< draft-ietf-dots-signal-channel-14.txt		draft-ietf-dots-signal-channel-15.txt >
	DOTS T. Reddy		DOTS T. Reddy, Ed.
	Internet-Draft McAfee		Internet-Draft McAfee
	Intended status: Standards Track M. Boucadair		Intended status: Standards Track M. Boucadair, Ed.
	Expires: June 21, 2018 Orange		Expires: July 14, 2018 Orange
	P. Patil		P. Patil
	Cisco		Cisco
	A. Mortensen		A. Mortensen
	Arbor Networks, Inc.		Arbor Networks, Inc.
	N. Teague		N. Teague
	Verisign, Inc.		Verisign, Inc.
	December 18, 2017		January 10, 2018
	Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal		Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal
	Channel		Channel
	draft-ietf-dots-signal-channel-14		draft-ietf-dots-signal-channel-15
	Abstract		Abstract
	This document specifies the DOTS signal channel, a protocol for		This document specifies the DOTS signal channel, a protocol for
	signaling the need for protection against Distributed Denial-of-		signaling the need for protection against Distributed Denial-of-
	Service (DDoS) attacks to a server capable of enabling network		Service (DDoS) attacks to a server capable of enabling network
	traffic mitigation on behalf of the requesting client.		traffic mitigation on behalf of the requesting client.
	A companion document defines the DOTS data channel, a separate		A companion document defines the DOTS data channel, a separate
	reliable communication layer for DOTS management and configuration		reliable communication layer for DOTS management and configuration
	skipping to change at page 2, line 20 ¶		skipping to change at page 2, line 20 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on June 21, 2018.		This Internet-Draft will expire on July 14, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2018 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	skipping to change at page 2, line 48 ¶		skipping to change at page 2, line 48 ¶
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Notational Conventions and Terminology . . . . . . . . . . . 5		2. Notational Conventions and Terminology . . . . . . . . . . . 5
	3. Design Overview . . . . . . . . . . . . . . . . . . . . . . . 6		3. Design Overview . . . . . . . . . . . . . . . . . . . . . . . 6
	4. DOTS Signal Channel: Messages & Behaviors . . . . . . . . . . 8		4. DOTS Signal Channel: Messages & Behaviors . . . . . . . . . . 8
	4.1. DOTS Server(s) Discovery . . . . . . . . . . . . . . . . 8		4.1. DOTS Server(s) Discovery . . . . . . . . . . . . . . . . 8
	4.2. CoAP URIs . . . . . . . . . . . . . . . . . . . . . . . . 8		4.2. CoAP URIs . . . . . . . . . . . . . . . . . . . . . . . . 8
	4.3. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . 9		4.3. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . 9
	4.4. DOTS Mitigation Methods . . . . . . . . . . . . . . . . . 10		4.4. DOTS Mitigation Methods . . . . . . . . . . . . . . . . . 10
	4.4.1. Request Mitigation . . . . . . . . . . . . . . . . . 11		4.4.1. Request Mitigation . . . . . . . . . . . . . . . . . 11
	4.4.2. Retrieve Information Related to a Mitigation . . . . 20		4.4.2. Retrieve Information Related to a Mitigation . . . . 22
	4.4.3. Efficacy Update from DOTS Clients . . . . . . . . . . 28		4.4.3. Efficacy Update from DOTS Clients . . . . . . . . . . 31
	4.4.4. Withdraw a Mitigation . . . . . . . . . . . . . . . . 30		4.4.4. Withdraw a Mitigation . . . . . . . . . . . . . . . . 33
	4.5. DOTS Signal Channel Session Configuration . . . . . . . . 32		4.5. DOTS Signal Channel Session Configuration . . . . . . . . 34
	4.5.1. Discover Configuration Parameters . . . . . . . . . . 33		4.5.1. Discover Configuration Parameters . . . . . . . . . . 36
	4.5.2. Convey DOTS Signal Channel Session Configuration . . 37		4.5.2. Convey DOTS Signal Channel Session Configuration . . 39
	4.5.3. Delete DOTS Signal Channel Session Configuration . . 43		4.5.3. Delete DOTS Signal Channel Session Configuration . . 45
	4.6. Redirected Signaling . . . . . . . . . . . . . . . . . . 44		4.6. Redirected Signaling . . . . . . . . . . . . . . . . . . 46
	4.7. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 45		4.7. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 47
	5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . . . 47		5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . . . 49
	5.1. Tree Structure . . . . . . . . . . . . . . . . . . . . . 47		5.1. Tree Structure . . . . . . . . . . . . . . . . . . . . . 49
	5.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 49		5.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 51
	6. Mapping Parameters to CBOR . . . . . . . . . . . . . . . . . 62		6. Mapping Parameters to CBOR . . . . . . . . . . . . . . . . . 66
	7. (D)TLS Protocol Profile and Performance Considerations . . . 63		7. (D)TLS Protocol Profile and Performance Considerations . . . 67
	7.1. (D)TLS Protocol Profile . . . . . . . . . . . . . . . . . 63		7.1. (D)TLS Protocol Profile . . . . . . . . . . . . . . . . . 67
	7.2. (D)TLS 1.3 Considerations . . . . . . . . . . . . . . . . 64		7.2. (D)TLS 1.3 Considerations . . . . . . . . . . . . . . . . 69
	7.3. MTU and Fragmentation . . . . . . . . . . . . . . . . . . 65		7.3. MTU and Fragmentation . . . . . . . . . . . . . . . . . . 70
	8. Mutual Authentication of DOTS Agents & Authorization of DOTS		8. Mutual Authentication of DOTS Agents & Authorization of DOTS
	Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 66		Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 68		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 72
	9.1. DOTS Signal Channel UDP and TCP Port Number . . . . . . . 68		9.1. DOTS Signal Channel UDP and TCP Port Number . . . . . . . 72
	9.2. Well-Known 'dots' URI . . . . . . . . . . . . . . . . . . 68		9.2. Well-Known 'dots' URI . . . . . . . . . . . . . . . . . . 72
	9.3. CoAP Response Code . . . . . . . . . . . . . . . . . . . 68		9.3. CoAP Response Code . . . . . . . . . . . . . . . . . . . 73
	9.4. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 69		9.4. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 73
	9.4.1. Registration Template . . . . . . . . . . . . . . . . 69		9.4.1. Registration Template . . . . . . . . . . . . . . . . 73
	9.4.2. Initial Registry Contents . . . . . . . . . . . . . . 69		9.4.2. Initial Registry Contents . . . . . . . . . . . . . . 74
	9.5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . 75		9.5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . 80
	10. Implementation Status . . . . . . . . . . . . . . . . . . . . 75		10. Implementation Status . . . . . . . . . . . . . . . . . . . . 80
	10.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 76		10.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 81
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 76		11. Security Considerations . . . . . . . . . . . . . . . . . . . 81
	12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 77		12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 82
	13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 77		13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 82
	14. References . . . . . . . . . . . . . . . . . . . . . . . . . 78		14. References . . . . . . . . . . . . . . . . . . . . . . . . . 82
	14.1. Normative References . . . . . . . . . . . . . . . . . . 78		14.1. Normative References . . . . . . . . . . . . . . . . . . 82
	14.2. Informative References . . . . . . . . . . . . . . . . . 80		14.2. Informative References . . . . . . . . . . . . . . . . . 85
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 84		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 89
	1. Introduction		1. Introduction
	A distributed denial-of-service (DDoS) attack is an attempt to make		A distributed denial-of-service (DDoS) attack is an attempt to make
	machines or network resources unavailable to their intended users.		machines or network resources unavailable to their intended users.
	In most cases, sufficient scale can be achieved by compromising		In most cases, sufficient scale can be achieved by compromising
	enough end-hosts and using those infected hosts to perpetrate and		enough end-hosts and using those infected hosts to perpetrate and
	amplify the attack. The victim in this attack can be an application		amplify the attack. The victim in this attack can be an application
	server, a host, a router, a firewall, or an entire network.		server, a host, a router, a firewall, or an entire network.
	skipping to change at page 6, line 36 ¶		skipping to change at page 6, line 36 ¶
	+---------------------+		+---------------------+
	| CoAP |		| CoAP |
	+----------+----------+		+----------+----------+
	| TLS | DTLS |		| TLS | DTLS |
	+----------+----------+		+----------+----------+
	| TCP | UDP |		| TCP | UDP |
	+----------+----------+		+----------+----------+
	| IP |		| IP |
	+---------------------+		+---------------------+
	Figure 3: Abstract Layering of DOTS signal channel over CoAP over		Figure 3: Abstract Layering of DOTS Signal Channel over CoAP over
	(D)TLS		(D)TLS
	By default, a DOTS signal channel MUST run over port number TBD as		By default, a DOTS signal channel MUST run over port number TBD as
	defined in Section 9.1, for both UDP and TCP, unless the DOTS server		defined in Section 9.1, for both UDP and TCP, unless the DOTS server
	has a mutual agreement with its DOTS clients to use a different port		has a mutual agreement with its DOTS clients to use a different port
	number. DOTS clients may alternatively support means to dynamically		number. DOTS clients may alternatively support means to dynamically
	discover the ports used by their DOTS servers. In order to use a		discover the ports used by their DOTS servers. In order to use a
	distinct port number (as opposed to TBD), DOTS clients and servers		distinct port number (as opposed to TBD), DOTS clients and servers
	should support a configurable parameter to supply the port number to		should support a configurable parameter to supply the port number to
	use. The rationale for not using the default port number 5684		use. The rationale for not using the default port number 5684
	skipping to change at page 7, line 33 ¶		skipping to change at page 7, line 33 ¶
	such as errors. In order to allow the use of the same data models,		such as errors. In order to allow the use of the same data models,
	[RFC7951] specifies the JSON encoding of YANG-modeled data. A		[RFC7951] specifies the JSON encoding of YANG-modeled data. A
	similar effort for CBOR is defined in [I-D.ietf-core-yang-cbor]. All		similar effort for CBOR is defined in [I-D.ietf-core-yang-cbor]. All
	parameters in the payload of the DOTS signal channel are mapped to		parameters in the payload of the DOTS signal channel are mapped to
	CBOR types as specified in Section 6.		CBOR types as specified in Section 6.
	From that standpoint, this document specifies a YANG data model for		From that standpoint, this document specifies a YANG data model for
	representing mitigation scopes and DOTS signal channel session		representing mitigation scopes and DOTS signal channel session
	configuration data (Section 5). Representing these data as CBOR data		configuration data (Section 5). Representing these data as CBOR data
	is assumed to follow the rules in [I-D.ietf-core-yang-cbor] or those		is assumed to follow the rules in [I-D.ietf-core-yang-cbor] or those
	in [RFC7951] combined with JSON/CBOR conversion rules in [RFC7049]. .		in [RFC7951] combined with JSON/CBOR conversion rules in [RFC7049].
	In order to prevent fragmentation, DOTS agents must follow the		In order to prevent fragmentation, DOTS agents must follow the
	recommendations documented in Section 4.6 of [RFC7252]. Refer to		recommendations documented in Section 4.6 of [RFC7252]. Refer to
	Section 7.3 for more details.		Section 7.3 for more details.
	DOTS agents MUST support GET, PUT, and DELETE CoAP methods. The		DOTS agents MUST support GET, PUT, and DELETE CoAP methods. The
	payload included in CoAP responses with 2.xx and 3.xx Response Codes		payload included in CoAP responses with 2.xx and 3.xx Response Codes
	MUST be of content type "application/cbor" (Section 5.5.1 of		MUST be of content type "application/cbor" (Section 5.5.1 of
	[RFC7252]). CoAP responses with 4.xx and 5.xx error Response Codes		[RFC7252]). CoAP responses with 4.xx and 5.xx error Response Codes
	MUST include a diagnostic payload (Section 5.5.2 of [RFC7252]). The		MUST include a diagnostic payload (Section 5.5.2 of [RFC7252]). The
	skipping to change at page 9, line 15 ¶		skipping to change at page 9, line 15 ¶
	desired DOTS operation.		desired DOTS operation.
	+-----------------------+----------------+-------------+		+-----------------------+----------------+-------------+
	| Operation | Operation path | Details |		| Operation | Operation path | Details |
	+-----------------------+----------------+-------------+		+-----------------------+----------------+-------------+
	| Mitigation | /v1/mitigate | Section 4.4 |		| Mitigation | /v1/mitigate | Section 4.4 |
	+-----------------------+----------------+-------------+		+-----------------------+----------------+-------------+
	| Session configuration | /v1/config | Section 4.5 |		| Session configuration | /v1/config | Section 4.5 |
	+-----------------------+----------------+-------------+		+-----------------------+----------------+-------------+
	Table 1: Operations and their corresponding URIs		Table 1: Operations and their Corresponding URIs
	4.3. Happy Eyeballs for DOTS Signal Channel		4.3. Happy Eyeballs for DOTS Signal Channel
	[I-D.ietf-dots-requirements] mentions that DOTS agents will have to		[I-D.ietf-dots-requirements] mentions that DOTS agents will have to
	support both connectionless and connection-oriented protocols. As		support both connectionless and connection-oriented protocols. As
	such, the DOTS signal channel is designed to operate with DTLS over		such, the DOTS signal channel is designed to operate with DTLS over
	UDP and TLS over TCP. Further, a DOTS client may acquire a list of		UDP and TLS over TCP. Further, a DOTS client may acquire a list of
	IPv4 and IPv6 addresses (Section 4.1), each of which can be used to		IPv4 and IPv6 addresses (Section 4.1), each of which can be used to
	contact the DOTS server using UDP and TCP. The following specifies		contact the DOTS server using UDP and TCP. The following specifies
	the procedure to follow to select the address family and the		the procedure to follow to select the address family and the
	skipping to change at page 12, line 11 ¶		skipping to change at page 12, line 11 ¶
	server can enable mitigation on behalf of the DOTS client by		server can enable mitigation on behalf of the DOTS client by
	communicating the DOTS client's request to the mitigator and relaying		communicating the DOTS client's request to the mitigator and relaying
	selected mitigator feedback to the requesting DOTS client.		selected mitigator feedback to the requesting DOTS client.
	Header: PUT (Code=0.03)		Header: PUT (Code=0.03)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
			Uri-Path: "cuid=xyz"
	Content-Type: "application/cbor"		Content-Type: "application/cbor"
	{		{
	"mitigation-scope": {		"mitigation-scope": {
	"client-identifier": [
	"string"
	],
	"scope": [		"scope": [
	{		{
	"mitigation-id": integer,		"mitigation-id": integer,
	"target-prefix": [		"target-prefix": [
	"string"		"string"
	],		],
	"target-port-range": [		"target-port-range": [
	{		{
	"lower-port": integer,		"lower-port": integer,
	"upper-port": integer		"upper-port": integer
	skipping to change at page 12, line 47 ¶		skipping to change at page 12, line 45 ¶
	],		],
	"alias-name": [		"alias-name": [
	"string"		"string"
	],		],
	"lifetime": integer		"lifetime": integer
	}		}
	]		]
	}		}
	}		}
	Figure 5: PUT to convey DOTS mitigation requests		Figure 5: PUT to Convey DOTS Mitigation Requests
	The parameters are described below:		The parameters are described below:
	client-identifier: The client identifier MAY be conveyed by a		cuid: Stands for Client Unique Identifier. A unique identifier that
	server-side DOTS gateway to propagate the DOTS client identity		is meant to prevent collisions among DOTS clients from the same
	from the gateway's client-side to the gateway's server-side, and		domain. It MUST be generated by DOTS clients. A variety of
	from the gateway's server-side to the DOTS server. 'client-		methods can be used to generate such identifier, e.g.,
	identifier' MAY be used by the final DOTS server for policy		cryptographic means [RFC4086], mimic the algorithm in [RFC4941],
	enforcement purposes.		prepend a timestamp to a randomly generated identifier, etc.
			Implementations MAY use the form "identifier@host", for example
	The 'client-identifier' value MUST be assigned by the server-side		"7dec-11d0-a765-00a0c91e6bf6@foo.bar.example".
	DOTS gateway in a manner that ensures that there is zero
	probability that the same value will be assigned to a different
	DOTS client. The server-side DOTS gateway MUST conceal
	potentially sensitive DOTS client identity information.
	If aggregating DOTS mitigation requests received from multiple		The CUID is intended to be stable when communicating with a given
	DOTS clients is enabled, the server-side DOTS gateway has to		DOTS server, i.e., the CUID used by a DOTS client SHOULD NOT
	include a list of 'client-identifier' values; each value is		change over time. Distinct CUIDs MAY be used per DOTS server.
	pointing to a unique DOTS client that is in the aggregated list.
	It is out of scope of this document to specify how aggregation is
	implemented by a DOTS gateway.
	The client-identifier attribute MUST NOT be generated and included		DOTS servers MUST treat CUIDs as opaque values and MUST only
	by DOTS clients.		compare CUIDs for equality. That is, DOTS servers must not
			interpret CUIDs. DOTS servers MUST return 4.09 (Conflict) error
			code to a DOTS peer to notify that the CUID is already in-use by
			another DOTS client of the same domain. Upon receipt of that
			error code, a new CUID MUST be generated by the DOTS peer.
	DOTS servers MUST ignore client-identifier attributes that are		Client-domain DOTS gateways MAY rewrite the CUIDs used by internal
	directly supplied by source DOTS clients. This implies that first		DOTS clients. Triggers for such rewriting are out of scope.
	server-side DOTS gateways MUST strip client-identifier attributes
	supplied by DOTS clients. DOTS servers MAY support a
	configuration parameter to identify DOTS gateways that are trusted
	to supply client-identifier attributes.
	This is an optional attribute.		This is a mandatory attribute.
	mitigation-id: Identifier for the mitigation request represented		mitigation-id: Identifier for the mitigation request represented
	with an integer. This identifier MUST be unique for each		with an integer. This identifier MUST be unique for each
	mitigation request bound to the DOTS client, i.e., the		mitigation request bound to the DOTS client, i.e., the
	'mitigation-id' parameter value in the mitigation request needs to		'mitigation-id' parameter value in the mitigation request needs to
	be unique relative to the 'mitigation-id' parameter values of		be unique relative to the 'mitigation-id' parameter values of
	active mitigation requests conveyed from the DOTS client to the		active mitigation requests conveyed from the DOTS client to the
	DOTS server. This identifier MUST be generated by the DOTS		DOTS server. This identifier MUST be generated by the DOTS
	client. This document does not make any assumption about how this		client. This document does not make any assumption about how this
	identifier is generated.		identifier is generated.
	skipping to change at page 15, line 8 ¶		skipping to change at page 14, line 47 ¶
	lifetime: Lifetime of the mitigation request in seconds. The		lifetime: Lifetime of the mitigation request in seconds. The
	RECOMMENDED lifetime of a mitigation request is 3600 seconds (60		RECOMMENDED lifetime of a mitigation request is 3600 seconds (60
	minutes) -- this value was chosen to be long enough so that		minutes) -- this value was chosen to be long enough so that
	refreshing is not typically a burden on the DOTS client, while		refreshing is not typically a burden on the DOTS client, while
	expiring the request where the client has unexpectedly quit in a		expiring the request where the client has unexpectedly quit in a
	timely manner. DOTS clients MUST include this parameter in their		timely manner. DOTS clients MUST include this parameter in their
	mitigation requests. Upon the expiry of this lifetime, and if the		mitigation requests. Upon the expiry of this lifetime, and if the
	request is not refreshed, the mitigation request is removed. The		request is not refreshed, the mitigation request is removed. The
	request can be refreshed by sending the same request again.		request can be refreshed by sending the same request again.
	A lifetime of 0 in a mitigation request is an invalid value.		A lifetime of '0' in a mitigation request is an invalid value.
	A lifetime of negative one (-1) indicates indefinite lifetime for		A lifetime of negative one (-1) indicates indefinite lifetime for
	the mitigation request. The DOTS server MAY refuse indefinite		the mitigation request. The DOTS server MAY refuse indefinite
	lifetime, for policy reasons; the granted lifetime value is		lifetime, for policy reasons; the granted lifetime value is
	returned in the response. DOTS clients MUST be prepared to not be		returned in the response. DOTS clients MUST be prepared to not be
	granted mitigations with indefinite lifetimes.		granted mitigations with indefinite lifetimes.
	The DOTS server MUST always indicate the actual lifetime in the		The DOTS server MUST always indicate the actual lifetime in the
	response and the remaining lifetime in status messages sent to the		response and the remaining lifetime in status messages sent to the
	DOTS client.		DOTS client.
	This is a mandatory attribute.		This is a mandatory attribute.
			In deployments where server-domain DOTS gateways are enabled,
			identity information about the origin source client domain has to be
			supplied to the DOTS server. That information is meant to assist the
			DOTS server to enforce some policies. Figure 6 shows an example of a
			request relayed by a server-domain DOTS gateway.
			Header: PUT (Code=0.03)
			Uri-Host: "host"
			Uri-Path: ".well-known"
			Uri-Path: "dots"
			Uri-Path: "version"
			Uri-Path: "mitigate"
			Uri-Path: "cuid=xyz"
			Content-Type: "application/cbor"
			{
			"mitigation-scope": {
			"client-domain-hash": "string",
			"scope": [
			{
			"mitigation-id": integer,
			"target-prefix": [
			"string"
			],
			"target-port-range": [
			{
			"lower-port": integer,
			"upper-port": integer
			}
			],
			"target-protocol": [
			integer
			],
			"target-fqdn": [
			"string"
			],
			"target-uri": [
			"string"
			],
			"alias-name": [
			"string"
			],
			"lifetime": integer
			}
			]
			}
			}
			Figure 6: PUT to Convey DOTS Mitigation Request as relayed by a
			Server-Domain DOTS Gateway
			The DOTS gateway may add the following parameter:
			client-domain-hash: The client identifier MAY be conveyed by a
			server-domain DOTS gateway to propagate the source domain identity
			from the gateway's client-side to the gateway's server-side, and
			from the gateway's server-side to the DOTS server. 'client-domain-
			hash' MAY be used by the final DOTS server for policy enforcement
			purposes (e.g., enforce a quota on filtering rules).
			The 'client-domain-hash' value MUST be assigned by the server-
			domain DOTS gateway in a manner that ensures that there is zero
			probability that the same value will be assigned to a different
			client domain.
			If the DOTS client is using the certificate provisioned by the
			Enrollment over Secure Transport (EST) server [RFC7030] in the
			DOTS gateway-domain to authenticate itself to the DOTS gateway,
			the 'client-domain-hash' value may be the output of a
			cryptographic hash algorithm whose input is the DER-encoded ASN.1
			representation of the Subject Public Key Info (SPKI) of an X.509
			certificate. In this version of the specification, the
			cryptographic hash algorithm used is SHA-256 [RFC6234]. The
			output of the cryptographic hash algorithm is truncated to 16
			bytes; truncation is done by stripping off the final 16 bytes.
			The truncated output is base64url encoded.
			The 'client-domain-hash' attribute MUST NOT be generated and
			included by DOTS clients.
			DOTS servers MUST ignore 'client-domain-hash' attributes that are
			directly supplied by source DOTS clients or client-domain DOTS
			gateways. This implies that first server-domain DOTS gateways
			MUST strip 'client-domain-hash' attributes supplied by DOTS
			clients. DOTS servers MAY support a configuration parameter to
			identify DOTS gateways that are trusted to supply 'client-domain-
			hash' attributes.
			Only singe-valued 'client-domain-hash' are defined in this
			document.
			This is an optional attribute.
	Because of the complexity to handle partial failure cases, this		Because of the complexity to handle partial failure cases, this
	specification does not allow for including multiple mitigation		specification does not allow for including multiple mitigation
	requests in the same PUT request. Concretely, a DOTS client MUST NOT		requests in the same PUT request. Concretely, a DOTS client MUST NOT
	include multiple 'scope' parameters in the same PUT request.		include multiple 'scope' parameters in the same PUT request.
	The CBOR key values for the parameters are defined in Section 6.		The CBOR key values for the parameters are defined in Section 6.
	Section 9 defines how the CBOR key values can be allocated to		Section 9 defines how the CBOR key values can be allocated to
	standard bodies and vendors.		standard bodies and vendors.
	FQDN and URI mitigation scopes may be thought of as a form of scope		FQDN 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		alias, in which the addresses to which the domain name or URI resolve
	represent the full scope of the mitigation.		represent the full scope of the mitigation.
	In the PUT request at least one of the attributes 'target-prefix' or		In the PUT request at least one of the attributes 'target-prefix' or
	'target-fqdn' or 'target-uri 'or 'alias-name' MUST be present.		'target-fqdn' or 'target-uri 'or 'alias-name' MUST be present.
	Attributes with emty values MUST NOT be present in a request.		Attributes with empty values MUST NOT be present in a request.
	The relative order of two mitigation requests from a DOTS client is		The relative order of two mitigation requests from a DOTS client is
	determined by comparing their respective 'mitigation-id' values. If		determined by comparing their respective 'mitigation-id' values. If
	two mitigation requests have overlapping mitigation scopes, the		two mitigation requests have overlapping mitigation scopes, the
	mitigation request with the highest numeric 'mitigation-id' value		mitigation request with the highest numeric 'mitigation-id' value
	will override the other mitigation request. Two mitigation-ids from		will override the other mitigation request. Two mitigation-ids from
	a DOTS client are overlapping if there is a common IP address, IP		a DOTS client are overlapping if there is a common IP address, IP
	prefix, FQDN, URI, or alias-name. To avoid maintaining a long list		prefix, FQDN, URI, or alias-name. To avoid maintaining a long list
	of overlapping mitigation requests from a DOTS client and avoid		of overlapping mitigation requests from a DOTS client and avoid
	error-prone provisioning of mitigation requests from a DOTS client,		error-prone provisioning of mitigation requests from a DOTS client,
	the overlapped lower numeric 'mitigation-id' MUST be automatically		the overlapped lower numeric 'mitigation-id' MUST be automatically
	deleted and no longer available at the DOTS server.		deleted and no longer available at the DOTS server.
	The Uri-Path option carries a major and minor version nomenclature to		The Uri-Path option carries a major and minor version nomenclature to
	manage versioning and DOTS signal channel in this specification uses		manage versioning and DOTS signal channel in this specification uses
	v1 major version.		v1 major version.
	Figure 6 shows a PUT request example to signal that ports 80, 8080,		Figure 7 shows a PUT request example to signal that ports 80, 8080,
	and 443 used by 2001:db8:6401::1 and 2001:db8:6401::2 servers are		and 443 used by 2001:db8:6401::1 and 2001:db8:6401::2 servers are
	under attack (illustrated in JSON diagnostic notation).		under attack (illustrated in JSON diagnostic notation). The presence
			of 'client-domain-hash' indicates that a server-domain DOTS gateway
			has modified the initial PUT request sent by the DOTS client.
	Header: PUT (Code=0.03)		Header: PUT (Code=0.03)
	Uri-Host: "www.example.com"		Uri-Host: "www.example.com"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "v1"		Uri-Path: "v1"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
			Uri-Path: "cuid=xyz"
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	{		{
	"mitigation-scope": {		"mitigation-scope": {
	"client-identifier": [		"client-domain-hash": "dz6pHjaADkaFTbjr0JGBpw",
	"dz6pHjaADkaFTbjr0JGBpw"
	],
	"scope": [		"scope": [
	{		{
	"mitigation-id": 12332,		"mitigation-id": 12332,
	"target-prefix": [		"target-prefix": [
	"2001:db8:6401::1/128",		"2001:db8:6401::1/128",
	"2001:db8:6401::2/128"		"2001:db8:6401::2/128"
	],		],
	"target-port-range": [		"target-port-range": [
	{		{
	"lower-port": 80		"lower-port": 80
	skipping to change at page 16, line 51 ¶		skipping to change at page 19, line 42 ¶
	}		}
	],		],
	"target-protocol": [		"target-protocol": [
	6		6
	]		]
	}		}
	]		]
	}		}
	}		}
	Figure 6: PUT for DOTS signal		Figure 7: PUT for DOTS Mitigation Request
	The corresponding CBOR encoding format is shown in Figure 7.		The corresponding CBOR encoding format is shown in Figure 8.
	A1 # map(1)		A1 # map(1)
	01 # unsigned(1)		01 # unsigned(1)
	A2 # map(2)		A2 # map(2)
	18 20 # unsigned(32)		18 24 # unsigned(36)
	81 # array(1)
	76 # text(22)		76 # text(22)
	647A3670486A6141446B614654626A72304A47427077 # "dz6pHjaADkaFTbjr0JGBpw"		647A3670486A6141446B614654626A72304A47427077 # "dz6pHjaADkaFTbjr0JGBpw"
	02 # unsigned(2)		02 # unsigned(2)
	81 # array(1)		81 # array(1)
	A4 # map(4)		A4 # map(4)
	03 # unsigned(3)		03 # unsigned(3)
	19 302C # unsigned(12332)		19 302C # unsigned(12332)
	04 # unsigned(4)		18 23 # unsigned(35)
	82 # array(2)		82 # array(2)
	74 # text(20)		74 # text(20)
	323030313A6462383A363430313A3A312F313238 # "2001:db8:6401::1/128"		323030313A6462383A363430313A3A312F313238 # "2001:db8:6401::1/128"
	74 # text(20)		74 # text(20)
	323030313A6462383A363430313A3A322F313238 # "2001:db8:6401::2/128"		323030313A6462383A363430313A3A322F313238 # "2001:db8:6401::2/128"
	05 # unsigned(5)		05 # unsigned(5)
	83 # array(3)		83 # array(3)
	A1 # map(1)		A1 # map(1)
	06 # unsigned(6)		06 # unsigned(6)
	18 50 # unsigned(80)		18 50 # unsigned(80)
	A1 # map(1)		A1 # map(1)
	06 # unsigned(6)		06 # unsigned(6)
	19 01BB # unsigned(443)		19 01BB # unsigned(443)
	A1 # map(1)		A1 # map(1)
	06 # unsigned(6)		06 # unsigned(6)
	19 1F90 # unsigned(8080)		19 1F90 # unsigned(8080)
	08 # unsigned(8)		08 # unsigned(8)
	81 # array(1)		81 # array(1)
	06 # unsigned(6)		06 # unsigned(6)
	Figure 7: PUT for DOTS signal (CBOR)		Figure 8: PUT for DOTS Mitigation Request (CBOR)
	If the DOTS client is using the certificate provisioned by the
	Enrollment over Secure Transport (EST) server [RFC7030] in the DOTS
	gateway-domain to authenticate itself to the DOTS gateway, then the
	'client-identifier' value can be the output of a cryptographic hash
	algorithm whose input is the DER-encoded ASN.1 representation of the
	Subject Public Key Info (SPKI) of an X.509 certificate.
	In this version of the specification, the cryptographic hash
	algorithm used is SHA-256 [RFC6234]. The output of the cryptographic
	hash algorithm is truncated to 16 bytes; truncation is done by
	stripping off the final 16 bytes. The truncated output is base64url
	encoded.
	In both DOTS signal and data channel sessions, the DOTS client MUST		In both DOTS signal and data channel sessions, the DOTS client MUST
	authenticate itself to the DOTS server (Section 8). The DOTS server		authenticate itself to the DOTS server (Section 8). The DOTS server
	may use the algorithm presented in Section 7 of [RFC7589] to derive		may use the algorithm presented in Section 7 of [RFC7589] to derive
	the DOTS client identity or username from the client certificate.		the DOTS client identity or username from the client certificate.
	The DOTS client identity allows the DOTS server to accept mitigation		The DOTS client identity allows the DOTS server to accept mitigation
	requests with scopes that the DOTS client is authorized to manage.		requests with scopes that the DOTS client is authorized to manage.
	The DOTS server couples the DOTS signal and data channel sessions		The DOTS server couples the DOTS signal and data channel sessions
	using the DOTS client identity and the 'client-identifier' parameter		using the DOTS client identity or the 'client-domain-hash' parameter
	value, so the DOTS server can validate whether the aliases conveyed		value, so the DOTS server can validate whether the aliases conveyed
	in the mitigation request were indeed created by the same DOTS client		in the mitigation request were indeed created by the same DOTS client
	using the DOTS data channel session. If the aliases were not created		using the DOTS data channel session. If the aliases were not created
	by the DOTS client, the DOTS server returns 4.00 (Bad Request) in the		by the DOTS client, the DOTS server MUST return 4.00 (Bad Request) in
	response.		the response.
	The DOTS server couples the DOTS signal channel sessions using the		The DOTS server couples the DOTS signal channel sessions using the
	DOTS client identity and the 'client-identifier' parameter value, and		DOTS client identity or the 'client-domain-hash' parameter value, and
	the DOTS server uses 'mitigation-id' parameter value to detect		the DOTS server uses 'mitigation-id' and 'cuid' parameter values to
	duplicate mitigation requests. If the mitigation request contains		detect duplicate mitigation requests. If the mitigation request
	the alias-name and other parameters identifying the target resources		contains the alias-name and other parameters identifying the target
	(such as, 'target-prefix', 'target-port-range', 'target-fqdn', or		resources (such as, 'target-prefix', 'target-port-range', 'target-
	'target-uri'), then the DOTS server appends the parameter values in		fqdn', or 'target-uri'), the DOTS server appends the parameter values
	'alias-name' with the corresponding parameter values in 'target-		in 'alias-name' with the corresponding parameter values in 'target-
	prefix', 'target-port-range', 'target-fqdn', or 'target-uri'.		prefix', 'target-port-range', 'target-fqdn', or 'target-uri'.
	The DOTS server indicates the result of processing the PUT request		The DOTS server indicates the result of processing the PUT request
	using CoAP response codes. CoAP 2.xx codes are success. CoAP 4.xx		using CoAP response codes. CoAP 2.xx codes are success. CoAP 4.xx
	codes are some sort of invalid requests (client errors). COAP 5.xx		codes are some sort of invalid requests (client errors). COAP 5.xx
	codes are returned if the DOTS server has erred or is currently		codes are returned if the DOTS server has erred or is currently
	unavailable to provide mitigation in response to the mitigation		unavailable to provide mitigation in response to the mitigation
	request from the DOTS client.		request from the DOTS client.
	Figure 8 shows an example of a PUT request that is successfully		Figure 9 shows an example of a PUT request that is successfully
	processed (i.e., CoAP 2.xx response codes).		processed by a DOTS server (i.e., CoAP 2.xx response codes).
	{		{
	"mitigation-scope": {		"mitigation-scope": {
	"client-identifier": [		"client-domain-hash": "dz6pHjaADkaFTbjr0JGBpw",
	"string"
	],
	"scope": [		"scope": [
	{		{
	"mitigation-id": 12332,		"mitigation-id": 12332,
	"lifetime": 3600		"lifetime": 3600
	}		}
	]		]
	}		}
	}		}
	Figure 8: 2.xx response body		Figure 9: 2.xx Response Body
	If the request is missing one or more mandatory attributes, or		If the request is missing one or more mandatory attributes, or
	includes multiple 'scope' parameters, or contains invalid or unknown		includes multiple 'scope' parameters, or contains invalid or unknown
	parameters, the DOTS server MUST reply with 4.00 (Bad Request). DOTS		parameters, the DOTS server MUST reply with 4.00 (Bad Request). DOTS
	agents can safely ignore Vendor-Specific parameters they don't		agents can safely ignore Vendor-Specific parameters they don't
	understand.		understand.
	A DOTS server that receives a mitigation request with a lifetime set		A DOTS server that receives a mitigation request with a lifetime set
	to '0' MUST reply with a 4.00 (Bad Request).		to '0' MUST reply with a 4.00 (Bad Request).
	If the DOTS server does not find the 'mitigation-id' parameter value		If the DOTS server does not find the 'mitigation-id' parameter value
	conveyed in the PUT request in its configuration data, it MAY accept		conveyed in the PUT request in its configuration data, it MAY accept
	the mitigation request by sending back a 2.01 (Created) response to		the mitigation request by sending back a 2.01 (Created) response to
	the DOTS client; the DOTS server will consequently try to mitigate		the DOTS client; the DOTS server will consequently try to mitigate
	the attack.		the attack.
	If the DOTS server finds the 'mitigation-id' parameter value conveyed		If the DOTS server finds the 'mitigation-id' parameter value conveyed
	in the PUT request in its configuration data, it MAY update the		in the PUT request in its configuration data bound to that DOTS
	mitigation request, and a 2.04 (Changed) response is returned to		client, it MAY update the mitigation request, and a 2.04 (Changed)
	indicate a successful update of the mitigation request.		response is returned to indicate a successful update of the
			mitigation request.
	If the request is conflicting with an existing mitigation request		If the request is conflicting with an existing mitigation request
	from a different DOTS client, and the DOTS server decides to maintain		from a different DOTS client, and the DOTS server decides to maintain
	the conflicting mitigation request, the DOTS server returns 4.09		the conflicting mitigation request, the DOTS server returns 4.09
	(Conflict) [RFC8132] to the requesting DOTS client. The response		(Conflict) [RFC8132] to the requesting DOTS client. The response
	includes enough information for a DOTS client to recognize the source		includes enough information for a DOTS client to recognize the source
	of the conflict (refer to 'conflict-information' specified in		of the conflict (refer to 'conflict-information' specified in
	Section 4.4.2).		Section 4.4.2).
	For a mitigation request to continue beyond the initial negotiated		For a mitigation request to continue beyond the initial negotiated
	lifetime, the DOTS client has to refresh the current mitigation		lifetime, the DOTS client has to refresh the current mitigation
	request by sending a new PUT request. This PUT request MUST use the		request by sending a new PUT request. This PUT request MUST use the
	same 'mitigation-id' value, and MUST repeat all the other parameters		same 'mitigation-id' value, and MUST repeat all the other parameters
	as sent in the original mitigation request apart from a possible		as sent in the original mitigation request apart from a possible
	change to the lifetime parameter value.		change to the lifetime parameter value.
	The DOTS gateway, which inserted a 'client-identifier' attribute in a		The DOTS gateway, which inserted a 'client-domain-hash' attribute in
	request, MUST strip the 'client-identifier' parameter in the		a request, MUST strip the 'client-domain-hash' parameter in the
	corresponding response before forwarding the response to the DOTS		corresponding response before forwarding the response to the DOTS
	client.		client. If we consider the example depicted in Figure 9, the message
			that will be relayed by the DOTS gateway is shown in Figure 10.
			{
			"mitigation-scope": {
			"scope": [
			{
			"mitigation-id": 12332,
			"lifetime": 3600
			}
			]
			}
			}
			Figure 10: 2.xx Response Body Relayed by a DOTS Gateway
	4.4.2. Retrieve Information Related to a Mitigation		4.4.2. Retrieve Information Related to a Mitigation
	A GET request is used by a DOTS client to retrieve information		A GET request is used by a DOTS client to retrieve information
	(including status) of DOTS mitigations from a DOTS server.		(including status) of DOTS mitigations from a DOTS server.
	The same considerations for manipulating 'client-identifier'		The same considerations for manipulating 'client-domain-hash'
	parameter by a DOTS gateway specified in Section 4.4.1 MUST be		parameter by server-domain DOTS gateways specified in Section 4.4.1
	followed for GET requests.		MUST be followed for GET requests.
	If the DOTS server does not find the 'mitigation-id' parameter value		If the DOTS server does not find the 'mitigation-id' parameter value
	conveyed in the GET request in its configuration data for the		conveyed in the GET request in its configuration data for the
	requesting DOTS client or the one identified by 'client-identifier',		requesting DOTS client or the one identified by 'client-domain-hash',
	it MUST respond with a 4.04 (Not Found) error response code.		it MUST respond with a 4.04 (Not Found) error response code.
	Likewise, the same error MUST be returned as a response to a request		Likewise, the same error MUST be returned as a response to a request
	to retrieve all mitigation records of a given DOTS client if the DOTS		to retrieve all mitigation records of a given DOTS client if the DOTS
	server does not find any mitigation record for that DOTS client or		server does not find any mitigation record for that DOTS client or
	the one identified by 'client-identifier'.		the one identified by 'client-domain-hash'.
	The 'c' (content) parameter and its permitted values defined in		The 'c' (content) parameter and its permitted values defined in
	[I-D.ietf-core-comi] can be used to retrieve non-configuration data		[I-D.ietf-core-comi] can be used to retrieve non-configuration data
	(attack mitigation status) or configuration data or both. The DOTS		(attack mitigation status) or configuration data or both. The DOTS
	server may support this optional filtering capability. It can safely		server may support this optional filtering capability. It can safely
	ignore it if not supported.		ignore it if not supported.
	The following examples illustrate how a DOTS client retrieves active		The following examples illustrate how a DOTS client retrieves active
	mitigation requests from a DOTS server. In particular:		mitigation requests from a DOTS server. In particular:
	o Figure 9 shows the example of a GET request to retrieve all DOTS		o Figure 11 shows the example of a GET request to retrieve all DOTS
	mitigation requests signaled by a DOTS client.		mitigation requests signaled by a DOTS client.
	o Figure 10 shows the example of a GET request to retrieve a		o Figure 12 shows the example of a GET request to retrieve a
	specific DOTS mitigation request signaled by a DOTS client. The		specific DOTS mitigation request signaled by a DOTS client. The
	configuration data to be reported in the response is formatted in		configuration data to be reported in the response is formatted in
	the same order it was processed by the DOTS server.		the same order it was processed by the DOTS server.
	These two examples assume the default of "c=a"; that is, the DOTS		These two examples assume the default of "c=a"; that is, the DOTS
	client asks for all data to be reported by the DOTS server.		client asks for all data to be reported by the DOTS server.
	Header: GET (Code=0.01)		Header: GET (Code=0.01)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
			Uri-Query: "cuid=xyz"
	Observe : 0		Observe : 0
	{
	"mitigation-scope": {
	"client-identifier": [
	"dz6pHjaADkaFTbjr0JGBpw"
	]
	}
	}
	Figure 9: GET to retrieve all DOTS mitigation requests		Figure 11: GET to Retrieve all DOTS Mitigation Requests
	Header: GET (Code=0.01)		Header: GET (Code=0.01)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
			Uri-Query: "cuid=xyz"
			Uri-Query: "mitigation-id=12332"
	Observe : 0		Observe : 0
	Content-Format: "application/cbor"
	{
	"mitigation-scope": {
	"client-identifier": [
	"dz6pHjaADkaFTbjr0JGBpw"
	],
	"scope": [
	{
	"mitigation-id": 12332
	}
	]
	}
	}
	Figure 10: GET to retrieve a specific DOTS mitigation request		Figure 12: GET to Retrieve a Specific DOTS Mitigation Request
	Figure 11 shows a response example of all active mitigation requests		Figure 13 shows a response example of all active mitigation requests
	associated with the DOTS client on the DOTS server and the mitigation		associated with the DOTS client on the DOTS server and the mitigation
	status of each mitigation request.		status of each mitigation request.
	{		{
	"mitigation-scope": {		"mitigation-scope": {
	"scope": [		"scope": [
	{		{
	"mitigation-id": 12332,		"mitigation-id": 12332,
	"mitigation-start": 1507818434.00,		"mitigation-start": 1507818434.00,
	"target-protocol": [		"target-prefix": [
	17		"2001:db8:6401::1/128",
	],		"2001:db8:6401::2/128"
	"lifetime": 1800,		],
	"status": 2,		"target-protocol": [
	"bytes-dropped": 134334555,		17
	"bps-dropped": 43344,		],
	"pkts-dropped": 333334444,		"lifetime": 1800,
	"pps-dropped": 432432		"status": 2,
	},		"bytes-dropped": 134334555,
	{		"bps-dropped": 43344,
	"mitigation-id": 12333,		"pkts-dropped": 333334444,
	"mitigation-start": 1507818393.00,		"pps-dropped": 432432
	"target-protocol": [		},
	6		{
	],		"mitigation-id": 12333,
	"lifetime": 1800,		"mitigation-start": 1507818393.00,
	"status": 3,		"target-prefix": [
	"bytes-dropped": 0,		"2001:db8:6401::1/128",
	"bps-dropped": 0,		"2001:db8:6401::2/128"
	"pkts-dropped": 0,		],
	"pps-dropped": 0		"target-protocol": [
	}		6
	]		],
			"lifetime": 1800,
			"status": 3,
			"bytes-dropped": 0,
			"bps-dropped": 0,
			"pkts-dropped": 0,
			"pps-dropped": 0
			}
			]
	}		}
	}		}
	Figure 11: Response body		Figure 13: Response Body to a Get Request
	The mitigation status parameters are described below:		The mitigation status parameters are described below:
	mitigation-start: Mitigation start time is expressed in seconds		mitigation-start: Mitigation start time is expressed in seconds
	relative to 1970-01-01T00:00Z in UTC time (Section 2.4.1 of		relative to 1970-01-01T00:00Z in UTC time (Section 2.4.1 of
	[RFC7049]). The encoding is modified so that the leading tag 1		[RFC7049]). The encoding is modified so that the leading tag 1
	(epoch-based date/time) MUST be omitted.		(epoch-based date/time) MUST be omitted.
	This is a mandatory attribute.		This is a mandatory attribute.
	lifetime: The remaining lifetime of the mitigation request, in		lifetime: The remaining lifetime of the mitigation request, in
	seconds.		seconds.
	This is a mandatory attribute.		This is a mandatory attribute.
	skipping to change at page 23, line 40 ¶		skipping to change at page 26, line 50 ¶
	conflict-cause: Indicates the cause of the conflict. The		conflict-cause: Indicates the cause of the conflict. The
	following values are defined:		following values are defined:
	1: Overlapping targets. 'conflict-scope' provides more details		1: Overlapping targets. 'conflict-scope' provides more details
	about the conflicting target clauses.		about the conflicting target clauses.
	2: Conflicts with an existing white list. This code is		2: Conflicts with an existing white list. This code is
	returned when the DDoS mitigation detects source addresses/		returned when the DDoS mitigation detects source addresses/
	prefixes in the white-listed ACLs are attacking the target.		prefixes in the white-listed ACLs are attacking the target.
			3: CUID Collision. This code is returned when a DOTS client
			uses a CUID that is already used by another DOTS client of
			the same domain.
	conflict-scope Indicates the conflict scope. It may include a		conflict-scope Indicates the conflict scope. It may include a
	list of IP addresses, a list of prefixes, a list of port		list of IP addresses, a list of prefixes, a list of port
	numbers, a list of target protocols, a list of FQDNs, a list of		numbers, a list of target protocols, a list of FQDNs, a list of
	URIs, a list of alias-names, or references to conflicting ACLs.		URIs, a list of alias-names, or references to conflicting ACLs.
	retry-timer Indicates, in seconds, the time after which the DOTS		retry-timer Indicates, in seconds, the time after which the DOTS
	client may re-issue the same request. The DOTS server returns		client may re-issue the same request. The DOTS server returns
	'retry-timer' only to DOTS client(s) for which a mitigation		'retry-timer' only to DOTS client(s) for which a mitigation
	request is deactivated. Any retransmission of the same		request is deactivated. Any retransmission of the same
	mitigation request before the expiry of this timer is likely to		mitigation request before the expiry of this timer is likely to
	skipping to change at page 25, line 14 ¶		skipping to change at page 28, line 14 ¶
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| Parameter | Description |		| Parameter | Description |
	| value | |		| value | |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 1 | Attack mitigation is in progress (e.g., changing the |		| 1 | Attack mitigation is in progress (e.g., changing the |
	| | network path to re-route the inbound traffic to DOTS |		| | network path to re-route the inbound traffic to DOTS |
	| | mitigator). |		| | mitigator). |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 2 | Attack is successfully mitigated (e.g., traffic is |		| 2 | Attack is successfully mitigated (e.g., traffic is |
	| | redirected to a DDOS mitigator and attack traffic is |		| | redirected to a DDoS mitigator and attack traffic is |
	| | dropped). |		| | dropped). |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 3 | Attack has stopped and the DOTS client can withdraw |		| 3 | Attack has stopped and the DOTS client can withdraw |
	| | the mitigation request. |		| | the mitigation request. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 4 | Attack has exceeded the mitigation provider |		| 4 | Attack has exceeded the mitigation provider |
	| | capability. |		| | capability. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 5 | DOTS client has withdrawn the mitigation request and |		| 5 | DOTS client has withdrawn the mitigation request and |
	| | the mitigation is active but terminating. |		| | the mitigation is active but terminating. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 6 | Attack mitigation is now terminated. |		| 6 | Attack mitigation is now terminated. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 7 | Attack mitigation is withdrawn. |		| 7 | Attack mitigation is withdrawn. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 8 | Attack mitigation is rejected. |		| 8 | Attack mitigation is rejected. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	Table 2: Values of 'status' parameter		Table 2: Values of 'status' Parameter
	The observe option defined in [RFC7641] extends the CoAP core		The observe option defined in [RFC7641] extends the CoAP core
	protocol with a mechanism for a CoAP client to "observe" a resource		protocol with a mechanism for a CoAP client to "observe" a resource
	on a CoAP server: The client retrieves a representation of the		on a CoAP server: The client retrieves a representation of the
	resource and requests this representation be updated by the server as		resource and requests this representation be updated by the server as
	long as the client is interested in the resource. A DOTS client		long as the client is interested in the resource. A DOTS client
	conveys the observe option set to '0' in the GET request to receive		conveys the observe option set to '0' in the GET request to receive
	unsolicited notifications of attack mitigation status from the DOTS		unsolicited notifications of attack mitigation status from the DOTS
	server.		server.
	Unidirectional notifications within the bidirectional signal channel		Unidirectional notifications within the bidirectional signal channel
	allows unsolicited message delivery, enabling asynchronous		allows unsolicited message delivery, enabling asynchronous
	notifications between the agents. Due to the higher likelihood of		notifications between the agents. Due to the higher likelihood of
	packet loss during a DDoS attack, the DOTS server periodically sends		packet loss during a DDoS attack, the DOTS server periodically sends
	attack mitigation status to the DOTS client and also notifies the		attack mitigation status to the DOTS client and also notifies the
	DOTS client whenever the status of the attack mitigation changes. If		DOTS client whenever the status of the attack mitigation changes. If
	the DOTS server cannot maintain a RTT estimate, it SHOULD NOT send		the DOTS server cannot maintain a RTT estimate, it SHOULD NOT send
	more than one unsolicited notification every 3 seconds, and SHOULD		more than one unsolicited notification every 3 seconds, and SHOULD
	use an even less aggressive rate whenever possible (case 2 in		use an even less aggressive rate whenever possible (case 2 in
	Section 3.1.3 of [RFC8085]).		Section 3.1.3 of [RFC8085]). The DOTS server MUST use the same CUID
			as the one used by the DOTS client to observe a mitigation request.
	When conflicting requests are detected, the DOTS server enforces the		When conflicting requests are detected, the DOTS server enforces the
	corresponding policy (e.g., accept all requests, reject all requests,		corresponding policy (e.g., accept all requests, reject all requests,
	accept only one request but reject all the others, ...). It is		accept only one request but reject all the others, ...). It is
	assumed that this policy is supplied by the DOTS server administrator		assumed that this policy is supplied by the DOTS server administrator
	or it is a default behavior of the DOTS server implementation. Then,		or it is a default behavior of the DOTS server implementation. Then,
	the DOTS server sends notification message(s) to the DOTS client(s)		the DOTS server sends notification message(s) to the DOTS client(s)
	at the origin of the conflict. A conflict notification message		at the origin of the conflict. A conflict notification message
	includes information about the conflict cause, scope, and the status		includes information about the conflict cause, scope, and the status
	of the mitigation request(s). For example,		of the mitigation request(s). For example,
	skipping to change at page 26, line 48 ¶		skipping to change at page 29, line 48 ¶
	A DOTS client that is no longer interested in receiving notifications		A DOTS client that is no longer interested in receiving notifications
	from the DOTS server can simply "forget" the observation. When the		from the DOTS server can simply "forget" the observation. When the
	DOTS server sends the next notification, the DOTS client will not		DOTS server sends the next notification, the DOTS client will not
	recognize the token in the message and thus will return a Reset		recognize the token in the message and thus will return a Reset
	message. This causes the DOTS server to remove the associated entry.		message. This causes the DOTS server to remove the associated entry.
	Alternatively, the DOTS client can explicitly deregister itself by		Alternatively, the DOTS client can explicitly deregister itself by
	issuing a GET request that has the Token field set to the token of		issuing a GET request that has the Token field set to the token of
	the observation to be cancelled and includes an Observe Option with		the observation to be cancelled and includes an Observe Option with
	the value set to '1' (deregister).		the value set to '1' (deregister).
	Figure 12 shows an example of a DOTS client requesting a DOTS server		Figure 14 shows an example of a DOTS client requesting a DOTS server
	to send notifications related to a given mitigation request.		to send notifications related to a given mitigation request.
	DOTS Client DOTS Server		+-----------+ +-----------+
	| |		|DOTS client| |DOTS server|
	| GET /<mitigation-id number> |		+-----------+ +-----------+
	| Token: 0x4a | Registration		| |
	| Observe: 0 |		| GET /<mitigation-id number> |
	+------------------------------>|		| Token: 0x4a | Registration
	| |		| Observe: 0 |
	| 2.05 Content |		+------------------------------>|
	| Token: 0x4a | Notification of		| |
	| Observe: 12 | the current state		| 2.05 Content |
	| status: "mitigation |		| Token: 0x4a | Notification of
	| in progress" |		| Observe: 12 | the current state
	|<------------------------------+		| status: "mitigation |
	| 2.05 Content |		| in progress" |
	| Token: 0x4a | Notification upon		|<------------------------------+
	| Observe: 44 | a state change		| 2.05 Content |
	| status: "mitigation |		| Token: 0x4a | Notification upon
	| complete" |		| Observe: 44 | a state change
	|<------------------------------+		| status: "mitigation |
	| 2.05 Content |		| complete" |
	| Token: 0x4a | Notification upon		|<------------------------------+
	| Observe: 60 | a state change		| 2.05 Content |
	| status: "attack stopped" |		| Token: 0x4a | Notification upon
	|<------------------------------+		| Observe: 60 | a state change
	| |		| status: "attack stopped" |
			|<------------------------------+
			| |
	Figure 12: Notifications of attack mitigation status		Figure 14: Notifications of Attack Mitigation Status
	4.4.2.1. Mitigation Status		4.4.2.1. Mitigation Status
	The DOTS client can send the GET request at frequent intervals		The DOTS client can send the GET request at frequent intervals
	without the Observe option to retrieve the configuration data of the		without the Observe option to retrieve the configuration data of the
	mitigation request and non-configuration data (i.e., the attack		mitigation request and non-configuration data (i.e., the attack
	status). The frequency of polling the DOTS server to get the		status). The frequency of polling the DOTS server to get the
	mitigation status should follow the transmission guidelines given in		mitigation status should follow the transmission guidelines given in
	Section 3.1.3 of [RFC8085]. If the DOTS server has been able to		Section 3.1.3 of [RFC8085]. If the DOTS server has been able to
	mitigate the attack and the attack has stopped, the DOTS server		mitigate the attack and the attack has stopped, the DOTS server
	indicates as such in the status, and the DOTS client recalls the		indicates as such in the status, and the DOTS client recalls the
	mitigation request by issuing a DELETE request for the mitigation-id.		mitigation request by issuing a DELETE request for the 'mitigation-
			id'.
	A DOTS client SHOULD react to the status of the attack as per the		A DOTS client SHOULD react to the status of the attack as per the
	information sent by the DOTS server rather than acknowledging by		information sent by the DOTS server rather than acknowledging by
	itself, using its own means, that the attack has been mitigated.		itself, using its own means, that the attack has been mitigated.
	This ensures that the DOTS client does not recall a mitigation		This ensures that the DOTS client does not recall a mitigation
	request prematurely because it is possible that the DOTS client does		request prematurely because it is possible that the DOTS client does
	not sense the DDOS attack on its resources but the DOTS server could		not sense the DDoS attack on its resources but the DOTS server could
	be actively mitigating the attack and the attack is not completely		be actively mitigating the attack and the attack is not completely
	averted.		averted.
	4.4.3. Efficacy Update from DOTS Clients		4.4.3. Efficacy Update from DOTS Clients
	While DDoS mitigation is active, due to the likelihood of packet		While DDoS mitigation is active, due to the likelihood of packet
	loss, a DOTS client MAY periodically transmit DOTS mitigation		loss, a DOTS client MAY periodically transmit DOTS mitigation
	efficacy updates to the relevant DOTS server. A PUT request is used		efficacy updates to the relevant DOTS server. A PUT request is used
	to convey the mitigation efficacy update to the DOTS server.		to convey the mitigation efficacy update to the DOTS server.
	skipping to change at page 28, line 32 ¶		skipping to change at page 31, line 35 ¶
	may send a PUT request to convey an efficacy update to the DOTS		may send a PUT request to convey an efficacy update to the DOTS
	server followed by a DELETE request to withdraw the mitigation		server followed by a DELETE request to withdraw the mitigation
	request, but the DELETE request arrives at the DOTS server before the		request, but the DELETE request arrives at the DOTS server before the
	PUT request. To handle out-of-order delivery of requests, if an If-		PUT request. To handle out-of-order delivery of requests, if an If-
	Match option is present in the PUT request and the 'mitigation-id' in		Match option is present in the PUT request and the 'mitigation-id' in
	the request matches a mitigation request from that DOTS client, then		the request matches a mitigation request from that DOTS client, then
	the request is processed. If no match is found, the PUT request is		the request is processed. If no match is found, the PUT request is
	silently ignored.		silently ignored.
	An example of an efficacy update message, which includes an If-Match		An example of an efficacy update message, which includes an If-Match
	option with an empty value, is depicted in Figure 13.		option with an empty value, is depicted in Figure 15.
	Header: PUT (Code=0.03)		Header: PUT (Code=0.03)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
			Uri-Path: "cuid=xyz"
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	If-Match:		If-Match:
	{		{
	"mitigation-scope": {		"mitigation-scope": {
	"client-identifier": [
	"string"
	],
	"scope": [		"scope": [
	{		{
	"mitigation-id": integer,		"mitigation-id": integer,
	"target-prefix": [		"target-prefix": [
	"string"		"string"
	],		],
	"target-port-range": [		"target-port-range": [
	{		{
	"lower-port": integer,		"lower-port": integer,
	"upper-port": integer		"upper-port": integer
	skipping to change at page 29, line 49 ¶		skipping to change at page 32, line 47 ¶
	"alias-name": [		"alias-name": [
	"string"		"string"
	],		],
	"lifetime": integer,		"lifetime": integer,
	"attack-status": integer		"attack-status": integer
	}		}
	]		]
	}		}
	}		}
	Figure 13: Efficacy Update		Figure 15: Efficacy Update
	The 'attack-status' parameter is a mandatory attribute when		The 'attack-status' parameter is a mandatory attribute when
	performing an efficacy update. The various possible values contained		performing an efficacy update. The various possible values contained
	in the 'attack-status' parameter are described in Table 3.		in the 'attack-status' parameter are described in Table 3.
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| Parameter | Description |		| Parameter | Description |
	| value | |		| value | |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 1 | The DOTS client determines that it is still under |		| 1 | The DOTS client determines that it is still under |
	| | attack. |		| | attack. |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| 2 | The DOTS client determines that the attack is |		| 2 | The DOTS client determines that the attack is |
	| | successfully mitigated (e.g., attack traffic is not |		| | successfully mitigated (e.g., attack traffic is not |
	| | seen). |		| | seen). |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	Table 3: Values of 'attack-status' parameter		Table 3: Values of 'attack-status' Parameter
	The DOTS server indicates the result of processing a PUT request		The DOTS server indicates the result of processing a PUT request
	using CoAP response codes. The response code 2.04 (Changed) is		using CoAP response codes. The response code 2.04 (Changed) is
	returned if the DOTS server has accepted the mitigation efficacy		returned if the DOTS server has accepted the mitigation efficacy
	update. The error response code 5.03 (Service Unavailable) is		update. The error response code 5.03 (Service Unavailable) is
	returned if the DOTS server has erred or is incapable of performing		returned if the DOTS server has erred or is incapable of performing
	the mitigation.		the mitigation.
	4.4.4. Withdraw a Mitigation		4.4.4. Withdraw a Mitigation
	A DELETE request is used to withdraw a DOTS mitigation request from a		A DELETE request is used to withdraw a DOTS mitigation request from a
	DOTS server (Figure 14).		DOTS server (Figure 16).
	The same considerations for manipulating 'client-identifier'		The same considerations for manipulating 'client-domain-hash'
	parameter by a DOTS gateway, as specified in Section 4.4.1, MUST be		parameter by DOTS gateways, as specified in Section 4.4.1, MUST be
	followed for DELETE requests.		followed for DELETE requests.
	Header: DELETE (Code=0.04)		Header: DELETE (Code=0.04)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "mitigate"		Uri-Path: "mitigate"
	Content-Format: "application/cbor"		Uri-Query: "cuid=xyz"
	{		Uri-Query: "mitigation-id=123"
	"mitigation-scope": {
	"client-identifier": [
	"string"
	],
	"scope": [
	{
	"mitigation-id": integer
	}
	]
	}
	}
	Figure 14: Withdraw DOTS signal		Figure 16: Withdraw a DOTS Mitigation
	If the request does not include a 'mitigation-id' parameter, the DOTS		If the request does not include a 'mitigation-id' parameter, the DOTS
	server MUST reply with a 4.00 (Bad Request).		server MUST reply with a 4.00 (Bad Request).
	Once the request is validated, the DOTS server immediately		Once the request is validated, the DOTS server immediately
	acknowledges a DOTS client's request to withdraw the DOTS signal		acknowledges a DOTS client's request to withdraw the DOTS signal
	using 2.02 (Deleted) response code with no response payload. A 2.02		using 2.02 (Deleted) response code with no response payload. A 2.02
	(Deleted) Response Code is returned even if the 'mitigation-id'		(Deleted) Response Code is returned even if the 'mitigation-id'
	parameter value conveyed in the DELETE request does not exist in its		parameter value conveyed in the DELETE request does not exist in its
	configuration data before the request.		configuration data before the request.
	skipping to change at page 32, line 35 ¶		skipping to change at page 35, line 5 ¶
	b. Missing heartbeats allowed (missing-hb-allowed): This variable		b. Missing heartbeats allowed (missing-hb-allowed): This variable
	indicates the maximum number of consecutive heartbeat messages		indicates the maximum number of consecutive heartbeat messages
	for which a DOTS agent did not receive a response before		for which a DOTS agent did not receive a response before
	concluding that the session is disconnected or defunct.		concluding that the session is disconnected or defunct.
	c. Acceptable signal loss ratio: Maximum retransmissions,		c. Acceptable signal loss ratio: Maximum retransmissions,
	retransmission timeout value, and other message transmission		retransmission timeout value, and other message transmission
	parameters for the DOTS signal channel.		parameters for the DOTS signal channel.
	The same or distinct configuration sets may be used during attack		The same or distinct configuration sets may be used during times when
	('attack-time-config') and peace times ('peace-time-config'). This		a mitigation is active ('mitigating-config') and when no mitigation
	is particularly useful for DOTS servers that might want to reduce		is active ('idle-config'). This is particularly useful for DOTS
	heartbeat frequency or cease heartbeat exchanges when an active DOTS		servers that might want to reduce heartbeat frequency or cease
	client has not requested mitigation. If distinct configuration are		heartbeat exchanges when an active DOTS client has not requested
	used, DOTS agents MUST follow the appropriate configuration set as a		mitigation. If distinct configurations are used, DOTS agents MUST
	function of the mitigation activity (e.g., if no mitigation request		follow the appropriate configuration set as a function of the
	is active, 'peace-time-config'-related values must be followed).		mitigation activity (e.g., if no mitigation request is active, 'idle-
	Additionally, DOTS agents MUST automatically switch to the other		config'-related values must be followed). Additionally, DOTS agents
	configuration upon a change in the mitigation activity (e.g., if an		MUST automatically switch to the other configuration upon a change in
	attack mitigation is launched after a peacetime, the DOTS agent		the mitigation activity (e.g., if an attack mitigation is launched
	switches from 'peace-time-config' to 'attack-time-config'-related		after a peacetime, the DOTS agent switches from 'idle-config' to
	values).		'mitigating-config'-related values).
	Requests and responses are deemed reliable by marking them as		Requests and responses are deemed reliable by marking them as
	Confirmable (CON) messages. DOTS signal channel session		Confirmable (CON) messages. DOTS signal channel session
	configuration requests and responses are marked as Confirmable		configuration requests and responses are marked as Confirmable
	messages. As explained in Section 2.1 of [RFC7252], a Confirmable		messages. As explained in Section 2.1 of [RFC7252], a Confirmable
	message is retransmitted using a default timeout and exponential		message is retransmitted using a default timeout and exponential
	back-off between retransmissions, until the DOTS server sends an		back-off between retransmissions, until the DOTS server sends an
	Acknowledgement message (ACK) with the same Message ID conveyed from		Acknowledgement message (ACK) with the same Message ID conveyed from
	the DOTS client.		the DOTS client.
	skipping to change at page 33, line 36 ¶		skipping to change at page 36, line 9 ¶
	that would help it correlate this response, thereby unexpecting		that would help it correlate this response, thereby unexpecting
	the retransmission message. The DOTS client will send a Reset		the retransmission message. The DOTS client will send a Reset
	message so it does not receive any more retransmissions. This		message so it does not receive any more retransmissions. This
	behavior is normal and not an indication of an error (see		behavior is normal and not an indication of an error (see
	Section 5.3.2 of [RFC7252] for more details).		Section 5.3.2 of [RFC7252] for more details).
	4.5.1. Discover Configuration Parameters		4.5.1. Discover Configuration Parameters
	A GET request is used to obtain acceptable (e.g., minimum and maximum		A GET request is used to obtain acceptable (e.g., minimum and maximum
	values) and current configuration parameters on the DOTS server for		values) and current configuration parameters on the DOTS server for
	DOTS signal channel session configuration.		DOTS signal channel session configuration. This procedure occurs
			between a DOTS client and its immediate peer DOTS server. As such,
			this GET request MUST NOT be relayed by an on-path DOTS gateway.
	Figure 15 shows how to obtain acceptable configuration parameters for		Figure 17 shows how to obtain acceptable configuration parameters for
	the DOTS server.		the DOTS server.
	Header: GET (Code=0.01)		Header: GET (Code=0.01)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "config"		Uri-Path: "config"
	Figure 15: GET to retrieve configuration		Figure 17: GET to Retrieve Configuration
	The DOTS server in the 2.05 (Content) response conveys the current,		The DOTS server in the 2.05 (Content) response conveys the current,
	minimum, and maximum attribute values acceptable by the DOTS server		minimum, and maximum attribute values acceptable by the DOTS server
	(Figure 16).		(Figure 18).
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	{		{
	"attack-time-config": {		"signal-config": {
			"mitigating-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	skipping to change at page 34, line 33 ¶		skipping to change at page 37, line 5 ¶
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": number,		"current-value-decimal": number,
	"min-value": number,		"min-value-decimal": number,
	"max-value": number		"max-value-decimal": number
	}		}
	},		},
	"peace-time-config": {		"idle-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	skipping to change at page 35, line 4 ¶		skipping to change at page 37, line 25 ¶
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": integer,		"current-value": integer,
	"min-value": integer,		"min-value": integer,
	"max-value": integer		"max-value": integer
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": number,		"current-value-decimal": number,
	"min-value": number,		"min-value-decimal": number,
	"max-value": number		"max-value-decimal": number
	}		}
	},		},
	"trigger-mitigation": {		"trigger-mitigation": {
	"current-value": boolean		"current-value": boolean
	},		}
	"config-interval": {
	"current-value": integer,
	"min-value": integer,
	"max-value": integer
	}
	}		}
			}
	Figure 16: GET response body		Figure 18: GET Configuration Response Body
	Figure 17 shows an example of acceptable and current configuration		Figure 19 shows an example of acceptable and current configuration
	parameters on a DOTS server for DOTS signal channel session		parameters on a DOTS server for DOTS signal channel session
	configuration. The same acceptable configuration is used during		configuration. The same acceptable configuration is used during
	attack and peace times.		attack and peace times.
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	{		{
	"attack-time-config": {		"signal-config": {
			"mitigating-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": 30,		"current-value": 30,
	"min-value": 15,		"min-value": 15,
	"max-value": 240		"max-value": 240
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": 5,		"current-value": 5,
	"min-value": 3,		"min-value": 3,
	"max-value": 9		"max-value": 9
	},		},
	skipping to change at page 36, line 9 ¶		skipping to change at page 38, line 27 ¶
	"current-value": 3,		"current-value": 3,
	"min-value": 2,		"min-value": 2,
	"max-value": 15		"max-value": 15
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": 2,		"current-value": 2,
	"min-value": 1,		"min-value": 1,
	"max-value": 30		"max-value": 30
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": 1.5,		"current-value-decimal": 1.5,
	"min-value": 1.1,		"min-value-decimal": 1.1,
	"max-value": 4.0		"max-value-decimal": 4.0
	}		}
	},		},
	"peace-time-config": {		"idle-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": 30,		"current-value": 30,
	"min-value": 15,		"min-value": 15,
	"max-value": 240		"max-value": 240
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": 5,		"current-value": 5,
	"min-value": 3,		"min-value": 3,
	"max-value": 9		"max-value": 9
	},		},
	skipping to change at page 36, line 34 ¶		skipping to change at page 39, line 4 ¶
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": 3,		"current-value": 3,
	"min-value": 2,		"min-value": 2,
	"max-value": 15		"max-value": 15
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": 2,		"current-value": 2,
	"min-value": 1,		"min-value": 1,
	"max-value": 30		"max-value": 30
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": 1.5,		"current-value-decimal": 1.5,
	"min-value": 1.1,		"min-value-decimal": 1.1,
	"max-value": 4.0		"max-value-decimal": 4.0
	}		}
	},		},
	"trigger-mitigation": {		"trigger-mitigation": {
	"current-value": true		"current-value": true
	},		}
	"config-interval": {
	"current-value": 1439,
	"min-value": 0,
	"max-value": 65535
	}
	}		}
			}
	Figure 17: Configuration response body		Figure 19: Example of a Configuration Response Body
	4.5.2. Convey DOTS Signal Channel Session Configuration		4.5.2. Convey DOTS Signal Channel Session Configuration
	A PUT request is used to convey the configuration parameters for the		A PUT request is used to convey the configuration parameters for the
	signal channel (e.g., heartbeat interval, maximum retransmissions).		signal channel (e.g., heartbeat interval, maximum retransmissions).
	Message transmission parameters for CoAP are defined in Section 4.8		Message transmission parameters for CoAP are defined in Section 4.8
	of [RFC7252]. The RECOMMENDED values of transmission parameter		of [RFC7252]. The RECOMMENDED values of transmission parameter
	values are ack-timeout (2 seconds), max-retransmit (3), ack-random-		values are ack-timeout (2 seconds), max-retransmit (3), ack-random-
	factor (1.5). In addition to those parameters, the RECOMMENDED		factor (1.5). In addition to those parameters, the RECOMMENDED
	specific DOTS transmission parameter values are 'heartbeat-interval'		specific DOTS transmission parameter values are 'heartbeat-interval'
	skipping to change at page 37, line 35 ¶		skipping to change at page 39, line 50 ¶
	standpoint, this specification recommends a minimum heartbeat-		standpoint, this specification recommends a minimum heartbeat-
	interval of 15 seconds and a maximum heartbeat-interval of 240		interval of 15 seconds and a maximum heartbeat-interval of 240
	seconds. The recommended value of 30 seconds is selected to		seconds. The recommended value of 30 seconds is selected to
	anticipate the expiry of NAT state.		anticipate the expiry of NAT state.
	A heartbeat-interval of 30 seconds may be seen as too chatty in		A heartbeat-interval of 30 seconds may be seen as too chatty in
	some deployments. For such deployments, DOTS agents may negotiate		some deployments. For such deployments, DOTS agents may negotiate
	longer heartbeat-interval values to prevent any network overload		longer heartbeat-interval values to prevent any network overload
	with too frequent keepalives.		with too frequent keepalives.
			Different heartbeat intervals can be defined for 'mitigation-
			config' and 'idle-config' to reduce being too chatty during idle
			times. If there is an on-path translator between the DOTS client
			(standalone or part of a DOTS gateway) and the DOTS server, the
			'mitigation-config' heartbeat-interval has to be smaller than the
			translator session timeout. It is recommended that the 'idle-
			config' heartbeat-interval is also smaller than the translator
			session timeout to prevent translator transversal issues, or set
			to '0'. Means to discover the lifetime assigned by a translator
			are out of scope.
	When a confirmable "CoAP Ping" is sent, and if there is no response,		When a confirmable "CoAP Ping" is sent, and if there is no response,
	the "CoAP Ping" is retransmitted max-retransmit number of times by		the "CoAP Ping" is retransmitted max-retransmit number of times by
	the CoAP layer using an initial timeout set to a random duration		the CoAP layer using an initial timeout set to a random duration
	between ack-timeout and (ack-timeout*ack-random-factor) and		between ack-timeout and (ack-timeout*ack-random-factor) and
	exponential back-off between retransmissions. By choosing the		exponential back-off between retransmissions. By choosing the
	recommended transmission parameters, the "CoAP Ping" will timeout		recommended transmission parameters, the "CoAP Ping" will timeout
	after 45 seconds. If the DOTS agent does not receive any response		after 45 seconds. If the DOTS agent does not receive any response
	from the peer DOTS agent for 'missing-hb-allowed' number of		from the peer DOTS agent for 'missing-hb-allowed' number of
	consecutive "CoAP Ping" confirmable messages, it concludes that the		consecutive "CoAP Ping" confirmable messages, it concludes that the
	DOTS signal channel session is disconnected. A DOTS client MUST NOT		DOTS signal channel session is disconnected. A DOTS client MUST NOT
	skipping to change at page 38, line 14 ¶		skipping to change at page 40, line 40 ¶
	The signal channel session configuration is applicable to a single		The signal channel session configuration is applicable to a single
	DOTS signal channel session between the DOTS agents.		DOTS signal channel session between the DOTS agents.
	Header: PUT (Code=0.03)		Header: PUT (Code=0.03)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "config"		Uri-Path: "config"
			Uri-Path: "session-id=123"
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	{		{
	"signal-config": {		"signal-config": {
	"session-id": integer,		"mitigating-config": {
	"attack-time-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": integer		"current-value": integer
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": integer		"current-value": integer
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": integer		"current-value": integer
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": integer		"current-value": integer
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": number		"current-value-decimal": number
	}		}
	},		},
	"peace-time-config": {		"idle-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": integer		"current-value": integer
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": integer		"current-value": integer
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": integer		"current-value": integer
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": integer		"current-value": integer
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": number		"current-value-decimal": number
	}		}
	},		},
	"trigger-mitigation": boolean,		"trigger-mitigation": boolean,
	"config-interval": integer		"config-interval": integer
	}		}
	}		}
	Figure 18: PUT to convey the DOTS signal channel session		Figure 20: PUT to Convey the DOTS Signal Channel Session
	configuration data.		Configuration Data
	The parameters in Figure 18 are described below:		The parameters in Figure 20 are described below:
	session-id: Identifier for the DOTS signal channel session		session-id: Identifier for the DOTS signal channel session
	configuration data represented as an integer. This identifier		configuration data represented as an integer. This identifier
	MUST be generated by the DOTS client. This document does not make		MUST be generated by the DOTS client. This document does not make
	any assumption about how this identifier is generated.		any assumption about how this identifier is generated.
	This is a mandatory attribute.		This is a mandatory attribute.
	attack-time-config: Set of configuration parameters to use when an		mitigation-config: Set of configuration parameters to use when a
	attack is active. The following parameters may be included:		mitigation is active. The following parameters may be included:
	heartbeat-interval: Time interval in seconds between two		heartbeat-interval: Time interval in seconds between two
	consecutive heartbeat messages.		consecutive heartbeat messages.
	'0' is used to disable the heartbeat mechanism.		'0' is used to disable the heartbeat mechanism.
	This is an optional attribute.		This is an optional attribute.
	missing-hb-allowed: Maximum number of consecutive heartbeat		missing-hb-allowed: Maximum number of consecutive heartbeat
	messages for which the DOTS agent did not receive a response		messages for which the DOTS agent did not receive a response
	skipping to change at page 40, line 5 ¶		skipping to change at page 42, line 32 ¶
	ACK_TIMEOUT parameter in CoAP).		ACK_TIMEOUT parameter in CoAP).
	This is an optional attribute.		This is an optional attribute.
	ack-random-factor: Random factor used to influence the timing of		ack-random-factor: Random factor used to influence the timing of
	retransmissions (referred to as ACK_RANDOM_FACTOR parameter in		retransmissions (referred to as ACK_RANDOM_FACTOR parameter in
	CoAP).		CoAP).
	This is an optional attribute.		This is an optional attribute.
	peace-time-config: Set of configuration parameters to use during		idle-config: Set of configuration parameters to use when no
	peacetime. This attribute has the same structure as 'attack-time-		mitigation is active. This attribute has the same structure as
	config'.		'mitigating-config'.
	trigger-mitigation: If the parameter value is set to 'false', then		trigger-mitigation: If the parameter value is set to 'false', then
	DDoS mitigation is triggered only when the DOTS signal channel		DDoS mitigation is triggered only when the DOTS signal channel
	session is lost. Automated mitigation on loss of signal is		session is lost. Automated mitigation on loss of signal is
	discussed in Section 3.3.3 of [I-D.ietf-dots-architecture].		discussed in Section 3.3.3 of [I-D.ietf-dots-architecture].
	If the DOTS client ceases to respond to heartbeat messages, the		If the DOTS client ceases to respond to heartbeat messages, the
	DOTS server can detect that the DOTS session is lost.		DOTS server can detect that the DOTS session is lost.
	The default value of the parameter is 'true'.		The default value of the parameter is 'true'.
	This is an optional attribute.		This is an optional attribute.
	config-interval: This parameter is returned to indicate the time		config-interval: This parameter is returned to indicate the time
	interval expressed in minutes, which a DOTS agent must wait for		interval expressed in seconds, which a DOTS agent must wait for
	before re-contacting its peer in order to retrieve the signal		before re-contacting its peer in order to retrieve the signal
	channel configuration data.		channel configuration data.
	'0' is used to disable this refresh mechanism.		'0' is used to disable this refresh mechanism.
	If a non-null value of 'config-interval' is received by a DOTS		If a non-zero value of 'config-interval' is received by a DOTS
	agent, it has to issue a PUT request to refresh the configuration		client, it has to issue a PUT request to refresh the configuration
	parameters for the signal channel before the expiry of 'config-		parameters for the signal channel before the expiry of 'config-
	interval'. When a DDoS attack is active, refresh requests MUST		interval'. When a DDoS attack is active, refresh requests MUST
	NOT be sent by DOTS clients and the DOTS server MUST NOT terminate		NOT be sent by DOTS clients and the DOTS server MUST NOT terminate
	the (D)TLS session after the expiry of 'config-interval'.		the (D)TLS session after the expiry of 'config-interval'.
	This mechanism allows to update the configuration data if a change		This mechanism allows to update the configuration data if a change
	occurs at the DOTS server side. For example, the new		occurs at the DOTS server side. For example, the new
	configuration may instruct a DOTS client to cease heartbeats or		configuration may instruct a DOTS client to cease heartbeats or
	reduce heartbeat frequency.		reduce heartbeat frequency.
	skipping to change at page 41, line 12 ¶		skipping to change at page 43, line 38 ¶
	This is an optional attribute.		This is an optional attribute.
	At least one of the attributes 'heartbeat-interval', 'missing-hb-		At least one of the attributes 'heartbeat-interval', 'missing-hb-
	allowed', 'max-retransmit', 'ack-timeout', 'ack-random-factor', and		allowed', 'max-retransmit', 'ack-timeout', 'ack-random-factor', and
	'trigger-mitigation' MUST be present in the PUT request. The PUT		'trigger-mitigation' MUST be present in the PUT request. The PUT
	request with a higher numeric 'session-id' value overrides the DOTS		request with a higher numeric 'session-id' value overrides the DOTS
	signal channel session configuration data installed by a PUT request		signal channel session configuration data installed by a PUT request
	with a lower numeric 'session-id' value.		with a lower numeric 'session-id' value.
	Figure 19 shows a PUT request example to convey the configuration		Figure 21 shows a PUT request example to convey the configuration
	parameters for the DOTS signal channel. In this example, heartbeat		parameters for the DOTS signal channel. In this example, heartbeat
	mechanism is disabled during peacetime, while the heartbeat interval		mechanism is disabled when no mitigation is active, while the
	is set to '91' when an attack is active.		heartbeat interval is set to '91' when a mitigation is active.
	Header: PUT (Code=0.03)		Header: PUT (Code=0.03)
	Uri-Host: "www.example.com"		Uri-Host: "www.example.com"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "v1"		Uri-Path: "v1"
	Uri-Path: "config"		Uri-Path: "config"
			Uri-Path: "session-id=123"
	Content-Format: "application/cbor"		Content-Format: "application/cbor"
	{		{
	"signal-config": {		"signal-config": {
	"session-id": 1234534333242,		"mitigating-config": {
	"attack-time-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": 91		"current-value": 91
	},		},
	"missing-hb-allowed": {		"missing-hb-allowed": {
	"current-value": 3		"current-value": 3
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": 7		"current-value": 7
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": 5		"current-value": 5
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": 1.5		"current-value-decimal": 1.5
	}		}
	},		},
	"peace-time-config": {		"idle-config": {
	"heartbeat-interval": {		"heartbeat-interval": {
	"current-value": 0		"current-value": 0
	},		},
	"max-retransmit": {		"max-retransmit": {
	"current-value": 7		"current-value": 7
	},		},
	"ack-timeout": {		"ack-timeout": {
	"current-value": 5		"current-value": 5
	},		},
	"ack-random-factor": {		"ack-random-factor": {
	"current-value": 1.5		"current-value-decimal": 1.5
	}		}
	},		},
	"trigger-mitigation": false		"trigger-mitigation": false
	}		}
	}		}
	Figure 19: PUT to convey the configuration parameters		Figure 21: PUT to Convey the Configuration Parameters
	The DOTS server indicates the result of processing the PUT request		The DOTS server indicates the result of processing the PUT request
	using CoAP response codes:		using CoAP response codes:
	o If the DOTS server finds the 'session-id' parameter value conveyed		o If the DOTS server finds the 'session-id' parameter value conveyed
	in the PUT request in its configuration data and if the DOTS		in the PUT request in its configuration data and if the DOTS
	server has accepted the updated configuration parameters, then		server has accepted the updated configuration parameters, then
	2.04 (Changed) code is returned in the response.		2.04 (Changed) code is returned in the response.
	o If the DOTS server does not find the 'session-id' parameter value		o If the DOTS server does not find the 'session-id' parameter value
	skipping to change at page 43, line 36 ¶		skipping to change at page 45, line 36 ¶
	DOTS server. Upon receipt of the 4.22 error response code, the		DOTS server. Upon receipt of the 4.22 error response code, the
	DOTS client should request the maximum and minimum attribute		DOTS client should request the maximum and minimum attribute
	values acceptable to the DOTS server (Section 4.5.1).		values acceptable to the DOTS server (Section 4.5.1).
	The DOTS client may re-try and send the PUT request with updated		The DOTS client may re-try and send the PUT request with updated
	attribute values acceptable to the DOTS server.		attribute values acceptable to the DOTS server.
	4.5.3. Delete DOTS Signal Channel Session Configuration		4.5.3. Delete DOTS Signal Channel Session Configuration
	A DELETE request is used to delete the installed DOTS signal channel		A DELETE request is used to delete the installed DOTS signal channel
	session configuration data (Figure 20).		session configuration data (Figure 22).
	Header: DELETE (Code=0.04)		Header: DELETE (Code=0.04)
	Uri-Host: "host"		Uri-Host: "host"
	Uri-Path: ".well-known"		Uri-Path: ".well-known"
	Uri-Path: "dots"		Uri-Path: "dots"
	Uri-Path: "version"		Uri-Path: "version"
	Uri-Path: "config"		Uri-Path: "config"
	Content-Format: "application/cbor"		Uri-Query: "session-id=123"
	Figure 20: DELETE configuration		Figure 22: DELETE Configuration
	The DOTS server resets the DOTS signal channel session configuration		The DOTS server resets the DOTS signal channel session configuration
	back to the default values and acknowledges a DOTS client's request		back to the default values and acknowledges a DOTS client's request
	to remove the DOTS signal channel session configuration using 2.02		to remove the DOTS signal channel session configuration using 2.02
	(Deleted) response code.		(Deleted) response code.
	4.6. Redirected Signaling		4.6. Redirected Signaling
	Redirected DOTS signaling is discussed in detail in Section 3.2.2 of		Redirected DOTS signaling is discussed in detail in Section 3.2.2 of
	[I-D.ietf-dots-architecture].		[I-D.ietf-dots-architecture].
	If a DOTS server wants to redirect a DOTS client to an alternative		If a DOTS server wants to redirect a DOTS client to an alternative
	DOTS server for a signal session, then the response code 3.00		DOTS server for a signal session, then the response code 3.00
	(alternate server) will be returned in the response to the client.		(alternate server) will be returned in the response to the DOTS
			client.
	The DOTS server can return the error response code 3.00 in response		The DOTS server can return the error response code 3.00 in response
	to a PUT request from the DOTS client or convey the error response		to a PUT request from the DOTS client or convey the error response
	code 3.00 in a unidirectional notification response from the DOTS		code 3.00 in a unidirectional notification response from the DOTS
	server.		server.
	The DOTS server in the error response conveys the alternate DOTS		The DOTS server in the error response conveys the alternate DOTS
	server's FQDN, and the alternate DOTS server's IP address(es) and		server's FQDN, and the alternate DOTS server's IP address(es) and
	time to live values in the CBOR body (Figure 21).		time to live values in the CBOR body (Figure 23).
	{		{
	"alt-server": "string",		"alt-server": "string",
	"alt-server-record": [		"alt-server-record": [
	{		{
	"addr": "string",		"addr": "string",
	"ttl" : integer		"ttl" : integer
	}		}
	]		]
	}		}
	Figure 21: Error response body		Figure 23: Redirected Server Error Response Body
	The parameters are described below:		The parameters are described below:
	alt-server: FQDN of an alternate DOTS server.		alt-server: FQDN of an alternate DOTS server.
	addr: IP address of an alternate DOTS server.		addr: IP address of an alternate DOTS server.
	ttl: Time to live (TTL) represented as an integer number of seconds.		ttl: Time to live (TTL) represented as an integer number of seconds.
	Figure 22 shows a 3.00 response example to convey the DOTS alternate		Figure 24 shows a 3.00 response example to convey the DOTS alternate
	server 'alt-server.example', its IP addresses 2001:db8:6401::1 and		server 'alt-server.example', its IP addresses 2001:db8:6401::1 and
	2001:db8:6401::2, and TTL values 3600 and 1800.		2001:db8:6401::2, and TTL values 3600 and 1800.
	{		{
	"alt-server": "alt-server.example",		"alt-server": "alt-server.example",
	"alt-server-record": [		"alt-server-record": [
	{		{
	"ttl" : 3600,		"ttl" : 3600,
	"addr": "2001:db8:6401::1"		"addr": "2001:db8:6401::1"
	},		},
	{		{
	"ttl" : 1800,		"ttl" : 1800,
	"addr": "2001:db8:6401::2"		"addr": "2001:db8:6401::2"
	}		}
	]		]
	}		}
	Figure 22: Example of error response body		Figure 24: Example of Redirected Server Error Response Body
	When the DOTS client receives 3.00 response, it considers the current		When the DOTS client receives 3.00 response, it considers the current
	request as failed, but SHOULD try re-sending the request to the		request as failed, but SHOULD try re-sending the request to the
	alternate DOTS server. During a DDOS attack, the DNS server may be		alternate DOTS server. During a DDoS attack, the DNS server may be
	the target of another DDoS attack, alternate DOTS server's IP		the target of another DDoS attack, alternate DOTS server's IP
	addresses conveyed in the 3.00 response help the DOTS client skip DNS		addresses conveyed in the 3.00 response help the DOTS client skip DNS
	lookup of the alternate DOTS server. The DOTS client can then try to		lookup of the alternate DOTS server. The DOTS client can then try to
	establish a UDP or a TCP session with the alternate DOTS server. The		establish a UDP or a TCP session with the alternate DOTS server. The
	DOTS client SHOULD implement a DNS64 function to handle the scenario		DOTS client SHOULD implement a DNS64 function to handle the scenario
	where an IPv6-only DOTS client communicates with an IPv4-only		where an IPv6-only DOTS client communicates with an IPv4-only
	alternate DOTS server.		alternate DOTS server.
	4.7. Heartbeat Mechanism		4.7. Heartbeat Mechanism
	skipping to change at page 45, line 48 ¶		skipping to change at page 47, line 48 ¶
	its peer DOTS agent, and may consider a session terminated in the		its peer DOTS agent, and may consider a session terminated in the
	prolonged absence of a peer agent heartbeat.		prolonged absence of a peer agent heartbeat.
	While the communication between the DOTS agents is quiescent, the		While the communication between the DOTS agents is quiescent, the
	DOTS client will probe the DOTS server to ensure it has maintained		DOTS client will probe the DOTS server to ensure it has maintained
	cryptographic state and vice versa. Such probes can also keep		cryptographic state and vice versa. Such probes can also keep
	firewalls and/or stateful translators bindings alive. This probing		firewalls and/or stateful translators bindings alive. This probing
	reduces the frequency of establishing a new handshake when a DOTS		reduces the frequency of establishing a new handshake when a DOTS
	signal needs to be conveyed to the DOTS server.		signal needs to be conveyed to the DOTS server.
	In order to avoid complications due to the presence of some stateful		DOTS servers MAY trigger their heartbeat requests immediately after
	translators and firewalls (e.g., discard an incoming packet because		receiving heartbeat probes from peer DOTS clients. As a reminder, it
	no matching state is found), DOTS servers MAY trigger their heartbeat		is the responsibility of DOTS clients to ensure that on-path
	requests immediately after receiving heartbeat probes from peer DOTS		translators/firewalls are maintaining a binding so that the same
	clients.		external IP address and/or port number is retained for the DOTS
			session.
	In case of a massive DDoS attack that saturates the incoming link(s)		In case of a massive DDoS attack that saturates the incoming link(s)
	to the DOTS client, all traffic from the DOTS server to the DOTS		to the DOTS client, all traffic from the DOTS server to the DOTS
	client will likely be dropped, although the DOTS server receives		client will likely be dropped, although the DOTS server receives
	heartbeat requests in addition to DOTS messages sent by the DOTS		heartbeat requests in addition to DOTS messages sent by the DOTS
	client. In this scenario, the DOTS agents MUST behave differently to		client. In this scenario, the DOTS agents MUST behave differently to
	handle message transmission and DOTS session liveliness during link		handle message transmission and DOTS session liveliness during link
	saturation:		saturation:
	o The DOTS client MUST NOT consider the DOTS session terminated even		o The DOTS client MUST NOT consider the DOTS session terminated even
	skipping to change at page 47, line 20 ¶		skipping to change at page 49, line 20 ¶
	5.1. Tree Structure		5.1. Tree Structure
	This document defines the YANG module "ietf-dots-signal"		This document defines the YANG module "ietf-dots-signal"
	(Section 5.2), which has the following tree structure. A DOTS signal		(Section 5.2), which has the following tree structure. A DOTS signal
	message can either be a mitigation or a configuration message.		message can either be a mitigation or a configuration message.
	module: ietf-dots-signal		module: ietf-dots-signal
	+--rw dots-signal		+--rw dots-signal
	+--rw (message-type)?		+--rw (message-type)?
	+--:(mitigation-scope)		+--:(mitigation-scope)
	| +--rw client-identifier* binary		| +--rw client-domain-hash? string
	| +--rw scope* [mitigation-id]		| +--rw scope* [cuid mitigation-id]
			| +--rw cuid string
	| +--rw mitigation-id int32		| +--rw mitigation-id int32
	| +--rw target-prefix* inet:ip-prefix		| +--rw target-prefix* inet:ip-prefix
	| +--rw target-port-range* [lower-port upper-port]		| +--rw target-port-range* [lower-port upper-port]
	| | +--rw lower-port inet:port-number		| | +--rw lower-port inet:port-number
	| | +--rw upper-port inet:port-number		| | +--rw upper-port inet:port-number
	| +--rw target-protocol* uint8		| +--rw target-protocol* uint8
	| +--rw target-fqdn* inet:domain-name		| +--rw target-fqdn* inet:domain-name
	| +--rw target-uri* inet:uri		| +--rw target-uri* inet:uri
	| +--rw alias-name* string		| +--rw alias-name* string
	| +--rw lifetime? int32		| +--rw lifetime? int32
	skipping to change at page 48, line 5 ¶		skipping to change at page 50, line 6 ¶
	| | +--ro target-fqdn* inet:domain-name		| | +--ro target-fqdn* inet:domain-name
	| | +--ro target-uri* inet:uri		| | +--ro target-uri* inet:uri
	| | +--ro alias-name* string		| | +--ro alias-name* string
	| | +--ro acl-list* [acl-name acl-type]		| | +--ro acl-list* [acl-name acl-type]
	| | +--ro acl-name -> /ietf-acl:access-lists/acl/acl-name		| | +--ro acl-name -> /ietf-acl:access-lists/acl/acl-name
	| | +--ro acl-type -> /ietf-acl:access-lists/acl/acl-type		| | +--ro acl-type -> /ietf-acl:access-lists/acl/acl-type
	| +--ro pkts-dropped? yang:zero-based-counter64		| +--ro pkts-dropped? yang:zero-based-counter64
	| +--ro bps-dropped? yang:zero-based-counter64		| +--ro bps-dropped? yang:zero-based-counter64
	| +--ro bytes-dropped? yang:zero-based-counter64		| +--ro bytes-dropped? yang:zero-based-counter64
	| +--ro pps-dropped? yang:zero-based-counter64		| +--ro pps-dropped? yang:zero-based-counter64
	+--:(configuration)		| +--rw attack-status? enumeration
	+--rw session-id int32		+--:(signal-config)
	+--rw attack-time-config		| +--rw session-id int32
	| +--rw heartbeat-interval		| +--rw mitigating-config
	| | +--rw max-value? int16		| | +--rw heartbeat-interval
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw missing-hb-allowed		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw missing-hb-allowed
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw max-retransmit		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw max-retransmit
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw ack-timeout		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw ack-timeout
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw ack-random-factor		| | | +--rw current-value? int16
	| +--rw max-value? decimal64		| | +--rw ack-random-factor
	| +--rw min-value? decimal64		| | +--rw max-value-decimal? decimal64
	| +--rw current-value? decimal64		| | +--rw min-value-decimal? decimal64
	+--rw peace-time-config		| | +--rw current-value-decimal? decimal64
	| +--rw heartbeat-interval		| +--rw idle-config
	| | +--rw max-value? int16		| | +--rw heartbeat-interval
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw missing-hb-allowed		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw missing-hb-allowed
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw max-retransmit		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw max-retransmit
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw ack-timeout		| | | +--rw current-value? int16
	| | +--rw max-value? int16		| | +--rw ack-timeout
	| | +--rw min-value? int16		| | | +--rw max-value? int16
	| | +--rw current-value? int16		| | | +--rw min-value? int16
	| +--rw ack-random-factor		| | | +--rw current-value? int16
	| +--rw max-value? decimal64		| | +--rw ack-random-factor
	| +--rw min-value? decimal64		| | +--rw max-value-decimal? decimal64
	| +--rw current-value? decimal64		| | +--rw min-value-decimal? decimal64
	+--rw trigger-mitigation? boolean		| | +--rw current-value-decimal? decimal64
	+--rw config-interval? int32		| +--rw trigger-mitigation? boolean
			| +--rw config-interval? int32
			+--:(redirected-signal)
			+--rw alt-server string
			+--rw alt-server-record* [addr]
			+--rw addr inet:ip-address
			+--rw ttl? int32
	5.2. YANG Module		5.2. YANG Module
	<CODE BEGINS> file "ietf-dots-signal@2017-12-19.yang"		<CODE BEGINS> file "ietf-dots-signal@2018-01-09.yang"
	module ietf-dots-signal {		module ietf-dots-signal {
	yang-version 1.1;		yang-version 1.1;
	namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal";		namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal";
	prefix "signal";		prefix "signal";
	import ietf-inet-types {prefix "inet";}		import ietf-inet-types {prefix "inet";}
	import ietf-yang-types {prefix yang;}		import ietf-yang-types {prefix yang;}
	import ietf-access-control-list {prefix "ietf-acl";}		import ietf-access-control-list {prefix "ietf-acl";}
	organization "IETF DDoS Open Threat Signaling (DOTS) Working Group";		organization "IETF DDoS Open Threat Signaling (DOTS) Working Group";
	contact		contact
	"Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>		"WG Web: <https://datatracker.ietf.org/wg/dots/>
	Mohamed Boucadair <mohamed.boucadair@orange.com>		WG List: <mailto:dots@ietf.org>
	Prashanth Patil <praspati@cisco.com>
	Andrew Mortensen <amortensen@arbor.net>
	Nik Teague <nteague@verisign.com>";
	description		Editor: Konda, Tirumaleswar Reddy
	"This module contains YANG definition for the signaling		<mailto:TirumaleswarReddy_Konda@McAfee.com>
	messages exchanged between a DOTS client and a DOTS server.
	Copyright (c) 2017 IETF Trust and the persons identified as		Editor: Mohamed Boucadair
	authors of the code. All rights reserved.		<mailto:mohamed.boucadair@orange.com>
	Redistribution and use in source and binary forms, with or		Author: Prashanth Patil
	without modification, is permitted pursuant to, and subject		<mailto:praspati@cisco.com>
	to the license terms contained in, the Simplified 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		Author: Andrew Mortensen
	the RFC itself for full legal notices.";		<mailto:amortensen@arbor.net>
	revision 2017-12-19 {		Author: Nik Teague
	description		<mailto:nteague@verisign.com>";
	"Initial revision.";
	reference
	"RFC XXXX: Distributed Denial-of-Service Open Threat
	Signaling (DOTS) Signal Channel";
	}
	grouping target {		description
	description		"This module contains YANG definition for the signaling
	"Specifies the scope of the mitigation request.";		messages exchanged between a DOTS client and a DOTS server.
	leaf-list target-prefix {		Copyright (c) 2017 IETF Trust and the persons identified as
	type inet:ip-prefix;		authors of the code. All rights reserved.
	description
	"IPv4 or IPv6 prefix identifying the target.";
	}
	list target-port-range {		Redistribution and use in source and binary forms, with or
	key "lower-port upper-port";		without modification, is permitted pursuant to, and subject
			to the license terms contained in, the Simplified 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).
	description		This version of this YANG module is part of RFC XXXX; see
	"Port range. When only lower-port is		the RFC itself for full legal notices.";
	present, it represents a single port.";
	leaf lower-port {		revision 2018-01-09 {
	type inet:port-number;		description
	mandatory true;		"Initial revision.";
	description "Lower port number.";		reference
	}		"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
	leaf upper-port {		grouping target {
	type inet:port-number;		description
	must ". >= ../lower-port" {		"Specifies the targets of the mitigation request.";
	error-message
	"The upper port number must be greater than
	or equal to lower port number.";
	}
	description "Upper port number.";
	}
	}
	leaf-list target-protocol {		leaf-list target-prefix {
	type uint8;		type inet:ip-prefix;
	description		description
	"Identifies the target protocol number.		"IPv4 or IPv6 prefix identifying the target.";
			}
	The value '0' means 'all protocols'.		list target-port-range {
			key "lower-port upper-port";
	Values are taken from the IANA protocol registry:		description
	https://www.iana.org/assignments/protocol-numbers/		"Port range. When only lower-port is
	protocol-numbers.xhtml		present, it represents a single port.";
	For example, 6 for TCP or 17 for UDP.";		leaf lower-port {
	}		type inet:port-number;
			mandatory true;
			description "Lower port number.";
			}
	leaf-list target-fqdn {		leaf upper-port {
	type inet:domain-name;		type inet:port-number;
	description "FQDN identifying the target.";		must ". >= ../lower-port" {
	}		error-message
			"The upper port number must be greater than
			or equal to lower port number.";
			}
			description "Upper port number.";
			}
			}
	leaf-list target-uri {		leaf-list target-protocol {
	type inet:uri;		type uint8;
	description "URI identifying the target.";		description
	}		"Identifies the target protocol number.
	leaf-list alias-name {		The value '0' means 'all protocols'.
	type string;
	description "alias name";
	}
	}
	grouping mitigation-scope {		Values are taken from the IANA protocol registry:
	description		https://www.iana.org/assignments/protocol-numbers/
	"Specifies the scope of the mitigation request.";		protocol-numbers.xhtml
	leaf-list client-identifier {		For example, 6 for TCP or 17 for UDP.";
	type binary;		}
	description
	"The client identifier may be conveyed by
	the DOTS gateway to propagate the DOTS client
	identification information from the gateway's
	client-side to the gateway's server-side,
	and from the gateway's server-side to the DOTS
	server.
	It may be used by the final DOTS server		leaf-list target-fqdn {
	for policy enforcement purposes.";		type inet:domain-name;
	}		description "FQDN identifying the target.";
			}
	list scope {		leaf-list target-uri {
	key mitigation-id;		type inet:uri;
	description		description "URI identifying the target.";
	"The scope of the request.";		}
	leaf mitigation-id {		leaf-list alias-name {
	type int32;		type string;
	description		description "alias name";
	"Mitigation request identifier.		}
			}
	This identifier must be unique for each mitigation		grouping mitigation-scope {
	request bound to the DOTS client.";		description
	}		"Specifies the scope of the mitigation request.";
	uses target;		leaf client-domain-hash {
	leaf lifetime {		type string;
	type int32;		description
	units "seconds";		"The client domain hash may be conveyed by
	default 3600;		the server-domain DOTS gateway to propagate the
	description		client domain identification information from the
	"Indicates the lifetime of the mitigation request.";		gateway's client-side to the gateway's server-side,
	reference		and from the gateway's server-side to the DOTS
	"RFC XXXX: Distributed Denial-of-Service Open Threat		server.
	Signaling (DOTS) Signal Channel";
	}
	leaf mitigation-start {		It may be used by the final DOTS server
	type int64;		for policy enforcement purposes.";
	units "seconds";		}
	description
	"Mitigation start time is represented in seconds
	relative to 1970-01-01T00:00Z in UTC time.";
	}
	leaf status {		list scope {
	type enumeration {		key "cuid mitigation-id";
	enum "attack-mitigation-in-progress" {		description
	value 1;		"The scope of the request.";
	description
	"Attack mitigation is in progress (e.g., changing
	the network path to re-route the inbound traffic
	to DOTS mitigator).";
	}
	enum "attack-successfully-mitigated" {		leaf cuid {
	value 2;		type string;
	description		description
	"Attack is successfully mitigated (e.g., traffic		"A unique identifier that is randomly
	is redirected to a DDOS mitigator and attack		generated by a DOTS client to prevent
	traffic is dropped or blackholed).";		request collisions.";
	}		}
	enum "attack-stopped" {		leaf mitigation-id {
	value 3;		type int32;
	description		description
	"Attack has stopped and the DOTS client can		"Mitigation request identifier.
	withdraw the mitigation request.";
	}
	enum "attack-exceeded-capability" {		This identifier must be unique for each mitigation
	value 4;		request bound to the DOTS client.";
	description		}
	"Attack has exceeded the mitigation provider
	capability.";
	}
	enum "dots-client-withdrawn-mitigation" {		uses target;
	value 5;
	description
	"DOTS client has withdrawn the mitigation
	request and the mitigation is active but
	terminating.";
	}
	enum "attack-mitigation-terminated" {		leaf lifetime {
	value 6;		type int32;
	description		units "seconds";
	"Attack mitigation is now terminated.";		default 3600;
	}		description
			"Indicates the lifetime of the mitigation request.";
			reference
			"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
	enum "attack-mitigation-withdrawn" {		leaf mitigation-start {
	value 7;		type int64;
	description		units "seconds";
	"Attack mitigation is withdrawn.";		description
	}		"Mitigation start time is represented in seconds
			relative to 1970-01-01T00:00Z in UTC time.";
			}
	enum "attack-mitigation-rejected" {		leaf status {
	value 8;		type enumeration {
	description		enum "attack-mitigation-in-progress" {
	"Attack mitigation is rejected.";		value 1;
	}		description
	}		"Attack mitigation is in progress (e.g., changing
	config false;		the network path to re-route the inbound traffic
	description		to DOTS mitigator).";
	"Indicates the status of a mitigation request.		}
	It must be included in responses only.";
	}
	container conflict-information {		enum "attack-successfully-mitigated" {
	config false;		value 2;
	description		description
	"Indicates that a conflict is detected.		"Attack is successfully mitigated (e.g., traffic
	Must only be used for responses.";		is redirected to a DDoS mitigator and attack
			traffic is dropped or blackholed).";
			}
	leaf conflict-status {		enum "attack-stopped" {
			value 3;
			description
			"Attack has stopped and the DOTS client can
			withdraw the mitigation request.";
			}
			enum "attack-exceeded-capability" {
			value 4;
			description
			"Attack has exceeded the mitigation provider
			capability.";
			}
			enum "dots-client-withdrawn-mitigation" {
			value 5;
			description
			"DOTS client has withdrawn the mitigation
			request and the mitigation is active but
			terminating.";
			}
			enum "attack-mitigation-terminated" {
			value 6;
			description
			"Attack mitigation is now terminated.";
			}
			enum "attack-mitigation-withdrawn" {
			value 7;
			description
			"Attack mitigation is withdrawn.";
			}
			enum "attack-mitigation-rejected" {
			value 8;
			description
			"Attack mitigation is rejected.";
			}
			}
			config false;
			description
			"Indicates the status of a mitigation request.
			It must be included in responses only.";
			}
			container conflict-information {
			config false;
			description
			"Indicates that a conflict is detected.
			Must only be used for responses.";
			leaf conflict-status {
			type enumeration {
			enum "request-inactive-other-active" {
			value 1;
			description
			"DOTS Server has detected conflicting mitigation
			requests from different DOTS clients.
			This mitigation request is currently inactive
			until the conflicts are resolved. Another
			mitigation request is active.";
			}
			enum "request-active" {
			value 2;
			description
			"DOTS Server has detected conflicting mitigation
			requests from different DOTS clients.
			This mitigation request is currently active.";
			}
			enum "all-requests-inactive" {
			value 3;
			description
			"DOTS Server has detected conflicting mitigation
			requests from different DOTS clients. All
			conflicting mitigation requests are inactive.";
			}
			}
			description
			"Indicates the conflict status.
			It must be included in responses only.";
			}
			leaf conflict-cause {
	type enumeration {		type enumeration {
	enum "request-inactive-other-active" {		enum "overlapping-targets" {
	value 1;		value 1;
	description		description
	"DOTS Server has detected conflicting mitigation		"Overlapping targets. conflict-scope provides
	requests from different DOTS clients.		more details about the exact conflict.";
	This mitigation request is currently inactive
	until the conflicts are resolved. Another
	mitigation request is active.";
	}		}
	enum "request-active" {		enum "conflict-with-whitelist" {
	value 2;		value 2;
	description		description
	"DOTS Server has detected conflicting mitigation		"Conflicts with an existing white list.
	requests from different DOTS clients.
	This mitigation request is currently active.";
	}
	enum "all-requests-inactive" {		This code is returned when the DDoS mitigation
			detects that some of the source addresses/prefixes
			listed in the white list ACLs are actually
			attacking the target.";
			}
			enum "cuid-collision" {
	value 3;		value 3;
	description		description
	"DOTS Server has detected conflicting mitigation		"Conflicts with the CUID used by another
	requests from different DOTS clients. All		DOTS client of the same domain.";
	conflicting mitigation requests are inactive.";
	}		}
	}		}
	description		description
	"Indicates the conflict status.		"Indicates the cause of the conflict.
	It must be included in responses only.";		It must be included in responses only.";
	}		}
	leaf conflict-cause {		leaf retry-timer {
	type enumeration {		type int32;
	enum "overlapping-targets" {		units "seconds";
	value 1;		description
	description		"The DOTS client must not re-send the
	"Overlapping targets. conflict-scope provides		same request before the expiry of this timer.
	more details about the exact conflict.";		It must be included in responses, only.";
	}		}
	enum "conflict-with-whitelist" {		container conflict-scope {
	value 2;		description
	description		"Provides more information about the conflict scope.";
	"Conflicts with an existing white list.
	This code is returned when the DDoS mitigation		uses target {
	detects that some of the source addresses/prefixes		when "../conflict-cause = 'overlapping-targets'";
	listed in the white list ACLs are actually		}
	attacking the target.";
			list acl-list {
			when "../../conflict-cause = 'conflict-with-whitelist'";
			key "acl-name acl-type";
			description
			"List of conflicting ACLs";
			leaf acl-name {
			type leafref {
			path "/ietf-acl:access-lists/ietf-acl:acl" +
			"/ietf-acl:acl-name";
	}		}
	}		description
	description		"Reference to the conflicting ACL name bound to
	"Indicates the cause of the conflict.		a DOTS client.";
			}
	It must be included in responses only.";		leaf acl-type {
	}		type leafref {
			path "/ietf-acl:access-lists/ietf-acl:acl" +
			"/ietf-acl:acl-type";
			}
			description
			"Reference to the conflicting ACL type bound to
			a DOTS client.";
			}
			}
			}
			}
	leaf retry-timer {		leaf pkts-dropped {
	type int32;		type yang:zero-based-counter64;
	units "seconds";		config false;
	description		description
	"The DOTS client must not re-send the		"Number of dropped packets";
	same request before the expiry of this timer.		}
	It must be included in responses, only.";
	}
	container conflict-scope {		leaf bps-dropped {
	description		type yang:zero-based-counter64;
	"Provides more information about the conflict scope.";		config false;
			description
			"The average number of dropped bytes per second for
			the mitigation request since the attack
			mitigation is triggered.";
			}
	uses target {		leaf bytes-dropped {
	when "../conflict-cause = 'overlapping-targets'";		type yang:zero-based-counter64;
	}		units 'bytes';
			config false;
			description
			"Counter for dropped packets; in bytes.";
			}
	list acl-list {		leaf pps-dropped {
	when "../../conflict-cause = 'conflict-with-whitelist'";		type yang:zero-based-counter64;
	key "acl-name acl-type";		config false;
	description		description
	"List of conflicting ACLs";		"The average number of dropped packets per second
			for the mitigation request since the attack
			mitigation is triggered.";
			}
	leaf acl-name {		leaf attack-status {
	type leafref {		type enumeration {
	path "/ietf-acl:access-lists/ietf-acl:acl" +		enum "under-attack" {
	"/ietf-acl:acl-name";		value 1;
	}		description
	description		"The DOTS client determines that it is still under
	"Reference to the conflicting ACL name bound to		attack.";
	a DOTS client.";		}
	}
	leaf acl-type {		enum "attack-successfully-mitigated" {
	type leafref {		value 2;
	path "/ietf-acl:access-lists/ietf-acl:acl" +		description
	"/ietf-acl:acl-type";		"The DOTS client determines that the attack is
	}		successfully mitigated.";
	description		}
	"Reference to the conflicting ACL type bound to		}
	a DOTS client.";		description
	}		"Indicates the status of an attack as seen by the
	}		DOTS client.";
	}		}
	}		}
	leaf pkts-dropped {		}
	type yang:zero-based-counter64;
	config false;
	description
	"Number of dropped packets";
	}
	leaf bps-dropped {		grouping config-parameters {
	type yang:zero-based-counter64;		description
	config false;		"Subset of DOTS signal channel session configuration.";
	description
	"The average number of dropped bytes per second for
	the mitigation request since the attack
	mitigation is triggered.";
	}
	leaf bytes-dropped {		container heartbeat-interval {
	type yang:zero-based-counter64;		description
	units 'bytes';		"DOTS agents regularly send heartbeats to each other
	config false;		after mutual authentication is successfully
	description		completed in order to keep the DOTS signal channel
	"Counter for dropped packets; in bytes.";		open.";
	}
	leaf pps-dropped {		leaf max-value {
	type yang:zero-based-counter64;		type int16;
	config false;		units "seconds";
	description		description
	"The average number of dropped packets per second		"Maximum acceptable value.";
	for the mitigation request since the attack		reference
	mitigation is triggered.";		"RFC XXXX: Distributed Denial-of-Service Open Threat
	}		Signaling (DOTS) Signal Channel";
	}		}
	}
	grouping config-parameters {		leaf min-value {
	description		type int16;
	"Subset of DOTS signal channel session configuration.";		units "seconds";
			description
			"Minimum acceptable value.";
			reference
			"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
			leaf current-value {
			type int16;
			units "seconds";
			default 30;
			description
			"Current value.
	container heartbeat-interval {		'0' means that heartbeat mechanism is deactivated.";
	description		reference
	"DOTS agents regularly send heartbeats to each other		"RFC XXXX: Distributed Denial-of-Service Open Threat
	after mutual authentication is successfully		Signaling (DOTS) Signal Channel";
	completed in order to keep the DOTS signal channel		}
	open.";		}
	leaf max-value {		container missing-hb-allowed {
	type int16;		description
	units "seconds";		"Maximum number of missing heartbeats allowed.";
	description
	"Maximum acceptable value.";
	reference
	"RFC XXXX: Distributed Denial-of-Service Open Threat
	Signaling (DOTS) Signal Channel";
	}
	leaf min-value {		leaf max-value {
	type int16;		type int16;
	units "seconds";		description
	description		"Maximum acceptable value.";
	"Minimum acceptable value.";
	reference
	"RFC XXXX: Distributed Denial-of-Service Open Threat
	Signaling (DOTS) Signal Channel";
	}
	leaf current-value {
	type int16;
	units "seconds";
	default 30;
	description
	"Current value.
	'0' means that heartbeat mechanism is deactivated.";		reference
	reference		"RFC XXXX: Distributed Denial-of-Service Open Threat
	"RFC XXXX: Distributed Denial-of-Service Open Threat		Signaling (DOTS) Signal Channel";
	Signaling (DOTS) Signal Channel";		}
	}
	}
	container missing-hb-allowed {		leaf min-value {
	description		type int16;
	"Maximum number of missing heartbeats allowed.";		description
			"Minimum acceptable value.";
			reference
			"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
			leaf current-value {
			type int16;
			default 5;
			description
			"Current value.";
			reference
			"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
			}
	leaf max-value {		container max-retransmit {
	type int16;		description
	description		"Maximum number of retransmissions of a Confirmable
	"Maximum acceptable value.";		message.";
	reference
	"RFC XXXX: Distributed Denial-of-Service Open Threat
	Signaling (DOTS) Signal Channel";
	}
	leaf min-value {		leaf max-value {
	type int16;		type int16;
	description		description
	"Minimum acceptable value.";		"Maximum acceptable value.";
			reference
			"Section 4.8 of RFC 7552.";
			}
	reference		leaf min-value {
	"RFC XXXX: Distributed Denial-of-Service Open Threat		type int16;
	Signaling (DOTS) Signal Channel";		description
	}		"Minimum acceptable value.";
	leaf current-value {		reference
	type int16;		"Section 4.8 of RFC 7552.";
	default 5;		}
	description		leaf current-value {
	"Current value.";		type int16;
	reference		default 3;
	"RFC XXXX: Distributed Denial-of-Service Open Threat		description
	Signaling (DOTS) Signal Channel";		"Current value.";
	}		reference
	}		"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
			}
	container max-retransmit {		container ack-timeout {
	description		description
	"Maximum number of retransmissions of a Confirmable		"Initial retransmission timeout value.";
	message.";
	leaf max-value {		leaf max-value {
	type int16;		type int16;
	description		units "seconds";
	"Maximum acceptable value.";		description
	reference		"Maximum value.";
	"Section 4.8 of RFC 7552.";		reference
	}		"Section 4.8 of RFC 7552.";
			}
	leaf min-value {		leaf min-value {
	type int16;		type int16;
	description		units "seconds";
	"Minimum acceptable value.";		description
	reference		"Minimum value.";
	"Section 4.8 of RFC 7552.";		reference
	}		"Section 4.8 of RFC 7552.";
	leaf current-value {		}
	type int16;		leaf current-value {
	default 3;		type int16;
	description		units "seconds";
	"Current value.";		default 2;
	reference		description
	"RFC XXXX: Distributed Denial-of-Service Open Threat		"Current value.";
	Signaling (DOTS) Signal Channel";		reference
	}		"Section 4.8 of RFC 7552.";
	}		}
			}
	container ack-timeout {		container ack-random-factor {
	description		description
	"Initial retransmission timeout value.";		"Random factor used to influence the timing of
			retransmissions.";
	leaf max-value {		leaf max-value-decimal {
	type int16;		type decimal64 {
	units "seconds";		fraction-digits 2;
	description		}
	"Maximum value.";		description
	reference		"Maximum acceptable value.";
	"Section 4.8 of RFC 7552.";		reference
	}		"Section 4.8 of RFC 7552.";
			}
	leaf min-value {		leaf min-value-decimal {
	type int16;		type decimal64 {
	units "seconds";		fraction-digits 2;
	description		}
	"Minimum value.";		description
	reference		"Minimum acceptable value.";
	"Section 4.8 of RFC 7552.";		reference
	}		"Section 4.8 of RFC 7552.";
	leaf current-value {		}
	type int16;		leaf current-value-decimal {
	units "seconds";		type decimal64 {
	default 2;		fraction-digits 2;
	description		}
	"Current value.";		default 1.5;
	reference		description
	"Section 4.8 of RFC 7552.";		"Current value.";
	}		reference
	}		"Section 4.8 of RFC 7552.";
			}
			}
			}
	container ack-random-factor {		grouping signal-config {
	description		description
	"Random factor used to influence the timing of		"DOTS signal channel session configuration.";
	retransmissions.";
	leaf max-value {		leaf session-id {
	type decimal64 {		type int32;
	fraction-digits 2;		mandatory true;
	}		description
	description		"An identifier for the DOTS signal channel
	"Maximum acceptable value.";		session configuration data.";
	reference		}
	"Section 4.8 of RFC 7552.";
	}
	leaf min-value {		container mitigating-config {
	type decimal64 {		description
	fraction-digits 2;		"Configuration parameters to use when a mitigation is active.";
			uses config-parameters;
			}
	}		container idle-config {
	description		description
	"Minimum acceptable value.";		"Configuration parameters to use when no mitigation is
	reference		active.";
	"Section 4.8 of RFC 7552.";		uses config-parameters;
	}		}
	leaf current-value {
	type decimal64 {
	fraction-digits 2;
	}
	default 1.5;
	description
	"Current value.";
	reference
	"Section 4.8 of RFC 7552.";
	}
	}
	}
	grouping signal-config {		leaf trigger-mitigation {
	description		type boolean;
	"DOTS signal channel session configuration.";		default true;
			description
			"If false, then mitigation is triggered
			only when the DOTS server channel session is lost";
			reference
			"RFC XXXX: Distributed Denial-of-Service Open Threat
			Signaling (DOTS) Signal Channel";
			}
	leaf session-id {		leaf config-interval {
	type int32;		type int32;
	mandatory true;		units "seconds";
	description		description
	"An identifier for the DOTS signal channel		"This parameter is returned by a DOTS server to
	session configuration data.";		a requesting DOTS client to indicate the time interval
	}		after which the DOTS client must contact the DOTS
			server in order to retrieve the signal channel
			configuration data.
	container attack-time-config {		This mechanism allows the update of the configuration
	description		data if a change occurs.
	"Configuration paramaters to use when an attack is active.";
	uses config-parameters;
	}
	container peace-time-config {		For example, the new configuration may instruct
	description		a DOTS client to cease heartbeats or reduce
	"Configuration paramaters to use in peacetime.";		heartbeat frequency.
	uses config-parameters;
	}
	leaf trigger-mitigation {		'0' is used to disable this refresh mechanism.";
	type boolean;		}
	default true;		}
	description
	"If false, then mitigation is triggered
	only when the DOTS server channel session is lost";
	reference
	"RFC XXXX: Distributed Denial-of-Service Open Threat
	Signaling (DOTS) Signal Channel";
	}
	leaf config-interval {		grouping redirected-signal {
	type int32;		description
	units "minutes";		"Grouping for the redirected signaling.";
	description
	"This parameter is returned by a DOTS server to
	a requesting DOTS client to indicate the time interval
	after which the DOTS client must contact the DOTS
	server in order to retrieve the signal channel
	configuration data.
	This mechanism allows the update of the configuration		leaf alt-server {
	data if a change occurs.		type string;
			mandatory true;
			description
			"Alias of an alternate server.";
			}
			list alt-server-record {
			key "addr";
			description
			"List of records for the alternate server.";
	For example, the new configuration may instruct		leaf addr {
	a DOTS client to cease heartbeats or reduce		type inet:ip-address;
	heartbeat frequency.		description
			"IPv4 or IPv6 address identifying the server.";
			}
	'0' is used to disable this refresh mechanism.";		leaf ttl {
	}		type int32;
	}		description
			"TTL associated with this record.";
			}
			}
			}
	container dots-signal {		container dots-signal {
	description		description
	"Main container for DOTS signal message.		"Main container for DOTS signal message.
	A DOTS signal message can be a mitigation message or		A DOTS signal message can be a mitigation message or
	a configuration message.";		a configuration message.";
	choice message-type {		choice message-type {
	description		description
	"Either a mitigation or a configuration message.";		"Can be a mitigation, a configuration, or a redirect
			message.";
	case mitigation-scope {		case mitigation-scope {
	description		description
	"Mitigation scope of a mitigation message.";		"Mitigation scope of a mitigation message.";
	uses mitigation-scope;		uses mitigation-scope;
	}		}
	case configuration {		case signal-config {
	description		description
	"Configuration message.";		"Configuration message.";
	uses signal-config;		uses signal-config;
	}		}
	}		case redirected-signal {
	}		description
	}		"Redirected signaling.";
	<CODE ENDS>		uses redirected-signal;
			}
			}
			}
			}
			<CODE ENDS>
	6. Mapping Parameters to CBOR		6. Mapping Parameters to CBOR
	All parameters in the payload of the DOTS signal channel MUST be		All parameters in the payload of the DOTS signal channel MUST be
	mapped to CBOR types as shown in Table 4 and are assigned an integer		mapped to CBOR types as shown in Table 4 and are assigned an integer
	key to save space. The recipient of the payload MAY reject the		key to save space. The recipient of the payload MAY reject the
	information if it is not suitably mapped.		information if it is not suitably mapped.
	/----------------------+----------------+--------------------------\		+-----------------------+----------+--------------------+
	| Parameter name | CBOR key | CBOR major type of value |		| Parameter Name | CBOR Key | CBOR Major Type |
	+----------------------+----------------+--------------------------+		+-----------------------+----------+--------------------+
	| mitigation-scope | 1 | 5 (map) |		| mitigation-scope | 1 | 5 (map) |
	| scope | 2 | 5 (map) |		| scope | 2 | 5 (map) |
	| mitigation-id | 3 | 0 (unsigned) |		| mitigation-id | 3 | 0 (unsigned) |
	| acl-list | 4 | 4 |		| acl-list | 4 | 4 |
	| target-port-range | 5 | 4 |		| target-port-range | 5 | 4 |
	| lower-port | 6 | 0 |		| lower-port | 6 | 0 |
	| upper-port | 7 | 0 |		| upper-port | 7 | 0 |
	| target-protocol | 8 | 4 |		| target-protocol | 8 | 4 |
	| target-fqdn | 9 | 4 |		| target-fqdn | 9 | 4 |
	| target-uri | 10 | 4 |		| target-uri | 10 | 4 |
	| alias-name | 11 | 4 |		| alias-name | 11 | 4 |
	| lifetime | 12 | 0 |		| lifetime | 12 | 0 |
	| attack-status | 13 | 0 |		| attack-status | 13 | 0 |
	| signal-config | 14 | 5 |		| signal-config | 14 | 5 (map) |
	| heartbeat-interval | 15 | 5 (map) |		| heartbeat-interval | 15 | 5 (map) |
	| max-retransmit | 16 | 5 (map) |		| max-retransmit | 16 | 5 (map) |
	| ack-timeout | 17 | 5 (map) |		| ack-timeout | 17 | 5 (map) |
	| ack-random-factor | 18 | 5 (map) |		| ack-random-factor | 18 | 5 (map) |
	| min-value | 19 | 0 |		| min-value | 19 | 0 |
	| max-value | 20 | 0 |		| max-value | 20 | 0 |
	| status | 21 | 0 |		| status | 21 | 0 |
	| conflict-information | 22 | 5 (map) |		| conflict-information | 22 | 5 (map) |
	| conflict-status | 23 | 0 |		| conflict-status | 23 | 0 |
	| conflict-cause | 24 | 0 |		| conflict-cause | 24 | 0 |
	| retry-timer | 25 | 0 |		| retry-timer | 25 | 0 |
	| bytes-dropped | 26 | 0 |		| bytes-dropped | 26 | 0 |
	| bps-dropped | 27 | 0 |		| bps-dropped | 27 | 0 |
	| pkts-dropped | 28 | 0 |		| pkts-dropped | 28 | 0 |
	| pps-dropped | 29 | 0 |		| pps-dropped | 29 | 0 |
	| session-id | 30 | 0 |		| session-id | 30 | 0 |
	| trigger-mitigation | 31 | 7 (simple types) |		| trigger-mitigation | 31 | 7 (simple types) |
	| missing-hb-allowed | 32 | 5 (map) |		| missing-hb-allowed | 32 | 5 (map) |
	| current-value | 33 | 0 |		| current-value | 33 | 0 |
	| mitigation-start | 34 | 7 (floating-point) |		| mitigation-start | 34 | 7 (floating-point) |
	| target-prefix | 35 | 4 (array) |		| target-prefix | 35 | 4 (array) |
	| client-identifier | 36 | 2 (byte string) |		| client-domain-hash | 36 | 3 |
	| alt-server | 37 | 2 |		| alt-server | 37 | 3 |
	| alt-server-record | 38 | 4 |		| alt-server-record | 38 | 4 |
	| addr | 39 | 2 |		| addr | 39 | 3 |
	| ttl | 40 | 0 |		| ttl | 40 | 0 |
	| conflict-scope | 41 | 5 (map) |		| conflict-scope | 41 | 5 (map) |
	| acl-name | 42 | 3 |		| acl-name | 42 | 3 |
	| acl-type | 43 | 3 |		| acl-type | 43 | 3 |
	| config-interval | 44 | 0 |		| config-interval | 44 | 0 |
	| attack-time-config | 45 | 5 (map) |		| mitigating-config | 45 | 5 (map) |
	| peace-time-config | 46 | 5 (map) |		| idle-config | 46 | 5 (map) |
	\----------------------+----------------+--------------------------/		| cuid | 47 | 3 |
	Table 4: CBOR mappings used in DOTS signal channel message		| min-value-decimal | 48 | 7 |
			| max-value-decimal | 49 | 7 |
			| current-value-decimal | 50 | 7 |
			+-----------------------+----------+--------------------+
			Table 4: CBOR Mappings Used in DOTS Signal Channel Messages
	7. (D)TLS Protocol Profile and Performance Considerations		7. (D)TLS Protocol Profile and Performance Considerations
	7.1. (D)TLS Protocol Profile		7.1. (D)TLS Protocol Profile
	This section defines the (D)TLS protocol profile of DOTS signal		This section defines the (D)TLS protocol profile of DOTS signal
	channel over (D)TLS and DOTS data channel over TLS.		channel over (D)TLS and DOTS data channel over TLS.
	There are known attacks on (D)TLS, such as man-in-the-middle and		There are known attacks on (D)TLS, such as man-in-the-middle and
	protocol downgrade attacks. These are general attacks on (D)TLS and,		protocol downgrade attacks. These are general attacks on (D)TLS and,
	skipping to change at page 63, line 48 ¶		skipping to change at page 68, line 4 ¶
	server, and connects to its configured DOTS server, the server may		server, and connects to its configured DOTS server, the server may
	present it with a PKIX certificate. In order to ensure proper		present it with a PKIX certificate. In order to ensure proper
	authentication, a DOTS client MUST verify the entire certification		authentication, a DOTS client MUST verify the entire certification
	path per [RFC5280]. The DOTS client additionally uses [RFC6125]		path per [RFC5280]. The DOTS client additionally uses [RFC6125]
	validation techniques to compare the domain name with the certificate		validation techniques to compare the domain name with the certificate
	provided.		provided.
	A key challenge to deploying DOTS is the provisioning of DOTS		A key challenge to deploying DOTS is the provisioning of DOTS
	clients, including the distribution of keying material to DOTS		clients, including the distribution of keying material to DOTS
	clients to enable the required mutual authentication of DOTS agents.		clients to enable the required mutual authentication of DOTS agents.
	EST defines a method of certificate enrollment by which domains		EST defines a method of certificate enrollment by which domains
	operating DOTS servers may provide DOTS clients with all the		operating DOTS servers may provide DOTS clients with all the
	necessary cryptographic keying material, including a private key and		necessary cryptographic keying material, including a private key and
	a certificate to authenticate themselves. One deployment option is		a certificate to authenticate themselves. One deployment option is
	DOTS clients behave as EST clients for certificate enrollment from an		DOTS clients behave as EST clients for certificate enrollment from an
	EST server provisioned by the mitigation provider. This document		EST server provisioned by the mitigation provider. This document
	does not specify which EST mechanism the DOTS client uses to achieve		does not specify which EST mechanism the DOTS client uses to achieve
	initial enrollment.		initial enrollment.
			The Server Name Indication (SNI) extension [RFC6066] defines a
			mechanism for a client to tell a (D)TLS server the name of the server
			it wants to contact. This is a useful extension for hosting
			environments where multiple virtual servers are reachable over a
			single IP address. The DOTS client may or may not know if it is
			interacting with a DOTS server in the hosting environment, so the
			DOTS client SHOULD include the DOTS server FQDN in the SNI extension.
	Implementations compliant with this profile MUST implement all of the		Implementations compliant with this profile MUST implement all of the
	following items:		following items:
	o DTLS record replay detection (Section 3.3 of [RFC6347]) to protect		o DTLS record replay detection (Section 3.3 of [RFC6347]) to protect
	against replay attacks.		against replay attacks.
	o (D)TLS session resumption without server-side state [RFC5077] to		o (D)TLS session resumption without server-side state [RFC5077] to
	resume session and convey the DOTS signal.		resume session and convey the DOTS signal.
	o Raw public keys [RFC7250] or PSK handshake [RFC4279] which reduces		o Raw public keys [RFC7250] or PSK handshake [RFC4279] which reduces
	skipping to change at page 65, line 22 ¶		skipping to change at page 69, line 38 ¶
	to convey the DOTS mitigation request message and, if there is no		to convey the DOTS mitigation request message and, if there is no
	response from the server after multiple retries, the DOTS client		response from the server after multiple retries, the DOTS client
	can resume the (D)TLS session in 0-RTT mode using PSK.		can resume the (D)TLS session in 0-RTT mode using PSK.
	Section 8 of [I-D.ietf-tls-tls13] discusses some mechanisms to		Section 8 of [I-D.ietf-tls-tls13] discusses some mechanisms to
	implement to limit the impact of replay attacks on 0-RTT data. If		implement to limit the impact of replay attacks on 0-RTT data. If
	TLS1.3 is used, DOTS servers must implement one of these		TLS1.3 is used, DOTS servers must implement one of these
	mechanisms.		mechanisms.
	A simplified TLS 1.3 handshake with 0-RTT DOTS mitigation request		A simplified TLS 1.3 handshake with 0-RTT DOTS mitigation request
	message exchange is shown in Figure 23.		message exchange is shown in Figure 25.
	DOTS Client DOTS Server		DOTS Client DOTS Server
	ClientHello		ClientHello
	(Finished)		(Finished)
	(0-RTT DOTS signal message)		(0-RTT DOTS signal message)
	(end_of_early_data) -------->		(end_of_early_data) -------->
	ServerHello		ServerHello
	{EncryptedExtensions}		{EncryptedExtensions}
	{ServerConfiguration}		{ServerConfiguration}
	{Certificate}		{Certificate}
	{CertificateVerify}		{CertificateVerify}
	{Finished}		{Finished}
	<-------- [DOTS signal message]		<-------- [DOTS signal message]
	{Finished} -------->		{Finished} -------->
	[DOTS signal message] <-------> [DOTS signal message]		[DOTS signal message] <-------> [DOTS signal message]
	Figure 23: TLS 1.3 handshake with 0-RTT		Figure 25: TLS 1.3 handshake with 0-RTT
	7.3. MTU and Fragmentation		7.3. MTU and Fragmentation
	To avoid DOTS signal message fragmentation and the subsequent		To avoid DOTS signal message fragmentation and the subsequent
	decreased probability of message delivery, DOTS agents MUST ensure		decreased probability of message delivery, DOTS agents MUST ensure
	that the DTLS record MUST fit within a single datagram. If the path		that the DTLS record MUST fit within a single datagram. If the path
	MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD		MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD
	be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP		be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP
	is used to convey the DOTS signal messages then the DOTS client must		is used to convey the DOTS signal messages then the DOTS client must
	consider the amount of record expansion expected by the DTLS		consider the amount of record expansion expected by the DTLS
	skipping to change at page 67, line 5 ¶		skipping to change at page 71, line 17 ¶
	(D)TLS based upon client certificate can be used for mutual		(D)TLS based upon client certificate can be used for mutual
	authentication between DOTS agents. If a DOTS gateway is involved,		authentication between DOTS agents. If a DOTS gateway is involved,
	DOTS clients and DOTS gateways MUST perform mutual authentication;		DOTS clients and DOTS gateways MUST perform mutual authentication;
	only authorized DOTS clients are allowed to send DOTS signals to a		only authorized DOTS clients are allowed to send DOTS signals to a
	DOTS gateway. The DOTS gateway and the DOTS server MUST perform		DOTS gateway. The DOTS gateway and the DOTS server MUST perform
	mutual authentication; a DOTS server only allows DOTS signal channel		mutual authentication; a DOTS server only allows DOTS signal channel
	messages from an authorized DOTS gateway, thereby creating a two-link		messages from an authorized DOTS gateway, thereby creating a two-link
	chain of transitive authentication between the DOTS client and the		chain of transitive authentication between the DOTS client and the
	DOTS server.		DOTS server.
			The DOTS server SHOULD support certificate-based client
			authentication. The DOTS client SHOULD respond to the DOTS server's
			TLS certificate request message with the PKIX certificate held by the
			DOTS client. DOTS client certificate validation MUST be performed as
			per [RFC5280] and the DOTS client certificate MUST conform to the
			[RFC5280] certificate profile. If a DOTS client does not support TLS
			client certificate authentication, it MUST support pre-shared key
			based or raw public key based client authentication.
	+-----------------------------------------------+		+-----------------------------------------------+
	| example.com domain +---------+ |		| example.com domain +---------+ |
	| | AAA | |		| | AAA | |
	| +---------------+ | Server | |		| +---------------+ | Server | |
	| | Application | +------+--+ |		| | Application | +------+--+ |
	| | server +<-----------------+ ^ |		| | server +<-----------------+ ^ |
	| | (DOTS client) | | | |		| | (DOTS client) | | | |
	| +---------------+ | | |		| +---------------+ | | |
	| V V | example.net domain		| V V | example.net domain
	| +-----+----+--+ | +---------------+		| +-----+----+--+ | +---------------+
	| +--------------+ | | | | |		| +--------------+ | | | | |
	| | Guest +<-----x----->+ DOTS +<------>+ DOTS |		| | Guest +<-----x----->+ DOTS +<------>+ DOTS |
	| | (DOTS client)| | Gateway | | | Server |		| | (DOTS client)| | gateway | | | server |
	| +--------------+ | | | | |		| +--------------+ | | | | |
	| +----+--------+ | +---------------+		| +----+--------+ | +---------------+
	| ^ |		| ^ |
	| | |		| | |
	| +----------------+ | |		| +----------------+ | |
	| | DDOS detector | | |		| | DDoS detector | | |
	| | (DOTS client) +<---------------+ |		| | (DOTS client) +<---------------+ |
	| +----------------+ |		| +----------------+ |
	+-----------------------------------------------+		+-----------------------------------------------+
	Figure 24: Example of Authentication and Authorization of DOTS Agents		Figure 26: Example of Authentication and Authorization of DOTS Agents
	In the example depicted in Figure 24, the DOTS gateway and DOTS		In the example depicted in Figure 26, the DOTS gateway and DOTS
	clients within the 'example.com' domain mutually authenticate with		clients within the 'example.com' domain mutually authenticate with
	each other. After the DOTS gateway validates the identity of a DOTS		each other. After the DOTS gateway validates the identity of a DOTS
	client, it communicates with the AAA server in the 'example.com'		client, it communicates with the AAA server in the 'example.com'
	domain to determine if the DOTS client is authorized to request DDoS		domain to determine if the DOTS client is authorized to request DDoS
	mitigation. If the DOTS client is not authorized, a 4.01		mitigation. If the DOTS client is not authorized, a 4.01
	(Unauthorized) is returned in the response to the DOTS client. In		(Unauthorized) is returned in the response to the DOTS client. In
	this example, the DOTS gateway only allows the application server and		this example, the DOTS gateway only allows the application server and
	DDoS attack detector to request DDOS mitigation, but does not permit		DDoS attack detector to request DDoS mitigation, but does not permit
	the user of type 'guest' to request DDoS mitigation.		the user of type 'guest' to request DDoS mitigation.
	Also, DOTS gateways and servers located in different domains MUST		Also, DOTS gateways and servers located in different domains MUST
	perform mutual authentication (e.g., using certificates). A DOTS		perform mutual authentication (e.g., using certificates). A DOTS
	server will only allow a DOTS gateway with a certificate for a		server will only allow a DOTS gateway with a certificate for a
	particular domain to request mitigation for that domain. In		particular domain to request mitigation for that domain. In
	reference to Figure 24, the DOTS server only allows the DOTS gateway		reference to Figure 26, the DOTS server only allows the DOTS gateway
	to request mitigation for 'example.com' domain and not for other		to request mitigation for 'example.com' domain and not for other
	domains.		domains.
	9. IANA Considerations		9. IANA Considerations
	This specification registers a service port (Section 9.1), an URI		This specification registers a service port (Section 9.1), an URI
	suffix in the Well-Known URIs registry (Section 9.2), a CoAP response		suffix in the Well-Known URIs registry (Section 9.2), a CoAP response
	code (Section 9.3), a YANG module (Section 9.5). It also creates a		code (Section 9.3), a YANG module (Section 9.5). It also creates a
	registry for mappings to CBOR (Section 9.4).		registry for mappings to CBOR (Section 9.4).
	skipping to change at page 68, line 46 ¶		skipping to change at page 73, line 14 ¶
	9.3. CoAP Response Code		9.3. CoAP Response Code
	IANA is requested to add the following entry to the "CoAP Response		IANA is requested to add the following entry to the "CoAP Response
	Codes" sub-registry available at https://www.iana.org/assignments/		Codes" sub-registry available at https://www.iana.org/assignments/
	core-parameters/core-parameters.xhtml#response-codes:		core-parameters/core-parameters.xhtml#response-codes:
	+------+------------------+-----------+		+------+------------------+-----------+
	| Code | Description | Reference |		| Code | Description | Reference |
	+------+------------------+-----------+		+------+------------------+-----------+
	| 3.00 | Alternate server | [RFCXXXX] |		| 3.00 | Alternate Server | [RFCXXXX] |
	+------+------------------+-----------+		+------+------------------+-----------+
	Table 4: CoAP Response Code		Table 5: CoAP Response Code
	9.4. DOTS Signal Channel CBOR Mappings Registry		9.4. DOTS Signal Channel CBOR Mappings Registry
	The document requests IANA to create a new registry, entitled "DOTS		The document requests IANA to create a new registry, entitled "DOTS
	Signal Channel CBOR Mappings Registry". The structure of this		Signal Channel CBOR Mappings Registry". The structure of this
	registry is provided in Section 9.4.1.		registry is provided in Section 9.4.1.
	The registry is initially populated with the values in Section 9.4.2.		The registry is initially populated with the values in Section 9.4.2.
	Values from that registry MUST be assigned via Expert Review		Values from that registry MUST be assigned via Expert Review
	skipping to change at page 74, line 4 ¶		skipping to change at page 78, line 17 ¶
	o CBOR Key Value: 33		o CBOR Key Value: 33
	o CBOR Major Type: 0		o CBOR Major Type: 0
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: mitigation-start		o Parameter Name: mitigation-start
	o CBOR Key Value: 34		o CBOR Key Value: 34
	o CBOR Major Type: 7		o CBOR Major Type: 7
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: target-prefix		o Parameter Name: target-prefix
	o CBOR Key Value: 35		o CBOR Key Value: 35
	o CBOR Major Type: 4		o CBOR Major Type: 4
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: client-identifier		o Parameter Name: client-domain-hash
	o CBOR Key Value: 36		o CBOR Key Value: 36
	o CBOR Major Type: 2		o CBOR Major Type: 3
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: alt-server		o Parameter Name: alt-server
	o CBOR Key Value: 37		o CBOR Key Value: 37
	o CBOR Major Type: 2		o CBOR Major Type: 3
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: alt-server-record		o Parameter Name: alt-server-record
	o CBOR Key Value: 38		o CBOR Key Value: 38
	o CBOR Major Type: 4		o CBOR Major Type: 4
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: addr		o Parameter Name: addr
	o CBOR Key Value: 39		o CBOR Key Value: 39
	o CBOR Major Type: 2		o CBOR Major Type: 3
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: ttl		o Parameter Name: ttl
	o CBOR Key Value: 40		o CBOR Key Value: 40
	o CBOR Major Type: 0		o CBOR Major Type: 0
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: conflict-scope		o Parameter Name: conflict-scope
	skipping to change at page 75, line 4 ¶		skipping to change at page 79, line 17 ¶
	o CBOR Key Value: 41		o CBOR Key Value: 41
	o CBOR Major Type: 5		o CBOR Major Type: 5
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: acl-name		o Parameter Name: acl-name
	o CBOR Key Value: 42		o CBOR Key Value: 42
	o CBOR Major Type: 3		o CBOR Major Type: 3
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: acl-type		o Parameter Name: acl-type
	o CBOR Key Value: 43		o CBOR Key Value: 43
	o CBOR Major Type: 3		o CBOR Major Type: 3
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: config-interval		o Parameter Name: config-interval
	o CBOR Key Value: 44		o CBOR Key Value: 44
	o CBOR Major Type: 0		o CBOR Major Type: 0
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: attack-time-config		o Parameter Name: mitigating-config
	o CBOR Key Value: 45		o CBOR Key Value: 45
	o CBOR Major Type: 5		o CBOR Major Type: 5
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
	o Parameter Name: peace-time-config		o Parameter Name: idle-config
	o CBOR Key Value: 46		o CBOR Key Value: 46
	o CBOR Major Type: 5		o CBOR Major Type: 5
	o Change Controller: IESG		o Change Controller: IESG
	o Specification Document(s): this document		o Specification Document(s): this document
			o Parameter Name: cuid
			o CBOR Key Value: 47
			o CBOR Major Type: 3
			o Change Controller: IESG
			o Specification Document(s): this document
			o Parameter Name: min-value-decimal
			o CBOR Key Value: 48
			o CBOR Major Type: 7
			o Change Controller: IESG
			o Specification Document(s): this document
			o Parameter Name: max-value-decimal
			o CBOR Key Value: 49
			o CBOR Major Type: 7
			o Change Controller: IESG
			o Specification Document(s): this document
			o Parameter Name: current-value-decimal
			o CBOR Key Value: 50
			o CBOR Major Type: 7
			o Change Controller: IESG
			o Specification Document(s): this document
	9.5. DOTS Signal Channel YANG Module		9.5. DOTS Signal Channel YANG Module
	This document requests IANA to register the following URI in the		This document requests IANA to register the following URI in the
	"IETF XML Registry" [RFC3688]:		"IETF XML Registry" [RFC3688]:
	URI: urn:ietf:params:xml:ns:yang:ietf-dots-signal		URI: urn:ietf:params:xml:ns:yang:ietf-dots-signal
	Registrant Contact: The IESG.		Registrant Contact: The IESG.
	XML: N/A; the requested URI is an XML namespace.		XML: N/A; the requested URI is an XML namespace.
	This document requests IANA to register the following YANG module in		This document requests IANA to register the following YANG module in
	skipping to change at page 76, line 38 ¶		skipping to change at page 81, line 28 ¶
	implement a full DOTS protocol specification in accordance with		implement a full DOTS protocol specification in accordance with
	the nurturing DOTS protocol.		the nurturing DOTS protocol.
	Implementation: https://github.com/nttdots/go-dots		Implementation: https://github.com/nttdots/go-dots
	Level of maturity: It is an early implementation of the DOTS		Level of maturity: It is an early implementation of the DOTS
	protocol. Messaging between DOTS clients and DOTS servers has		protocol. Messaging between DOTS clients and DOTS servers has
	been tested. Level of maturity will increase in accordance with		been tested. Level of maturity will increase in accordance with
	the nurturing DOTS protocol.		the nurturing DOTS protocol.
	Coverage: Capability of DOTS client: sending DOTS messages to the		Coverage: Capability of DOTS client: sending DOTS messages to the
	DOTS server in CoAP over DTLS as dots-signal. Capability of DOTS		DOTS server in CoAP over DTLS as dots-signal. Capability of DOTS
	server: receiving dots-signal, validating received dots-signal,		server: receiving dots-signal, validating received dots-signal,
	starting mitigation by handing over the dots-signal to DDOS		starting mitigation by handing over the dots-signal to DDoS
	mitigator.		mitigator.
	Licensing: It will be open-sourced with BSD 3-clause license.		Licensing: It will be open-sourced with BSD 3-clause license.
	Implementation experience: It is implemented in Go-lang. Core		Implementation experience: It is implemented in Go-lang. Core
	specification of signaling is mature to be implemented, however,		specification of signaling is mature to be implemented, however,
	finding good libraries(like DTLS, CoAP) is rather difficult.		finding good libraries(like DTLS, CoAP) is rather difficult.
	Contact: Kaname Nishizuka <kaname@nttv6.jp>		Contact: Kaname Nishizuka <kaname@nttv6.jp>
	11. Security Considerations		11. Security Considerations
	Authenticated encryption MUST be used for data confidentiality and		Authenticated encryption MUST be used for data confidentiality and
	skipping to change at page 77, line 24 ¶		skipping to change at page 82, line 13 ¶
	TLS authentication is used. Because the application data is TLS		TLS authentication is used. Because the application data is TLS
	protected, this will not result in the application receiving bogus		protected, this will not result in the application receiving bogus
	data, but it will constitute a DoS on the connection. This attack		data, but it will constitute a DoS on the connection. This attack
	can be countered by using TCP-AO [RFC5925]. If TCP-AO is used, then		can be countered by using TCP-AO [RFC5925]. If TCP-AO is used, then
	any bogus packets injected by an attacker will be rejected by the		any bogus packets injected by an attacker will be rejected by the
	TCP-AO integrity check and therefore will never reach the TLS layer.		TCP-AO integrity check and therefore will never reach the TLS layer.
	In order to prevent leaking internal information outside a client-		In order to prevent leaking internal information outside a client-
	domain, DOTS gateways located in the client-domain SHOULD NOT reveal		domain, DOTS gateways located in the client-domain SHOULD NOT reveal
	the identification information that pertains to internal DOTS clients		the identification information that pertains to internal DOTS clients
	(client-identifier) unless explicitly configured to do so.		(e.g., source IP address, client's hostname) unless explicitly
			configured to do so.
	Special care should be taken in order to ensure that the activation		Special care should be taken in order to ensure that the activation
	of the proposed mechanism will not impact the stability of the		of the proposed mechanism will not impact the stability of the
	network (including connectivity and services delivered over that		network (including connectivity and services delivered over that
	network).		network).
	12. Contributors		12. Contributors
	The following individuals have contributed to this document:		The following individuals have contributed to this document:
	skipping to change at page 78, line 13 ¶		skipping to change at page 83, line 9 ¶
	enhanced this specification.		enhanced this specification.
	14. References		14. References
	14.1. Normative References		14.1. Normative References
	[I-D.ietf-core-coap-tcp-tls]		[I-D.ietf-core-coap-tcp-tls]
	Bormann, C., Lemay, S., Tschofenig, H., Hartke, K.,		Bormann, C., Lemay, S., Tschofenig, H., Hartke, K.,
	Silverajan, B., and B. Raymor, "CoAP (Constrained		Silverajan, B., and B. Raymor, "CoAP (Constrained
	Application Protocol) over TCP, TLS, and WebSockets",		Application Protocol) over TCP, TLS, and WebSockets",
	draft-ietf-core-coap-tcp-tls-10 (work in progress),		draft-ietf-core-coap-tcp-tls-11 (work in progress),
	October 2017.		December 2017.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,		[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
	DOI 10.17487/RFC3688, January 2004,		DOI 10.17487/RFC3688, January 2004,
	<https://www.rfc-editor.org/info/rfc3688>.		<https://www.rfc-editor.org/info/rfc3688>.
	skipping to change at page 79, line 5 ¶		skipping to change at page 83, line 46 ¶
	[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known		[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
	Uniform Resource Identifiers (URIs)", RFC 5785,		Uniform Resource Identifiers (URIs)", RFC 5785,
	DOI 10.17487/RFC5785, April 2010,		DOI 10.17487/RFC5785, April 2010,
	<https://www.rfc-editor.org/info/rfc5785>.		<https://www.rfc-editor.org/info/rfc5785>.
	[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP		[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
	Authentication Option", RFC 5925, DOI 10.17487/RFC5925,		Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
	June 2010, <https://www.rfc-editor.org/info/rfc5925>.		June 2010, <https://www.rfc-editor.org/info/rfc5925>.
			[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
			Extensions: Extension Definitions", RFC 6066,
			DOI 10.17487/RFC6066, January 2011,
			<https://www.rfc-editor.org/info/rfc6066>.
	[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and		[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
	Verification of Domain-Based Application Service Identity		Verification of Domain-Based Application Service Identity
	within Internet Public Key Infrastructure Using X.509		within Internet Public Key Infrastructure Using X.509
	(PKIX) Certificates in the Context of Transport Layer		(PKIX) Certificates in the Context of Transport Layer
	Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March		Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
	2011, <https://www.rfc-editor.org/info/rfc6125>.		2011, <https://www.rfc-editor.org/info/rfc6125>.
	[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms		[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
	(SHA and SHA-based HMAC and HKDF)", RFC 6234,		(SHA and SHA-based HMAC and HKDF)", RFC 6234,
	DOI 10.17487/RFC6234, May 2011,		DOI 10.17487/RFC6234, May 2011,
	skipping to change at page 80, line 34 ¶		skipping to change at page 85, line 34 ¶
	Mortensen, A., Andreasen, F., Reddy, T.,		Mortensen, A., Andreasen, F., Reddy, T.,
	christopher_gray3@cable.comcast.com, c., Compton, R., and		christopher_gray3@cable.comcast.com, c., Compton, R., and
	N. Teague, "Distributed-Denial-of-Service Open Threat		N. Teague, "Distributed-Denial-of-Service Open Threat
	Signaling (DOTS) Architecture", draft-ietf-dots-		Signaling (DOTS) Architecture", draft-ietf-dots-
	architecture-05 (work in progress), October 2017.		architecture-05 (work in progress), October 2017.
	[I-D.ietf-dots-data-channel]		[I-D.ietf-dots-data-channel]
	Reddy, T., Boucadair, M., Nishizuka, K., Xia, L., Patil,		Reddy, T., Boucadair, M., Nishizuka, K., Xia, L., Patil,
	P., Mortensen, A., and N. Teague, "Distributed Denial-of-		P., Mortensen, A., and N. Teague, "Distributed Denial-of-
	Service Open Threat Signaling (DOTS) Data Channel", draft-		Service Open Threat Signaling (DOTS) Data Channel", draft-
	ietf-dots-data-channel-10 (work in progress), December		ietf-dots-data-channel-11 (work in progress), December
	2017.		2017.
	[I-D.ietf-dots-requirements]		[I-D.ietf-dots-requirements]
	Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed		Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed
	Denial of Service (DDoS) Open Threat Signaling		Denial of Service (DDoS) Open Threat Signaling
	Requirements", draft-ietf-dots-requirements-08 (work in		Requirements", draft-ietf-dots-requirements-10 (work in
	progress), December 2017.		progress), January 2018.
	[I-D.ietf-dots-use-cases]		[I-D.ietf-dots-use-cases]
	Dobbins, R., Migault, D., Fouant, S., Moskowitz, R.,		Dobbins, R., Migault, D., Fouant, S., Moskowitz, R.,
	Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS		Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS
	Open Threat Signaling", draft-ietf-dots-use-cases-09 (work		Open Threat Signaling", draft-ietf-dots-use-cases-09 (work
	in progress), November 2017.		in progress), November 2017.
	[I-D.ietf-netmod-yang-tree-diagrams]		[I-D.ietf-netmod-yang-tree-diagrams]
	Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-		Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
	ietf-netmod-yang-tree-diagrams-02 (work in progress),		ietf-netmod-yang-tree-diagrams-04 (work in progress),
	October 2017.		December 2017.
	[I-D.ietf-tls-dtls13]		[I-D.ietf-tls-dtls13]
	Rescorla, E., Tschofenig, H., and N. Modadugu, "The		Rescorla, E., Tschofenig, H., and N. Modadugu, "The
	Datagram Transport Layer Security (DTLS) Protocol Version		Datagram Transport Layer Security (DTLS) Protocol Version
	1.3", draft-ietf-tls-dtls13-22 (work in progress),		1.3", draft-ietf-tls-dtls13-22 (work in progress),
	November 2017.		November 2017.
	[I-D.ietf-tls-tls13]		[I-D.ietf-tls-tls13]
	Rescorla, E., "The Transport Layer Security (TLS) Protocol		Rescorla, E., "The Transport Layer Security (TLS) Protocol
	Version 1.3", draft-ietf-tls-tls13-22 (work in progress),		Version 1.3", draft-ietf-tls-tls13-22 (work in progress),
	skipping to change at page 81, line 34 ¶		skipping to change at page 86, line 34 ¶
	[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network		[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
	Address Translator (Traditional NAT)", RFC 3022,		Address Translator (Traditional NAT)", RFC 3022,
	DOI 10.17487/RFC3022, January 2001,		DOI 10.17487/RFC3022, January 2001,
	<https://www.rfc-editor.org/info/rfc3022>.		<https://www.rfc-editor.org/info/rfc3022>.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66,		Resource Identifier (URI): Generic Syntax", STD 66,
	RFC 3986, DOI 10.17487/RFC3986, January 2005,		RFC 3986, DOI 10.17487/RFC3986, January 2005,
	<https://www.rfc-editor.org/info/rfc3986>.		<https://www.rfc-editor.org/info/rfc3986>.
			[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
			"Randomness Requirements for Security", BCP 106, RFC 4086,
			DOI 10.17487/RFC4086, June 2005,
			<https://www.rfc-editor.org/info/rfc4086>.
	[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram		[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
	Congestion Control Protocol (DCCP)", RFC 4340,		Congestion Control Protocol (DCCP)", RFC 4340,
	DOI 10.17487/RFC4340, March 2006,		DOI 10.17487/RFC4340, March 2006,
	<https://www.rfc-editor.org/info/rfc4340>.		<https://www.rfc-editor.org/info/rfc4340>.
	[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing		[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
	(CIDR): The Internet Address Assignment and Aggregation		(CIDR): The Internet Address Assignment and Aggregation
	Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August		Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
	2006, <https://www.rfc-editor.org/info/rfc4632>.		2006, <https://www.rfc-editor.org/info/rfc4632>.
	[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet		[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
	Denial-of-Service Considerations", RFC 4732,		Denial-of-Service Considerations", RFC 4732,
	DOI 10.17487/RFC4732, December 2006,		DOI 10.17487/RFC4732, December 2006,
	<https://www.rfc-editor.org/info/rfc4732>.		<https://www.rfc-editor.org/info/rfc4732>.
	[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address		[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address
	Translation (NAT) Behavioral Requirements for Unicast		Translation (NAT) Behavioral Requirements for Unicast
	UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January		UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January
	2007, <https://www.rfc-editor.org/info/rfc4787>.		2007, <https://www.rfc-editor.org/info/rfc4787>.
			[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
			Extensions for Stateless Address Autoconfiguration in
			IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
			<https://www.rfc-editor.org/info/rfc4941>.
	[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",		[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
	RFC 4960, DOI 10.17487/RFC4960, September 2007,		RFC 4960, DOI 10.17487/RFC4960, September 2007,
	<https://www.rfc-editor.org/info/rfc4960>.		<https://www.rfc-editor.org/info/rfc4960>.
	[RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common		[RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common
	Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007,		Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007,
	<https://www.rfc-editor.org/info/rfc4987>.		<https://www.rfc-editor.org/info/rfc4987>.
	[RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig,		[RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig,
	"Transport Layer Security (TLS) Session Resumption without		"Transport Layer Security (TLS) Session Resumption without
	skipping to change at page 84, line 7 ¶		skipping to change at page 89, line 15 ¶
	[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",		[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
	RFC 7951, DOI 10.17487/RFC7951, August 2016,		RFC 7951, DOI 10.17487/RFC7951, August 2016,
	<https://www.rfc-editor.org/info/rfc7951>.		<https://www.rfc-editor.org/info/rfc7951>.
	[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage		[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage
	Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,		Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,
	March 2017, <https://www.rfc-editor.org/info/rfc8085>.		March 2017, <https://www.rfc-editor.org/info/rfc8085>.
	Authors' Addresses		Authors' Addresses
	Tirumaleswar Reddy		Tirumaleswar Reddy (editor)
	McAfee, Inc.		McAfee, Inc.
	Embassy Golf Link Business Park		Embassy Golf Link Business Park
	Bangalore, Karnataka 560071		Bangalore, Karnataka 560071
	India		India
	Email: kondtir@gmail.com		Email: kondtir@gmail.com
	Mohamed Boucadair		Mohamed Boucadair (editor)
	Orange		Orange
	Rennes 35000		Rennes 35000
	France		France
	Email: mohamed.boucadair@orange.com		Email: mohamed.boucadair@orange.com
	Prashanth Patil		Prashanth Patil
	Cisco Systems, Inc.		Cisco Systems, Inc.
	Email: praspati@cisco.com		Email: praspati@cisco.com
End of changes. 257 change blocks.
	990 lines changed or deleted		1226 lines changed or added
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