\
IDR                                                             Q. Xiong
Internet-Draft                                                     H. Wu
Intended status: Standards Track                         ZTE Corporation
Expires: 7 September 2022                                        J. Zhao
                                                                   CAICT
                                                              March 2022


         BGP Flow Specification for DetNet and TSN Flow Mapping
                 draft-xiong-idr-detnet-flow-mapping-02

Abstract

   This document proposes extensions to BGP Flow Specification for the
   flow mapping of Deterministic Networking (DetNet) when interconnected
   with IEEE 802.1 Time-Sensitive Networking (TSN).  The BGP flowspec is
   used for the filtering of the packets that match the DetNet newtworks
   and the mapping between TSN streams and DetNet flows in the control
   plane.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 2 September 2022.

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.










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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  The Requirements for DetNet Control Plane . . . . . . . . . .   3
     3.1.  Functions for DetNet Flow to TSN Stream Mapping . . . . .   3
     3.2.  Aggregation during DetNet Flow to TSN Stream Mapping  . .   5
   4.  BGP Extensions for Flow Specification Encoding  . . . . . . .   5
     4.1.  Filtering Rules for TSN Streams . . . . . . . . . . . . .   5
     4.2.  Traffic Action for TSN Streams  . . . . . . . . . . . . .   6
     4.3.  Filtering Rules for DetNet Flows  . . . . . . . . . . . .   7
     4.4.  Traffic Action for DetNet Flows . . . . . . . . . . . . .   8
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   [RFC8655] specifies the architecture of Deterministic Networking
   (DetNet), which provide a capability for the delivery of data flows
   with extremely low packet loss rates and bounded end-to-end delivery
   latency.  DetNet-enabled end systems and DetNet nodes can be
   interconnected by sub-networks, i.e., Layer 2 technologies such as
   IEEE 802.1 Time-Sensitive Networking (TSN).

   As defined in [RFC8655], the DetNet IP and MPLS flows can be carried
   over TSN sub-networks.  DetNet needs to be mapped to the sub-networks
   technology used to interconnect DetNet nodes.  For example, a TSN
   node may be used to interconnect DetNet-aware nodes, and these DetNet
   nodes can map DetNet flows to TSN streams.  When the Detnet provide
   the deterministic service for the TSN end system, a DetNet edge node
   may be used to interconnect the TSN end system, and the DetNet nodes
   can map the TSN streams to DetNet flows.





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   As described in [RFC8938], one of the primary requirements of the
   DetNet Controller Plane is restricting flows to IEEE 802.1 TSN and
   the requirement could use the centralized network management
   provisioning mechanisms such as BGP protocol.  As defined in
   [RFC8955], the Flow Specifications for BGP is an n-tuple consisting
   of several matching criteria which is comprised of traffic filtering
   rules and is associated with actions that can be applied to the
   traffic flows.  The DetNet edge nodes can provide the capability to
   process the traffic including classifing, shaping, rate limiting,
   filtering, and redirecting packets based on the policies configured
   by the BGP Flow Specification.

   BGP flow specification version 1 (FSv1) has been defined in [RFC8955]
   and version 2 of the BGP flow specification (FSv2) protocol has been
   proposed in [I-D.hares-idr-flowspec-v2].  This document proposes
   extensions to BGP FSv2 for the interconnection of DetNet and TSN.
   The BGP flowspec is used for the filtering of the packets that match
   the DetNet newtworks and the mapping between TSN streams and DetNet
   flows in the control plane.

2.  Conventions used in this document

2.1.  Terminology

   The terminology is defined as [RFC8655], [RFC8938], [RFC8955] and
   [I-D.hares-idr-flowspec-v2].

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  The Requirements for DetNet Control Plane

3.1.  Functions for DetNet Flow to TSN Stream Mapping

   As described in [RFC9024], TSN networks can be interconnected over a
   DetNet MPLS Network.  And as discussed in [RFC9023] and [RFC9037],
   DetNet IP or MPLS networks can be operating over a TSN sub-network.
   The mapping between TSN Streams and DetNet flows is required for the
   service proxy function at DetNet Edge nodes.  And the mapping table
   can be configured and maintained in the control plane.  When a DetNet
   Edge Node receives a packet, it MUST identify and check whether such
   flow is present in its mapping table and decide to drop (when not
   match) or to forward the packet (when match) to the associated



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   service.

   As Figure 1 shows, it is required to configue the identification
   information when mapping received TSN Streams to the DetNet flows at
   Edge Node-1.  Mechanisms and Parameters of TSN stream identification
   (e.g.,Mask-and-Match Stream identification) defined in [IEEE8021CB]
   and [IEEEP8021CBdb] can be used for service proxy function.  After
   the identification of the TSN stream, it need to map the packet to
   the DetNet flow information such as S-Label, d-CW when in DetNet MPLS
   data plane and handle the packet as defined in [RFC8964].

   When the DetNet Edge Node-2 receives a DetNet flow, it MUST identify
   the DetNet flow-ID information such as IP 6-tuple in DetNet IP data
   plane or S-Label and d-CW information in DetNet MPLS data plane.
   Then the Service proxy function need to map the DetNet flow-ID and
   flow related parameters to the associated TSN Stream IDs and streams
   related parameters.



   TSN             Edge             Transit       Edge         TSN
   End System      Node-1           Node          Node-2       End System
   +----------+                                             +----------+
   |   TSN    | <---------End to End TSN Service----------> |   TSN    |
   |  Applic. |                                             |  Applic. |
   +----------+  +.........+                   +.........+  +----------+
   |          |  |Service-Proxy             Service-Proxy|  |          |
   |   TSN    |  |   +.+---+<-- DetNet flow -->+---+.|   |  |   TSN    |
   |          |  |TSN| |Svc|                   |Svc| |TSN|  |          |
   +----------+  +---+ +---+    +----------+   +---+ +---+  +----------+
   |   L2     |  | L2| |Fwd|    |Forwarding|   |Fwd| |L2 |  |   L2     |
   +------.---+  +-.-+ +-.-+    +---.----.-+   +--.+ +-.-+  +---.------+
          :  Link  :     /  ,-----.  \   :  Link  :   /  ,-----. \
          +........+     +-[  Sub  ]-+   +........+   +-[  TSN  ]-+
                           [Network]                    [Network]
                            `-----'                      `-----'
Flow Mapping:
       |TSN : DetNet|<--------- DetNet ---------->|DetNet : TSN|



     Figure 1: Figure 1: Flow Mapping in TSN over DetNet Network









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3.2.  Aggregation during DetNet Flow to TSN Stream Mapping

   As described in [RFC8938], the DetNet data plane allows for the
   aggregation of DetNet flows, which should also be accomplished in the
   control plane.  IP, MPLS and TSN aggregation has both data plane and
   controller Plane aspects.  Bandwidth reservations, resource
   assignment, path computation, delay, delay variation and aggregate
   number should be taken into considerations in the controller plane.
   Moreover, as defined in [RFC9023] and [RFC9037], 1:1 and N:1 mapping
   (aggregating multiple TSN Streams in a single DetNet flow) MUST be
   supported.

4.  BGP Extensions for Flow Specification Encoding

   As defined in [RFC8955], the nodes that applied a Flow Specification
   can fillter the received pakects according to the matching criteria
   and can forward the flows based on the associated actions.  This
   document proposes extensions to BGP Flow Specification for the
   mapping of DetNet flows and TSN streams by using the traffic
   filtering rules to identify the packet and using the associated
   action to map the packet to the related service.

4.1.  Filtering Rules for TSN Streams

   As IEEE Std 802.1Q defined, a Stream ID is a 64-bit field that
   uniquely identifies a stream and can be generated by the system
   offering the stream, or possibly a device controlling that system.
   But it is not carried in the header of the TSN Stream.  As defined in
   [IEEE8021CB] and [IEEEP8021CBdb], five specific Stream identification
   functions are described: Null Stream identification, Source MAC and
   VLAN Stream identification, Active Destination MAC and VLAN Stream
   identification, and IP Stream identification, and Mask-and-match
   Stream identification.  It needs to examines the header of the
   streams such as destination_address, vlan_identifier, IP source
   address, IP destination address, DSCP, IP next protocol, source port,
   destination port and mac_service_data_unit.

   As defined in [I-D.ietf-idr-flowspec-l2vpn], the Ethernet Layer 2
   (L2) related fields has been covered by the L2 traffic filtering
   rules except the mac_service_data_unit in Mask-and-Match Stream
   identification.  A mac_service_data_unit mask is defined to identify
   communication flows supported by various higher-layer protocols.  L2
   Traffic Rules and L2 header TLV in BGP FSv2 of has been defined in
   [I-D.hares-idr-flowspec-v2] section 3.4.  This document proposes a
   new L2 SubTLV for TSN Streams in L2 Flow Specification Component
   shown in Figure 2.





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                       +----------------------------------+
                       |  SubTLV type = TBD1 (1 octet)    |
                       +----------------------------------+
                       |  length (1 octet)                |
                       + ---------------------------------+
                       |  Mac Service Data Unit (6 octets)|
                       +----------------------------------+

                       Figure 2: Figure 2: TSN SubTLV


   SubTLV type = TBD1: Mac Service Data Unit

   Encoding: <type (1 octet), length (1 octet), [op, value]+>

   Defines a list of {operation, value} pairs used to match 6-octet Mac
   Service Data Unit field.  Values are encoded as 6-octet quantities.
   op is encoded as specified in Section 4.2.1.1 of [RFC8955].

4.2.  Traffic Action for TSN Streams

   The action for an TSN traffic filtering flowspec is to accept the TSN
   streams that matches that particular rule and map the streams to the
   DetNet flows.  The action for L3 traffic with extended communities
   types per [RFC8955] and [RFC8956] such as traffic-rate, traffic-
   marking, traffic-action, and redirect can be used for TSN to DetNet
   IP flow mapping.  The Wide Community has been proposed for FSv2
   actions in [I-D.hares-idr-flowspec-v2] section 3.2.

   The DetNet flow is identified by a S-Label and the DetNet Header
   consists of d-CW and F-Labels.  The MPLS label related action for an
   TSN stream mapping to a DetNet MPLS network can use the Label-action
   defined in [I-D.ietf-idr-bgp-flowspec-label].  And the action for the
   sequence in d-CW field, this document proposes a new Action SubTLV in
   BGP FSv2 Wide Community for TSN Streams as following shown.

                   +======+=================+==========+
                   | type | Wide Community  | encoding |
                   +======+=================+==========+
                   | TBD2 | Sequence Action | bitmask  |
                   +------+-----------------+----------+

                                  Table 1

   The The Sequence Action SubTLV is shown in Figure 3.






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                0                                              15
                +-----------------------------------------------+
                |        SubTLV type = TBD2 (2 octet)           |
                +-----------------------------------------------+
                |               length (2 octet)                |
                +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
                |    Type   |        Sequence Number            |
                +--+--+--+--+                                   +
                |                       ~                       |
                +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+



                    Figure 3: Figure 3: Sequence Action


   Type: 4 bits, indicates the length type of the sequence number:

   0: 0 bits

   1: 16 bits

   2: 28 bits

   Sequence Number: 28 bits, an unsigned value implementing the DetNet
   sequence number.

4.3.  Filtering Rules for DetNet Flows

   The L3 traffic filtering rules defined in [RFC8955] and [RFC8956] can
   be used for DetNet IP flow.

   As defined in RFC8964, the MPLS-based DetNet data plane encapsulation
   consists of d-CW, S-Label and F-Labels.  The MPLS label filtering
   rules have been defined in [I-D.ietf-idr-flowspec-mpls-match].  IP
   header TLV in BGP FSv2 of has been defined in
   [I-D.hares-idr-flowspec-v2] section 3.1.

   This document proposes a new IP header SubTLV for DetNet MPLS flows
   shown in Figure 4.











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                      +----------------------------------+
                      |  SubTLV type = TBD3 (1 octet)    |
                      +----------------------------------+
                      |  length (1 octet)                |
                      + ---------------------------------+
                      |  d-CW (4 octets)                  |
                      +----------------------------------+

                     Figure 4: Figure 4: DetNet SubTLV


   MPLS Match Type TBD3: d-CW , indicates Sequence in Label stack.

   Encoding: <type (1 octet), length (1 octet), [op, value]+>

   Defines a list of {operation, value} pairs used to match Sequence.
   Values are encoded as 4-octet quantities, where the four most
   significant bits are set to zero and ignored for matching and the 28
   least significant bits contain the sequence value. op is encoded as
   specified in Section 4.2.1.1 of [RFC8955].

4.4.  Traffic Action for DetNet Flows

   The extended action for an DetNet traffic filtering flowspec is to
   accept the DetNet flows that matches that particular rule and map the
   flows to the TSN streams.  This document proposes a new Action SubTLV
   in BGP FSv2 Wide Community for DetNet flows as the following shown.

                   +======+================+==========+
                   | type | Wide Community | encoding |
                   +======+================+==========+
                   | TBD4 | TSN Action     | bitmask  |
                   +------+----------------+----------+

                                 Table 2

   The TSN Action SubTLV is shown in Figure 3.














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                0                                              15
                +-----------------------------------------------+
                |        SubTLV type = TBD4 (2 octet)           |
                +-----------------------------------------------+
                |        length (2 octet)                       |
                +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
                |        Type           |       Resv            |
                +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
                |                TSN-Profile                    |
                |                    ~                          |
                +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


                       Figure 5: Figure 5: TSN Action


   Type: 1-octet, indicates the type of TSN profiles.  The value of the
   types is TBD:

   Resv: 1-octet, reserved for future use.  MUST be sent as zero and
   ignored on receipt.

   TSN-profile: 4-octet, can be converted to the TSN Stream ID and
   stream related parameters and requirements as the following shown.

   stream_handle: identifying the Stream to which the packet belongs in
   TSN networks.

   sequence_number: identifying the order in which the packet was
   transmitted relative to other packets in the same Compound Stream in
   TSN networks.

   traffic_scheduling: identifying the traffic scheduling mechanisms
   including traffic policy, queuing and forwarding methods in TSN
   networks.

5.  Security Considerations

   TBA

6.  Acknowledgements

   TBA

7.  IANA Considerations

   TBA




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8.  Normative References

   [I-D.hares-idr-flowspec-v2]
              Hares, S., Eastlake, D., Yadlapalli, C., and S. Maduschke,
              "BGP Flow Specification Version 2", Work in Progress,
              Internet-Draft, draft-hares-idr-flowspec-v2-05, 4 February
              2022, <https://www.ietf.org/internet-drafts/draft-hares-
              idr-flowspec-v2-05.txt>.

   [I-D.ietf-idr-bgp-flowspec-label]
              Liang, Q., Hares, S., You, J., Raszuk, R., and D. Ma,
              "Carrying Label Information for BGP FlowSpec", Work in
              Progress, Internet-Draft, draft-ietf-idr-bgp-flowspec-
              label-01, 6 December 2016,
              <https://www.ietf.org/archive/id/draft-ietf-idr-bgp-
              flowspec-label-01.txt>.

   [I-D.ietf-idr-flowspec-l2vpn]
              Hao, W., Eastlake, D. E., Litkowski, S., and S. Zhuang,
              "BGP Dissemination of L2 Flow Specification Rules", Work
              in Progress, Internet-Draft, draft-ietf-idr-flowspec-
              l2vpn-18, 24 October 2021,
              <https://www.ietf.org/archive/id/draft-ietf-idr-flowspec-
              l2vpn-18.txt>.

   [I-D.ietf-idr-flowspec-mpls-match]
              Yong, L., Hares, S., Liang, Q., and J. You, "BGP Flow
              Specification Filter for MPLS Label", Work in Progress,
              Internet-Draft, draft-ietf-idr-flowspec-mpls-match-01, 6
              December 2016, <https://www.ietf.org/archive/id/draft-
              ietf-idr-flowspec-mpls-match-01.txt>.

   [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>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8655]  Finn, N., Thubert, P., Varga, B., and J. Farkas,
              "Deterministic Networking Architecture", RFC 8655,
              DOI 10.17487/RFC8655, October 2019,
              <https://www.rfc-editor.org/info/rfc8655>.






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   [RFC8938]  Varga, B., Ed., Farkas, J., Berger, L., Malis, A., and S.
              Bryant, "Deterministic Networking (DetNet) Data Plane
              Framework", RFC 8938, DOI 10.17487/RFC8938, November 2020,
              <https://www.rfc-editor.org/info/rfc8938>.

   [RFC8955]  Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
              Bacher, "Dissemination of Flow Specification Rules",
              RFC 8955, DOI 10.17487/RFC8955, December 2020,
              <https://www.rfc-editor.org/info/rfc8955>.

   [RFC8956]  Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
              "Dissemination of Flow Specification Rules for IPv6",
              RFC 8956, DOI 10.17487/RFC8956, December 2020,
              <https://www.rfc-editor.org/info/rfc8956>.

   [RFC8964]  Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant,
              S., and J. Korhonen, "Deterministic Networking (DetNet)
              Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January
              2021, <https://www.rfc-editor.org/info/rfc8964>.

   [RFC9023]  Varga, B., Ed., Farkas, J., Malis, A., and S. Bryant,
              "Deterministic Networking (DetNet) Data Plane: IP over
              IEEE 802.1 Time-Sensitive Networking (TSN)", RFC 9023,
              DOI 10.17487/RFC9023, June 2021,
              <https://www.rfc-editor.org/info/rfc9023>.

   [RFC9024]  Varga, B., Ed., Farkas, J., Malis, A., Bryant, S., and D.
              Fedyk, "Deterministic Networking (DetNet) Data Plane: IEEE
              802.1 Time-Sensitive Networking over MPLS", RFC 9024,
              DOI 10.17487/RFC9024, June 2021,
              <https://www.rfc-editor.org/info/rfc9024>.

   [RFC9037]  Varga, B., Ed., Farkas, J., Malis, A., and S. Bryant,
              "Deterministic Networking (DetNet) Data Plane: MPLS over
              IEEE 802.1 Time-Sensitive Networking (TSN)", RFC 9037,
              DOI 10.17487/RFC9037, June 2021,
              <https://www.rfc-editor.org/info/rfc9037>.

Authors' Addresses

   Quan Xiong
   ZTE Corporation
   No.6 Huashi Park Rd
   Wuhan
   Hubei, 430223
   China
   Email: xiong.quan@zte.com.cn




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   Haisheng Wu
   ZTE Corporation
   Nanjing
   Jiangsu,
   China
   Email: wu.haisheng@zte.com.cn


   Junfeng Zhao
   CAICT
   China
   Email: zhaojunfeng@caict.ac.cn







































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