the role of tsn in the future industrial world and ... · p1 p2 p3 e1 p3 (contd.) 4 express packets...

1 Copyright © 2018 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.|Copyright © 2018 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.

The Role of TSN in the Future Industrial World and Broadcom’s New Low-power Switching IC

March 2018

Copyright © 2018 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.

Introduction – Industry 4.0 and TSN

3 Copyright © 2018 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.|

Industry 4.0 – Computerization of Manufacturing

1st Industrial Revolution

Mechanical production facilities

2nd Industrial Revolution

Electrical power enables mass production

3rd Industrial Revolution

Combining IT and electronics to automate production processes

4th Industrial Revolution

Integrating production facilities with the Internet

Of Things (IoT)

Production Facilities

Electricity

Process Automation

IoT – Cyber Physical


Industry 4.0 – Computerization of Manufacturing Cont.

1st Industrial Revolution

Mechanical production facilities

2nd Industrial Revolution

Electrical power enables mass production

3rd Industrial Revolution

Combining IT and electronics to automate production processes

4th Industrial Revolution

Integrating production facilities with the

Internet Of Things (IoT)

Production Facilities

Electricity

Process Automation

IoT – Cyber Physical

Communication &

Interoperability

Data Collection &

Transparency

Visualizing info &

Assisting Us

Autonomous & Decentralized


• Current Industrial market is extremely fragmented

– ICS (PLC) vendors >> 50

– Protocols – Bus & Ethernet >> 20

– Delays innovation, complicate manufacturing automation environment

• Transition to Ethernet had minimal impact on interoperability

– Required complex solutions to achieve deterministic

high-quality communication

Industry 4.0 – Communication and Interoperability

Source: “Industrial Ethernet technologies, part 1” ; Control Engineering; April 2014

Source: http://www.n-tpa.com/Vendors.htm

Industrial Ethernet Protocols Market Share


• Asynchronous: Each device transmits frames at its own schedule, based on local clock

• Determinism: Guaranteed upper bound for Latency and Jitter as well as fixed Bandwidth

– High-Priority (P) frames get priority over Low-Priority (L) frames based on scheduling mechanism but will

wait their turn if L frames are in transmission

– Latency and jitter of P frames transmission, certainly of L frames, is not guaranteed

The Shortcomings of Ethernet

1

TSN flow (P)

BE flow (L)

1

Ingress port X

Egress port Z

2

2

P Latency1 P Latency2

1’Ingress port Y

3

31’

P Latency3

port X

port Yport Z

Latency: P Latency3 >> Latency 2 , 1

Jitter: (Latency 3 / latency2) >> (latency2 / latency 1)

Ethernet is an Asynchronized Technology and Not Deterministic


• Some Industrial applications require deterministic communication with low latency

• Its all about the control loop (cycle): Sample sensors; Compute action; Push out

command(s)

• Cycles times are application specific

– Low speed process cycle times 100s mSec

– High speed process cycle times 250 µSec

• Different applications support different

cycle times

Industrial Communication – The Requirement for Determinism

Ap

pli

cati

on

s

Cycle time

10 µSec 100 µSec 1 mSec 10 mSec

Printing

Machines

250 µSecPackaging

Machinery

Standard Production

Lines

Profinet RTProfinet IRTProfinet IRT

V2.3

Standard IO; Simple applications

Diagnostics Information

TCP/IP

High-Speed IO ; Motion Control

31.25 µSec

Sercos ISercos IISercos

III


• Hierarchical topology with deterministic communication requirement (depends on the app)

• Common topology for industrial applications is daisy chain with many hopes, this forces use

of low latency per hope

• Requirements for high speed process:

– Jitter: Within the cell ±500 nsec, Within the factory ±100 μsec

– Delay: Within the cell < 5 μSec, Within the factory< 125 μsec

Industrial Communication – The Requirement for Determinism Cont.

Cell

Floor

Factory

Enterprise


Introduction to Time Sensitive Networking


• Set of standards developed by the TSN task group of IEEE 802.1

working group

• Improved on previously defined AVB (Audio-Video Bridging) standards

– Reduced worst-case delays (4 μs or less per hop @ 1 Gbps speed)

– Extend use cases from audio/video applications to control systems

• Interoperable, low latency, deterministic, Ethernet communication

• L2 technology – more is needed to achieve interoperable environment

What is Time Sensitive Networking (TSN)Multiple

Standards

Deterministic

More use-cases

Low-Latency

Interoperable

L2


• Building local TDM-like mechanism by defining clock cycles and sub cycles:

– Transmission of HP ‘P’ frames

– Transmission of LP ‘L’ frames

– Guard Band – ‘G’

• ‘G’ prevents transmission of

‘L’ frames that might spill into

the ‘P’ sub-cycle

• Synchronize all nodes so that all will transmit ‘P’/’L’ frames in the right window – 802.1AS

• Control-loop latency is subject to PLC calculation and minimal switches cut-through latency TSN

supported clock cycles can be significantly lower than other protocols

Time Sensitive Networking – Basic Concept

Moving from Asynchronized Frame Based to Synchronized Time Based Networks

Cycle1

TSNGuardBand

G P

BE

L

Cycle2

TSNGuardBand

G P

BE

L


TSN – A Look at Relevant Standards

Determinism

Ensuring A Common System Clock

• IEEE 1588 (a.k.a. PTP)

– 802.1AS

• Synchronous Ethernet

Improving Forwarding and Queueing

• Time Aware Scheduling (1Qbv)

• Credit Based Shapers (1Qav)

• Cyclic Forwarding and Que’ (1Qch)

Overlay Protocols

• Stream Reservation Prot’ (1Qat)

• OPC-UA (IEC 62541)

• Profinet

Complementary Standards

• Seamless Redundancy (802.1Qcb)

• Cut-through mode

• Per-Stream Filtering (802.1Qci)

1

2 4

3


• Issue 1: Store-and-Forward

– The first bit of a packet can be transmitted only

after the last bit of a packet is received

– Significant latency for large packets

• Solution 1: Cut through

– The first bit of a packet (E1..En) can be

transmitted after a part of the packet is received

by the switch – reduces latency of large packets

– In cases of congestion (frames are stored in the

buffers) cut-through mode might behave like

Store-and-Forward

TSN – Ensuring Low Latency in Non-Congestion Scenario

Reducing Latency even without TSN

E1 En

E1 En

Tx Packets

L

First bit of E1 received

Last bit of E1 received

First bit of E1 transmitted

Last bit of E1 transmitted

Time

TimeR x Packets

E1 En

E1 En

Tx Packets

L

First bit of E1 received

Last bit of E1 received

First bit of E1 transmitted

Last bit of E1 transmitted

Time

TimeR x Packets

Store and Forward

Cut Through

Lets Assume N frames E1 to En


• Time-critical traffic (P) should get higher priority

• Issue 2: What If low-priority traffic Interferes?

– P frames must wait until L frames finish transmission

• Solution 2a: Preemption (802.3br) only

– L traffic which is in transmission can be split (preempted) into

fragments to allow P traffic to be transmitted.

– We’ll still have latency that is governed by minimal fragment size

Ensuring Low Latency in Congestion Scenario

Express MAC (eMAC)

Preemtible MAC (pMAC)

Express Traffic (COS7)

Preemptable traffic (COS6..0)

MAC Merge Layer

MAC Merge Control (MM_CTL)

Time-stamped Express Traffic

Q5

Q0

Pre-

empt

ive

SP+D

RR S

ched

uler

Q7

Time-stamped Express Traffic

+ Preemptable Traffic

Credit based shaper

Port shaper

Q6

Pree

mpt

ible

Tra

ffic

P1 P2 P3 E1 P3 (contd.) P4

Express packets (Mframe)

Preemptible packets ( Mframe ) P1 and P2

Initial fragment of Preempted packet (Mframe) P3

Non initial fragment (Mframe) of preempted packet P3

Preemptible packet ( Mframe) P4

Express Traffic

En

Pre- emptible Traffic

Non-Engineered Network


• Solution 2b: Time Aware Scheduling – TAS (802.1Qbv)

– P and L are due to start in fixed times (windows) – 802.1AS needed

– A guard band (G) is created before P window to ensure completion of L

transmission. G > MTU transmission and L is not transmitted in G.

– Existing of G reduces network utilization (wasted bandwidth)

– Solution 1: Use preemption , transmit L frames inside G and preempt them

before the P window

– Solution 2: If it can be determined that a frame size can be transmitted

within G but before the P window we can do so will not work in Cut-

Through

Ensuring Low Latency in Congestion Scenario Cont.

High Priority Traffic(Scheduled Traffic)

Q5

Q0

Port # 0Port # 0

Pre

-em

pti

ve S

P+D

RR

Sch

edu

ler

Lower Priority Traffic

Q6


Q7

High Priority Traffic

+ Low Priority Traffic

Credit based shaper

Port shaper

Time Aware Shaper(TAS)

T00 oCoooCoo

T01 CoCCCCCC

T02 CCCCCCCo

Tn REPEAT

Time (Txx) = Delta Time in nanoseconds relative to UTC clock· Accuracy < 10nsec.

T03 CCCCCCoC

Engineered Network

L1 L2 H1 L3 L4

lower priority packets L1

and L2

high priority packets H1

through Hnlower priority packets L3

and L4

High Priority Traffic

+


Hn

Fixed Start of Guard Band (T0)

Start of Protected Window (T1)

End of Protected Window (T2)

T1-T0 = length of max-sized frame


• M-2-M machine communication protocol for

industrial automation developed by the OPC

Foundation

• Replacing legacy OPC that was designed using

proprietary Microsoft components (DCOM)

• Used in a service-oriented architecture (SOA)

manner with client server model

TSN – The Overlay Protocol Model

• Promoted by the Profibus & Profinet International

(PI) consortium (Hannover Fair 2017)

OPC-UA over TSN Profinet over TSN

BROADCOM SUPPORTS BOTH

Source: Profinet-Profibus PI members HereSource: Industrial Ethernet book; OPC-UA over TSN gain momentum Here

http://myemail.constantcontact.com/Profibus---Profinet-Southern-Africa-Newsletter.html?soid=1122762192587&aid=kryW6ynsKlQ

https://www.google.com/search?q=OPC-UA+members&rlz=1C1GGRV_enUS751US752&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj1m4uYtvHZAhUHyaQKHSIuD3MQ_AUICigB&biw=1221&bih=514#imgrc=11lWUEZHi45NwM:


RoboSwitch™-2 Avenger – An Industry 4.0 IC


• Low to Medium Bandwidth L2 Switching: <50 GbE

• Broadcom’s lowest-power, lowest-cost: <10W

• Optimal solution for these markets

– SMB: Unmanaged & Web-Managed

– Broadband: HGW and MDU

– Industrial Ethernet: I-Temp; Low-Power; TSN

– Embedded (on board): Connectivity only

– Enterprise and SP markets: vCPE; Security Appliances

• Serving above markets since 1999

The RoboSwitch™ Product Line

StrataDNX™

• Medium to very high bandwidth

• Higher Power

• L2+L3

• Higher-end features

• Service-Providers, Data-Centers

StrataXGS®

• Low to very high bandwidth

• Higher Power

• L2+L3

• Medium-end features

• Service-Providers,Data-Centers, Enterprises

StrataXGS®

• Medium to high Bandwidth

• Medium Power

• L2 + L3

• Medium-end features

• Smart SMB, Enterprise, SP Access, High-Port count Industrial

RoboSwitch

• Low to Medium Bandwidth

• Low power

• L2

• Low-to-Medium-end features

• Industrial, Un/Web-Managed SMB, HGW/MDU, Embedded

Broadcom Switching Product Lines


RoboSwitch™-2 – New Architecture For Industry 4.0

Ultra low-power design with integrated high-

speed ports 1/2.5/10GbE ports

• 28nm technology with Power reduced GPHYs

• Designed for small port count that can scale through cascading

• Small form-factor (13x13/19x19 package)

IoT/IIoT software (Robo-OS™) provided

• Embedded arch’ (running on embedded processor and memory)

• Modular designed with open source

• Cloud protocols and Autodiscovery mechanisms

(MQTT, REST-API, UpNP, Bonjour)


Improved scalability and security

• More resources and larger tables for future growth

• Embedded ARM processor to offload tasks from main processor

• Virtual switching instance (VSI) for better traffic segregation

• Security mechanisms, e.g. 802.1x, for authenticating connected

devices

RoboSwitch™-2 – New Architecture For Industry 4.0 Cont.

TSN support

• Clock sync standards – SyncE; 1588 ; 802.1AS

• Forwarding and queuing standards – 802.1Qav ; 802.1Qbv

• Cut-through mode support

• Per-stream filtering


BCM5311X – FE BCM5315X – GE

Avenger – The First Family in the RoboSwitch®-2 architecture

EPHY

MAC MACMACMAC

EPHY EPHYEPHY EPHY

MAC MACMACMAC

EPHY EPHYEPHY

4x10/100Base-T

Quad GMAC

QUADSGMII

4x10/100Base-T 4x1GE

Packet Buffer(1MB)

8 COS SP.WRR

L2 Processing(16K MAC)

CFP(1K rules)

ARMCortex M7

2 SGMIII

SPI2 x 1GE/2.5GE RGMII MDIO GPIO

GMAC

Meters & Counters(512 flows meters, 128 port meters)

I2CQSPI MFIO

LED Processor

LED

uController 8051

Time Sync2 x GMAC

8 x 10/100Base-T + 4 x 1GE + 2 x 1/2.5GE

GPHY

GMAC GMACGMACGMAC

GPHY GPHYGPHY GPHY

GMAC GMACGMACGMAC

GPHY GPHYGPHY

4x10/100/1000Base-T

Quad GMAC

QSGMII

4x10/100/1000Base-T QSGMII

Packet Buffer(1MB)

8 COS SP.WRR


CFP(1K rules)

ARMCortex M7

2 SGMIII

SPI2 x

1GE/2.5/10GE RGMII MDIO GPIO

GMAC

Meters & Counters(512 flows meters, 128 port meters)

I2CQSPI MFIO

LED Processor

LED

uController 8051

Time Sync2 x GMAC

8x10/100/1000Base-T+ QSGMII+ 2x1/2.5/10GE


BCM5316X – 2.5GE Common Features and Benefits

Features and Benefits

• 28nm technology ; 13x13mm / 19x19mm packages

• Ultra low power: BCM5311X: 2.7W ; BCM5315X:

3.8W ; BCM5316X: 4W

• ARM Processor

• 8 COS queues per port with shapers, SP and WRR

• 1K-entry ACL/CFP support

• From 3-port switch to 26-p (through cascading)

• TSN:

– Sync: IEEE1588/SyncE, 802.1AS rev2,

– Cut-through and Store-and-Forward mode

– AVB and TAS shapers

– Per-Stream-Filtering

• Port Extender (802.1BR) ; MAC-in-MAC;

Avenger – The First Family in the RoboSwitch-2 architecture

GPHY

GMAC GMACGMACGMAC

GPHY GPHYGPHY GPHY

GMAC GMACGMACGMAC

GPHY GPHYGPHY

4x10/100/1000Base-T

GMAC

QUAD SERDESSGM-2+

4x10/100/1000Base-T 4x1GE/2.5GE

Packet Buffer(1MB)

Memory Manager8 COS SP.WDRR.

WRR, WRED


CFP(1K rules)

ARMCortex M7

2 SERDES(SGMII+ or

XFI/SFI)

SPIRGM-2 MDIO GPIO

GMAC

Meters and Counters(512 flows meters,

128 port meters)

I2CQSPI MFIO

LED Processor

LED

uController 8051

Time Sync

2 x XMAC(10/2.5G)

2 x 1GE/2.5/10GE

8x10/100/1000Base-T + 4x1/2.5GE + 2x1/2.5/10GE


Avenger BCM53154: 4-p TSN Switch for Industrial Daisy-Chain App


• Part of new product line based on next-generation architecture named RoboSwitch™-2

• Ultra low-power, 28nm technology, switching ICs designed for industrial applications

• Supports all speeds for current and future industrial applications, 100 Mbps to 10 Gbbps

– Fast-Ethernet BCM5311X; Gigabit-Ethernet BCM5315X; 2.5-Gigabit-Ethernet BCM5316X

– From 3-p to 26-p (via cascading)

• Time-Sensitive-Networking support for Industry 4.0

• Three software suites for different industrial automation applications

Avenger Summary

the role of tsn in the future industrial world and ... · p1 p2 p3 e1 p3 (contd.) 4 express packets...

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