Deterministic Ethernet - TTEthernet
0 likes1,699 views
Deterministic Ethernet is an advanced communication method designed to provide varying levels of determinism from packet-switching technology, addressing the needs of critical embedded system applications. Features include time-triggered extensions, fault-tolerant synchronization, and capabilities for synchronous real-time communication. These improvements enable reliable performance and lower latency while accommodating both hard real-time and standard applications on the same network.
Deterministic Ethernet - TTEthernet
- 1. Deterministic Ethernet & System Integration Mirko Jakovljevic products@tttech.com www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 1
- 2. Deterministic Ethernet Deterministic communication in Ethernet? • Ethernet is a packet-switching technology (best-effort communication) • Can be more or less deterministic (priorities and traffic classes for data streams) The determinism is a spectrum! Ethernet Today „indeterministic“ „more deterministic“ „very deterministic“ „strictly deterministic“ Strictly deterministic = circuit-switching only? www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 2
- 3. More / Very Deterministic More Deterministic • improved chance high-priority data is delivered within specified time Very Deterministic • defined end-to-end latency (or frame dropped) • Many trade-offs (latency/jitter vs. bandwidth) • Assumption: overprovisioning (max. 5-15% of bandwidth really used) Sh TD Et Ful ap M Et M o Ha h l Pa ing D + Et lf- du wi ern -du we c / he pl th et ple ll- ket Poli (e he ve rn ex Pr Sw x tra un Dr cin m et tra iori itc ffi der op g/ ul a rn r Bu s ffi tize h c d c p st , ro oo sw tion itc of et fil d hi ci e ing irc ) ui t „indeterministic“ „more deterministic“ „very deterministic“ „strictly deterministic“ www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 3
- 4. Deterministic Ethernet www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 4
- 5. TTEthernet and Determinism Strict determinism can be defined as full control of timing/jitter in a system Synchronous & asynchronous communication via Ethernet Packet sent just-in-time Receiver knows exact packet arrival time packet Eth NIC packet Eth T1 NIC Switch knows exact packet T1 Switch knows forwarding (M +De in fi La imiz ned exact packet time forwarding time ten ed cy ) Synchronous (TDMA-style) Communication www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 5
- 6. Extensions & Standard Ethernet Time-triggered extensions on the top of standard switched Gigabit-Ethernet • Startup Application • Recovery Layer • Robust fault-tolerant distributed clock 3-7 Core TTEthernet services Time-Triggered Extension Ethernet IEEE 802.3 Makes Ethernet viable for any critical embedded system application www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 6
- 7. TTEthernet Standard www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 7
- 8. Priority-based Synchronous www.tttech.com Asynchronous Ethernet Traffic (TDM) Traffic Best-Effort (BE) Rate- Ethernet Traffic Constrained (RC) Traffic TTEthernet Capabilities Copyright © TTTech Computertechnik AG. All rights reserved. Page 8
- 9. Priority-based Synchronous www.tttech.com Asynchronous Ethernet Traffic (TDM) Traffic Rate- Best-Effort (BE) Constrained Ethernet Traffic (RC) Traffic TTEthernet Capabilities Copyright © TTTech Computertechnik AG. All rights reserved. Page 9
- 10. Time-Triggered Services in TTEthernet Time-triggered services (SAE AS6802) add: • Distributed fault-tolerant synchronization • Continuous time service in case of multiple system faults; no master clock; formally verified • Synchronous hard real-time communication (audio/video/hard RT controls) • Robust TDMA-style bandwidth partitioning • Enables parallel low-latency/lossless/hard RT and standard LAN applications in one network www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 10
- 11. TTEthernet, a Communication Infrastructure Highlight: Fault Tolerance and Incorporated Redundancy E E E TT TT TT TT E E TT E TTE TT TT 0E E TT TT TT E TT E E E TT E TT TT TT E E E TT E TT E TT E TT E TT E TT E E TT TT www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 11
- 12. www.tttech.com www.tttech.com Copyright © TTTech Computertechnik AG. All rights reserved. Page 15