DOTS client carry ddos attack informations in signal channel
draft-chen-dots-attack-informations-03

Versions: 00 01 02 03                                                   
DOTS                                                             M. Chen
Internet-Draft                                                    Li. Su
Intended status: Standards Track                               Jin. Peng
Expires: February 23, 2020                                          CMCC
                                                         August 22, 2019


      DOTS client carry ddos attack informations in signal channel
                 draft-chen-dots-attack-informations-03

Abstract

   This document describes DDoS attack information which can be obtained
   by DOTS client when the enterprise suspects it is under DDoS attack,
   these informations will be send from DOTS client to DOTS server in
   mitigation request using Signal channel or Data channel.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on February 23, 2020.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Key Words . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Definition of Terms . . . . . . . . . . . . . . . . . . .   4
   3.  Alarm attributes for mitigation request . . . . . . . . . . .   5
     3.1.  Bandwidth consuming attack  . . . . . . . . . . . . . . .   5
       3.1.1.  Attack_Target_IP  . . . . . . . . . . . . . . . . . .   5
       3.1.2.  Alarm_Begin_time  . . . . . . . . . . . . . . . . . .   5
       3.1.3.  Direction . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.4.  Target_Attack_Type  . . . . . . . . . . . . . . . . .   5
       3.1.5.  Target_Attack_Type_Threshold  . . . . . . . . . . . .   5
       3.1.6.  Attack_Target_IP_Peak . . . . . . . . . . . . . . . .   5
       3.1.7.  Attack_Source_IP_Num  . . . . . . . . . . . . . . . .   5
       3.1.8.  Attack_Bandwidth  . . . . . . . . . . . . . . . . . .   6
     3.2.  Host resource consuming attack  . . . . . . . . . . . . .   6
       3.2.1.  Attack_Target_IP  . . . . . . . . . . . . . . . . . .   6
       3.2.2.  Attack_Target_Packet_Rate . . . . . . . . . . . . . .   6
       3.2.3.  Alarm_Begin_Time  . . . . . . . . . . . . . . . . . .   6
       3.2.4.  Direction . . . . . . . . . . . . . . . . . . . . . .   6
       3.2.5.  Target_Attack_Type  . . . . . . . . . . . . . . . . .   6
   4.  mitigation attributes for mitigation response . . . . . . . .   6
     4.1.  Bandwidth consuming attack  . . . . . . . . . . . . . . .   6
       4.1.1.  Attack_Target_IP  . . . . . . . . . . . . . . . . . .   6
       4.1.2.  Alarm_End_time  . . . . . . . . . . . . . . . . . . .   7
       4.1.3.  Target_Attack_Type  . . . . . . . . . . . . . . . . .   7
       4.1.4.  Total_Traffic . . . . . . . . . . . . . . . . . . . .   7
       4.1.5.  Residual_Traffic  . . . . . . . . . . . . . . . . . .   7
       4.1.6.  Attack_Traffic  . . . . . . . . . . . . . . . . . . .   7
       4.1.7.  Attack_Target_IP_Peak . . . . . . . . . . . . . . . .   7
       4.1.8.  Attack_Source_IP_Num  . . . . . . . . . . . . . . . .   7
     4.2.  Host resource consuming attack  . . . . . . . . . . . . .   7
       4.2.1.  Attack_Target_IP  . . . . . . . . . . . . . . . . . .   7
       4.2.2.  Alarm_End_time  . . . . . . . . . . . . . . . . . . .   7
       4.2.3.  Target_Attack_Type  . . . . . . . . . . . . . . . . .   8
       4.2.4.  Attack_Source_IP  . . . . . . . . . . . . . . . . . .   8
       4.2.5.  Attack_Target_Packet_Rate . . . . . . . . . . . . . .   8
   5.  Mitigation Use Case 1 . . . . . . . . . . . . . . . . . . . .   8
     5.1.  Mitigations for attack flow . . . . . . . . . . . . . . .   8
     5.2.  Optimal device selection  . . . . . . . . . . . . . . . .   9
     5.3.  Optimum path for disposal . . . . . . . . . . . . . . . .   9
     5.4.  Mitigation request parameters . . . . . . . . . . . . . .  10
   6.  Mitigation Use Case 2 . . . . . . . . . . . . . . . . . . . .  10
     6.1.  classified disposal . . . . . . . . . . . . . . . . . . .  10
     6.2.  Standard of Attack Type Definition  . . . . . . . . . . .  11
   7.  Mitigation Use Case 3 . . . . . . . . . . . . . . . . . . . .  12
     7.1.  Mitigation alarm baseline . . . . . . . . . . . . . . . .  12



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   8.  Mitigation request optional parameters  . . . . . . . . . . .  13
     8.1.  Bandwidth consuming attack  . . . . . . . . . . . . . . .  13
     8.2.  Host resource consuming attack  . . . . . . . . . . . . .  14
   9.  Mitigation response parameters  . . . . . . . . . . . . . . .  16
     9.1.  Bandwidth consuming attack  . . . . . . . . . . . . . . .  16
     9.2.  Host resource consuming attack  . . . . . . . . . . . . .  17
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  18
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  19
   12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  19
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  19
     13.1.  Normative References . . . . . . . . . . . . . . . . . .  19
     13.2.  Informative References . . . . . . . . . . . . . . . . .  19
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20

1.  Introduction

   Distributed Denial of Service (DDoS) is a type of resource-consuming
   attack, which exploits a large number of attack resources and uses
   standard protocols to attack target objects.  DDoS attacks consume a
   large amount of target network resources or server resources
   (including computing power, storage capacity, etc.), this means there
   are two types of the DDoS attack, one is bandwidth consuming attack,
   the other is host resource consuming attack.  At present, DDoS attack
   is one of the most powerful and indefensible attacks on the Internet,
   and due to the extensive use of mobile devices and IoT devices in
   recent years, it is easier for DDoS attackers to attack with real
   attack sources (broilers).

   The IETF is specifying the DDoS Open Threat Signaling (DOTS)
   [I-D.ietf-dots-architecture]architecture, where a DOTS client can
   inform a DOTS server that the attack target is under a potential
   attack and that appropriate mitigation actions are required.  In the
   architecture draft, it says in the draft the enterprise has a DOTS
   client, which obtains information about the DDoS attack, and signals
   the DOTS server for help in mitigating the attack. but it doesn't
   says what the information of DDoS attack is. the scope of this draft
   is about the information of DDoS attack which DOTS client can obtain.

   In the architecture draft, it says in the draft the client signal may
   also include telemetry information about the attack, if the DOTS
   client has such information available.  But in the signal channel
   draft it doesn't define optional parameter about the telemetry
   information which will be regarded as DDoS portrait information.

   "DDoS portrait information" is defined as the collection of
   attributes characterizing the attacks(or suspected attack) that have
   been detected and mitigated.  The DDoS portrait information is an




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   optional set of attributes that can be signaled.  The portrait can be
   optionally sent from the DOTS Client to Server and vice versa.

   This document will divide into two directions, before mitigation
   request and after mitigation is complete.  Before mitigation request,
   DOTS client can obtain informations of attack; After mitigation, DOTS
   server can obtain from mitigator.

2.  Terminology

2.1.  Key Words

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   [RFC2119]

2.2.  Definition of Terms

   The readers should be familiar with the terms defined in
   [I-D.ietf-dots-requirements] [I-D.ietf-dots-use-cases]

   The terminology related to YANG data modules is defined in [RFC7950]

   In addition, this document uses the terms defined below:

   Bandwidth consuming attack  DDoS attack that causes network
      congestion.

   Host resources consuming attack  DDoS attack that consuming the
      ability of the protocol stack to process resources, or make host
      engaged in high-consumption business, thus unable to respond to
      normal business

   Attack-bandwidth:  the amount of traffic under attack, it is usually
      expressed numerically.

   Flow clean:  one selection of Attack traffic deposition, the
      operation contains recognize, discard and reinage.

   Attack Type:  used to distinguish between different methods of ddos
      attack.

   Attack type definition:  General definition method, Covers most
      current attack types.

   Attack-source-ip-number:  Number of all attack sources(ip).




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   Target-attack-type-threshold:  The DDoS detection device sets a
      threshold for each type of attack, this threshold is usually
      exceeded to generate DDoS alarms.

3.  Alarm attributes for mitigation request

3.1.  Bandwidth consuming attack

3.1.1.  Attack_Target_IP

   The IP address of attack target, which can be either IPv4 or IPv6,
   supports address block notation.  For example, if a company's IP
   address is attacked, it can aggregate IP addresses.

3.1.2.  Alarm_Begin_time

   If the alarm is confirmed to be real and effective after mitigation,
   the alarm start time is the same as the attack start time.

3.1.3.  Direction

   The direction of the attack, divided into inward and outward, 0 means
   inward, 1 means outward.  Inward means attack target suffers DDoS
   attack, outward means attack target is launching DDoS attack.

3.1.4.  Target_Attack_Type

   A list of attack types involved in an attack.

3.1.5.  Target_Attack_Type_Threshold

   The alarm threshold set for each attack type, measurement unit can be
   pps or bps.

3.1.6.  Attack_Target_IP_Peak

   Peak of attack traffic, measurement unit can be pps or bps.  We use
   peak of attack traffic rather than averages because peak of attack is
   more indicative of attacks.

3.1.7.  Attack_Source_IP_Num

   The number of attack source ip, measure the number of attacker's is
   much more helpful for the scale of attack for Bandwidth consuming
   attack.






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3.1.8.  Attack_Bandwidth

   The proportion of the current traffic bandwidth to the total
   bandwidth of the pipeline.  The attack bandwidth is described in
   terms of percentage.  The total bandwidth is preset in the attack
   target.

3.2.  Host resource consuming attack

3.2.1.  Attack_Target_IP

   The IP address of attack target, which can be either IPv4 or IPv6,
   supports address block notation.  For example, if a company's IP
   address is attacked, it can aggregate IP addresses.

3.2.2.  Attack_Target_Packet_Rate

   All packet rates for the same protocol and the same attack target in
   one period. for example, A is suffering CC attack, then
   attack_target_packet_rate is used to calculate the number of all HTTP
   packets in 5 minites.

3.2.3.  Alarm_Begin_Time

   If the alarm is confirmed to be real and effective after mitigation,
   the alarm start time is the same as the attack start time.

3.2.4.  Direction

   The direction of the attack, divided into inward and outward, 0 means
   inward, 1 means outward.  Inward means attack target suffers DDoS
   attack, outward means attack target is launching DDoS attack.

3.2.5.  Target_Attack_Type

   A list of attack types involved in an attack.

4.  mitigation attributes for mitigation response

4.1.  Bandwidth consuming attack

4.1.1.  Attack_Target_IP

   The IP address of attack target, which can be either IPv4 or IPv6,
   supports address block notation.  For example, if a company's IP
   address is attacked, it can aggregate IP addresses.





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4.1.2.  Alarm_End_time

   The end time of mitigation, denoted by -1 if the remission is not
   finished temporarily

4.1.3.  Target_Attack_Type

   A list of attack types involved in an attack.

4.1.4.  Total_Traffic

   Total traffic received by the attack target, measurement unit can be
   pps or bps.

4.1.5.  Residual_Traffic

   Residual traffic can also be considered normal business traffic, In
   the actual cleaning operation, that is the normal service flow
   injected into the link.

4.1.6.  Attack_Traffic

   The total attack traffic, It can be calculated by the Total_Traffic
   minus the Residual_Traffic

4.1.7.  Attack_Target_IP_Peak

   Peak of attack traffic, measurement unit can be pps or bps.  After
   mitigation, the Attack_Target_IP_peak will be more precise for
   measurement.

4.1.8.  Attack_Source_IP_Num

   The number of attackers in the case of this whole attack.

4.2.  Host resource consuming attack

4.2.1.  Attack_Target_IP

   The IP address of attack target, which can be either IPv4 or IPv6,
   supports address block notation.  For example, if a company's IP
   address is attacked, it can aggregate IP addresses.

4.2.2.  Alarm_End_time

   The end time of mitigation, denoted by -1 if the remission is not
   finished temporarily




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4.2.3.  Target_Attack_Type

   A list of attack types involved in an attack.

4.2.4.  Attack_Source_IP

   All the attack IP addresses involved in an attack.

4.2.5.  Attack_Target_Packet_Rate

   All packet rates for the same protocol and the same attack target in
   one period. for example, A is suffering CC attack, then
   attack_target_packet_rate is used to calculate the number of all HTTP
   packets in 5 minites.

5.  Mitigation Use Case 1

5.1.  Mitigations for attack flow

   when attack target is under attack, it has to make corresponding
   disposal, there are two options for disposal, one is blackhole
   directly which may be take effect in routers, in this way all the
   attack flow will be discarded by router upper path of attack target,
   this means that the attack target will not receive any traffic during
   the attack depending on the routing strategy, all the traffic
   forwards attack target will be discarded, this has a huge impact on
   the work environment, especially the host that provide external
   service.  The other way of the disposition is to drainage all the
   traffic flow to clean center from router, then the clean center will
   use pattern matching or any other method to find out the attack
   traffic flow to discard, finally, clean center reinage the normal
   business traffic back to attack target by upper router, the whole
   process above is defined as flow clean(Figure 1).


               attack flow +--------+                   +--------+
               ----------->| router |------------------>| clean  |
                 1         +--------+         2         | center |
                            |                           +--------+
                          3 |                               |
                            |       +--------+              |
                            +------>| attack |<-------------+
                                    | target |
                                    +--------+


               Figure 1: diagram of DDoS Mitigation usecase




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   Generally, the bandwidth of the link 1 must be larger than link 2 and
   link 3, and the clean ability of clean center limited to hardware
   resources.  An example of link situation is as below(Figure 2):


            +------------+------------+
            |   figure   | bandwidth/ |
            |   tag      | capability |
            +------------+------------+
            |  link 1    | 100Gb      |
            |  link 2    | 50Gb       |
            |  link 3    | 10Gb       |
            |clean center| 80Gb       |
            +------------+------------+


                  Figure 2: an example of link bandwidth

   The Figure2 is a scenario of the link bandwidth, when a ddos attack
   is ongoing, if the link 1 bandwidth is completely jammed, the best
   way to mitigate the attack is to discard all the attack flow; if the
   amount of the traffic flow is lower than the remainder cleaning
   ability, the most suitable disposition is to drainage all the attack
   flow to clean center.  Therefore, it is an obvious requirement in the
   current network environment.

5.2.  Optimal device selection

   Mitigator may owns a cleaning device cluster and can manage cleaning
   devices.  The capacity of each cleaning equipment is variable,
   usually each cleaning equipment utilization rate is different, then
   the remaining cleaning capacity is not consistent.  When the attack
   flow is less than the ability of a cleaning equipment, according to
   the attack-bandwidth can choose a suitable cleaning equipment, that
   is conducive to the utilization of equipment; When the attack flow is
   larger than the cleaning capacity of one cleaning device, several
   cleaning devices can be optimally scheduled according to the attack-
   bandwidth.

5.3.  Optimum path for disposal

   When mitigator is an attack flow cleaning service, they typically
   deployed the mitigator in a distributed way because of the cost of
   bandwidth usage with their own leased operator's link bandwidth, and
   choosing the best traction path was the key to profitability.  If the
   parameter of attack-bandwidth is carried, then the generation of the
   best drainage path is very meaningful.




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   When mitigator is at the upstream service operator level, they might
   have multiple networks, with the attack alert using one network and
   the flow drainage using another, and the link load is not the same,
   then carrying the attack-bandwidth is very beneficial for choosing
   the drainage path, mainly for link load balancing.

5.4.  Mitigation request parameters

   When a DOTS client requires mitigation for some reason, the DOTS
   client uses the CoAP PUT method to send a mitigation request to its
   DOTS server(s).  If a DOTS client is entitled to solicit the DOTS
   service, the DOTS server enables mitigation on behalf of the DOTS
   client by communicating the DOTS client's request to a mitigator
   (which may be colocated with the DOTS server) and relaying the
   feedback of the thus-selected mitigator to the requesting DOTS
   client.

   DOTS clients use the PUT method to request mitigation from a DOTS
   server.  During active mitigation, DOTS clients may use PUT requests
   to carry mitigation efficacy updates to the DOTS server.  We suggest
   to add attack bandwidth to satiesfy the requirement.

   total traffic when ddos attack occur, reflects the urgency of the
   current attack.  Serious attacks are treated with blackhole, Other
   cases use flow cleaning, attack-bandwidth is conducive to the
   selection of disposal mode.

   This is an optional attribute.

6.  Mitigation Use Case 2

6.1.  classified disposal

   DDoS attack is a hybrid attack across multiple protocol layers and
   multiple method, when we deal with DDoS attacks, we find it more
   reasonable and effective to deal with them according to the types of
   attacks, It is easier to handle if the type of attack is already
   included in the mitigation request.  There is no doubt that the
   information may not be accurate, but we can take it as a reference.
   Therefore, with attack type the disposal process is more helpful.
   The ddos attack alarm in the industry is set according to the attack
   type, from the point of view of cleaning, different types of attacks
   are handled differently.  For example, Memcached reflection flood use
   UDP 11211 port for DDoS flood, but tcp syn flood use defects of TCP
   three-way handshake to consuming connection resources.  This two
   attacks are alarmed respectively and cleaned in different ways.  We
   suggest to add attack type to satiesfy the requirement.




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   A list of attack types involved in an attack.

   There is no uniform definition of attack types, It is often the case
   that the same type of attack has different names, An attack type is
   defined in section 4.

   The parameter of Target_Attack_Type contains three values:
   Attack_Name, Attack_Alias and Target_Attack_Type_Threshold,
   Attack_Alias will solve the abbreviation problem.An attack could be a
   hybrid attack, then the target_Attack_Type represents major types of
   attacks

   This is an optional attribute.

6.2.  Standard of Attack Type Definition

   For the Target_Attack_Type field, we define it as a string Type, and
   define the two fields according to the attack method and extension
   name. there may be problems in the actual network environment, that
   attack target and mitigator (such as cleaning equipment) belong to
   different models of different vendors, because different vendors have
   different definitions of Attack in understanding and implementation.
   When an attack occurs, some devices may not be considered as an
   attack.  It is also possible that the detection device considere it
   as A type attack, while the cleaning device consider it as B type
   attack.  When performing the cleaning schedule, it will cause the
   problem of incorrect cleaning or over-cleaning.  Both of these errors
   will cause the normal business to fail to link.  Therefore, it is
   necessary to unify the attack definition, form a standard attack
   definition, and solve the problem of cleaning errors from the source.
   we give out a complete format for DDoS attacks as below:

   [protocol layer] [protocol name] [message name/operation name/port]
   [attack methods feature description field 1] [attack methods feature
   description field 2] [attack methods describe the standard field]

   protocol layer(mandatory): Network layer, transport layer,
   application layer;

   protocol name(mandatory): The protocol type used for the attack, such
   as http, TCP, ICMP, NTP...;

   message name/ operation name/ port(optional): The message name,
   operation name, or port used for the attack is a further addition to
   the protocol used for the attack, with message names such as SYN and
   operation names such as GET, Post, SYN, ACK, Query...;





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   attack methods feature description field 1 or 2 (optional):
   Description of the method used in the attack, such as Fragment,
   Amplification, Misuse, Slow...;

   attack methods describe the standard field(mandatory): Used to
   describe the type of attack, as the end field, such as flood, attack;

   The protocol name and message name must contain at least one item in
   the abbreviation.

   interval between each field operators use special symbol or any other
   symbol agreed.  For example:HTTP Get Flood(CC) definition, we defined
   the Target_Attack_Type field as below(Figure 3):

     {
       "Attack_Name":" Application_Layer, HTTP, Get,,, Flood"
       "Attack_Alias":"HTTP CC Flood"
       "Target_Attack_Type_Threshold":"1000pps"

     }

                 Figure 3: Attack type definition example

   An example of abbreviation: Define the target-attack-type using the
   methods specified above, complete attack name: Transport_Layer TCP
   SYN Flood; abbreviated form: TCP SYN Flood.

7.  Mitigation Use Case 3

7.1.  Mitigation alarm baseline

   Attack target looks like to be attacked by DDoS, then DOTS client
   send mitigation request to DOTS server, So there are exist false
   alarms.  In practice, there are standards for alerting whether or not
   they are appropriate, such as alarm baseline.  With this parameter,
   it is possible to determine whether the standard is reasonable or
   not, False alarms can be corrected and normal alarms can be
   optimized.  It is suggested to use Target_Attack_Type_Threshold to
   carry this information.

   DDoS attacks are distributed attacks, it means there are many sources
   of attack that the traffic from each attack source varies little, so
   it is more efficient to record the numbers of source ip than the
   details ip address.  Blocking every IP address is a thankless task
   and short-lived.  After mitigation, mitigators can feedback the
   source ip number to DOTS server, and this information must be more
   closer to the attack scene, these informations will be used in the
   feedback module for more application.



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   Target_Attack_Type_Threshold:  Baseline for a type of attack .

      If attack target have the ability to classify each type of DDoS
      attack, it must have ability to feedback criteria for each type of
      attack.  It doesn't matter that if it can not provide this
      information, it is just an optional attribute.

      This is an optional attribute.

8.  Mitigation request optional parameters

8.1.  Bandwidth consuming attack

   Added parameters show in put method for Bandwidth consuming attack
   are show as below(Figure 4)

  Content-Format: "application/dots+cbor"
                   {
                   "ietf-dots-signal-channel:mitigation-scope": {
                     "scope": [
                       {
                         "target-prefix": [
                            "string"
                          ],
                         "target-port-range": [
                            {
                              "lower-port": number,
                              "upper-port": number
                            }
                          ],
                          "target-protocol": [
                            number
                          ],
                          "target-fqdn": [
                            "string"
                          ],
                          "Attack_Target_IP":[
                                 "string"
                          ],
                          "Alarm_Begin_time":[
                                 "string"
                          ],
                          "Direction":[
                                  number
                          ],
                          "Attack_Target_IP_peak":[
                                 "string"
                          ],



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                          "Attack_Source_IP_Num":[
                                 "string"
                          ],
                          "Target_Attack_Type": [
                             {
                               "Attack-Name": ["string"],
                               "Attack-Alias": ["string"],
                               "Target_attack_Type_threshold":["string"]
                             }
                           ],
                           "Attack_Bandwidth":[
                                 "string"
                           ],
                           attack_src_ip_number:[
                             "string"
                           ],

                           "target-uri": [
                            "string"
                          ],
                          "alias-name": [
                            "string"
                          ],
                         "lifetime": number,
                         "trigger-mitigation": true|false
                       }
                     ]
                   }
                   }


        Figure 4: Mitigation request for Bandwidth consuming attack

8.2.  Host resource consuming attack

   Added parameters show in put method for Host resource consuming
   attack are show as below(Figure 5)

    Content-Format: "application/dots+cbor"
                     {
                     "ietf-dots-signal-channel:mitigation-scope": {
                       "scope": [
                         {
                           "target-prefix": [
                              "string"
                            ],
                           "target-port-range": [
                              {



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                                "lower-port": number,
                                "upper-port": number
                              }
                            ],
                            "target-protocol": [
                              number
                            ],
                            "target-fqdn": [
                              "string"
                            ],
                            "Attack_Target_IP":[
                                   "string"
                            ],
                            "Alarm_Begin_time":[
                                   "string"
                            ],
                            "Direction":[
                                    number
                            ],
                            "Attack_Target_Packet_Rate":[
                                   "string"
                            ],
                           "Target_Attack_Type": [
                               {
                                 "Attack-Name": ["string"],
                                 "Attack-Alias": ["string"],
                                }
                             ],
                             "target-uri": [
                              "string"
                            ],
                            "alias-name": [
                              "string"
                            ],
                           "lifetime": number,
                           "trigger-mitigation": true|false
                         }
                       ]
                     }
                     }


      Figure 5: Mitigation request for Host resource consuming attack








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9.  Mitigation response parameters

   After the mitigation of a DDoS attack, DOTS server can obtain some
   informations from mitigator, these informations are optional
   parameters only as a suggestion when use DOTS to inform the message
   between attack target and mitigator.

9.1.  Bandwidth consuming attack

   added parameters of Mitigation response for Bandwidth consuming
   attack, Figure6Figure 6

  Content-Format: "application/dots+cbor"
                   {
                   "ietf-dots-signal-channel:mitigation-scope": {
                     "scope": [
                       {
                         "target-prefix": [
                            "string"
                          ],
                         "target-port-range": [
                            {
                              "lower-port": number,
                              "upper-port": number
                            }
                          ],
                          "target-protocol": [
                            number
                          ],
                          "target-fqdn": [
                            "string"
                          ],
                          "Attack_Target_IP":[
                                 "string"
                          ],
                          "Alarm_End_time":[
                                 "string"
                          "],
                          "Total_Traffic":[
                                  "string"
                          ],
                          "Residual_Traffic":[
                                 "string"
                          ],
                          "Attack_Traffic":[
                                 "string"
                          ],
                          "Attack_Target_IP_Peak":[



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                                 "string"
                          ],
                          "Attack-Source-IP-Num":[
                                 "string"
                          ],
                         "Target_Attack_Type": [
                             {
                               "Attack-Name": ["string"],
                               "Attack-Alias": ["string"],
                               "Target_attack_Type_threshold":["string"]
                             }
                           ],
                           "target-uri": [
                            "string"
                          ],
                          "alias-name": [
                            "string"
                          ],
                         "lifetime": number,
                         "trigger-mitigation": true|false
                       }
                     ]
                   }
                   }


       Figure 6: Mitigation response for Bandwidth consuming attack

9.2.  Host resource consuming attack

   added parameters of Mitigation response for Bandwidth consuming
   attack, Figure7Figure 7

    Content-Format: "application/dots+cbor"
                     {
                     "ietf-dots-signal-channel:mitigation-scope": {
                       "scope": [
                         {
                           "target-prefix": [
                              "string"
                            ],
                           "target-port-range": [
                              {
                                "lower-port": number,
                                "upper-port": number
                              }
                            ],
                            "target-protocol": [



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                              number
                            ],
                            "target-fqdn": [
                              "string"
                            ],
                            "Attack_Target_IP":[
                                   "string"
                            ],
                            "Alarm_End_time":[
                                   "string"
                            "],

                            "Attack_Source_IP":[
                                   "string"
                            ],
                            "Attack_Target_Packet_Rate":[
                                   "string"
                            ],
                           "Target_Attack_Type": [
                               {
                                 "Attack-Name": ["string"],
                                 "Attack-Alias": ["string"],
                               }
                             ],
                             "target-uri": [
                              "string"
                            ],
                            "alias-name": [
                              "string"
                            ],
                           "lifetime": number,
                           "trigger-mitigation": true|false
                         }
                       ]
                     }
                     }


     Figure 7: Mitigation response for Host resource consuming attack

10.  Security Considerations

   TBD








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11.  IANA Considerations

   TBD

12.  Acknowledgement

   TBD

13.  References

13.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

13.2.  Informative References

   [I-D.ietf-dots-architecture]
              Mortensen, A., K, R., Andreasen, F., Teague, N., and R.
              Compton, "Distributed-Denial-of-Service Open Threat
              Signaling (DOTS) Architecture", draft-ietf-dots-
              architecture-14 (work in progress), May 2019.

   [I-D.ietf-dots-requirements]
              Mortensen, A., K, R., and R. Moskowitz, "Distributed
              Denial of Service (DDoS) Open Threat Signaling
              Requirements", draft-ietf-dots-requirements-22 (work in
              progress), March 2019.

   [I-D.ietf-dots-signal-channel]
              K, R., Boucadair, M., Patil, P., Mortensen, A., and N.
              Teague, "Distributed Denial-of-Service Open Threat
              Signaling (DOTS) Signal Channel Specification", draft-
              ietf-dots-signal-channel-37 (work in progress), July 2019.

   [I-D.ietf-dots-use-cases]
              Dobbins, R., Migault, D., Fouant, S., Moskowitz, R.,
              Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS
              Open Threat Signaling", draft-ietf-dots-use-cases-19 (work
              in progress), July 2019.





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Authors' Addresses

   Meiling Chen
   CMCC
   32, Xuanwumen West
   BeiJing , BeiJing   100053
   China

   Email: chenmeiling@chinamobile.com


   Li Su
   CMCC
   32, Xuanwumen West
   BeiJing   100053
   China

   Email: suli@chinamobile.com


   Jin Peng
   CMCC
   32, Xuanwumen West
   BeiJing   100053
   China

   Email: pengjin@chinamobile.com
























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