Phase Delivery Over PTP Unaware Networks
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The document discusses challenges related to phase delivery in existing brownfield network deployments, highlighting issues such as asymmetry and packet delay variation (PDV). It presents solutions for improving phase delivery, specifically proposing to position the grand master closer to slave devices and utilizing various standards such as G.8275.1 and G.8275.2 for effective last-mile delivery. Additionally, the document emphasizes the importance of conducting sync surveys and utilizing quality of service (QoS) measures to mitigate PDV and asymmetry in network elements unaware of Precision Time Protocol (PTP).
Phase Delivery Over PTP Unaware Networks
- 1. Nir Laufer , Director Product Line Management ITSF 2015 Phase Delivery over PTP Unaware Networks
- 2. © 2014 ADVA Optical Networking. All rights reserved. Confidential.2 Phase Delivery Challenges in Brownfield Deployments • Existing network introduce high level of asymmetry and PDV • The asymmetry and PDV varies over time • Existing networks include different transport technologies • Upgrading/forklifting the existing NE to Sync-E/BC is very costly Do we really need frequency and phase in the core network?
- 3. © 2014 ADVA Optical Networking. All rights reserved. Confidential.3 Bypass the problem: Get the Grand Master closer to the Slave Core/Mobile Backhaul Provider Mobile Network Operator High PDV/ Asymmetry PTP Slave Clock Slave 4G Base Station / Small Cell Grand Master GNSS The Solution
- 4. © 2014 ADVA Optical Networking. All rights reserved. Confidential.4 Grand Master GNSS Core/Mobile Backhaul Provider Mobile Network Operator High PDV/ Asymmetry PTP Slave Clock Slave 4G Base Station / Small Cell Packet-Based Backhaul Network Grand Master GNSS Bypass the problem: Get the Grand Master closer to the Slave The Solution
- 5. © 2014 ADVA Optical Networking. All rights reserved. Confidential.5 Phase Delivery: Small Scale GM & G.8275.1 – Last Mile • G.8275.1 – Uses hop by hop , Ethernet multicast mini-GM Local Macro Base Station GNSS T-SC Core/Mobile Backhaul Provider Mobile Network Operator High PDV/ Asymmetry Packet-Based Backhaul Network PTP Slave Clock Slave Each network element needs to be PTP-aware (T-BC) with Sync-E BC & Sync-E BC & Sync-E BC & Sync-E 4G Base Station / Small Cell 16ppb & +/-1.1us Ethernet Multicast G.8275.1 Last mile full on path support Small Scale GM as a head of G.8275.1 chain
- 6. © 2014 ADVA Optical Networking. All rights reserved. Confidential.6 Phase Delivery: Small Scale GM & G.8275.2 – Last Mile • G.8275.2 – Uses IP unicast for phase delivery over last mile mini-GM Local Macro Base Station GNSS T-SC Core/Mobile Backhaul Provider Mobile Network Operator High PDV/ Asymmetry Packet-Based Backhaul Network PTP Slave Clock Slave 4G Base Station / Small Cell 16ppb & +/-1.1us G.8275.2 Small Scale GM as a head of G.8275.2 chain ? Slave Slave
- 7. © 2014 ADVA Optical Networking. All rights reserved. Confidential.7 PDV of a single NE • Single congestion point Two types of traffic loads have been considered: • Case A: The size of the data traffic packets was variable, from 64 bytes to 1518 bytes • Case B: All the data traffic packets have a 1518 bytes fixed size Source - France Télécom Orange
- 8. © 2014 ADVA Optical Networking. All rights reserved. Confidential.8 PDV of a single NE – Case A 1Gbps, variable size data traffic: Source - France Télécom Orange
- 9. © 2014 ADVA Optical Networking. All rights reserved. Confidential.9 PDV of a single NE – Case B 1Gbps, 1518 bytes data traffic: : Source - France Télécom Orange
- 10. © 2014 ADVA Optical Networking. All rights reserved. Confidential.10 Setup #1 Tester Traffic Analyzer DUT #1 DUT #2 PTP flow Disturbance traffic PTP GM PTP TS & Probe Clk+1pps pps Reference PRTC GPS splitter pps Traffic Generator Congestion point
- 11. © 2014 ADVA Optical Networking. All rights reserved. Confidential.11 Test 1: G.8261 Traffic model #1 • Single Congestion , VLAN Priority • PTP - 64 packets per second (on both directions) • Single congestion point (on forward) • Forward load traffic (no load on reverse direction) • 80% -minimum size packets (64 octets) • 15% - maximum size packets (1518 octets) • 5% - medium size packets (576 octets)
- 12. © 2014 ADVA Optical Networking. All rights reserved. Confidential.12 Test #1 - Forward & Reverse Filtered Packet TIE (Tester) • Window size – 200 sec , 0.3% 100% 90% 80%70%60%50%40%30%20%10% 800400TIE(nsec)
- 13. © 2014 ADVA Optical Networking. All rights reserved. Confidential.13 Test #1 – Probe Measured Forward Delay • Window size – 5sec , Lucky packet 10%-100% 100%-10% 25265 TE(nsec) 26505
- 14. © 2014 ADVA Optical Networking. All rights reserved. Confidential.14 Test #1 – Probe Measured Reverse Delay • Window size – 5sec , Lucky packet 10%-100% (Fr) 100%-10% (Fr) 25308TE(nsec)25612
- 15. © 2014 ADVA Optical Networking. All rights reserved. Confidential.15 Test #1 – Probe Measured Asymmetry • Window size – 5sec , Lucky packet 10%-100% 100%-10% -370 TE(nsec) 296
- 16. © 2014 ADVA Optical Networking. All rights reserved. Confidential.16 Test #1 – 1PPS TE (Tester) • Time Error within +/- 150nsec – well within +/- 1100nsec -150 100 TE(nsec)
- 17. © 2014 ADVA Optical Networking. All rights reserved. Confidential.17 Test #1 – 1PPS TE Probe Vs ref PRTC • Time Error within +/- 150nsec – well within +/- 1100nsec -196 TE(nsec) 56
- 18. © 2014 ADVA Optical Networking. All rights reserved. Confidential.18 Test #1 – 1PPS MTIE (Tester) • MTIE well under G.8271.1 network limits mask
- 19. © 2014 ADVA Optical Networking. All rights reserved. Confidential.19 Test #1 – 1PPS MTIE Probe Vs Ref PRTC • MTIE well under G.823 pdh mask
- 20. © 2014 ADVA Optical Networking. All rights reserved. Confidential.20 • Single Congestion , VLAN Priority • PTP - 64 packets per second (on both directions) • Single congestion point (on forward) • Forward load traffic (no load on reverse direction) • 30% -minimum size packets (64 octets) • 60% - maximum size packets (1518 octets) • 10% - medium size packets (576 octets) Test 2: G.8261 Traffic model #2
- 21. © 2014 ADVA Optical Networking. All rights reserved. Confidential.21 Test #2 - Forward & Reverse Filtered Packet TIE (Tester) • Window size – 200 sec , 0.3% 100% 90% 80%70%60%50%40%30%20%10% 630720 TIE(nsec) 360
- 22. © 2014 ADVA Optical Networking. All rights reserved. Confidential.22 Test #2 – 1PPS TE (Tester) • Time Error within +/- 200nsec – well within +/- 1100nsec 60 TE(nsec)-180
- 23. © 2014 ADVA Optical Networking. All rights reserved. Confidential.23 Test #2 – 1PPS MTIE (Tester) • MTIE well under G.8271.1 network limits mask
- 24. © 2014 ADVA Optical Networking. All rights reserved. Confidential.24 Setup #2 Tester Traffic Analyzer DUT #1 DUT #2 PTP flow Disturbance traffic PTP GM PTP TS & Probe Clk+1pps pps Reference PRTC GPS splitter pps Traffic Generator Congestion point DUT #3
- 25. © 2014 ADVA Optical Networking. All rights reserved. Confidential.25 Test 3: G.8261 Traffic model #1 • Two Congestion points , VLAN Priority • PTP - 64 packets per second (on both directions) • Single congestion point (on forward) • Forward load traffic (no load on reverse direction) • 60% -minimum size packets (64 octets) • 15% - maximum size packets (1518 octets) • 5% - medium size packets (576 octets)
- 26. © 2014 ADVA Optical Networking. All rights reserved. Confidential.26 Test #3 - Forward & Reverse Filtered Packet TIE (Tester) • Window size – 200 sec , 0.3% 100% 90% 80%70%60%50%40%30%20%10% 200012000 TIE(nsec) 8000
- 27. © 2014 ADVA Optical Networking. All rights reserved. Confidential.27 Test #3 – 1PPS TE (Tester) • Time Error within +/- 250nsec – well within +/- 1100nsec -60 240 TE(nsec) 6000
- 28. © 2014 ADVA Optical Networking. All rights reserved. Confidential.28 Test #3 – 1PPS MTIE (Tester) • MTIE well under G.8271.1 network limits mask
- 29. © 2014 ADVA Optical Networking. All rights reserved. Confidential.29 Other Access Technologies • WDM/GPON/DSLAM/MW tend to include high level of PDV & Asymmetry • In most cases would require on path support (BC/TC) in order to deliver accurate phase • Highly dependent on the vendor implementation – Sync Survey is recommended mini-GM GNSS Core/Mobile Backhaul Provider Mobile Network Operator High PDV/ Asymmetry Slave MW+TC Slave Slave BC/TC
- 30. © 2014 ADVA Optical Networking. All rights reserved. Confidential.30 GPON • GPON G.984.3 include mechanism for Time of Day distribution over G-PON – interworking with PTP is still being developed but some proprietary solutions are already proposed • Very accurate phase delivery can be achieved mini-GM GNSS Slave Probe Time Error below 500 nsec GNSS
- 31. © 2014 ADVA Optical Networking. All rights reserved. Confidential.31 Microwave • Highly dependent on the MW implementation • PTP should be assigned to the highest QoS flow – can help reduce asymmetry and PDV caused by adaptive modulation • Proprietary BC/TC implementations are available GPS Transport unit Transport unit PTP Slave & Probe Grand Master GPS Network asymmetry of 14usec over single MW hop Vendor A
- 32. © 2014 ADVA Optical Networking. All rights reserved. Confidential.32 Microwave –Cont GPS Transport unit Transport unit PTP Slave & Probe Grand Master GPS Vendor B Slave recovered clock within +/-250nsec
- 33. © 2014 ADVA Optical Networking. All rights reserved. Confidential.33 Phase Delivery over PTP unaware networks • Phase delivery over PTP unaware network elements is possible with the following network engineering guidelines: • Conduct Sync Survey - Test your access network elements PDV and asymmetry under realistic load scenario • Use QoS to prioritize PTP packets • Avoid speed mismatch (or compensate for known asymmetry generated by the mismatch) • Avoid network traffic utilization above 90% • If needed , use PTP aware network element for access technologies (MW/WDM/DSLAM/GPON)
- 34. Nlaufer@advaoptical.com Questions? Thank you! IMPORTANT NOTICE The content of this presentation is strictly confidential. ADVA Optical Networking is the exclusive owner or licensee of the content, material, and information in this presentation. Any reproduction, publication or reprint, in whole or in part, is strictly prohibited. The information in this presentation may not be accurate, complete or up to date, and is provided without warranties or representations of any kind, either express or implied. ADVA Optical Networking shall not be responsible for and disclaims any liability for any loss or damages, including without limitation, direct, indirect, incidental, consequential and special damages, alleged to have been caused by or in connection with using and/or relying on the information contained in this presentation. Copyright © for the entire content of this presentation: ADVA Optical Networking.