DM-001 Structure: The data-model structure for the DOTS protocol MAY be described by a single module or be divided into related collections of hierarchical modules and submodules. If the data model structure is split across modules, those distinct modules MUST allow references to describe the overall data model's structural dependencies.


DM-002 Versioning: To ensure interoperability between DOTS protocol implementations, data models MUST be versioned. How the protocols represent data-model versions is not defined in this document.


DM-003 Mitigation Status Representation: The data model MUST provide the ability to represent a request for mitigation and the withdrawal of such a request. The data model MUST also support a representation of currently-requested mitigation status, including failures and their causes.


DM-004 Mitigation Scope Representation: The data model MUST support representation of a requested mitigation's scope. As mitigation scope may be represented in several different ways, per SIG-008, the data model MUST include extensible representation of mitigation scope.

DM-004軽減範囲の表現:データモデルは、要求された軽減の範囲の表現をサポートする必要があります。 SIG-008によると、緩和範囲はいくつかの異なる方法で表すことができるため、データモデルには緩和範囲の拡張可能な表現を含める必要があります。

DM-005 Mitigation Lifetime Representation: The data model MUST support representation of a mitigation request's lifetime, including mitigations with no specified end time.


DM-006 Mitigation Efficacy Representation: The data model MUST support representation of a DOTS client's understanding of the efficacy of a mitigation enabled through a mitigation request.


DM-007 Acceptable Signal Loss Representation: The data model MUST be able to represent the DOTS agent's preference for acceptable signal loss when establishing a signal channel. Measurements of loss might include, but are not restricted to, number of consecutive missed heartbeat messages, retransmission count, or request timeouts.


DM-008 Heartbeat Interval Representation: The data model MUST be able to represent the DOTS agent's preferred heartbeat interval, which the client may include when establishing the signal channel, as described in SIG-003.


DM-009 Relationship to Transport: The DOTS data model MUST NOT make any assumptions about specific characteristics of any given transport into the data model, but instead represent the fields in the model explicitly.


3. Congestion Control Considerations
3. 輻輳制御に関する考慮事項
3.1. Signal Channel
3.1. 信号チャネル

As part of a protocol expected to operate over links affected by DDoS attack traffic, the DOTS signal channel MUST NOT contribute significantly to link congestion. To meet the signal channel requirements above, DOTS signal channel implementations SHOULD support connectionless transports. However, some connectionless transports, when deployed naively, can be a source of network congestion, as discussed in [RFC8085]. Signal channel implementations using such connectionless transports, such as UDP, therefore MUST include a congestion control mechanism.


Signal channel implementations using an IETF standard congestion-controlled transport protocol (like TCP) may rely on built-in transport congestion control support.


3.2. Data Channel
3.2. データチャンネル

As specified in DATA-001, the data channel requires reliable, in-order message delivery. Data channel implementations using an IETF standard congestion-controlled transport protocol may rely on the transport implementation's built-in congestion control mechanisms.

DATA-001で指定されているように、データチャネルには信頼性の高い順序どおりのメッセージ配信が必要です。 IETF標準の輻輳制御トランスポートプロトコルを使用するデータチャネル実装は、トランスポート実装の組み込みの輻輳制御メカニズムに依存する場合があります。

4. Security Considerations
4. セキュリティに関する考慮事項

This document informs future protocols under development and so does not have security considerations of its own. However, operators should be aware of potential risks involved in deploying DOTS. DOTS agent impersonation and signal blocking are discussed here. Additional DOTS security considerations may be found in [DOTS-ARCH] and DOTS protocol documents.


Impersonation of either a DOTS server or a DOTS client could have catastrophic impact on operations in either domain. If an attacker has the ability to impersonate a DOTS client, that attacker can affect policy on the network path to the DOTS client's domain up to and including instantiation of drop-lists blocking all inbound traffic to networks for which the DOTS client is authorized to request mitigation.


Similarly, an impersonated DOTS server may be able to act as a sort of malicious DOTS gateway, intercepting requests from the downstream DOTS client and modifying them before transmission to the DOTS server to inflict the desired impact on traffic to or from the DOTS client's domain. Among other things, this malicious DOTS gateway might receive and discard mitigation requests from the DOTS client, ensuring no requested mitigation is ever applied.


To detect misuse, as detailed in Section 2.4, DOTS implementations require mutual authentication of DOTS agents in order to make agent impersonation more difficult. However, impersonation may still be possible as a result of credential theft, implementation flaws, or DOTS agents being compromised.


To detect compromised DOTS agents, DOTS operators should carefully monitor and audit DOTS agents to detect misbehavior and deter misuse while employing best current practices to secure network communications to reduce attack surface.


Blocking communication between DOTS agents has the potential to disrupt the core function of DOTS, which is to request mitigation of active or expected DDoS attacks. The DOTS signal channel is expected to operate over congested inbound links, and, as described in Section 2.2, the signal channel protocol must be designed for minimal data transfer to reduce the incidence of signal loss.

DOTSエージェント間の通信をブロックすると、アクティブまたは予期されるDDoS攻撃の軽減を要求するDOTSのコア機能を混乱させる可能性があります。 DOTS信号チャネルは、輻輳したインバウンドリンク上で動作することが期待されており、セクション2.2で説明されているように、信号チャネルプロトコルは、信号損失の発生を減らすために最小限のデータ転送用に設計する必要があります。

5. IANA Considerations
5. IANAに関する考慮事項

This document has no IANA actions.


6. References
6. 参考文献
6.1. Normative References
6.1. 引用文献

[RFC768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, <>.

[RFC768] Postel、J。、「User Datagram Protocol」、STD 6、RFC 768、DOI 10.17487 / RFC0768、1980年8月、<>。

[RFC791] Postel, J., "Internet Protocol", STD 5, RFC 791, DOI 10.17487/RFC0791, September 1981, <>.

[RFC791] Postel、J。、「インターネットプロトコル」、STD 5、RFC 791、DOI 10.17487 / RFC0791、1981年9月、<>。

[RFC793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, DOI 10.17487/RFC0793, September 1981, <>.

[RFC793] Postel、J。、「Transmission Control Protocol」、STD 7、RFC 793、DOI 10.17487 / RFC0793、1981年9月、<>。

[RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, November 1987, <>.

[RFC1035] Mockapetris、P。、「ドメイン名-実装および仕様」、STD 13、RFC 1035、DOI 10.17487 / RFC1035、1987年11月、<>。

[RFC1122] Braden, R., Ed., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, DOI 10.17487/RFC1122, October 1989, <>.

[RFC1122] Braden、R。、編、「インターネットホストの要件-通信層」、STD 3、RFC 1122、DOI 10.17487 / RFC1122、1989年10月、< rfc1122>。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <>.

[RFC2119] Bradner、S。、「要件レベルを示すためにRFCで使用するキーワード」、BCP 14、RFC 2119、DOI 10.17487 / RFC2119、1997年3月、< rfc2119>。

[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <>.

[RFC3986] Berners-Lee、T.、Fielding、R。、およびL. Masinter、「Uniform Resource Identifier(URI):Generic Syntax」、STD 66、RFC 3986、DOI 10.17487 / RFC3986、2005年1月、<https:/ />。

[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, February 2006, <>.

[RFC4291] Hinden、R。およびS. Deering、「IPバージョン6アドレッシングアーキテクチャ」、RFC 4291、DOI 10.17487 / RFC4291、2006年2月、<>。

[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August 2006, <>.

[RFC4632] Fuller、V。およびT. Li、「Classless Inter-domain Routing(CIDR):the Internet Address Assignment and Aggregation Plan」、BCP 122、RFC 4632、DOI 10.17487 / RFC4632、2006年8月、<https://>。

[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address Translation (NAT) Behavioral Requirements for Unicast UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January 2007, <>.

[RFC4787]オーデ、F、エド。およびC.ジェニングス、「ユニキャストUDPのネットワークアドレス変換(NAT)動作要件」、BCP 127、RFC 4787、DOI 10.17487 / RFC4787、2007年1月、<> 。

[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 Address Text Representation", RFC 5952, DOI 10.17487/RFC5952, August 2010, <>.

[RFC5952] Kawamura、S. and M. Kawashima、 "A Recommendation for IPv6 Address Text Representation"、RFC 5952、DOI 10.17487 / RFC5952、August 2010、<> 。

[RFC6888] Perreault, S., Ed., Yamagata, I., Miyakawa, S., Nakagawa, A., and H. Ashida, "Common Requirements for Carrier-Grade NATs (CGNs)", BCP 127, RFC 6888, DOI 10.17487/RFC6888, April 2013, <>.

[RFC6888] Perreault、S.、Ed。、Yamagata、I.、Miyakawa、S.、Nakagawa、A.、and H. Ashida、 "Common Requirements for Carrier-Grade NATs(CGNs)"、BCP 127、RFC 6888、 DOI 10.17487 / RFC6888、2013年4月、<>。

[RFC7857] Penno, R., Perreault, S., Boucadair, M., Ed., Sivakumar, S., and K. Naito, "Updates to Network Address Translation (NAT) Behavioral Requirements", BCP 127, RFC 7857, DOI 10.17487/RFC7857, April 2016, <>.

[RFC7857] Penno、R.、Perreault、S.、Boucadair、M.、Ed。、Sivakumar、S.、and K. Naito、 "Updates to Network Address Translation(NAT)Behavioral Requirements"、BCP 127、RFC 7857、 DOI 10.17487 / RFC7857、2016年4月、<>。

[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, March 2017, <>.

[RFC8085] Eggert、L.、Fairhurst、G。、およびG. Shepherd、「UDP使用ガイドライン」、BCP 145、RFC 8085、DOI 10.17487 / RFC8085、2017年3月、< / info / rfc8085>。

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <>.

[RFC8174] Leiba、B。、「RFC 2119キーワードの大文字と小文字のあいまいさ」、BCP 14、RFC 8174、DOI 10.17487 / RFC8174、2017年5月、< rfc8174>。

[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, <>.

[RFC8200] Deering、S。およびR. Hinden、「インターネットプロトコル、バージョン6(IPv6)仕様」、STD 86、RFC 8200、DOI 10.17487 / RFC8200、2017年7月、< / info / rfc8200>。

6.2. Informative References
6.2. 参考引用

[DOTS-ARCH] Mortensen, A., Ed., Reddy, T., Ed., Andreasen, F., Teague, N., and R. Compton, "Distributed-Denial-of-Service Open Threat Signaling (DOTS) Architecture", Work in Progress, draft-ietf-dots-architecture-13, April 2019.

[DOTS-ARCH] Mortensen、A.、Ed。、Reddy、T.、Ed。、Andreasen、F.、Teague、N.、and R. Compton、 "Distributed-Denial-of-Service Open Threat Signaling(DOTS)アーキテクチャ」、Work in Progress、draft-ietf-dots-architecture-13、2019年4月。

[DOTS-USE] Dobbins, R., Migault, D., Fouant, S., Moskowitz, R., Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS Open Threat Signaling", Work in Progress, draft-ietf-dots-use-cases-17, January 2019.

[DOTS-USE] Dobbins、R.、Migault、D.、Fouant、S.、Moskowitz、R.、Teague、N.、Xia、L。、およびK.西塚、「DDoS Open Threat Signalingの使用例」、 Work in Progress、draft-ietf-dots-use-cases-17、2019年1月。

[IP-FRAG-FRAGILE] Bonica, R., Baker, F., Huston, G., Hinden, R., Troan, O., and F. Gont, "IP Fragmentation Considered Fragile", Work in Progress, draft-ietf-intarea-frag-fragile-10, May 2019.

[IP-FRAG-FRAGILE]ボニカ、R。、ベイカー、F。、ヒューストン、G。、ヒンデン、R。、トローン、O。、およびF.ゴント、「IPフラグメンテーションは壊れやすいと考えられている」、進行中の作業、ドラフト- ietf-intarea-frag-fragile-10、2019年5月。

[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, DOI 10.17487/RFC3261, June 2002, <>.

[RFC3261] Rosenberg、J.、Schulzrinne、H.、Camarillo、G.、Johnston、A.、Peterson、J.、Sparks、R.、Handley、M。、およびE. Schooler、「SIP:Session Initiation Protocol」 、RFC 3261、DOI 10.17487 / RFC3261、2002年6月、<>。

[RFC7092] Kaplan, H. and V. Pascual, "A Taxonomy of Session Initiation Protocol (SIP) Back-to-Back User Agents", RFC 7092, DOI 10.17487/RFC7092, December 2013, <>.

[RFC7092] Kaplan、H。およびV. Pascual、「A Sessiononomy of Session Initiation Protocol(SIP)Back-to-Back User Agents」、RFC 7092、DOI 10.17487 / RFC7092、2013年12月、<https://www.rfc>。

[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet Denial-of-Service Considerations", RFC 4732, DOI 10.17487/RFC4732, December 2006, <>.

[RFC4732] Handley、M.、Ed。、Rescorla、E.、Ed。、およびIAB、「インターネットサービス拒否の考慮事項」、RFC 4732、DOI 10.17487 / RFC4732、2006年12月、<https:// www。>。

[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007, <>.

[RFC4949] Shirey、R。、「インターネットセキュリティ用語集、バージョン2」、FYI 36、RFC 4949、DOI 10.17487 / RFC4949、2007年8月、<>。

[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, "Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 2015, <>.

[RFC7525] Sheffer、Y.、Holz、R。、およびP. Saint-Andre、「Transport Layer Security(TLS)およびDatagram Transport Layer Security(DTLS)の安全な使用に関する推奨事項」、BCP 195、RFC 7525、DOI 10.17487 / RFC7525、2015年5月、<>。



Thanks to Roman Danyliw, Matt Richardson, Joe Touch, Scott Bradner, Robert Sparks, Brian Weis, Benjamin Kaduk, Eric Rescorla, Alvaro Retana, Suresh Krishnan, Ben Campbell, Mirja Kuehlewind, and Jon Shallow for their careful reading and feedback.

Roman Danyliw、Matt Richardson、Joe Touch、Scott Bradner、Robert Sparks、Brian Weis、Benjamin Kaduk、Eric Rescorla、Alvaro Retana、Suresh Krishnan、Ben Campbell、Mirja Kuehlewind、Jon Shallowの各氏の注意深い読書とフィードバックに感謝します。



Mohamed Boucadair Orange



Flemming Andreasen Cisco Systems, Inc.

Flemming Andreasen Cisco Systems、Inc.


Dave Dolson Sandvine



Authors' Addresses


Andrew Mortensen Arbor Networks 2727 S. State St. Ann Arbor, MI 48104 United States of America

Andrew Mortensen Arbor Networks 2727 S. State St. Ann Arbor、MI 48104アメリカ合衆国


Tirumaleswar Reddy McAfee Embassy Golf Link Business Park Bangalore, Karnataka 560071 India

Tirumaleswar Reddy McAfee Embassy Golf Link Business Park Ba​​ngalore、Karnatakaインド


Robert Moskowitz Huawei Oak Park, MI 42837 United States of America

Robert Moskowitz Huawei Oak Park、MI 42837アメリカ合衆国