--- 1/draft-ietf-detnet-tsn-vpn-over-mpls-00.txt 2019-10-28 06:13:14.975370478 -0700 +++ 2/draft-ietf-detnet-tsn-vpn-over-mpls-01.txt 2019-10-28 06:13:15.007371283 -0700 @@ -1,137 +1,128 @@ DetNet B. Varga, Ed. Internet-Draft J. Farkas Intended status: Standards Track Ericsson -Expires: November 6, 2019 A. Malis +Expires: April 29, 2020 A. Malis + Independent S. Bryant - Huawei Technologies - J. Korhonen - May 5, 2019 + Futurewei Technologies + D. Fedyk + LabN Consulting, L.L.C. + October 27, 2019 DetNet Data Plane: IEEE 802.1 Time Sensitive Networking over MPLS - draft-ietf-detnet-tsn-vpn-over-mpls-00 + draft-ietf-detnet-tsn-vpn-over-mpls-01 Abstract This document specifies the Deterministic Networking data plane when - TSN networks interconnected over an MPLS Packet Switched Networks. + TSN networks are interconnected over a DetNet MPLS Network. 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 November 6, 2019. + This Internet-Draft will expire on April 29, 2020. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. 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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 - 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 2.1. Terms Used in This Document . . . . . . . . . . . . . . . 2 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2.1. Terms Used in This Document . . . . . . . . . . . . . . . 3 2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 - 3. Requirements Language . . . . . . . . . . . . . . . . . . . . 4 - 4. IEEE 802.1 TSN Over DetNet MPLS Data Plane Scenario . . . . . 4 - 5. DetNet MPLS Data Plane Considerations . . . . . . . . . . . . 6 - 5.1. End-System Specific Considerations . . . . . . . . . . . 7 - 6. MPLS-Based DetNet Data Plane Solution . . . . . . . . . . . . 8 - 6.1. DetNet Over MPLS Encapsulation Components . . . . . . . . 8 - 6.2. TSN over MPLS Data Plane Encapsulation . . . . . . . . . 9 - 6.2.1. Edge Node Processing . . . . . . . . . . . . . . . . 9 - 6.2.2. Layer 2 Addressing and QoS Considerations . . . . . . 10 - 7. Controller Plane (Management and Control) - Considerations . . . . . . . . . . . . . . . . . . . . . . . 11 - 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 - 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 - 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 11 - 11.2. Informative References . . . . . . . . . . . . . . . . . 13 - Appendix A. Example of TSN over DetNet Data Plane Operation . . 17 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 + 2.3. Requirements Language . . . . . . . . . . . . . . . . . . 4 + 3. IEEE 802.1 TSN Over DetNet MPLS Data Plane Scenario . . . . . 4 + 4. DetNet MPLS Data Plane . . . . . . . . . . . . . . . . . . . 6 + 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6 + 4.2. TSN over DetNet MPLS Encapsulation . . . . . . . . . . . 7 + 5. TSN over MPLS Data Plane Procedures . . . . . . . . . . . . . 8 + 5.1. Edge Node TSN Procedures . . . . . . . . . . . . . . . . 8 + 5.2. Edge Node DetNet Service Proxy Procedures . . . . . . . . 9 + 5.3. Edge Node DetNet Service and Forwarding Sub-Layer + Procedures . . . . . . . . . . . . . . . . . . . . . . . 9 + 6. Controller Plane (Management and Control) Considerations . . 10 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 11 + 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 + 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 10.2. Informative References . . . . . . . . . . . . . . . . . 12 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction - [Editor's note: Introduction to be made specific to TSN over DetNet - scenario. Do we intend to cover both TSN over DetNet IP and TSN over - DetNet MPLS? Or this document is limited to MPLS scenarios?]. + The Time-Sensitive Networking Task Group (TSN TG) within IEEE 802.1 + Working Group deals with deterministic services through IEEE 802 + networks. Deterministic Networking (DetNet) defined by IETF is a + service that can be offered by a L3 network to DetNet flows. General + background and concepts of DetNet can be found in + [I-D.ietf-detnet-architecture]. -2. Terminology + This document specifies the use of a DetNet MPLS network to + interconnect TSN nodes/network segments. DetNet MPLS data plane is + defined in [I-D.ietf-detnet-mpls]. - [Editor's note: text to be review what is really needed here.]. +2. Terminology 2.1. Terms Used in This Document - This document uses the terminology established in the DetNet - architecture [I-D.ietf-detnet-architecture], and the reader is - assumed to be familiar with that document and its terminology. - - The following terminology is introduced in this document: - - F-Label A Detnet "forwarding" label that identifies the LSP - used to forward a DetNet flow across an MPLS PSN, e.g., - a hop-by-hop label used between label switching routers - (LSR). - - S-Label A DetNet "service" label that is used between DetNet - nodes that implement also the DetNet service sub-layer - functions. An S-Label is also used to identify a - DetNet flow at DetNet service sub-layer. - - d-CW A DetNet Control Word (d-CW) is used for sequencing and - identifying duplicate packets of a DetNet flow at the - DetNet service sub-layer. + This document uses the terminology and concepts established in the + DetNet architecture [I-D.ietf-detnet-architecture] and + [I-D.ietf-detnet-data-plane-framework], and [I-D.ietf-detnet-mpls]. + The reader is assumed to be familiar with these documents and their + terminology. 2.2. Abbreviations - [Editor's note: text to be cleaned up]. - The following abbreviations are used in this document: AC Attachment Circuit. CE Customer Edge equipment. CoS Class of Service. CW Control Word. DetNet Deterministic Networking. DF DetNet Flow. - DN-IWF DetNet Inter-Working Function. + FRER Frame Replication and Elimination for Redundancy (TSN + function). L2 Layer 2. L2VPN Layer 2 Virtual Private Network. L3 Layer 3. LSR Label Switching Router. MPLS Multiprotocol Label Switching. @@ -161,634 +152,454 @@ PW PseudoWire. QoS Quality of Service. S-PE Switching Provider Edge. T-PE Terminating Provider Edge. TSN Time-Sensitive Network. -3. Requirements Language +2.3. 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. -4. IEEE 802.1 TSN Over DetNet MPLS Data Plane Scenario +3. IEEE 802.1 TSN Over DetNet MPLS Data Plane Scenario + + Figure 1 shows IEEE 802.1 TSN end stations operating over a TSN aware + DetNet service running over an MPLS network. DetNet Edge Nodes sit + at the boundary of a DetNet domain. They are responsible for mapping + non-DetNet aware L2 traffic to DetNet services. They also support + the imposition and disposition of the required DetNet encapsulation. + These are functionally similar to pseudowire (PW) Terminating + Provider Edge (T-PE) nodes which use MPLS-TE LSPs. In this example + TSN Streams are simple applicaions over DetNet flows. The specific + of this operation are discussed later in this document. - [Author's note: review required on his part.] TSN Edge Transit Edge TSN End System Node Node Node End System (T-PE) (LSR) (T-PE) + +----------+ +----------+ + | TSN | <---------End to End TSN Service----------> | TSN | + | Applic. | | Applic. | +----------+ +.........+ +.........+ +----------+ - | Appl. |<-:Svc Proxy:--End to End Svc.--:Svc Proxy:->| Appl. | - +----------+ +---------+ +---------+ +----------+ - | TSN | |TSN| |Svc|<-- DetNet flow -->|Svc| |TSN| | TSN | + | | | \S-Proxy: :S-Proxy/ | | | + | TSN | | +.+---+<-- DetNet flow -->+---+ | | | TSN | + | | |TSN| |Svc| |Svc| |TSN| | | +----------+ +---+ +---+ +----------+ +---+ +---+ +----------+ - |Forwarding| |Fwd| |Fwd| |Forwarding| |Fwd| |Fwd| |Forwarding| - +------.---+ +--.+ +-.-+ +---.----.-+ +--.+ +-.-+ +----.-----+ + | L2 | | L2| |Fwd| |Forwarding| |Fwd| |L2 | | L2 | + +------.---+ +-.-+ +-.-+ +---.----.-+ +--.+ +-.-+ +---.------+ : Link : / ,-----. \ : Link : / ,-----. \ - +.........+ +-[ Sub ]-+ +........+ +-[ Sub ]-+ + +........+ +-[ Sub ]-+ +........+ +-[ TSN ]-+ [Network] [Network] `-----' `-----' - |<- TSN ->| |<------ DetNet MPLS ------>| |<-- TSN --->| + |<------ DetNet MPLS ------>| + |<---------------------- TSN --------------------->| Figure 1: A TSN over DetNet MPLS Enabled Network - Figure 1 shows IEEE 802.1 TSN end stations operating over a TSN aware - DetNet service running over an MPLS network. DetNet Edge Nodes sit - at the boundary of a DetNet domain. They are responsible for mapping - non-DetNet aware L2 traffic to DetNet services. They also support - the imposition and disposition of the required DetNet encapsulation. - These are functionally similar to pseudowire (PW) Terminating - Provider Edge (T-PE) nodes which use MPLS-TE LSPs. In this example - they understand and support IEEE 802.1 TSN and are able to map TSN - flows into DetNet flows. The specific of this operation are - discussed later in this document. - - Native TSN flow and DetNet MPLS flow differ not only by the - additional MPLS specific encapsulation, but DetNet MPLS flows have on - each DetNet node an associated DetNet specific data structure, what - defines flow related characteristics and required forwarding - functions. In this example, edge Nodes provide a service proxy - function that "associates" the DetNet flows and native flows at the - edge of the DetNet domain. This ensures that the DN Flow is properly - served at the Edge node (and inside the domain). + In this example, edge nodes provide a service proxy function that + "associates" the DetNet flows and native flows (i.e., TSN Streams) at + the edge of the DetNet domain. TSN streams are treated as App-flows + for DetNet. The whole DetNet domain behaves as a TSN relay node for + the TSN streams. The service proxy behaves as a port of that TSN + relay node. - Figure 2 illustrates how DetNet can provide services for IEEE - 802.1TSN end systems, CE1 and CE2, over a DetNet enabled MPLS - network. Edge nodes, E1 and E2, insert and remove required DetNet - data plane encapsulation. The 'X' in the edge nodes and relay node, - R1, represent a potential DetNet compound flow packet replication and + Figure 2 illustrates how DetNet can provide services for IEEE 802.1 + TSN end systems, CE1 and CE2, over a DetNet enabled MPLS network. + Edge nodes, E1 and E2, insert and remove required DetNet data plane + encapsulation. The 'X' in the edge nodes and relay node, R1, + represent a potential DetNet compound flow packet replication and elimination point. This conceptually parallels L2VPN services, and could leverage existing related solutions as discussed below. TSN |<------- End to End DetNet Service ------>| TSN Service | Transit Transit | Service TSN (AC) | |<-Tnl->| |<-Tnl->| | (AC) TSN End | V V 1 V V 2 V V | End System | +--------+ +--------+ +--------+ | System +---+ | | E1 |=======| R1 |=======| E2 | | +---+ | |--|----|._X_....|..DF1..|.._ _...|..DF3..|...._X_.|---|---| | |CE1| | | \ | | X | | / | | |CE2| | | | \_.|..DF2..|._/ \_..|..DF4..|._/ | | | +---+ | |=======| |=======| | +---+ ^ +--------+ +--------+ +--------+ ^ | Edge Node Relay Node Edge Node | | (T-PE) (S-PE) (T-PE) | | | |<- TSN -> <------- TSN Over DetNet MPLS -------> <- TSN ->| | | - |<--- Emulated Time Sensitive Networking (TSN) Service --->| + |<-------- Time Sensitive Networking (TSN) Service ------->| X = Service protection DFx = DetNet member flow x over a TE LSP Figure 2: IEEE 802.1TSN Over DetNet -5. DetNet MPLS Data Plane Considerations - - [Editor's note: Needs clean up, what is relevant for TSN over DetNet - scenarios.]. - - This section provides informative considerations related to providing - DetNet service to flows which are identified based on their header - information. At a high level, the following are provided on a per - flow basis: - - Eliminating contention loss and jitter reduction: - - Use of allocated resources (queuing, policing, shaping) to ensure - that the congestion-related loss and latency/jitter requirements - of a DetNet flow are met. +4. DetNet MPLS Data Plane - Explicit routes: +4.1. Overview - Use of a specific path for a flow. This limits misordering and - bounds latency. + The basic approach defined in [I-D.ietf-detnet-mpls] supports the + DetNet service sub-layer based on existing pseudowire (PW) + encapsulations and mechanisms, and supports the DetNet forwarding + sub-layer based on existing MPLS Traffic Engineering encapsulations + and mechanisms. - Service protection: + A node operating on a DetNet flow in the Detnet service sub-layer, + i.e. a node processing a DetNet packet which has the S-Label as top + of stack uses the local context associated with that S-Label, for + example a received F-Label, to determine what local DetNet + operation(s) are applied to that packet. An S-Label may be unique + when taken from the platform label space [RFC3031], which would + enable correct DetNet flow identification regardless of which input + interface or LSP the packet arrives on. The service sub-layer + functions (i.e., PREOF) use a DetNet control word (d-CW). - Which in the case of this document primarily relates to - replication and elimination. Changing the explicit path after a - failure is detected in order to restore delivery of the required - DetNet service characteristics is also possible. Path changes, - even in the case of failure recovery, can lead to the out of order - delivery of data. + The DetNet MPLS data plane builds on MPLS Traffic Engineering + encapsulations and mechanisms to provide a forwarding sub-layer that + is responsible for providing resource allocation and explicit routes. - Load sharing: + The forwarding sub-layer is supported by one or more forwarding + labels (F-Labels). - Generally, distributing packets of the same DetNet flow over - multiple paths is not recommended. Such load sharing, e.g., via - ECMP or UCMP, impacts ordering and possibly jitter. + DetNet edge/relay nodes are DetNet service sub-layer aware, + understand the particular needs of DetNet flows and provide both + DetNet service and forwarding sub-layer functions. They add, remove + and process d-CWs, S-Labels and F-labels as needed. MPLS enabled + DetNet nodes can enhance the reliability of delivery by enabling the + replication of packets where multiple copies, possibly over multiple + paths, are forwarded through the DetNet domain. They can also + eliminate surplus previously replicated copies of DetNet packets. + MPLS (DetNet) nodes also include DetNet forwarding sub-layer + functions, support for notably explicit routes, and resources + allocation to eliminate (or reduce) congestion loss and jitter. - Troubleshooting: + DetNet transit nodes reside wholly within a DetNet domain, and also + provide DetNet forwarding sub-layer functions in accordance with the + performance required by a DetNet flow carried over an LSP. Unlike + other DetNet node types, transit nodes provide no service sub-layer + processing. - For example, to support identification of misbehaving flows. +4.2. TSN over DetNet MPLS Encapsulation - Recognize flow(s) for analytics: + The basic encapsulation approach is to treat a TSN Stream as an app- + flow from the DetNet MPLS perspective. The corresponding example + shown in Figure 3. - For example, increase counters. + /-> +------+ +------+ +------+ TSN ^ ^ + | | X | | X | | X |<- Appli : : + App-Flow <-+ +------+ +------+ +------+ cation : :(1) + for MPLS | |TSN-L2| |TSN-L2| |TSN-L2| : v + \-> +---+======+--+======+--+======+-----+ : + | d-CW | | d-CW | | d-CW | : + DetNet-MPLS +------+ +------+ +------+ :(2) + |Labels| |Labels| |Labels| v + +---+======+--+======+--+======+-----+ + Link/Sub-Network | L2 | | TSN | | UDP | + +------+ +------+ +------+ + | IP | + +------+ + | L2 | + +------+ + (1) TSN Stream + (2) DetNet MPLS Flow - Correlate events with flows: + Figure 3: Example TSN over MPLS Encapsulation Formats - For example, unexpected loss. + In the figure, "Application" indicates the application payload + carried by the TSN network. "MPLS App-Flow" indicates that the TSN + Stream is the payload from the perspective of the DetNet MPLS data + plane defined in [I-D.ietf-detnet-mpls]. A single DetNet MPLS flow + can aggregate multiple TSN Streams. - The DetNet data plane also allows for the aggregation of DetNet - flows, e.g., via MPLS hierarchical LSPs, to improved scaling. When - DetNet flows are aggregated, transit nodes provide service to the - aggregate and not on a per-DetNet flow basis. In this case, nodes - performing aggregation will ensure that per-flow service requirements - are achieved. +5. TSN over MPLS Data Plane Procedures -5.1. End-System Specific Considerations + Description of Edge Nodes procedures and functions for TSN over + DetNet MPLS scenario follows the concept of [RFC3985] and covers the + Edge Nodes components shown on Figure 1. In this section the + following procedures of DetNet Edge Nodes are described: - Data-flows requiring DetNet service are generated and terminated on - end-systems. Encapsulation depends on application and its - preferences. In a DetNet MPLS domain the DN functions use the d-CWs, - S-Labels and F-Labels to provide DetNet services. However, an - application may exchange further flow related parameters (e.g., time- - stamp), which are not provided by DN functions. + o TSN related (Section 5.1) - Specifics related to non-MPLS DetNet end station behavior are out - side the scope of this document. For example, details on support for - DetNet IP data flows can be found in [I-D.ietf-detnet-dp-sol-ip]. - This document is also useful for end stations that map IP flows to - DetNet flows. + o DetNet Service Proxy (Section 5.2) - As a general rule, DetNet MPLS domains are capable of forwarding any - DetNet MPLS flows and the DetNet domain does not mandate the end- - system or edge system encapsulation format. Unless there is a proxy - of some form present, end-systems peer with similar end-systems using - the same application encapsulation format. For example, as shown in - Figure 3, IP applications peer with IP applications and Ethernet - L2VPN applications peer with Ethernet L2VPN applications. + o DetNet service and forwarding sub-layer (Section 5.3) - +-----+ - | X | +-----+ - +-----+ | X | - | Eth | ________ +-----+ - +-----+ _____ / \ | Eth | - \ / \__/ \___ +-----+ - \ / \ / - 0======== tunnel-1 ========0_ - | \ - \ | - 0========= tunnel-2 =========0 - / \ __/ \ - +-----+ \__ DetNet MPLS domain / \ - | X | \ __ / +-----+ - +-----+ \_______/ \_____/ | X | - | IP | +-----+ - +-----+ | IP | - +-----+ +5.1. Edge Node TSN Procedures - Figure 3: End-Systems and The DetNet MPLS Domain + The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1 + Working Group have defined (and are defining) a number of amendments + to IEEE 802.1Q [IEEE8021Q] that provide zero congestion loss and + bounded latency in bridged networks. IEEE 802.1CB [IEEE8021CB] + defines packet replication and elimination functions for a TSN + network. -6. MPLS-Based DetNet Data Plane Solution + TSN specific functions are executed on the data received by the PE + from the CE before presentation to the DetNet PW for transmission + across the DetNet domain, or on the data received from a DetNet PW by + a PE before it is output on the Attachment Circuit (AC). - [Editor's note: Needs clean up. Text should focus on Edge node - related topics.]. + TSN specific function(s) of Edge Nodes (T-PE) are belonging to the + native service processing (NSP) [RFC3985] block. This is similar to + other functionalities being defined by standard bodies other than the + IETF (for example in case of Ethernet: stripping, overwriting or + adding VLAN tags, etc.). Depending on the TSN role of the Edge Node + in the end-to-end TSN service selected TSN functions must be + supported. -6.1. DetNet Over MPLS Encapsulation Components + Implementations of this document SHALL use management and control + information to ensure TSN specific functions of the Edge Node + according to the expectations of the connected TSN network. - To carry DetNet over MPLS the following is required: +5.2. Edge Node DetNet Service Proxy Procedures - 1. A method of identifying the MPLS payload type. + The Service Proxy function maps between App-flows and DetNet flows. + The DetNet Edge Node TSN function MUST support the TSN Stream + identification functions and the related managed objects as defined + in IEEE 802.1CB [IEEE8021CB] and IEEE P802.1CBdb [IEEEP8021CBdb] to + recognize the App-flow related packets. The Service Proxy presents + TSN Streams as an App-flow to a DetNet Flow. - 2. A method of identifying the DetNet flow group to the processing - element. + Implementations of this document SHALL use management and control + information to map a TSN Stream to a DetNet flow. N:1 mapping + (aggregating multiple TSN Streams in a single DetNet flow) SHALL be + supported. The management or control function that provisions flow + mapping SHALL ensure that adequate resources are allocated and + configured to provide proper service requirements of the mapped + flows. - 3. A method of distinguishing DetNet OAM packets from DetNet data - packets. + Due to the (intentional) similarities of the DetNet PREOF and TSN + FRER functions service protection function interworking is possible + between the TSN and the DetNet domains. Such service protection + interworking scenarios MAY require to copy sequence number fields + from TSN (L2) to PW (MPLS) encapsulation. However, such interworking + is out-of-scope in this document and left for further study. - 4. A method of carrying the DetNet sequence number. + A MPLS DetNet flow is configured to carry any number of TSN flows. + The DetNet flow specific bandwidth profile SHOULD match the required + bandwidth of the App-flow aggregate. - 5. A suitable LSP to deliver the packet to the egress PE. +5.3. Edge Node DetNet Service and Forwarding Sub-Layer Procedures - 6. A method of carrying queuing and forwarding indication. + In the design of [I-D.ietf-detnet-mpls] an MPLS service label (the + S-Label), similar to a pseudowire (PW) label [RFC3985], is used to + identify both the DetNet flow identity and the payload MPLS payload + type. The DetNet sequence number is carried in the DetNet Control + word (d-CW) which carries the Data/OAM discriminator as well. In + [I-D.ietf-detnet-mpls] two sequence number sizes are supported: a 16 + bit sequence number and a 28 bit sequence number. - In this design an MPLS service label (the S-Label), similar to a - pseudowire (PW) label [RFC3985], is used to identify both the DetNet - flow identity and the payload MPLS payload type satisfying (1) and - (2) in the list above. OAM traffic discrimination happens through - the use of the Associated Channel method described in [RFC4385]. The - DetNet sequence number is carried in the DetNet Control word which - carries the Data/OAM discriminator. To simplify implementation and - to maximize interoperability two sequence number sizes are supported: - a 16 bit sequence number and a 28 bit sequence number. The 16 bit - sequence number is needed to support some types of legacy clients. - The 28 bit sequence number is used in situations where it is - necessary ensure that in high speed networks the sequence number - space does not wrap whilst packets are in flight. + PREOF functions and the provided service recovery is available only + within the DetNet domain as the DetNet flow-ID and the DetNet + sequence number are not valid outside the DetNet network. MPLS + (DetNet) Edge node terminates all related information elements + encoded in the MPLS labels. The LSP used to forward the DetNet packet may be of any type (MPLS- LDP, MPLS-TE, MPLS-TP [RFC5921], or MPLS-SR [I-D.ietf-spring-segment-routing-mpls]). The LSP (F-Label) label and/or the S-Label may be used to indicate the queue processing as - well as the forwarding parameters. Note that the possible use of - Penultimate Hop Popping (PHP) means that the only label in a received - label stack may be the S-Label. - -6.2. TSN over MPLS Data Plane Encapsulation - -6.2.1. Edge Node Processing - - An edge node is resposable for matching ingress packets to the - service they require and encapsulating them accordingly.An edge node - may participate in the packet replication and duplication - elimination. - - The DetNet-aware forwarder selects the egress DetNet member flow - segment based on the flow identification. The mapping of ingress - DetNet member flow segment to egress DetNet member flow segment may - be statically or dynamically configured. Additionally the DetNet- - aware forwarder does duplicate frame elimination based on the flow - identification and the sequence number combination. The packet - replication is also done within the DetNet-aware forwarder. During - elimination and the replication process the sequence number of the - DetNet member flow MUST be preserved and copied to the egress DetNet - member flow. - - The internal design of a relay node is out of scope of this document. - However the reader's attention is drawn to the need to make any PREOF - state available to the packet processor(s) dealing with packets to - which the PREOF functions must be applied, and to maintain that state - is such as way that it is available to the packet processor operation - on the next packet in the DetNet flow (which may be a duplicate, a - late packet, or the next packet in sequence. - - [Editor's note: I think the rest of this section belongs in a new - "802.1 TSN (island Interconnect) over DetNet MPLS" section.] - - This may be done in the DetNet layer, or where the native service - processing (NSP) [RFC3985] is IEEE 802.1CB [IEEE8021CB] capable, the - packet replication and duplicate elimination MAY entirely be done in - the NSP, bypassing the DetNet flow encapsulation and logic entirely. - This enables operating over unmodified implementations and - deployments. The NSP approach works only between edge nodes and - cannot make use of relay nodes. + well as the forwarding parameters. - The NSP approach is useful end to end tunnel and for for "island - interconnect" scenarios. However, when there is a need to do PREOF - in a middle of the network, such plain edge to edge operation is not - sufficient. + For further details see [I-D.ietf-detnet-mpls]. - The extended forwarder MAY copy the sequencing information from the - native DetNet packet into the DetNet sequence number field and vice - versa. If there is no existing sequencing information available in - the native packet or the forwarder chose not to copy it from the - native packet, then the extended forwarder MUST maintain a sequence - number counter for each DetNet flow (indexed by the DetNet flow - identification). +6. Controller Plane (Management and Control) Considerations -6.2.2. Layer 2 Addressing and QoS Considerations + TSN Stream(s) to DetNet flow mapping related information are required + only for the service proxy function of MPLS (DetNet) Edge nodes. + From the Data Plane perspective there is no practical difference + based on the origin of flow mapping related information (management + plane or control plane). - [Editor's NOTE: review and simplify this section if possible.] + MPLS DetNet Edge nodes are member of both the DetNet domain and the + connected TSN network. From the TSN network perspective the MPLS + (DetNet) Edge node has a "TSN relay node" role, so TSN specific + management and control plane functionalities must be implemented. + There are many similarities in the management plane techniques used + in DetNet and TSN, but that is not the case for the control plane + protocols. For example, RSVP-TE and MSRP behaves differently. + Therefore management and control plane design is an important aspect + of scenarios, where mapping between DetNet and TSN is required. - The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1 - Working Group have defined (and are defining) a number of amendments - to IEEE 802.1Q [IEEE8021Q] that provide zero congestion loss and - bounded latency in bridged networks. IEEE 802.1CB [IEEE8021CB] - defines packet replication and elimination functions that should - prove both compatible with and useful to, DetNet networks. + Note that, as the DetNet network is just a portion of the end to end + TSN path (i.e., single hop from Ethernet perspective), some + parameters (e.g., delay) may differ significantly. Since there is no + interworking function the bandwidth of DetNet network is assumed to + be set large enough to handle all TSN Flows it will support. At the + egress of the Detnet Domain the MPLS headers are stripped and the TSN + flow continues on as a normal TSN flow. - As is the case for DetNet, a Layer 2 network node such as a bridge - may need to identify the specific DetNet flow to which a packet - belongs in order to provide the TSN/DetNet QoS for that packet. It - also will likely need a CoS marking, such as the priority field of an - IEEE Std 802.1Q VLAN tag, to give the packet proper service. + In order to use a DetNet network to interconnect TSN segments, TSN + specific information must be converted to DetNet domain specific + ones. TSN Stream ID(s) and stream(s) related parameters/requirements + must be converted to a DetNet flow-ID and flow related parameters/ + requirements. - Although the flow identification methods described in IEEE 802.1CB - [IEEE8021CB] are flexible, and in fact, include IP 5-tuple - identification methods, the baseline TSN standards assume that every - Ethernet frame belonging to a TSN stream (i.e. DetNet flow) carries - a multicast destination MAC address that is unique to that flow - within the bridged network over which it is carried. Furthermore, - IEEE 802.1CB [IEEE8021CB] describes three methods by which a packet - sequence number can be encoded in an Ethernet frame. + In some case it may be challenging to determine some egress node + related information. For example, it may be not trivial to locate + the egress point/interface of a TSN Streams with a multicast + destination MAC address. Such scenarios may require interaction + between control and management plane functions and between DetNet and + TSN domains. - Ensuring that the proper Ethernet VLAN tag priority and destination - MAC address are used on a DetNet/TSN packet may require further - clarification of the customary L2/L3 transformations carried out by - routers and edge label switches. Edge nodes may also have to move - sequence number fields among Layer 2, PW, and IP encapsulations. + Mapping between DetNet flow identifiers and TSN Stream identifiers, + if not provided explicitly, can be done by the service proxy function + of an MPLS (DetNet) Edge node locally based on information provided + for configuration of the TSN Stream identification functions (e.g., + Mask-and-Match Stream identification). -7. Controller Plane (Management and Control) Considerations + Triggering the setup/modification of a DetNet flow in the DetNet + network is an example where management and/or control plane + interactions are required between the DetNet and the TSN network. - [Editor's note: requires considerations related to TSN over DetNet.]. + Configuration of TSN specific functions (e.g., FRER) inside the TSN + network is a TSN domain specific decision and may not be visible in + the DetNet domain. Service protection interworking scenarios are + left for further study. -8. Security Considerations +7. Security Considerations - The security considerations of DetNet in general are discussed in - [I-D.ietf-detnet-architecture] and [I-D.sdt-detnet-security]. Other - security considerations will be added in a future version of this - draft. + Security considerations for DetNet are described in detail in + [I-D.ietf-detnet-security]. General security considerations are + described in [I-D.ietf-detnet-architecture]. DetNet MPLS data plane + specific considerations are summarized in [I-D.ietf-detnet-mpls]. + The primary considerations for the data plane is to maintain + integrity of data and delivery of the associated DetNet service + traversing the DetNet network. Application flows can be protected + through whatever means is provided by the underlying technology. For + example, encryption may be used, such as that provided by IPSec + [RFC4301] for IP flows and/or by an underlying sub-net using MACSec + [IEEE802.1AE-2018] for IP over Ethernet (Layer-2) flows. -9. IANA Considerations +8. IANA Considerations This document makes no IANA requests. -10. Acknowledgements +9. Acknowledgements - Thanks for Norman Finn and Lou Berger for their comments and - contributions. + The authors wish to thank Norman Finn, Lou Berger, Craig Gunther, + Christophe Mangin and Jouni Korhonen for their various contributions + to this work. -11. References +10. References -11.1. Normative References +10.1. 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, . - [RFC2211] Wroclawski, J., "Specification of the Controlled-Load - Network Element Service", RFC 2211, DOI 10.17487/RFC2211, - September 1997, . - - [RFC2212] Shenker, S., Partridge, C., and R. Guerin, "Specification - of Guaranteed Quality of Service", RFC 2212, - DOI 10.17487/RFC2212, September 1997, - . - [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, DOI 10.17487/RFC3031, January 2001, . - [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., - Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack - Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001, - . - - [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., - and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP - Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, - . - - [RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen, - P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi- - Protocol Label Switching (MPLS) Support of Differentiated - Services", RFC 3270, DOI 10.17487/RFC3270, May 2002, - . - - [RFC3443] Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing - in Multi-Protocol Label Switching (MPLS) Networks", - RFC 3443, DOI 10.17487/RFC3443, January 2003, - . - - [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label - Switching (GMPLS) Signaling Resource ReserVation Protocol- - Traffic Engineering (RSVP-TE) Extensions", RFC 3473, - DOI 10.17487/RFC3473, January 2003, - . - - [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) - Hierarchy with Generalized Multi-Protocol Label Switching - (GMPLS) Traffic Engineering (TE)", RFC 4206, - DOI 10.17487/RFC4206, October 2005, - . - - [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, - "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for - Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385, - February 2006, . - - [RFC5085] Nadeau, T., Ed. and C. Pignataro, Ed., "Pseudowire Virtual - Circuit Connectivity Verification (VCCV): A Control - Channel for Pseudowires", RFC 5085, DOI 10.17487/RFC5085, - December 2007, . - - [RFC5129] Davie, B., Briscoe, B., and J. Tay, "Explicit Congestion - Marking in MPLS", RFC 5129, DOI 10.17487/RFC5129, January - 2008, . - - [RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching - (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic - Class" Field", RFC 5462, DOI 10.17487/RFC5462, February - 2009, . - - [RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black, - "Encapsulating MPLS in UDP", RFC 7510, - DOI 10.17487/RFC7510, April 2015, - . - [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . -11.2. Informative References - - [G.8275.1] - International Telecommunication Union, "Precision time - protocol telecom profile for phase/time synchronization - with full timing support from the network", ITU-T - G.8275.1/Y.1369.1 G.8275.1, June 2016, - . - - [G.8275.2] - International Telecommunication Union, "Precision time - protocol telecom profile for phase/time synchronization - with partial timing support from the network", ITU-T - G.8275.2/Y.1369.2 G.8275.2, June 2016, - . +10.2. Informative References [I-D.ietf-detnet-architecture] Finn, N., Thubert, P., Varga, B., and J. Farkas, "Deterministic Networking Architecture", draft-ietf- - detnet-architecture-12 (work in progress), March 2019. + detnet-architecture-13 (work in progress), May 2019. - [I-D.ietf-detnet-dp-sol-ip] - Korhonen, J., Varga, B., "DetNet IP Data Plane - Encapsulation", 2018. + [I-D.ietf-detnet-data-plane-framework] + Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., + Bryant, S., and J. Korhonen, "DetNet Data Plane + Framework", draft-ietf-detnet-data-plane-framework-02 + (work in progress), September 2019. - [I-D.ietf-detnet-flow-information-model] - Farkas, J., Varga, B., Cummings, R., and Y. Jiang, "DetNet - Flow Information Model", draft-ietf-detnet-flow- - information-model-03 (work in progress), March 2019. + [I-D.ietf-detnet-mpls] + Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., + Bryant, S., and J. Korhonen, "DetNet Data Plane: MPLS", + draft-ietf-detnet-mpls-01 (work in progress), July 2019. - [I-D.ietf-pce-pcep-extension-for-pce-controller] - Zhao, Q., Li, Z., Negi, M., and C. Zhou, "PCEP Procedures - and Protocol Extensions for Using PCE as a Central - Controller (PCECC) of LSPs", draft-ietf-pce-pcep- - extension-for-pce-controller-01 (work in progress), - February 2019. + [I-D.ietf-detnet-security] + Mizrahi, T., Grossman, E., Hacker, A., Das, S., Dowdell, + J., Austad, H., Stanton, K., and N. Finn, "Deterministic + Networking (DetNet) Security Considerations", draft-ietf- + detnet-security-05 (work in progress), August 2019. [I-D.ietf-spring-segment-routing-mpls] Bashandy, A., Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing with MPLS data plane", draft-ietf-spring-segment-routing-mpls-22 (work in progress), May 2019. - [I-D.sdt-detnet-security] - Mizrahi, T., Grossman, E., Hacker, A., Das, S., - "Deterministic Networking (DetNet) Security - Considerations, draft-sdt-detnet-security, work in - progress", 2017. - - [IEEE1588] - IEEE, "IEEE 1588 Standard for a Precision Clock - Synchronization Protocol for Networked Measurement and - Control Systems Version 2", 2008. + [IEEE802.1AE-2018] + IEEE Standards Association, "IEEE Std 802.1AE-2018 MAC + Security (MACsec)", 2018, + . [IEEE8021CB] Finn, N., "Draft Standard for Local and metropolitan area networks - Seamless Redundancy", IEEE P802.1CB /D2.1 P802.1CB, December 2015, - . + . [IEEE8021Q] IEEE 802.1, "Standard for Local and metropolitan area networks--Bridges and Bridged Networks (IEEE Std 802.1Q- 2014)", 2014, . - [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. - Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 - Functional Specification", RFC 2205, DOI 10.17487/RFC2205, - September 1997, . - - [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, - "Definition of the Differentiated Services Field (DS - Field) in the IPv4 and IPv6 Headers", RFC 2474, - DOI 10.17487/RFC2474, December 1998, - . - - [RFC3272] Awduche, D., Chiu, A., Elwalid, A., Widjaja, I., and X. - Xiao, "Overview and Principles of Internet Traffic - Engineering", RFC 3272, DOI 10.17487/RFC3272, May 2002, - . + [IEEEP8021CBdb] + Mangin, C., "Extended Stream identification functions", + IEEE P802.1CBdb /D0.2 P802.1CBdb, August 2019, + . [RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture", RFC 3985, DOI 10.17487/RFC3985, March 2005, . - [RFC4448] Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron, - "Encapsulation Methods for Transport of Ethernet over MPLS - Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006, - . - - [RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou, - Ed., "RSVP-TE Extensions in Support of End-to-End - Generalized Multi-Protocol Label Switching (GMPLS) - Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007, - . - - [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, - "GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873, - May 2007, . - - [RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S. - Yasukawa, Ed., "Extensions to Resource Reservation - Protocol - Traffic Engineering (RSVP-TE) for Point-to- - Multipoint TE Label Switched Paths (LSPs)", RFC 4875, - DOI 10.17487/RFC4875, May 2007, - . - - [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation - Element (PCE) Communication Protocol (PCEP)", RFC 5440, - DOI 10.17487/RFC5440, March 2009, - . - - [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., - "MPLS Generic Associated Channel", RFC 5586, - DOI 10.17487/RFC5586, June 2009, - . - - [RFC5654] Niven-Jenkins, B., Ed., Brungard, D., Ed., Betts, M., Ed., - Sprecher, N., and S. Ueno, "Requirements of an MPLS - Transport Profile", RFC 5654, DOI 10.17487/RFC5654, - September 2009, . + [RFC4301] Kent, S. and K. Seo, "Security Architecture for the + Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, + December 2005, . [RFC5921] Bocci, M., Ed., Bryant, S., Ed., Frost, D., Ed., Levrau, L., and L. Berger, "A Framework for MPLS in Transport Networks", RFC 5921, DOI 10.17487/RFC5921, July 2010, . - [RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters", - RFC 6003, DOI 10.17487/RFC6003, October 2010, - . - - [RFC6006] Zhao, Q., Ed., King, D., Ed., Verhaeghe, F., Takeda, T., - Ali, Z., and J. Meuric, "Extensions to the Path - Computation Element Communication Protocol (PCEP) for - Point-to-Multipoint Traffic Engineering Label Switched - Paths", RFC 6006, DOI 10.17487/RFC6006, September 2010, - . - - [RFC6073] Martini, L., Metz, C., Nadeau, T., Bocci, M., and M. - Aissaoui, "Segmented Pseudowire", RFC 6073, - DOI 10.17487/RFC6073, January 2011, - . - - [RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J. - Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label - Switched Paths (LSPs)", RFC 6387, DOI 10.17487/RFC6387, - September 2011, . - - [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and - L. Yong, "The Use of Entropy Labels in MPLS Forwarding", - RFC 6790, DOI 10.17487/RFC6790, November 2012, - . - - [RFC7551] Zhang, F., Ed., Jing, R., and R. Gandhi, Ed., "RSVP-TE - Extensions for Associated Bidirectional Label Switched - Paths (LSPs)", RFC 7551, DOI 10.17487/RFC7551, May 2015, - . - - [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", - RFC 7950, DOI 10.17487/RFC7950, August 2016, - . - - [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF - Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, - . - - [RFC8169] Mirsky, G., Ruffini, S., Gray, E., Drake, J., Bryant, S., - and A. Vainshtein, "Residence Time Measurement in MPLS - Networks", RFC 8169, DOI 10.17487/RFC8169, May 2017, - . - -Appendix A. Example of TSN over DetNet Data Plane Operation - - [Editor's note: Add a simplified example of DetNet data plane and how - labels etc work in the case of TSN over DetNet MPLS and utilizing - e.g., PREOF.] - Authors' Addresses Balazs Varga (editor) Ericsson Magyar Tudosok krt. 11. Budapest 1117 Hungary Email: balazs.a.varga@ericsson.com - Janos Farkas Ericsson Magyar Tudosok krt. 11. Budapest 1117 Hungary Email: janos.farkas@ericsson.com Andrew G. Malis - Huawei Technologies + Independent Email: agmalis@gmail.com Stewart Bryant - Huawei Technologies + Futurewei Technologies Email: stewart.bryant@gmail.com - Jouni Korhonen + Don Fedyk + LabN Consulting, L.L.C. - Email: jouni.nospam@gmail.com + Email: dfedyk@labn.net