< draft-ietf-dots-signal-channel-03.txt   draft-ietf-dots-signal-channel-04.txt >
DOTS T. Reddy DOTS T. Reddy
Internet-Draft McAfee Internet-Draft McAfee
Intended status: Standards Track M. Boucadair Intended status: Standards Track M. Boucadair
Expires: February 17, 2018 Orange Expires: April 5, 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.
August 16, 2017 October 2, 2017
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-03 draft-ietf-dots-signal-channel-04
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. A companion traffic mitigation on behalf of the requesting client. A companion
document defines the DOTS data channel, a separate reliable document defines the DOTS data channel, a separate reliable
communication layer for DOTS management and configuration. communication layer for DOTS management and configuration.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 http://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 February 17, 2018. This Internet-Draft will expire on April 5, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 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
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions and Terminology . . . . . . . . . . . 3 2. Notational Conventions and Terminology . . . . . . . . . . . 3
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4 3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4
4. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . . . 5 4. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . . . 5
5. DOTS Signal Channel . . . . . . . . . . . . . . . . . . . . . 7 5. DOTS Signal Channel . . . . . . . . . . . . . . . . . . . . . 7
5.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. DOTS Signal YANG Model . . . . . . . . . . . . . . . . . 8 5.2. DOTS Signal YANG Module . . . . . . . . . . . . . . . . . 8
5.2.1. Mitigation Request Model structure . . . . . . . . . 8 5.2.1. Mitigation Request YANG Module Tree Structure . . . . 8
5.2.2. Mitigation Request Model . . . . . . . . . . . . . . 8 5.2.2. Mitigation Request YANG Module . . . . . . . . . . . 8
5.2.3. Session Configuration Model structure . . . . . . . . 10 5.2.3. Session Configuration YANG Module Tree Structure . . 10
5.2.4. Session Configuration Model . . . . . . . . . . . . . 10 5.2.4. Session Configuration YANG Module . . . . . . . . . . 11
5.3. Mitigation Request . . . . . . . . . . . . . . . . . . . 12 5.3. Mitigation Request . . . . . . . . . . . . . . . . . . . 12
5.3.1. Requesting mitigation . . . . . . . . . . . . . . . . 12 5.3.1. Requesting mitigation . . . . . . . . . . . . . . . . 13
5.3.2. Withdraw a DOTS Signal . . . . . . . . . . . . . . . 17 5.3.2. Withdraw a DOTS Signal . . . . . . . . . . . . . . . 19
5.3.3. Retrieving a DOTS Signal . . . . . . . . . . . . . . 18 5.3.3. Retrieving a DOTS Signal . . . . . . . . . . . . . . 20
5.3.4. Efficacy Update from DOTS Client . . . . . . . . . . 23 5.3.4. Efficacy Update from DOTS Client . . . . . . . . . . 25
5.4. DOTS Signal Channel Session Configuration . . . . . . . . 25 5.4. DOTS Signal Channel Session Configuration . . . . . . . . 27
5.4.1. Discover Acceptable Configuration Parameters . . . . 26 5.4.1. Discover Configuration Parameters . . . . . . . . . . 28
5.4.2. Convey DOTS Signal Channel Session Configuration . . 27 5.4.2. Convey DOTS Signal Channel Session Configuration . . 30
5.4.3. Delete DOTS Signal Channel Session Configuration . . 30 5.4.3. Delete DOTS Signal Channel Session Configuration . . 33
5.4.4. Retrieving DOTS Signal Channel Session Configuration 30 5.4.4. Retrieving DOTS Signal Channel Session Configuration 34
5.5. Redirected Signaling . . . . . . . . . . . . . . . . . . 31 5.5. Redirected Signaling . . . . . . . . . . . . . . . . . . 34
5.6. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 32 5.6. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 36
6. Mapping parameters to CBOR . . . . . . . . . . . . . . . . . 33 6. Mapping parameters to CBOR . . . . . . . . . . . . . . . . . 36
7. (D)TLS Protocol Profile and Performance considerations . . . 34 7. (D)TLS Protocol Profile and Performance considerations . . . 37
7.1. MTU and Fragmentation Issues . . . . . . . . . . . . . . 34 7.1. MTU and Fragmentation Issues . . . . . . . . . . . . . . 38
8. (D)TLS 1.3 considerations . . . . . . . . . . . . . . . . . . 35 8. (D)TLS 1.3 considerations . . . . . . . . . . . . . . . . . . 39
9. Mutual Authentication of DOTS Agents & Authorization of DOTS 9. Mutual Authentication of DOTS Agents & Authorization of DOTS
Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42
10.1. CoAP Response Code . . . . . . . . . . . . . . . . . . . 38 10.1. CoAP Response Code . . . . . . . . . . . . . . . . . . . 42
10.2. DOTS signal channel CBOR Mappings Registry . . . . . . . 38 10.2. DOTS signal channel CBOR Mappings Registry . . . . . . . 42
10.2.1. Registration Template . . . . . . . . . . . . . . . 38 10.2.1. Registration Template . . . . . . . . . . . . . . . 42
10.2.2. Initial Registry Contents . . . . . . . . . . . . . 39 10.2.2. Initial Registry Contents . . . . . . . . . . . . . 43
11. Implementation Status . . . . . . . . . . . . . . . . . . . . 42 11. Implementation Status . . . . . . . . . . . . . . . . . . . . 46
11.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 43 11.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 47
12. Security Considerations . . . . . . . . . . . . . . . . . . . 43 12. Security Considerations . . . . . . . . . . . . . . . . . . . 47
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 44 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 48
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 44 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 48
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 44 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 49
15.1. Normative References . . . . . . . . . . . . . . . . . . 44 15.1. Normative References . . . . . . . . . . . . . . . . . . 49
15.2. Informative References . . . . . . . . . . . . . . . . . 45 15.2. Informative References . . . . . . . . . . . . . . . . . 50
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 52
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 7, line 20 skipping to change at page 7, line 20
Application Protocol (CoAP) [RFC7252], a lightweight protocol Application Protocol (CoAP) [RFC7252], a lightweight protocol
originally designed for constrained devices and networks. CoAP's originally designed for constrained devices and networks. CoAP's
expectation of packet loss, support for asynchronous non-confirmable expectation of packet loss, support for asynchronous non-confirmable
messaging, congestion control, small message overhead limiting the messaging, congestion control, small message overhead limiting the
need for fragmentation, use of minimal resources, and support for need for fragmentation, use of minimal resources, and support for
(D)TLS make it a good foundation on which to build the DOTS signaling (D)TLS make it a good foundation on which to build the DOTS signaling
mechanism. mechanism.
The DOTS signal channel is layered on existing standards (Figure 4). The DOTS signal channel is layered on existing standards (Figure 4).
TBD: The default port number for DOTS signal channel is 5684
(Section 12.7 of [RFC7252] and Section 10.4 of
[I-D.ietf-core-coap-tcp-tls]), for both UDP and TCP.
+--------------+ +--------------+
| DOTS | | DOTS |
+--------------+ +--------------+
| CoAP | | CoAP |
+--------------+ +--------------+
| TLS | DTLS | | TLS | DTLS |
+--------------+ +--------------+
| TCP | UDP | | TCP | UDP |
+--------------+ +--------------+
| IP | | IP |
skipping to change at page 8, line 5 skipping to change at page 8, line 9
Messages exchanged between DOTS client and server are serialized Messages exchanged between DOTS client and server are serialized
using Concise Binary Object Representation (CBOR) [RFC7049], CBOR is using Concise Binary Object Representation (CBOR) [RFC7049], CBOR is
a binary encoding designed for small code and message size. CBOR a binary encoding designed for small code and message size. CBOR
encoded payloads are used to convey signal channel specific payload encoded payloads are used to convey signal channel specific payload
messages that convey request parameters and response information such messages that convey request parameters and response information such
as errors. This specification uses the encoding rules defined in as errors. This specification uses the encoding rules defined in
[I-D.ietf-core-yang-cbor] for representing mitigation scope and DOTS [I-D.ietf-core-yang-cbor] for representing mitigation scope and DOTS
signal channel session configuration data defined using YANG signal channel session configuration data defined using YANG
(Section 5.2) as CBOR data. (Section 5.2) as CBOR data.
5.2. DOTS Signal YANG Model DOTS agents MUST support GET, PUT, and DELETE CoAP methods. The
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
[RFC7252]). CoAP responses with 4.xx and 5.xx error Response Codes
MUST include a diagnostic payload (Section 5.5.2 of [RFC7252]). The
Diagnostic Payload may contain additional information to aid
troubleshooting.
This document defines a YANG [RFC6020] data model for mitigation 5.2. DOTS Signal YANG Module
scope and DOTS signal channel session configuration data.
5.2.1. Mitigation Request Model structure This document defines a YANG [RFC6020] module for mitigation scope
and DOTS signal channel session configuration data.
5.2.1. Mitigation Request YANG Module Tree Structure
This document defines the YANG module "ietf-dots-signal", which has This document defines the YANG module "ietf-dots-signal", which has
the following structure: the following tree structure:
module: ietf-dots-signal module: ietf-dots-signal
+--rw mitigation-scope +--rw mitigation-scope
+--rw scope* [mitigation-id] +--rw scope* [mitigation-id]
+--rw mitigation-id int32 +--rw mitigation-id int32
+--rw target-ip* inet:ip-address +--rw target-ip* inet:ip-address
+--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 fqdn* inet:domain-name +--rw fqdn* inet:domain-name
+--rw uri* inet:uri +--rw uri* inet:uri
+--rw alias* string +--rw alias-name* string
+--rw lifetime? int32 +--rw lifetime? int32
5.2.2. Mitigation Request Model 5.2.2. Mitigation Request YANG Module
<CODE BEGINS> file "ietf-dots-signal@2017-08-03.yang" <CODE BEGINS> file "ietf-dots-signal@2017-08-03.yang"
module ietf-dots-signal { module ietf-dots-signal {
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 { import ietf-inet-types {
prefix "inet"; prefix "inet";
} }
organization "McAfee, Inc."; organization "McAfee, Inc.";
contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>"; contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>";
description description
"This module contains YANG definition for DOTS "This module contains YANG definition for DOTS
signal sent by the DOTS client to the DOTS server."; signal sent by the DOTS client to the DOTS server.";
revision 2017-08-03 { revision 2017-08-03 {
reference reference
"https://tools.ietf.org/html/draft-reddy-dots-signal-channel"; "https://tools.ietf.org/html/draft-reddy-dots-signal-channel";
skipping to change at page 10, line 4 skipping to change at page 10, line 17
equal to lower port number."; equal to lower port number.";
} }
description "Upper port number."; description "Upper port number.";
} }
} }
leaf-list target-protocol { leaf-list target-protocol {
type uint8; type uint8;
description "Identifies the target protocol number."; description "Identifies the target protocol number.";
} }
leaf-list fqdn { leaf-list fqdn {
type inet:domain-name; type inet:domain-name;
description "FQDN"; description "FQDN";
} }
leaf-list uri { leaf-list uri {
type inet:uri; type inet:uri;
description "URI"; description "URI";
} }
leaf-list alias { leaf-list alias-name {
type string; type string;
description "alias name"; description "alias name";
} }
leaf lifetime { leaf lifetime {
type int32; type int32;
description description
"Indicates the lifetime of the mitigation request."; "Indicates the lifetime of the mitigation request.";
} }
} }
} }
} }
<CODE ENDS> <CODE ENDS>
5.2.3. Session Configuration Model structure 5.2.3. Session Configuration YANG Module Tree Structure
This document defines the YANG module "ietf-dots-signal-config", This document defines the YANG module "ietf-dots-signal-config",
which has the following structure: which has the following structure:
module: ietf-dots-signal-config module: ietf-dots-signal-config
+--rw signal-config +--rw signal-config
+--rw session-id? int32 +--rw session-id? int32
+--rw heartbeat-timeout? int16 +--rw heartbeat-interval? int16
+--rw missing-hb-allowed? int16
+--rw max-retransmit? int16 +--rw max-retransmit? int16
+--rw ack-timeout? int16 +--rw ack-timeout? int16
+--rw ack-random-factor? decimal64 +--rw ack-random-factor? decimal64
+--rw trigger-mitigation? boolean +--rw trigger-mitigation? boolean
5.2.4. Session Configuration Model 5.2.4. Session Configuration YANG Module
<CODE BEGINS> file "ietf-dots-signal-config@2016-11-28.yang" <CODE BEGINS> file "ietf-dots-signal-config@2016-11-28.yang"
module ietf-dots-signal-config { module ietf-dots-signal-config {
namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal-config"; namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal-config";
prefix "config"; prefix "config";
organization "McAfee, Inc."; organization "McAfee, Inc.";
contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>"; contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>";
skipping to change at page 11, line 25 skipping to change at page 11, line 45
container signal-config { container signal-config {
description "Top level container for DOTS signal channel session description "Top level container for DOTS signal channel session
configuration."; configuration.";
leaf session-id { leaf session-id {
type int32; type int32;
description "An identifier for the DOTS signal channel description "An identifier for the DOTS signal channel
session configuration data."; session configuration data.";
} }
leaf heartbeat-timeout { leaf heartbeat-interval {
type int16; type int16;
description description
"DOTS agents regularly send heartbeats to each other "DOTS agents regularly send heartbeats to each other
after mutual authentication in order to keep after mutual authentication in order to keep
the DOTS signal channel open."; the DOTS signal channel open.";
} }
leaf missing-hb-allowed {
type int16;
description
"Maximum number of missing heartbeats allowed";
}
leaf max-retransmit { leaf max-retransmit {
type int16; type int16;
description description
"Maximum retransmissions of a Confirmable message."; "Maximum number of retransmissions of a
Confirmable message.";
} }
leaf ack-timeout { leaf ack-timeout {
type int16; type int16;
description description
"Initial retransmission timeout value."; "Initial retransmission timeout value.";
} }
leaf ack-random-factor { leaf ack-random-factor {
type decimal64 { type decimal64 {
skipping to change at page 13, line 39 skipping to change at page 14, line 37
], ],
"target-protocol": [ "target-protocol": [
integer integer
], ],
"fqdn": [ "fqdn": [
"string" "string"
], ],
"uri": [ "uri": [
"string" "string"
], ],
"alias": [ "alias-name": [
"string" "string"
], ],
"lifetime": integer "lifetime": integer
} }
] ]
} }
} }
Figure 5: PUT to convey DOTS signals Figure 5: PUT to convey DOTS signals
skipping to change at page 14, line 41 skipping to change at page 15, line 37
attribute. attribute.
fqdn: A list of Fully Qualified Domain Names. Fully Qualified fqdn: A list of Fully Qualified Domain Names. Fully Qualified
Domain Name (FQDN) is the full name of a system, rather than just Domain Name (FQDN) is the full name of a system, rather than just
its hostname. For example, "venera" is a hostname, and its hostname. For example, "venera" is a hostname, and
"venera.isi.edu" is an FQDN. This is an optional attribute. "venera.isi.edu" is an FQDN. This is an optional attribute.
uri: A list of Uniform Resource Identifiers (URI). This is an uri: A list of Uniform Resource Identifiers (URI). This is an
optional attribute. optional attribute.
alias: A list of aliases. Aliases can be created using the DOTS alias-name: A list of aliases. Aliases can be created using the
data channel (Section 3.1.1 in [I-D.ietf-dots-data-channel]) or DOTS data channel (Section 3.1.1 of [I-D.ietf-dots-data-channel])
direct configuration, or other means and then used in subsequent or direct configuration, or other means and then used in
signal channel exchanges to refer more efficiently to the subsequent signal channel exchanges to refer more efficiently to
resources under attack. This is an optional attribute. the resources under attack. This is an optional attribute.
lifetime: Lifetime of the mitigation request in seconds. Upon the lifetime: Lifetime of the mitigation request in seconds. Upon the
expiry of this lifetime, and if the request is not refreshed, the expiry of this lifetime, and if the request is not refreshed, the
mitigation request is removed. The request can be refreshed by mitigation request is removed. The request can be refreshed by
sending the same request again. The default lifetime of the sending the same request again. The default lifetime of the
mitigation request is 3600 seconds (60 minutes) -- this value was mitigation request is 3600 seconds (60 minutes) -- this value was
chosen to be long enough so that refreshing is not typically a chosen to be long enough so that refreshing is not typically a
burden on the DOTS client, while expiring the request where the burden on the DOTS client, while expiring the request where the
client has unexpectedly quit in a timely manner. A lifetime of client has unexpectedly quit in a timely manner. A lifetime of
negative one (-1) indicates indefinite lifetime for the mitigation negative one (-1) indicates indefinite lifetime for the mitigation
request. The server MUST always indicate the actual lifetime in request. The 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 client. This is an optional attribute in the request. the client. This is an optional attribute in the request.
The CBOR key values for the parameters are defined in Section 6. The The CBOR key values for the parameters are defined in Section 6. The
IANA Considerations section defines how the CBOR key values can be IANA Considerations section defines how the CBOR key values can be
allocated to standards bodies and vendors. FQDN and URI mitigation allocated to standards bodies and vendors. FQDN and URI mitigation
scopes may be thought of as a form of scope alias, in which the scopes may be thought of as a form of scope alias, in which the
addresses to which the domain name or URI resolve represent the full addresses to which the domain name or URI resolve represent the full
scope of the mitigation. In the PUT request at least one of the scope of the mitigation. In the PUT request at least one of the
attributes target-ip or target-prefix or fqdn or uri or alias MUST be attributes target-ip or target-prefix or fqdn or uri or alias-name
present. DOTS agents can safely ignore Vendor-Specific parameters MUST be present. DOTS agents can safely ignore Vendor-Specific
they don't understand. The relative order of two mitigation requests parameters they don't understand. The relative order of two
from a DOTS client is determined by comparing their respective mitigation requests from a DOTS client is determined by comparing
mitigation-id values. If two mitigation requests have overlapping their respective mitigation-id values. If two mitigation requests
mitigation scopes the mitigation request with higher numeric have overlapping mitigation scopes the mitigation request with higher
mitigation-id value will override the mitigation request with a lower numeric mitigation-id value will override the mitigation request with
numeric mitigation-id value. The Uri-Path option carries a major and a lower numeric mitigation-id value. Two mitigation-ids are
minor version nomenclature to manage versioning and DOTS signal overlapping if there is a common IP, IP Prefix, FQDN, URI or alias-
channel in this specification uses v1 major version. name. The overlapped lower numeric mitigation-id is automatically
deleted and no longer available at the DOTS server. The Uri-Path
option carries a major and minor version nomenclature to manage
versioning and DOTS signal channel in this specification uses v1
major version.
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 9). The DOTS server authenticate itself to the DOTS server (Section 9). The DOTS server
can use the algorithm discussed in Section 7 of [RFC7589] to derive can use the algorithm discussed 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 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, so the DOTS server can validate using the DOTS client identity, so the DOTS server can validate
whether the aliases conveyed in the mitigation request were indeed whether the aliases conveyed in the mitigation request were indeed
created by the same DOTS client using the DOTS data channel session. created by the same DOTS client using the DOTS data channel session.
If the aliases were not created by the DOTS client then the DOTS If the aliases were not created by the DOTS client then the DOTS
server returns 4.00 (Bad Request) in the response. The DOTS server server returns 4.00 (Bad Request) in the response. The DOTS server
couples the DOTS signal channel sessions using the DOTS client couples the DOTS signal channel sessions using the DOTS client
identity, and the DOTS server uses mitigation-id parameter value to identity, and the DOTS server uses mitigation-id parameter value to
detect duplicate mitigation requests. If the mitigation request detect duplicate mitigation requests. If the mitigation request
contains both alias and other parameters identifying the target contains both alias-name and other parameters identifying the target
resource (such as, target-ip, target-prefix, target-port-range, fqdn, resources (such as, target-ip, target-prefix, target-port-range,
or uri) then the DOTS server appends the parameter values in alias fqdn, or uri) then the DOTS server appends the parameter values in
with the corresponding parameter values in target-ip, target-prefix, alias-name with the corresponding parameter values in target-ip,
target-port-range, fqdn, or uri. target-prefix, target-port-range, fqdn, or uri.
Figure 6 shows a PUT request example to signal that ports 80, 8080, Figure 6 shows an PUT request example to signal that ports 80, 8080,
and 443 on the servers 2001:db8:6401::1 and 2001:db8:6401::2 are and 443 on the servers 2001:db8:6401::1 and 2001:db8:6401::2 are
being attacked (illustrated in JSON diagnostic notation). being attacked (illustrated in JSON diagnostic notation).
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "www.example.com" Uri-Host: "www.example.com"
Uri-Path: "v1" Uri-Path: "v1"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "signal" Uri-Path: "signal"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
skipping to change at page 17, line 24 skipping to change at page 18, line 26
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 6: PUT for DOTS signal Figure 6: PUT for DOTS signal
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. COAP 5.xx codes are codes are some sort of invalid requests. Figure 7 shows an PUT
returned if the DOTS server has erred or is currently unavailable to response for CoAP 2.xx response codes.
provide mitigation in response to the mitigation request from the
DOTS client. If the DOTS server does not find the mitigation-id {
parameter value conveyed in the PUT request in its configuration data "mitigation-scope": {
then the server MAY accept the mitigation request, and a 2.01 "scope": [
(Created) response is returned to the DOTS client, and the DOTS {
server will try to mitigate the attack. If the DOTS server finds the "mitigation-id": integer,
mitigation-id parameter value conveyed in the PUT request in its "lifetime": integer
configuration data then the server MAY update the mitigation request, }
and a 2.04 (Changed) response is returned to indicate a successful ]
update of the mitigation request. If the request is missing one or }
more mandatory attributes, then 4.00 (Bad Request) will be returned }
in the response or if the request contains invalid or unknown
parameters then 4.02 (Invalid query) will be returned in the Figure 7: 2.xx response body
response. For responses indicating a client or server error, the
payload explains the error situation of the result of the requested COAP 5.xx codes are returned if the DOTS server has erred or is
action (Section 5.5 in [RFC7252]). currently unavailable to provide mitigation in response to the
mitigation request from the DOTS client. If the DOTS server does not
find the mitigation-id parameter value conveyed in the PUT request in
its configuration data then the server MAY accept the mitigation
request, and a 2.01 (Created) response is returned to the DOTS
client, and the DOTS server will try to mitigate the attack. If the
DOTS server finds the mitigation-id parameter value conveyed in the
PUT request in its configuration data then the server MAY update the
mitigation request, and a 2.04 (Changed) response is returned to
indicate a successful update of the mitigation request. If the
request is missing one or more mandatory attributes, then 4.00 (Bad
Request) will be returned in the response or if the request contains
invalid or unknown parameters then 4.02 (Invalid query) will be
returned in the response.
For the mitigation request to continue beyond the initial negotiated
lifetime, the DOTS client will need to refresh the current mitigation
request by sending a new PUT request. The PUT request MUST use the
same mitigation-id value, and MUST repeat all the other parameters as
sent in the original mitigation request apart from a possible change
to the lifetime parameter value.
5.3.2. Withdraw a DOTS Signal 5.3.2. Withdraw a DOTS Signal
A DELETE request is used to withdraw a DOTS signal from a DOTS server A DELETE request is used to withdraw a DOTS signal from a DOTS server
(Figure 7). (Figure 8).
Header: DELETE (Code=0.04) Header: DELETE (Code=0.04)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "signal" Uri-Path: "signal"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"mitigation-scope": { "mitigation-scope": {
"scope": [ "scope": [
{ {
"mitigation-id": integer "mitigation-id": integer
} }
] ]
} }
} }
Figure 7: Withdraw DOTS signal Figure 8: Withdraw DOTS signal
The DOTS server immediately acknowledges a DOTS client's request to The DOTS server immediately acknowledges a DOTS client's request to
withdraw the DOTS signal using 2.02 (Deleted) response code. A 2.02 withdraw the DOTS signal using 2.02 (Deleted) response code with no
(Deleted) Response Code is returned even if the mitigation-id response payload. A 2.02 (Deleted) Response Code is returned even if
parameter value conveyed in the DELETE request does not exist in its the mitigation-id parameter value conveyed in the DELETE request does
configuration data before the request. If the DOTS server finds the not exist in its configuration data before the request. If the DOTS
mitigation-id parameter value conveyed in the DELETE request in its server finds the mitigation-id parameter value conveyed in the DELETE
configuration data, then to protect against route or DNS flapping request in its configuration data, then to protect against route or
caused by a client rapidly toggling mitigation, and to dampen the DNS flapping caused by a client rapidly toggling mitigation, and to
effect of oscillating attacks, DOTS servers MAY allow mitigation to dampen the effect of oscillating attacks, DOTS servers MAY allow
continue for a limited period after acknowledging a DOTS client's mitigation to continue for a limited period after acknowledging a
withdrawal of a mitigation request. During this period, DOTS server DOTS client's withdrawal of a mitigation request. During this
status messages SHOULD indicate that mitigation is active but period, DOTS server status messages SHOULD indicate that mitigation
terminating. The active-but-terminating period is initially 30 is active but terminating. The active-but-terminating period is
seconds. If the client requests mitigation again before that 30 initially 30 seconds. If the client requests mitigation again before
second window elapses, the DOTS server MAY exponentially increase the that 30 second window elapses, the DOTS server MAY exponentially
active- but-terminating period up to a maximum of 240 seconds (4 increase the active- but-terminating period up to a maximum of 240
minutes). After the active-but-terminating period elapses, the DOTS seconds (4 minutes). After the active-but-terminating period
server MUST treat the mitigation as terminated, as the DOTS client is elapses, the DOTS server MUST treat the mitigation as terminated, as
no longer responsible for the mitigation. For example, if there is a the DOTS client is no longer responsible for the mitigation. For
financial relationship between the DOTS client and server domains, example, if there is a financial relationship between the DOTS client
the DOTS client ceases incurring cost at this point. and server domains, the DOTS client ceases incurring cost at this
point.
5.3.3. Retrieving a DOTS Signal 5.3.3. Retrieving a DOTS Signal
A GET request is used to retrieve information and status of a DOTS A GET request is used to retrieve information and status of a DOTS
signal from a DOTS server (Figure 8). If the DOTS server does not signal from a DOTS server (Figure 9). If the DOTS server does not
find the mitigation-id parameter value conveyed in the GET request in find the mitigation-id parameter value conveyed in the GET request in
its configuration data, then it responds with a 4.04 (Not Found) its configuration data, then it responds with a 4.04 (Not Found)
error response code. The 'c' (content) parameter and its permitted error response code. The 'c' (content) parameter and its permitted
values defined in [I-D.ietf-core-comi] can be used to retrieve non- values defined in [I-D.ietf-core-comi] can be used to retrieve non-
configuration data or configuration data or both. configuration data or configuration data or both.
1) To retrieve all DOTS signals signaled by the DOTS client. 1) To retrieve all DOTS signals signaled by the DOTS client.
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
skipping to change at page 19, line 37 skipping to change at page 21, line 35
{ {
"mitigation-scope": { "mitigation-scope": {
"scope": [ "scope": [
{ {
"mitigation-id": integer "mitigation-id": integer
} }
] ]
} }
} }
Figure 8: GET to retrieve the rules Figure 9: GET to retrieve the rules
Figure 9 shows a response example of all the active mitigation Figure 10 shows a response example of all the active mitigation
requests associated with the DOTS client on the DOTS server and the requests associated with the DOTS client on the DOTS server and the
mitigation status of each mitigation request. mitigation status of each mitigation request.
{ {
"mitigation-scope":[ "mitigation-scope": {
{ "scope": [
"scope": [
{ {
"mitigation-id": 12332, "mitigation-id": 12332,
"target-protocol": [ "target-protocol": [
17 17
], ],
"lifetime":1800, "lifetime":1800,
"status":2, "status":2,
"bytes-dropped": 134334555, "bytes-dropped": 134334555,
"bps-dropped": 43344, "bps-dropped": 43344,
"pkts-dropped": 333334444, "pkts-dropped": 333334444,
"pps-dropped": 432432 "pps-dropped": 432432
} },
]
},
{
"scope": [
{ {
"mitigation-id": 12333, "mitigation-id": 12333,
"target-protocol": [ "target-protocol": [
6 6
], ],
"lifetime":1800, "lifetime":1800,
"status":3 "status":3
"bytes-dropped": 0, "bytes-dropped": 0,
"bps-dropped": 0, "bps-dropped": 0,
"pkts-dropped": 0, "pkts-dropped": 0,
"pps-dropped": 0 "pps-dropped": 0
} }
] ]
} }
] }
}
Figure 9: Response body Figure 10: Response body
The mitigation status parameters are described below. The mitigation status parameters are described below.
lifetime: The remaining lifetime of the mitigation request in
seconds.
mitigation-start: Mitigation start time is represented in seconds
relative to 1970-01-01T00:00Z in UTC time (Section 2.4.1 of
[RFC7049]).
bytes-dropped: The total dropped byte count for the mitigation bytes-dropped: The total dropped byte count for the mitigation
request. This is a optional attribute. request since the attack mitigation is triggered. The count wraps
around when it reaches the maximum value of unsigned integer.
This is an optional attribute.
bps-dropped: The average dropped bytes per second for the mitigation bps-dropped: The average dropped bytes per second for the mitigation
request. This is a optional attribute. request since the attack mitigation is triggered. This is an
optional attribute.
pkts-dropped: The total dropped packet count for the mitigation pkts-dropped: The total dropped packet count for the mitigation
request. This is a optional attribute. request since the attack mitigation is triggered. This is an
optional attribute.
pps-dropped: The average dropped packets per second for the pps-dropped: The average dropped packets per second for the
mitigation request. This is a optional attribute. mitigation request since the attack mitigation is triggered. This
is an optional attribute.
status: Status of attack mitigation. The 'status' parameter is a status: Status of attack mitigation. The 'status' parameter is a
mandatory attribute. mandatory attribute.
The various possible values of 'status' parameter are explained The various possible values of 'status' parameter are explained
below: below:
/--------------------+---------------------------------------------------\ /--------------------+---------------------------------------------------\
| Parameter value | Description | | Parameter value | Description |
|--------------------+---------------------------------------------------| |--------------------+---------------------------------------------------|
skipping to change at page 22, line 36 skipping to change at page 24, line 42
| status: "mitigation | | status: "mitigation |
| complete" | | complete" |
|<------------------------------+ |<------------------------------+
| 2.05 Content | | 2.05 Content |
| Token: 0x4a | Notification upon | Token: 0x4a | Notification upon
| Observe: 60 | a state change | Observe: 60 | a state change
| status: "attack stopped" | | status: "attack stopped" |
|<------------------------------+ |<------------------------------+
| | | |
Figure 10: Notifications of attack mitigation status Figure 11: Notifications of attack mitigation status
5.3.3.1. Mitigation Status 5.3.3.1. Mitigation Status
A DOTS client retrieves the information about a DOTS signal at The DOTS client can send the GET request at frequent intervals
frequent intervals to determine the status of an attack. If the DOTS without the Observe option to retrieve the configuration data of the
server has been able to mitigate the attack and the attack has mitigation request and non-configuration data (i.e., the attack
stopped, the DOTS server indicates as such in the status, and the status). The frequency of polling the DOTS server to get the
DOTS client recalls the mitigation request. mitigation status should follow the transmission guidelines given in
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
indicates as such in the status, and the DOTS client recalls the
mitigation request by issuing a DELETE for the mitigation-id.
A DOTS client should react to the status of the attack from the DOTS A DOTS client should react to the status of the attack from the DOTS
server and not the fact that it has recognized, using its own means, server and not the fact that it has recognized, using its own means,
that the attack has been mitigated. This ensures that the DOTS that the attack has been mitigated. This ensures that the DOTS
client does not recall a mitigation request in a premature fashion client does not recall a mitigation request in a premature fashion
because it is possible that the DOTS client does not sense the DDOS because it is possible that the DOTS client does not sense the DDOS
attack on its resources but the DOTS server could be actively attack on its resources but the DOTS server could be actively
mitigating the attack and the attack is not completely averted. mitigating the attack and the attack is not completely averted.
5.3.4. Efficacy Update from DOTS Client 5.3.4. Efficacy Update from DOTS Client
While DDoS mitigation is active, a DOTS client MAY frequently While DDoS mitigation is active, a DOTS client MAY frequently
transmit DOTS mitigation efficacy updates to the relevant DOTS transmit DOTS mitigation efficacy updates to the relevant DOTS
server. An PUT request (Figure 11) is used to convey the mitigation server. An PUT request (Figure 12) is used to convey the mitigation
efficacy update to the DOTS server. The PUT request MUST include all efficacy update to the DOTS server. The PUT request MUST include all
the parameters used in the PUT request to convey the DOTS signal the parameters used in the PUT request to convey the DOTS signal
(Section 5.3.1). The If-Match Option (Section 5.10.8.1 of [RFC7252]) (Section 5.3.1) unchanged apart from the lifetime parameter value.
with an empty value is used to make the PUT request conditional on If this is not the case, the DOTS server MUST reject the request with
the current existence of the mitigation request. If UDP is used as a 4.02 error response code. The If-Match Option (Section 5.10.8.1 of
transport, CoAP requests may arrive out-of-order. For example, the [RFC7252]) with an empty value is used to make the PUT request
DOTS client may send a PUT request to convey efficacy update to the conditional on the current existence of the mitigation request. If
DOTS server followed by a DELETE request to withdraw the mitigation UDP is used as transport, CoAP requests may arrive out-of-order. For
request, but DELETE request arrives at the DOTS server before the PUT example, the DOTS client may send a PUT request to convey efficacy
request. To handle out-of-order delivery of requests, if an If-Match update to the DOTS server followed by a DELETE request to withdraw
option is present in the PUT request and the mitigation-id in the the mitigation request, but DELETE request arrives at the DOTS server
request matches a mitigation request from the DOTS client then the before the PUT request. To handle out-of-order delivery of requests,
request is processed, and if no match is found then the PUT request if an If-Match option is present in the PUT request and the
is silently ignored. mitigation-id in the request matches a mitigation request from the
DOTS client then the request is processed, and if no match is found
then the PUT request is silently ignored.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "signal" Uri-Path: "signal"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"mitigation-scope": { "mitigation-scope": {
"scope": [ "scope": [
skipping to change at page 24, line 34 skipping to change at page 26, line 34
], ],
"target-protocol": [ "target-protocol": [
integer integer
], ],
"fqdn": [ "fqdn": [
"string" "string"
], ],
"uri": [ "uri": [
"string" "string"
], ],
"alias": [ "alias-name": [
"string" "string"
], ],
"lifetime": integer, "lifetime": integer,
"attack-status": integer "attack-status": integer
} }
] ]
} }
} }
Figure 11: Efficacy Update Figure 12: Efficacy Update
The 'attack-status' parameter is a mandatory attribute. The various The 'attack-status' parameter is a mandatory attribute. The various
possible values contained in the 'attack-status' parameter are possible values contained in the 'attack-status' parameter are
explained below: explained below:
/--------------------+------------------------------------------------------\ /--------------------+------------------------------------------------------\
| Parameter value | Description | | Parameter value | Description |
|--------------------+------------------------------------------------------| |--------------------+------------------------------------------------------|
| 1 | DOTS client determines that it is still under attack.| | 1 | DOTS client determines that it is still under attack.|
+---------------------------------------------------------------------------+ +---------------------------------------------------------------------------+
| 2 | DOTS client determines that the attack is | | 2 | DOTS client determines that the attack is |
| | successfully mitigated | | | successfully mitigated |
| | (e.g., attack traffic is not seen). | | | (e.g., attack traffic is not seen). |
\--------------------+------------------------------------------------------/ \--------------------+------------------------------------------------------/
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. The response code 2.04 (Changed) will be using CoAP response codes. The response code 2.04 (Changed) will be
returned in the response if the DOTS server has accepted the returned in the response if the DOTS server has accepted the
mitigation efficacy update. The 5.xx response codes are returned if mitigation efficacy update. The error response code 5.03 (Service
the DOTS server has erred or is incapable of performing the Unavailable) is returned if the DOTS server has erred or is incapable
mitigation. of performing the mitigation.
5.4. DOTS Signal Channel Session Configuration 5.4. DOTS Signal Channel Session Configuration
The DOTS client can negotiate, configure and retrieve the DOTS signal The DOTS client can negotiate, configure and retrieve the DOTS signal
channel session behavior. The DOTS signal channel can be used, for channel session behavior. The DOTS signal channel can be used, for
example, to configure the following: example, to configure the following:
a. Heartbeat timeout: DOTS agents regularly send heartbeats (Ping/ a. Heartbeat interval: DOTS agents regularly send heartbeats (Ping/
Pong) to each other after mutual authentication in order to keep Pong) to each other after mutual authentication in order to keep
the DOTS signal channel open, heartbeat timeout is the time to the DOTS signal channel open, heartbeat messages are exchanged
wait for a Pong in milliseconds. between the DOTS agents every heartbeat-interval seconds to
detect the current status of the DOTS signal channel session.
b. Acceptable signal loss ratio: Maximum retransmissions, b. Missing heartbeats allowed: This variable indicates the maximum
number of consecutive heartbeat messages for which a DOTS agent
did not receive a response before concluding that the session is
disconnected or defunct.
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.
Reliability is provided to requests and responses by marking them as Reliability is provided to requests and responses 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 (CON) configuration requests and responses are marked as Confirmable (CON)
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
skipping to change at page 26, line 7 skipping to change at page 28, line 13
Section 4.8 of [RFC7252]. Reliability is provided to the responses Section 4.8 of [RFC7252]. Reliability is provided to the responses
by marking them as Confirmable (CON) messages. The DOTS server can by marking them as Confirmable (CON) messages. The DOTS server can
either piggyback the response in the acknowledgement message or if either piggyback the response in the acknowledgement message or if
the DOTS server is not able to respond immediately to a request the DOTS server is not able to respond immediately to a request
carried in a Confirmable message, it simply responds with an Empty carried in a Confirmable message, it simply responds with an Empty
Acknowledgement message so that the DOTS client can stop Acknowledgement message so that the DOTS client can stop
retransmitting the request. Empty Acknowledgement message is retransmitting the request. Empty Acknowledgement message is
explained in Section 2.2 of [RFC7252]. When the response is ready, explained in Section 2.2 of [RFC7252]. When the response is ready,
the server sends it in a new Confirmable message which then in turn the server sends it in a new Confirmable message which then in turn
needs to be acknowledged by the DOTS client (see Sections 5.2.1 and needs to be acknowledged by the DOTS client (see Sections 5.2.1 and
Sections 5.2.2 in [RFC7252]). Requests and responses exchanged Sections 5.2.2 of [RFC7252]). Requests and responses exchanged
between DOTS agents during peacetime are marked as Confirmable between DOTS agents during peacetime are marked as Confirmable
messages. messages.
Implementation Note: A DOTS client that receives a response in a CON Implementation Note: A DOTS client that receives a response in a CON
message may want to clean up the message state right after sending message may want to clean up the message state right after sending
the ACK. If that ACK is lost and the DOTS server retransmits the the ACK. If that ACK is lost and the DOTS server retransmits the
CON, the DOTS client may no longer have any state to which to CON, the DOTS client may no longer have any state to which to
correlate this response, making the retransmission an unexpected correlate this response, making the retransmission an unexpected
message; the DOTS client will send a Reset message so it does not message; the DOTS client will send a Reset message so it does not
receive any more retransmissions. This behavior is normal and not an receive any more retransmissions. This behavior is normal and not an
indication of an error (see Section 5.3.2 in [RFC7252] for more indication of an error (see Section 5.3.2 of [RFC7252] for more
details). details).
5.4.1. Discover Acceptable Configuration Parameters 5.4.1. Discover Configuration Parameters
A GET request is used to obtain acceptable configuration parameters A GET request is used to obtain acceptable and current configuration
on the DOTS server for DOTS signal channel session configuration. parameters on the DOTS server for DOTS signal channel session
Figure 12 shows how to obtain acceptable configuration parameters for configuration. Figure 13 shows how to obtain acceptable
the server. configuration parameters for the server.
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "config" Uri-Path: "config"
Figure 12: GET to retrieve configuration Figure 13: GET to retrieve configuration
The DOTS server in the 2.05 (Content) response conveys the minimum The DOTS server in the 2.05 (Content) response conveys the minimum
and maximum attribute values acceptable by the DOTS server. and maximum attribute values acceptable by the DOTS server.
Content-Format: "application/cbor" Content-Format: "application/cbor"
{
"heartbeat-interval": {
"CurrentValue": integer,
"MinValue": integer,
"MaxValue" : integer,
},
"missing-hb-allowed": {
"CurrentValue": integer,
"MinValue": integer,
"MaxValue" : integer,
},
"max-retransmit": {
"CurrentValue": integer,
"MinValue": integer,
"MaxValue" : integer,
},
"ack-timeout": {
"CurrentValue": integer,
"MinValue": integer,
"MaxValue" : integer,
},
"ack-random-factor": {
"CurrentValue": number,
"MinValue": number,
"MaxValue" : number,
}
}
Figure 14: GET response body
Figure 15 shows an example of acceptable and current configuration
parameters on the DOTS server for DOTS signal channel session
configuration.
Content-Format: "application/cbor"
{ {
"heartbeat-timeout": {"MinValue": integer, "MaxValue" : integer}, "heartbeat-interval": {
"max-retransmit": {"MinValue": integer, "MaxValue" : integer}, "CurrentValue": 91,
"ack-timeout": {"MinValue": integer, "MaxValue" : integer}, "MinValue": 60,
"ack-random-factor": {"MinValue": number, "MaxValue" : number} "MaxValue" : 240,
} },
"missing-hb-allowed": {
"CurrentValue": 3,
"MinValue": 1,
"MaxValue" : 7,
},
"max-retransmit": {
"CurrentValue": 4,
"MinValue": 3,
"MaxValue" : 15,
},
"ack-timeout": {
"CurrentValue": 2,
"MinValue": 1,
"MaxValue" : 30,
},
"ack-random-factor": {
"CurrentValue": 1.5,
"MinValue": 1.0,
"MaxValue" : 4.0,
}
}
Figure 13: GET response body Figure 15: configuration response body
5.4.2. Convey DOTS Signal Channel Session Configuration 5.4.2. 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
signaling channel (e.g., heartbeat timeout, maximum retransmissions signaling channel (e.g., heartbeat interval, maximum retransmissions
etc). Message transmission parameters for CoAP are defined in etc). Message transmission parameters for CoAP are defined in
Section 4.8 of [RFC7252]. The RECOMMENDED values of transmission Section 4.8 of [RFC7252]. The RECOMMENDED values of transmission
parameter values are ack_timeout (2 seconds), max-retransmit (7), parameter values are ack_timeout (2 seconds), max-retransmit (4),
ack-random-factor (1.5) and heartbeat-timeout (371 seconds). The ack-random-factor (1.5), heartbeat-interval (93 seconds) and missing-
heartbeat-timeout value is equal to the MAX_TRANSMIT_WAIT counter hb-allowed (3). The heartbeat-interval value is equal to the
(Section 4.8.2 in [RFC7252]) whose value is derived from transmission MAX_TRANSMIT_WAIT counter (Section 4.8.2 of [RFC7252]) whose value is
parameters. If the DOTS agent wishes to change the default values of derived from transmission parameters. For the default transmission
message transmission parameters then it should follow the guidance parameters, if the DOTS agent does not receive any response from the
given in Section 4.8.1 of [RFC7252]. The DOTS agents MUST use the peer DOTS agent for three (missing-hb-allowed) consecutive "CoAP
negotiated values for message transmission parameters and default ping" confirmable messages then it concludes that the DOTS signal
values for non-negotiated message transmission parameters. The channel session is disconnected, and a "CoAP ping" confirmable
signaling channel session configuration is applicable to a single message is retransmitted four (max-retransmit) times using a initial
DOTS signal channel session between the DOTS agents. timeout set to random duration between 2 (ack_timeout) and 3 seconds
(ack-timeout*ack-random-factor) and exponential back-off between
retransmissions.
If the DOTS agent wishes to change the default values of message
transmission parameters then it should follow the guidance given in
Section 4.8.1 of [RFC7252]. The DOTS agents MUST use the negotiated
values for message transmission parameters and default values for
non-negotiated message transmission parameters. The signaling
channel session configuration is applicable to a single 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: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "config" Uri-Path: "config"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": integer, "session-id": integer,
"heartbeat-timeout": integer, "heartbeat-interval": integer,
"missing-hb-allowed": integer,
"max-retransmit": integer, "max-retransmit": integer,
"ack-timeout": integer, "ack-timeout": integer,
"ack-random-factor": number "ack-random-factor": number
"trigger-mitigation": boolean "trigger-mitigation": boolean
} }
} }
Figure 14: PUT to convey the DOTS signal channel session Figure 16: PUT to convey the DOTS signal channel session
configuration data. configuration data.
The parameters are described below: The parameters 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. This is a any assumption about how this identifier is generated. This is a
mandatory attribute. mandatory attribute.
heartbeat-timeout: Heartbeat timeout is the time to wait for a heartbeat-interval: Time interval in seconds between two
response in milliseconds to check the DOTS peer health. This is consecutive heartbeat messages. This is an optional attribute.
an optional attribute.
missing-hb-allowed: Maximum number of consecutive heartbeat
messages for which the DOTS agent did not receive a response
before concluding that the session is disconnected. This is an
optional attribute.
max-retransmit: Maximum number of retransmissions for a message max-retransmit: Maximum number of retransmissions for a message
(referred to as MAX_RETRANSMIT parameter in CoAP). This is an (referred to as MAX_RETRANSMIT parameter in CoAP). This is an
optional attribute. optional attribute.
ack-timeout: Timeout value in seconds used to calculate the initial ack-timeout: Timeout value in seconds used to calculate the initial
retransmission timeout value (referred to as ACK_TIMEOUT parameter retransmission timeout value (referred to as ACK_TIMEOUT parameter
in CoAP). This is an optional attribute. in CoAP). 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
skipping to change at page 28, line 29 skipping to change at page 32, line 25
CoAP). This is an optional attribute. CoAP). This is an optional attribute.
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 mtigation on loss of signal is session is lost. Automated mtigation on loss of signal is
discussed in Section 3.3.3 of [I-D.ietf-dots-architecture]. If discussed in Section 3.3.3 of [I-D.ietf-dots-architecture]. If
the DOTS client ceases to respond to heartbeat messages, then the the DOTS client ceases to respond to heartbeat messages, then the
DOTS server can detect that the DOTS session is lost. The default DOTS server can detect that the DOTS session is lost. The default
value of the parameter is 'true'. This is an optional attribute. value of the parameter is 'true'. This is an optional attribute.
In the PUT request at least one of the attributes heartbeat-timeout, In the PUT request at least one of the attributes heartbeat-interval,
max-retransmit, ack-timeout, ack-random-factor, and trigger- missing-hb-allowed, max-retransmit, ack-timeout, ack-random-factor,
mitigation MUST be present. The PUT request with higher numeric and trigger-mitigation MUST be present. The PUT request with higher
session-id value over-rides the DOTS signal channel session numeric session-id value over-rides the DOTS signal channel session
configuration data installed by a PUT request with a lower numeric configuration data installed by a PUT request with a lower numeric
session-id value. session-id value.
Figure 15 shows a PUT request example to convey the configuration Figure 17 shows an PUT request example to convey the configuration
parameters for the DOTS signal channel. parameters for the DOTS signal channel.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "www.example.com" Uri-Host: "www.example.com"
Uri-Path: "v1" Uri-Path: "v1"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "config" Uri-Path: "config"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": 1234534333242, "session-id": 1234534333242,
"heartbeat-timeout": 30, "heartbeat-interval": 91,
"missing-hb-allowed": 3,
"max-retransmit": 7, "max-retransmit": 7,
"ack-timeout": 5, "ack-timeout": 5,
"ack-random-factor": 1.5, "ack-random-factor": 1.5,
"trigger-mitigation": false "trigger-mitigation": false
} }
} }
Figure 15: PUT to convey the configuration parameters Figure 17: 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. The CoAP response will include the CBOR using CoAP response codes. If the DOTS server finds the session-id
body received in the request. If the DOTS server finds the session- parameter value conveyed in the PUT request in its configuration data
id parameter value conveyed in the PUT request in its configuration and if the DOTS server has accepted the updated configuration
data and if the DOTS server has accepted the updated configuration
parameters then the a 2.04 (Changed) response will be returned in the parameters then the a 2.04 (Changed) response will be returned in the
response. If the DOTS server does not find the session-id parameter response. If the DOTS server does not find the session-id parameter
value conveyed in the PUT request in its configuration data and if value conveyed in the PUT request in its configuration data and if
the DOTS server has accepted the configuration parameters then a the DOTS server has accepted the configuration parameters then a
response code 2.01 (Created) will be returned in the response. If response code 2.01 (Created) will be returned in the response. If
the request is missing one or more mandatory attributes then 4.00 the request is missing one or more mandatory attributes then 4.00
(Bad Request) will be returned in the response or if the request (Bad Request) will be returned in the response or if the request
contains invalid or unknown parameters then 4.02 (Invalid query) will contains invalid or unknown parameters then 4.02 (Invalid query) will
be returned in the response. Response code 4.22 (Unprocessable be returned in the response. Response code 4.22 (Unprocessable
Entity) will be returned in the response if any of the heartbeat- Entity) will be returned in the response if any of the heartbeat-
timeout, max-retransmit, target-protocol, ack-timeout and ack-random- interval, missing-hb-allowed, max-retransmit, target-protocol, ack-
factor attribute values is not acceptable to the DOTS server. The timeout and ack-random-factor attribute values are not acceptable to
DOTS server in the error response conveys the minimum and maximum the DOTS server. On receipt of the 4.22 error response code, the
attribute values acceptable by the DOTS server. The DOTS client can DOTS client should request the maximum and minumum attribute values
acceptable to the DOTS server (Section 5.4.1). The DOTS client can
re-try and send the PUT request with updated attribute values re-try and send the PUT request with updated attribute values
acceptable to the DOTS server. acceptable to the DOTS server.
Content-Format: "application/cbor"
{
"heartbeat-timeout": {"MinValue": 15, "MaxValue" : 60},
"max-retransmit": {"MinValue": 3, "MaxValue" : 15},
"ack-timeout": {"MinValue": 1, "MaxValue" : 30},
"ack-random-factor": {"MinValue": 1.0, "MaxValue" : 4.0}
}
Figure 16: Error response body
5.4.3. Delete DOTS Signal Channel Session Configuration 5.4.3. 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 17). session configuration data (Figure 18).
Header: DELETE (Code=0.04) Header: DELETE (Code=0.04)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "config" Uri-Path: "config"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": integer "session-id": integer
} }
} }
Figure 17: DELETE configuration Figure 18: DELETE configuration
If the DOTS server does not find the session-id parameter value If the DOTS server does not find the session-id parameter value
conveyed in the DELETE request in its configuration data, then it conveyed in the DELETE request in its configuration data, then it
responds with a 4.04 (Not Found) error response code. The DOTS responds with a 4.04 (Not Found) error response code. The DOTS
server successfully acknowledges a DOTS client's request to remove server successfully acknowledges a DOTS client's request to remove
the DOTS signal channel session configuration using 2.02 (Deleted) the DOTS signal channel session configuration using 2.02 (Deleted)
response code. response code.
5.4.4. Retrieving DOTS Signal Channel Session Configuration 5.4.4. Retrieving DOTS Signal Channel Session Configuration
A GET request is used to retrieve the installed DOTS signal channel A GET request is used to retrieve the installed DOTS signal channel
session configuration data from a DOTS server. Figure 18 shows how session configuration data from a DOTS server. Figure 19 shows how
to retrieve the DOTS signal channel session configuration data. to retrieve the DOTS signal channel session configuration data.
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "dots-signal" Uri-Path: "dots-signal"
Uri-Path: "config" Uri-Path: "config"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": integer "session-id": integer
} }
} }
Figure 18: GET to retrieve configuration Figure 19: GET to retrieve configuration
5.5. Redirected Signaling 5.5. Redirected Signaling
Redirected Signaling is discussed in detail in Section 3.2.2 of Redirected Signaling is discussed in detail in Section 3.2.2 of
[I-D.ietf-dots-architecture]. If the DOTS server wants to redirect [I-D.ietf-dots-architecture]. If the DOTS server wants to redirect
the DOTS client to an alternative DOTS server for a signaling session the DOTS client to an alternative DOTS server for a signaling session
then the response code 3.00 (alternate server) will be returned in then the response code 3.00 (alternate server) will be returned in
the response to the client. The DOTS server can return the error the response to the client. The DOTS server can return the error
response code 3.00 in response to a PUT request from the DOTS client response code 3.00 in response to a PUT request from the DOTS client
or convey the error response code 3.00 in a unidirectional or convey the error response code 3.00 in a unidirectional
skipping to change at page 31, line 44 skipping to change at page 35, line 22
{ {
"alt-server": "string", "alt-server": "string",
"alt-server-record": [ "alt-server-record": [
{ {
"addr": "string", "addr": "string",
"ttl" : integer, "ttl" : integer,
} }
] ]
} }
Figure 19: Error response body Figure 20: 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 20 shows a 3.00 response example to convey the DOTS alternate Figure 21 shows a 3.00 response example to convey the DOTS alternate
server www.example-alt.com, its IP addresses 2001:db8:6401::1 and server www.example-alt.com, 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": "www.example-alt.com", "alt-server": "www.example-alt.com",
"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 20: Example of error response body Figure 21: Example of 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 having failed, but SHOULD try the request with the request as having failed, but SHOULD try the request with 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
subjected to DDOS attack, alternate DOTS server IP addresses conveyed subjected to DDOS attack, alternate DOTS server IP addresses conveyed
in the 3.00 response help the DOTS client to skip DNS lookup of the in the 3.00 response help the DOTS client to skip DNS lookup of the
alternate DOTS server and can try to establish UDP or TCP session alternate DOTS server and can try to establish UDP or TCP session
with the alternate DOTS server IP addresses. The DOTS client SHOULD with the alternate DOTS server IP addresses. The DOTS client SHOULD
implement DNS64 function to handle the scenario where IPv6-only DOTS implement DNS64 function to handle the scenario where IPv6-only DOTS
client communicates with IPv4-only alternate DOTS server. client communicates with IPv4-only alternate DOTS server.
5.6. Heartbeat Mechanism 5.6. Heartbeat Mechanism
To provide a metric of signal health and distinguish an 'idle' signal To provide a metric of signal health and distinguish an 'idle' signal
channel from a 'disconnected' or 'defunct' session, the DOTS agent channel from a 'disconnected' or 'defunct' session, the DOTS agent
sends a heartbeat over the signal channel to maintain its half of the sends a heartbeat over the signal channel to maintain its half of the
channel. The DOTS agent similarly expects a heartbeat from its peer channel. The DOTS agent similarly expects a heartbeat from its peer
agent, and may consider a session terminated in the extended absence DOTS agent, and may consider a session terminated in the extended
of a peer agent heartbeat. While the communication between the DOTS absence of a peer agent heartbeat.
agents is quiescent, the DOTS client will probe the DOTS server to
ensure it has maintained cryptographic state and vice versa. Such While the communication between the DOTS agents is quiescent, the
probes can also keep alive firewall and/or NAT bindings. This DOTS client will probe the DOTS server to ensure it has maintained
probing reduces the frequency of establishing a new handshake when a cryptographic state and vice versa. Such probes can also keep alive
DOTS signal needs to be conveyed to the DOTS server. In DOTS over firewall and/or NAT bindings. This probing reduces the frequency of
UDP, heartbeat messages can be exchanged between the DOTS agents establishing a new handshake when a DOTS signal needs to be conveyed
using the "COAP ping" mechanism (Section 4.2 in [RFC7252]). The DOTS to the DOTS server.
agent sends an Empty Confirmable message and the peer DOTS agent will
respond by sending an Reset message. In DOTS over TCP, heartbeat In DOTS over UDP, heartbeat messages may be exchanged between the
messages can be exchanged between the DOTS agents using the Ping and DOTS agents using the "COAP ping" mechanism defined in Section 4.2 of
Pong messages (Section 4.4 in [I-D.ietf-core-coap-tcp-tls]). The [RFC7252]. Concretely, the DOTS agent sends an Empty Confirmable
DOTS agent sends a Ping message and the peer DOTS agent would respond message and the peer DOTS agent will respond by sending an Reset
by sending a single Pong message. message.
In DOTS over TCP, heartbeat messages can be exchanged between the
DOTS agents using the Ping and Pong messages specified in Section 4.4
of [I-D.ietf-core-coap-tcp-tls]. That is, the DOTS agent sends a
Ping message and the peer DOTS agent would respond by sending a
single Pong message.
6. Mapping parameters to CBOR 6. Mapping parameters to CBOR
All parameters in DOTS signal channel are mapped to CBOR types as All parameters in the payload in the DOTS signal channel MUST be
follows and are given an integer key value to save space. mapped to CBOR types as follows and are given an integer key to save
space. The recipient of the payload MAY reject the information if it
is not suitably mapped.
/--------------------+------------------------+--------------------------\ /--------------------+------------------------+--------------------------\
| Parameter name | CBOR key | CBOR major type of value | | Parameter name | CBOR key | CBOR major type of value |
|--------------------+------------------------+--------------------------| |--------------------+------------------------+--------------------------|
| 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) |
| target-ip | 4 | 4 (array) | | target-ip | 4 | 4 (array) |
| 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 |
| fqdn | 9 | 4 | | fqdn | 9 | 4 |
| uri | 10 | 4 | | uri | 10 | 4 |
| alias | 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 |
| heartbeat-timeout | 15 | 0 | | heartbeat-interval | 15 | 0 |
| max-retransmit | 16 | 0 | | max-retransmit | 16 | 0 |
| ack-timeout | 17 | 0 | | ack-timeout | 17 | 0 |
| ack-random-factor | 18 | 7 | | ack-random-factor | 18 | 7 |
| MinValue | 19 | 0 | | MinValue | 19 | 0 |
| MaxValue | 20 | 0 | | MaxValue | 20 | 0 |
| status | 21 | 0 | | status | 21 | 0 |
| bytes-dropped | 22 | 0 | | bytes-dropped | 22 | 0 |
| bps-dropped | 23 | 0 | | bps-dropped | 23 | 0 |
| pkts-dropped | 24 | 0 | | pkts-dropped | 24 | 0 |
| pps-dropped | 25 | 0 | | pps-dropped | 25 | 0 |
| session-id | 26 | 0 | | session-id | 26 | 0 |
| trigger-mitigation | 27 | 7 (simple types) | | trigger-mitigation | 27 | 7 (simple types) |
| missing-hb-allowed | 28 | 0 |
| CurrentValue | 29 | 0 |
| mitigation-start | 30 | 7 (floating-point) |
\--------------------+------------------------+--------------------------/ \--------------------+------------------------+--------------------------/
Figure 21: CBOR mappings used in DOTS signal channel message Figure 22: CBOR mappings used in DOTS signal channel message
7. (D)TLS Protocol Profile and Performance considerations 7. (D)TLS Protocol Profile and Performance considerations
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 machine-in-the-middle and There are known attacks on (D)TLS, such as machine-in-the-middle and
protocol downgrade. These are general attacks on (D)TLS and not protocol downgrade. These are general attacks on (D)TLS and not
specific to DOTS over (D)TLS; please refer to the (D)TLS RFCs for specific to DOTS over (D)TLS; please refer to the (D)TLS RFCs for
discussion of these security issues. DOTS agents MUST adhere to the discussion of these security issues. DOTS agents MUST adhere to the
(D)TLS implementation recommendations and security considerations of (D)TLS implementation recommendations and security considerations of
[RFC7525] except with respect to (D)TLS version. Since encryption of [RFC7525] except with respect to (D)TLS version. Since encryption of
DOTS using (D)TLS is virtually a green-field deployment DOTS agents DOTS using (D)TLS is virtually a green-field deployment DOTS agents
MUST implement only (D)TLS 1.2 or later. MUST implement only (D)TLS 1.2 or later.
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 DOTS agents MUST support DTLS record replay detection (Section 3.3 o DOTS agents MUST support DTLS record replay detection (Section 3.3
in [RFC6347]) to protect against replay attacks. of [RFC6347]) to protect against replay attacks.
o DOTS client can use (D)TLS session resumption without server-side o DOTS client can use (D)TLS session resumption without server-side
state [RFC5077] to resume session and convey the DOTS signal. state [RFC5077] to resume session and convey the DOTS signal.
o Raw public keys [RFC7250] which reduce the size of the o Raw public keys [RFC7250] which reduce the size of the
ServerHello, and can be used by servers that cannot obtain ServerHello, and can be used by servers that cannot obtain
certificates (e.g., DOTS gateways on private networks). certificates (e.g., DOTS gateways on private networks).
Implementations compliant with this profile SHOULD implement all of Implementations compliant with this profile SHOULD implement all of
the following items to reduce the delay required to deliver a DOTS the following items to reduce the delay required to deliver a DOTS
skipping to change at page 35, line 51 skipping to change at page 39, line 41
send DOTS signal message on its first flight, thus reducing send DOTS signal message on its first flight, thus reducing
handshake latency. 0-RTT only works if the DOTS client has handshake latency. 0-RTT only works if the DOTS client has
previously communicated with that DOTS server, which is very previously communicated with that DOTS server, which is very
likely with the DOTS signal channel. The DOTS client SHOULD likely with the DOTS signal channel. The DOTS client SHOULD
establish a (D)TLS session with the DOTS server during peacetime establish a (D)TLS session with the DOTS server during peacetime
and share a PSK. During DDOS attack, the DOTS client can use the and share a PSK. During DDOS attack, the DOTS client can use the
(D)TLS session to convey the DOTS signal message and if there is (D)TLS session to convey the DOTS signal message and if there is
no response from the server after multiple re-tries then the DOTS no response from the server after multiple re-tries then the DOTS
client can resume the (D)TLS session in 0-RTT mode using PSK. A client can resume the (D)TLS session in 0-RTT mode using PSK. A
simplified TLS 1.3 handshake with 0-RTT DOTS signal message simplified TLS 1.3 handshake with 0-RTT DOTS signal message
exchange is shown in Figure 22. exchange is shown in Figure 23.
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 22: TLS 1.3 handshake with 0-RTT Figure 23: TLS 1.3 handshake with 0-RTT
9. Mutual Authentication of DOTS Agents & Authorization of DOTS Clients 9. Mutual Authentication of DOTS Agents & Authorization of DOTS Clients
(D)TLS based on client certificate can be used for mutual (D)TLS based on 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 gateway MUST perform mutual authentication; DOTS clients and DOTS gateway 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. DOTS gateway and DOTS server MUST perform mutual DOTS gateway. DOTS gateway and DOTS server MUST perform mutual
authentication; DOTS server only allows DOTS signals from authorized authentication; DOTS server only allows DOTS signals from authorized
DOTS gateway, creating a two-link chain of transitive authentication DOTS gateway, creating a two-link chain of transitive authentication
skipping to change at page 37, line 29 skipping to change at page 41, line 29
| +----+--------+ | +---------------+ | +----+--------+ | +---------------+
| ^ | | ^ |
| | | | | |
| +----------------+ | | | +----------------+ | |
| | DDOS detector | | | | | DDOS detector | | |
| | (DOTS client) +<--------------+ | | | (DOTS client) +<--------------+ |
| +----------------+ | | +----------------+ |
| | | |
+-------------------------------------------------+ +-------------------------------------------------+
Figure 23: Example of Authentication and Authorization of DOTS Agents Figure 24: Example of Authentication and Authorization of DOTS Agents
In the example depicted in Figure 23, the DOTS gateway and DOTS In the example depicted in Figure 24, 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 detector to request DDOS mitigation, but does not permit the DDOS detector to request DDOS mitigation, but does not permit the
user of type 'guest' to request DDOS mitigation. user of type 'guest' to request DDOS mitigation.
Also, DOTS gateway and DOTS server MUST perform mutual authentication Also, DOTS gateway and DOTS server located in different domains MUST
using certificates. A DOTS server will only allow a DOTS gateway perform mutual authentication using certificates. A DOTS server will
with a certificate for a particular domain to request mitigation for only allow a DOTS gateway with a certificate for a particular domain
that domain. In reference to Figure 23, the DOTS server only allows to request mitigation for that domain. In reference to Figure 24,
the DOTS gateway to request mitigation for 'example.com' domain and the DOTS server only allows the DOTS gateway to request mitigation
not for other domains. for 'example.com' domain and not for other domains.
10. IANA Considerations 10. IANA Considerations
This specification registers new CoAP response code, new parameters This specification registers new CoAP response code, new parameters
for DOTS signal channel and establishes registries for mappings to for DOTS signal channel and establishes registries for mappings to
CBOR. CBOR.
10.1. CoAP Response Code 10.1. CoAP Response Code
The following entry is added to the "CoAP Response Codes" sub- The following entry is added to the "CoAP Response Codes" sub-
registry: registry:
+------+------------------------------+-----------+ +------+------------------------------+-----------+
| Code | Description | Reference | | Code | Description | Reference |
+------+------------------------------+-----------+ +------+------------------------------+-----------+
| 3.00 | Alternate server | [RFCXXXX] | | 3.00 | Alternate server | [RFCXXXX] |
+------+------------------------------+-----------+ +------+------------------------------+-----------+
Figure 24: CoAP Response Code Figure 25: CoAP Response Code
[Note to RFC Editor: Please replace XXXX with the RFC number of this [Note to RFC Editor: Please replace XXXX with the RFC number of this
specification.] specification.]
10.2. DOTS signal channel CBOR Mappings Registry 10.2. DOTS signal channel CBOR Mappings Registry
A new registry will be requested from IANA, entitled "DOTS signal A new registry will be requested from IANA, entitled "DOTS signal
channel CBOR Mappings Registry". The registry is to be created as channel CBOR Mappings Registry". The registry is to be created as
Expert Review Required. Expert Review Required.
skipping to change at page 40, line 10 skipping to change at page 44, line 10
o CBOR Key Value: 7 o CBOR Key Value: 7
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: target-protocol o Parameter Name: target-protocol
o CBOR Key Value: 8 o CBOR Key Value: 8
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: "FQDN" o Parameter Name: "fqdn"
o CBOR Key Value: 9 o CBOR Key Value: 9
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: "URI" o Parameter Name: "uri"
o CBOR Key Value: 10 o CBOR Key Value: 10
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: alias o Parameter Name: alias-name
o CBOR Key Value: 11 o CBOR Key Value: 11
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: "lifetime" o Parameter Name: "lifetime"
o CBOR Key Value: 12 o CBOR Key Value: 12
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
skipping to change at page 40, line 46 skipping to change at page 44, line 46
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: signal-config o Parameter Name: signal-config
o CBOR Key Value: 14 o CBOR Key Value: 14
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: heartbeat-timeout o Parameter Name: heartbeat-interval
o CBOR Key Value: 15 o CBOR Key Value: 15
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: max-retransmit o Parameter Name: max-retransmit
o CBOR Key Value: 16 o CBOR Key Value: 16
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
skipping to change at page 42, line 28 skipping to change at page 46, line 28
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: trigger-mitigation o Parameter Name: trigger-mitigation
o CBOR Key Value: 27 o CBOR Key Value: 27
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: missing-hb-allowed
o CBOR Key Value: 28
o CBOR Major Type: 0
o Change Controller: IESG
o Specification Document(s): this document
o Parameter Name: CurrentValue
o CBOR Key Value: 29
o CBOR Major Type: 0
o Change Controller: IESG
o Specification Document(s): this document
11. Implementation Status 11. Implementation Status
[Note to RFC Editor: Please remove this section and reference to [Note to RFC Editor: Please remove this section and reference to
[RFC7942] prior to publication.] [RFC7942] prior to publication.]
This section records the status of known implementations of the This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942]. Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to assist the IETF in its decision processes in progressing drafts to
skipping to change at page 43, line 13 skipping to change at page 47, line 25
they see fit". they see fit".
11.1. nttdots 11.1. nttdots
Organization: NTT Communication is developing a DOTS client and Organization: NTT Communication is developing a DOTS client and
DOTS server software based on DOTS signal channel specified in DOTS server software based on DOTS signal channel specified in
this draft. It will be open-sourced. this draft. It will be open-sourced.
Description: Early implementation of DOTS protocol. It is aimed to Description: Early implementation of DOTS protocol. It is aimed to
implement a full DOTS protocol spec in accordance with maturing of implement a full DOTS protocol spec in accordance with maturing of
DOTS protocol itself. DOTS protocol itself.
Implementation: To be open-sourced. Implementation: https://github.com/nttdots/go-dots
Level of maturity: It is a early implementation of DOTS protocol. Level of maturity: It is a early implementation of DOTS protocol.
Messaging between DOTS clients and DOTS servers has been tested. Messaging between DOTS clients and DOTS servers has been tested.
Level of maturity will increase in accordance with maturing of Level of maturity will increase in accordance with maturing of
DOTS protocol itself. DOTS protocol itself.
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.
skipping to change at page 44, line 34 skipping to change at page 48, line 47
Robert Moskowitz HTT Consulting Oak Park, MI 42837 United States Robert Moskowitz HTT Consulting Oak Park, MI 42837 United States
Email: rgm@htt-consult.com Email: rgm@htt-consult.com
Dan Wing Email: dwing-ietf@fuggles.com Dan Wing Email: dwing-ietf@fuggles.com
14. Acknowledgements 14. Acknowledgements
Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen, Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen,
Roman D. Danyliw, Michael Richardson, Ehud Doron, Kaname Nishizuka, Roman D. Danyliw, Michael Richardson, Ehud Doron, Kaname Nishizuka,
Dave Dolson, Liang Xia, Jon Shallow and Gilbert Clark for the Dave Dolson, Liang Xia, Jon Shallow, and Gilbert Clark for the
discussion and comments. discussion and comments.
15. References 15. References
15.1. Normative References 15.1. 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-09 (work in progress), May draft-ietf-core-coap-tcp-tls-09 (work in progress), May
2017. 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,
<http://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, (TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008, DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>. <https://www.rfc-editor.org/info/rfc5246>.
[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, <http://www.rfc-editor.org/info/rfc5925>. June 2010, <https://www.rfc-editor.org/info/rfc5925>.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <http://www.rfc-editor.org/info/rfc6347>. January 2012, <https://www.rfc-editor.org/info/rfc6347>.
[RFC7250] Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J., [RFC7250] Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J.,
Weiler, S., and T. Kivinen, "Using Raw Public Keys in Weiler, S., and T. Kivinen, "Using Raw Public Keys in
Transport Layer Security (TLS) and Datagram Transport Transport Layer Security (TLS) and Datagram Transport
Layer Security (DTLS)", RFC 7250, DOI 10.17487/RFC7250, Layer Security (DTLS)", RFC 7250, DOI 10.17487/RFC7250,
June 2014, <http://www.rfc-editor.org/info/rfc7250>. June 2014, <https://www.rfc-editor.org/info/rfc7250>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252, Application Protocol (CoAP)", RFC 7252,
DOI 10.17487/RFC7252, June 2014, DOI 10.17487/RFC7252, June 2014,
<http://www.rfc-editor.org/info/rfc7252>. <https://www.rfc-editor.org/info/rfc7252>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer "Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <http://www.rfc-editor.org/info/rfc7525>. 2015, <https://www.rfc-editor.org/info/rfc7525>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained [RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641, Application Protocol (CoAP)", RFC 7641,
DOI 10.17487/RFC7641, September 2015, DOI 10.17487/RFC7641, September 2015,
<http://www.rfc-editor.org/info/rfc7641>. <https://www.rfc-editor.org/info/rfc7641>.
15.2. Informative References 15.2. Informative References
[I-D.ietf-core-comi] [I-D.ietf-core-comi]
Veillette, M., Stok, P., Pelov, A., and A. Bierman, "CoAP Veillette, M., Stok, P., Pelov, A., and A. Bierman, "CoAP
Management Interface", draft-ietf-core-comi-01 (work in Management Interface", draft-ietf-core-comi-01 (work in
progress), July 2017. progress), July 2017.
[I-D.ietf-core-yang-cbor] [I-D.ietf-core-yang-cbor]
Veillette, M., Pelov, A., Somaraju, A., Turner, R., and A. Veillette, M., Pelov, A., Somaraju, A., Turner, R., and A.
skipping to change at page 46, line 16 skipping to change at page 50, 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-04 (work in progress), July 2017. architecture-04 (work in progress), July 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-02 (work in progress), June 2017. ietf-dots-data-channel-03 (work in progress), August 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-06 (work in Requirements", draft-ietf-dots-requirements-06 (work in
progress), July 2017. progress), July 2017.
[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
skipping to change at page 46, line 47 skipping to change at page 51, line 17
Datagram Transport Layer Security (DTLS) Protocol Version Datagram Transport Layer Security (DTLS) Protocol Version
1.3", draft-rescorla-tls-dtls13-01 (work in progress), 1.3", draft-rescorla-tls-dtls13-01 (work in progress),
March 2017. March 2017.
[proto_numbers] [proto_numbers]
"IANA, "Protocol Numbers"", 2011, "IANA, "Protocol Numbers"", 2011,
<http://www.iana.org/assignments/protocol-numbers>. <http://www.iana.org/assignments/protocol-numbers>.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
DOI 10.17487/RFC0791, September 1981, DOI 10.17487/RFC0791, September 1981,
<http://www.rfc-editor.org/info/rfc791>. <https://www.rfc-editor.org/info/rfc791>.
[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, <http://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,
<http://www.rfc-editor.org/info/rfc4732>. <https://www.rfc-editor.org/info/rfc4732>.
[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,
<http://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
Server-Side State", RFC 5077, DOI 10.17487/RFC5077, Server-Side State", RFC 5077, DOI 10.17487/RFC5077,
January 2008, <http://www.rfc-editor.org/info/rfc5077>. January 2008, <https://www.rfc-editor.org/info/rfc5077>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020, the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010, DOI 10.17487/RFC6020, October 2010,
<http://www.rfc-editor.org/info/rfc6020>. <https://www.rfc-editor.org/info/rfc6020>.
[RFC6555] Wing, D. and A. Yourtchenko, "Happy Eyeballs: Success with [RFC6555] Wing, D. and A. Yourtchenko, "Happy Eyeballs: Success with
Dual-Stack Hosts", RFC 6555, DOI 10.17487/RFC6555, April Dual-Stack Hosts", RFC 6555, DOI 10.17487/RFC6555, April
2012, <http://www.rfc-editor.org/info/rfc6555>. 2012, <https://www.rfc-editor.org/info/rfc6555>.
[RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown, [RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown,
"Default Address Selection for Internet Protocol Version 6 "Default Address Selection for Internet Protocol Version 6
(IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012, (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012,
<http://www.rfc-editor.org/info/rfc6724>. <https://www.rfc-editor.org/info/rfc6724>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <http://www.rfc-editor.org/info/rfc7049>. October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP [RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP
Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014, Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014,
<http://www.rfc-editor.org/info/rfc7413>. <https://www.rfc-editor.org/info/rfc7413>.
[RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the [RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
NETCONF Protocol over Transport Layer Security (TLS) with NETCONF Protocol over Transport Layer Security (TLS) with
Mutual X.509 Authentication", RFC 7589, Mutual X.509 Authentication", RFC 7589,
DOI 10.17487/RFC7589, June 2015, DOI 10.17487/RFC7589, June 2015,
<http://www.rfc-editor.org/info/rfc7589>. <https://www.rfc-editor.org/info/rfc7589>.
[RFC7918] Langley, A., Modadugu, N., and B. Moeller, "Transport [RFC7918] Langley, A., Modadugu, N., and B. Moeller, "Transport
Layer Security (TLS) False Start", RFC 7918, Layer Security (TLS) False Start", RFC 7918,
DOI 10.17487/RFC7918, August 2016, DOI 10.17487/RFC7918, August 2016,
<http://www.rfc-editor.org/info/rfc7918>. <https://www.rfc-editor.org/info/rfc7918>.
[RFC7924] Santesson, S. and H. Tschofenig, "Transport Layer Security [RFC7924] Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", RFC 7924, (TLS) Cached Information Extension", RFC 7924,
DOI 10.17487/RFC7924, July 2016, DOI 10.17487/RFC7924, July 2016,
<http://www.rfc-editor.org/info/rfc7924>. <https://www.rfc-editor.org/info/rfc7924>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205, Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016, RFC 7942, DOI 10.17487/RFC7942, July 2016,
<http://www.rfc-editor.org/info/rfc7942>. <https://www.rfc-editor.org/info/rfc7942>.
[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, <http://www.rfc-editor.org/info/rfc8085>. March 2017, <https://www.rfc-editor.org/info/rfc8085>.
Authors' Addresses Authors' Addresses
Tirumaleswar Reddy Tirumaleswar Reddy
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
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