IEEE 802.1 TSN - An Introduction...Submission doc.: IEEE 802.11-19/1298r0 IEEE 802.1 TSN – An Introduction Date: 2019-07-16 July 2019 Slide 1 János Farkas, Ericsson Name Affiliations

Submission

doc.: IEEE 802.11-19/1298r0

IEEE 802.1 TSN – An IntroductionDate: 2019-07-16

July 2019

János Farkas, EricssonSlide 1

Name Affiliations Address Phone email János Farkas Ericsson +3614377100 [email protected]

Authors:

Name

Affiliations

Address

Phone

email

János Farkas

Ericsson

+3614377100

[email protected]

Submission

doc.: IEEE 802.11-19/1298r0

Abstract

This presentation gives an introduction to IEEE 802.1 Time-Sensitive Networking (TSN) for the joint session of 802.11 TGbe and 802.1 TSN TG held at the IEEE 802 Plenary, July 2019.

Slide 2 János Farkas, Ericsson

July 2019

Submission

doc.: IEEE 802.11-19/1298r0

Outline

• Deterministic service• TSN standards and projects• Basic concepts• Example TSN tools

• Scheduled Traffic (802.1Qbv)• Asynchronous Traffic Shaping (P802.1Qcr)• Frame Replication and Elimination for Reliability (802.1CB)• TSN Configuration (802.1Qcc)

• Summary


July 2019

Submission

doc.: IEEE 802.11-19/1298r0

We Are Interested in Deterministic Service

July 2019


Deterministic ServicePacket loss is at most due to equipment failure

(zero congestion loss)Bounded latency, no tailsThe right packet at the right time

Traditional ServiceCurves have long tail Average latency is goodLowering the latency means

losing packets (or overprovisioning)

Loss

pro

babi

lity

Buffers allocated

End-to-end latency

Latency variation

Prob

abili

ty

Prob

abili

ty

Average

App

licat

ion’

s re

quir

emen

t

Loss

pro

babi

lity

Buffers allocated

End-to-end latency

Latency variation

Prob

abili

ty

Prob

abili

ty

App

licat

ion’

s re

quir

emen

tHigh Priority

Average

Submission

doc.: IEEE 802.11-19/1298r0July 2019


TSN Components(Tools of the TSN toolbox)

5

LatencyBounded low latency:

Credit Based Shaper (802.1Qav) Frame preemption (802.3br & 802.1Qbu)

Scheduled Traffic (802.1Qbv) Cyclic Queuing and Forwarding (802.1Qch) Asynchronous Traffic Shaping (P802.1Qcr)

QoS Provisions (P802.1DC)

High Availability /Ultra reliability:Frame Replication and Elimination (802.1CB)Path Control and Reservation (802.1Qca)Per-Stream Filtering and Policing (802.1Qci)Reliability for time sync (P802.1AS-Rev)

Time synchronization:Timing and Synchronization (802.1AS)

includes a profile of IEEE 1588(revision ongoing: P802.1AS-Rev)

Zero congestion loss =Bounded latency

Resource Mgmt

Dedicated resources & APIStream Reservation Protocol (802.1Qat)TSN configuration (802.1Qcc)Basic YANG (802.1Qcp)YANG for CFM (P802.1Qcx)YANG for LLDP (P802.1ABcu)YANG for Qbv, Qbu, and Qci (P802.1Qcw)YANG & MIB for FRER (P802.1CBcv)Link-local Registration Protocol (P802.1CS)Resource Allocation Protocol (P802.1Qdd)Extended Stream Identification (P802.1CBdb)

Reliability

Synchronization

Resource Mgmt

Note: P upfront of an ID indicates ongoing Project

TSN Profiles (Selection and use of TSN tools)Audio Video Bridging

(802.1BA)Fronthaul(802.1CM)

Industrial Automation(IEC/IEEE P60802)

Automotive In-Vehicle(P802.1DG)

Service Provider(P802.1DF)

Submission

doc.: IEEE 802.11-19/1298r0

TSN Profiles

• Wide breadth of choices in IEEE 802 standards• A TSN Profile

• Narrows the focus ease interoperability and deployment• Selects features, options, defaults, protocols, and procedures• Describes how to build a network for a particular use• Provides configuration guideline if needed

• TSN Profiles so far• Published TSN Profiles:

• IEEE Std 802.1BA for Audio-Video Bridging (AVB) networks• IEEE Std 802.1CM TSN for Fronthaul (for cellular networks)

• Ongoing: • IEC/IEEE 60802 TSN Profile for Industrial Automation• P802.1DF TSN Profile for Service Provider Networks• P802.1DG TSN Profile for Automotive In-Vehicle Ethernet Communications


July 2019

IEEE 802

AVBFronthaul

IndustrialAutomation

…

Profiles

Submission

doc.: IEEE 802.11-19/1298r0

Basic Components• From IEEE 802.1 perspective, the world is divided into two types of devices: bridges and end stations• Talker: The end station that is the source or producer of a stream• Listener: The end station that is the destination, receiver, or consumer of a stream• Stream: A unidirectional flow of data from a Talker to one or more Listeners• Bridge: see next slides


July 2019

bridged network

Legend:

11bridge

end station

21

11

bridge ID

port ID

12

3

13

22

1312

3

1212

3

22 13

2

321 2

34

talker

talker &listener

listener

listener

talker & listeneredge

bridge

corebridge

edgebridge

stream1

stream2

stream3

Submission

doc.: IEEE 802.11-19/1298r0

Bridge ArchitectureControl Plane Separated from Data Plane

July 2019


• Control protocols are implemented as Higher Layer Entities

• External Agent (SDN Controller) may provide control instead of the distributed protocols

• The data plane is comprised ofA MAC Relay andAt least two portsD

ata

Pla

neC

ontr

ol P

lane

RelayP

ort

Por

t

External (aka Agent SDN Ctrl)

MAC BridgeHigher Layer

Entities

Simplified “baggy pants” model

LAN

Media Access Method Specific Functions

IEEE 802.n

802.

1 B

ridg

ing

LAN see Figure 8-2 – “VLAN-aware Bridge architecture” of 802.1Q for more details

Submission

doc.: IEEE 802.11-19/1298r0

Bridge Forwarding Process Functions

July 2019


Submission

doc.: IEEE 802.11-19/1298r0

Illustration of QoS Functions

July 2019


Per Class

frame transmission

Transmission Selection

Filteringand Policing

Queuing

frame reception

Shaping

can bePer Stream,Per Class, etc.

can

be v

iew

ed a

s a

hier

arch

ical

app

roac

h

note: other functions are not shown in this figure, e.g., relay, reliability

Submission

doc.: IEEE 802.11-19/1298r0

Scheduled Traffic [802.1Qbv]

• Reduces latency variation for frames with known timing• Time-based control and programming of the bridge queues• Time-Gated queues• Transmission Gate (G): Open or Closed• Periodically repeated time schedule• Time synchronization is needed


July 2019



Queuing

Shaping

critical critical critical

open Closed open Closed open Closed open

frame transmitted:critical / non-critical

gate(s) fornon-critical traffic

Note: gate of non-critical data can be closed in advance to protect critical data

Priority selection

G GG G G G G G

Submission

doc.: IEEE 802.11-19/1298r0

Per-Stream Filtering and Policing (PSFP) [802.1Qci]• Protection against bandwidth violation, malfunctioning, attacks, etc.• Decisions on per-stream, per-priority, etc.• Filter

• Filters, Counters• Stream Gate

• Time scheduled gate• Open or Closed

• Internal Priority Value (IPV)• Bridge internal traffic class of the frame

• Meter• Bandwidth Profile of MEF 10.3• Red/Yellow/Green Marking


July 2019

Filter

Stream GateInternal Priority

Queueing

Meter

incomingframe



Queuing

Shaping

Submission

doc.: IEEE 802.11-19/1298r0

Asynchronous Traffic Shaping (ATS) [P802.1Qcr]

• Zero congestion loss without time sync• Similar to per-flow IntServ shaping, except that:• All streams from one input port to the same output port share the same queue

• A shaper state machine for a set of streams, and the right shaper applied to the packet upfront of the queue

• Smoothen traffic patterns by re-shaping per hop

• Prioritize urgent traffic over relaxed traffic


July 2019

Link

BE

High

Low

High

Lowsele

ct

sele

ct

Submission

doc.: IEEE 802.11-19/1298r0

ATS Components [P802.1Qcr]

• Filter• Selects treatment for frames of a stream, e.g., IPV, shaper

• Internal Priority Value (IPV)• Bridge internal traffic class of the frame• Used for ATS operations

• ATS Shaper• Applies a token bucket algorithm• Uses bridge local time variables• Pre-computes local transmission time for each frame• Eligibility Time is assigned to each frame• Eligibility Time becomes effective in the queueing• Transmit frames that reached their Eligibility Time


July 2019

Filter

Stream GateInternal Priority

ATS Queueing

ATS Eligibility TimeAssignment

incomingframe



Queuing

Shaping

Submission

doc.: IEEE 802.11-19/1298r0

Frame Replication and Elimination for Reliability (FRER) [802.1CB]

• Avoid frame loss due to equipment failure• It is a per-frame 1+1 (or 1+n) redundancy

• NO failure detection / switchover• Send frames on 2 (or more) maximally disjoint paths, then combine and

delete extras


July 2019

N1 N2

141516

141516

disjoint pathsframe flow

Replication Elimination

Submission

doc.: IEEE 802.11-19/1298r0

TSN Configuration [802.1Qcc]July 2019


Fully distributed

Fully centralizedCentralized network & distributed user

Submission

doc.: IEEE 802.11-19/1298r0

Summary

• TSN provides deterministic service• Multiple TSN tools provide bounded low latency

• Time-based control of queueing provides deterministic behavior• Time synchronization is required

• Asynchronous Traffic Shaping• High availability / ultra reliability• Configuration and resource reservation


July 2019

Submission

doc.: IEEE 802.11-19/1298r0

Further Readinghttp://www.ieee802.org/1/tsnTSN feature topic of the June 2018 Issue of IEEE Communications Standards Magazine

https://ieeexplore.ieee.org/document/8412457Tutorial on TSN at IETF 99

https://datatracker.ietf.org/meeting/99/materials/slides-99-edu-sessf-time-sensitive-networking-tutorial-english-language-janos-farkas-norman-finn-patricia-thaler

Tutorial on IEEE 802 Ethernet Networks for Automotivehttp://www.ieee802.org/802_tutorials/2017-07/tutorial-Automotive-Ethernet-0717-v02.pdf

“A Time-Sensitive Networking Primer: Putting It All Together” https://drive.google.com/file/d/0B6Xurc4m_PVsZ1lzWWoxS0pTNVE/view?usp=sharing

“Heterogeneous Networks for Audio and Video: Using IEEE 802.1 Audio Video Bridging” http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6595589

Tutorial on IEEE 802.3br Interspersing Express Traffic (IET) and IEEE 802.1 Time-Sensitive Networking http://www.ieee802.org/802_tutorials/2015-03/8023-IET-TF-1501-Winkel-Tutorial-20150115_r06.pptx

Tutorial on Deterministic Ethernet http://www.ieee802.org/802_tutorials/2012-11/8021-tutorial-final-v4.pdfTutorial on IEEE 802.1Q at IETF 86 https://www6.ietf.org/meeting/86/tutorials/86-IEEE-8021-Thaler.pdfPaper on 802.1Q bridging https://arxiv.org/ftp/arxiv/papers/1405/1405.6953.pdf


July 2019

http://www.ieee802.org/1/tsnhttps://ieeexplore.ieee.org/document/8412457/http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=7886829https://ieeexplore.ieee.org/document/8412457https://datatracker.ietf.org/meeting/99/materials/slides-99-edu-sessf-time-sensitive-networking-tutorial-english-language-janos-farkas-norman-finn-patricia-thalerhttp://www.ieee802.org/802_tutorials/2017-07/tutorial-Automotive-Ethernet-0717-v02.pdfhttps://drive.google.com/file/d/0B6Xurc4m_PVsZ1lzWWoxS0pTNVE/view?usp=sharinghttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6595589http://www.ieee802.org/802_tutorials/2015-03/8023-IET-TF-1501-Winkel-Tutorial-20150115_r06.pptxhttp://www.ieee802.org/802_tutorials/2012-11/8021-tutorial-final-v4.pdfhttps://www6.ietf.org/meeting/86/tutorials/86-IEEE-8021-Thaler.pdfhttps://arxiv.org/ftp/arxiv/papers/1405/1405.6953.pdf

IEEE 802.1 TSN – An IntroductionAbstractOutlineWe Are Interested in Deterministic ServiceSlide Number 5TSN ProfilesBasic ComponentsBridge Architecture�Control Plane Separated from Data PlaneBridge Forwarding Process FunctionsIllustration of QoS FunctionsScheduled Traffic [802.1Qbv]Per-Stream Filtering and Policing (PSFP) [802.1Qci]Asynchronous Traffic Shaping (ATS) [P802.1Qcr]ATS Components [P802.1Qcr]Frame Replication and Elimination for Reliability (FRER) [802.1CB]TSN Configuration [802.1Qcc]SummaryFurther Reading

Documents

IEEE 802.1 TSN - An Introduction...Submission doc.: IEEE 802.11-19/1298r0 IEEE 802.1 TSN – An Introduction Date: 2019-07-16 July 2019 Slide 1 János Farkas, Ericsson Name Affiliations