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X-Lap : A Systems Approach for Cross-Layer Profjling and Latency - - PowerPoint PPT Presentation

Dec 22, 2023 316 likes •684 views

X-Lap : A Systems Approach for Cross-Layer Profjling and Latency Analysis for Cyber-Physical Networks RTN 2017 Stefan Reif, Timo Hnig, Wolfgang Schrder-Preikschat Department of Computer Science 4 (Distributed Systems and Operating Systems)

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X-Lap: A Systems Approach for Cross-Layer Profjling and Latency Analysis for Cyber-Physical Networks

RTN 2017 Stefan Reif, Timo Hönig, Wolfgang Schröder-Preikschat Department of Computer Science 4 (Distributed Systems and Operating Systems) Friedrich-Alexander-Universität Erlangen-Nürnberg Andreas Schmidt, Thorsten Herfet Telecommunications Lab Saarland Informatics Campus - Saarbrücken June 27, 2017

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Cyber-Physical Networks (CPNs)

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Cyber-Physical Networks (CPNs)

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Cyber-Physical Networks (CPNs)

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Cyber-Physical Networks (CPNs)

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Existing Solutions Single-Host Evaluation Tools

▶ Local evaluation ▶ Network-oblivious

Network Evaluation Tools

▶ Network protocol evaluation ▶ Abstract from host-related delays

Need for Cross-Layer-Analysis of communication stacks

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Existing Solutions Single-Host Evaluation Tools

▶ Local evaluation ▶ Network-oblivious

Network Evaluation Tools

▶ Network protocol evaluation ▶ Abstract from host-related delays

Need for Cross-Layer-Analysis of communication stacks

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Outline

Introduction X-Lap PRRT Evaluation Conclusion

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Outline

Introduction X-Lap PRRT Evaluation Conclusion

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X-Lap | Introduction

X-Lap Application Transport protocol Operating system Channel Packet creation Error correction ... Inter-process communication (IPC) Resource management ... Transmission delay Propagation delay ...

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X-Lap | Introduction

X-Lap Application Transport protocol Operating system Channel

▶ Packet creation ▶ Error correction ▶ ... ▶ Inter-process communication (IPC) ▶ Resource management ▶ ... ▶ Transmission delay ▶ Propagation delay ▶ ...

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X-Lap | Architecture jk Run-time evaluationjk

▶ Timestamping functions ▶ ⇒ Timestamps ▶ C codejk

Ofg-line analysisjk

▶ Data analysis ▶ ⇒ Latency and jitter ▶ Python code

*.csv Trace every packet Minimize run-time interference Embedded into protocol source code Collect traces Combine trace data Single-packet traces Jitter amongst packets Outlier analysis Correlation analysis

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X-Lap | Architecture jk Run-time evaluationjk

▶ Timestamping functions ▶ ⇒ Timestamps ▶ C codejk

Ofg-line analysisjk

▶ Data analysis ▶ ⇒ Latency and jitter ▶ Python code

*.csv

▶ Trace every packet ▶ Minimize run-time

interference

▶ Embedded into protocol

source code Collect traces Combine trace data Single-packet traces Jitter amongst packets Outlier analysis Correlation analysis

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X-Lap | Architecture jk Run-time evaluationjk

▶ Timestamping functions ▶ ⇒ Timestamps ▶ C codejk

Ofg-line analysisjk

▶ Data analysis ▶ ⇒ Latency and jitter ▶ Python code

*.csv Trace every packet Minimize run-time interference Embedded into protocol source code

▶ Collect traces ▶ Combine trace data

Single-packet traces Jitter amongst packets Outlier analysis Correlation analysis

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X-Lap | Architecture jk Run-time evaluationjk

▶ Timestamping functions ▶ ⇒ Timestamps ▶ C codejk

Ofg-line analysisjk

▶ Data analysis ▶ ⇒ Latency and jitter ▶ Python code

*.csv Trace every packet Minimize run-time interference Embedded into protocol source code Collect traces Combine trace data

▶ Single-packet traces ▶ Jitter amongst packets ▶ Outlier analysis ▶ Correlation analysis

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Outline

Introduction X-Lap PRRT Evaluation Conclusion

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Predictably Reliable Real-time Transport (PRRT) UDP

▶ Data integrity checks ▶ No timeliness guarantees

TCP

▶ Error control ▶ No timeliness guarantees

Not suitable for reliable real-time networks

PRRT

Error correction Latency-awareness

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Predictably Reliable Real-time Transport (PRRT) UDP

▶ Data integrity checks ▶ No timeliness guarantees

TCP

▶ Error control ▶ No timeliness guarantees

  • Not suitable for reliable

real-time networks

PRRT

Error correction Latency-awareness

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Predictably Reliable Real-time Transport (PRRT) UDP

▶ Data integrity checks ▶ No timeliness guarantees

TCP

▶ Error control ▶ No timeliness guarantees

  • Not suitable for reliable

real-time networks

PRRT

▶ Error correction ▶ Latency-awareness

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Error Control and Timeliness

Automated Repeat reQuest (ARQ) Forward Error Correction (FEC) Hybrid Error Correction (HEC) Adaptive HEC (AHEC) + Application Constraints Channel State Information (CSI) Run-time CSI System Information Jitter

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PRRT | Interaction with X-Lap Benefjts from X-Lap

▶ Obtain system information ▶ Analyse jitter

Goals: Latency and jitter ...

▶ ... avoidance

→ Eliminate causes of latency and jitter

▶ ... hiding

→ Preparatory/Clean-up tasks → Optimise resource management

▶ ... tolerance

→ Parameters for AHEC

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Outline

Introduction X-Lap PRRT Evaluation Conclusion

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X-Lap | Evaluation scope

X-Lap Application Transport protocol Operating system Channel

Evaluation focus

▶ PRRT ▶ Interaction with OS

Future work

▶ Application delays ▶ Network transmission time

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PRRT | Results: Packet Trace

20 40 60 80 Time [us] EndToEnd SenderTotal Send Submit SenderIPC Enqueue SenderEnqueued PrrtTransmit LinkTransmit ReceiverTotal HandlePacket ReceiverIPC Feedback

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PRRT | Results: Trace Jitter

20 40 60 80 100 Time [us] EndToEnd SenderTotal Send Submit SenderIPC Enqueue SenderEnqueued PrrtTransmit LinkTransmit ReceiverTotal HandlePacket ReceiverIPC Feedback

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PRRT | Results: Outliers

R e c e i v e r I P C H a n d l e P a c k e t S e n d e r E n q u e u e d P r r t T r a n s m i t S e n d e r I P C L i n k T r a n s m i t F e e d b a c k D e c

  • d

i n g E n q u e u e S e n d S u b m i t 10 20 30 40 Frequency

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PRRT | Results: Correlation SenderTotal

20 40 60 80 100 SenderTotal [us] 40 60 80 100 120 140 EndToEnd [us]

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PRRT | Results: Correlation ReceiverIPC

5 10 15 20 25 ReceiverIPC [us] 40 60 80 100 120 140 EndToEnd [us]

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Outline

Introduction X-Lap PRRT Evaluation Conclusion

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Conclusion X-Lap

▶ Cross-layer, inter-host timing analysis tool ▶ Evaluation of real-time network protocols

PRRT Analysis

Sender Receiver Network-related Latency PrrtTransmit SendFeedback LinkTransmit Jitter SenderEnqueue ReceiverIPC LinkTransmit Source Code available at: → http://xlap.larn.systems Thank you for your attention. Questions?

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Conclusion X-Lap

▶ Cross-layer, inter-host timing analysis tool ▶ Evaluation of real-time network protocols

PRRT Analysis

Sender Receiver Network-related Latency PrrtTransmit SendFeedback LinkTransmit Jitter SenderEnqueue ReceiverIPC LinkTransmit Source Code available at: → http://xlap.larn.systems Thank you for your attention. Questions?

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