Field Measurement Options for Network Operators
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The document discusses field measurement options for network operators to monitor synchronization. It describes how synchronization probes can be used to monitor slave clocks, boundary clocks, and the network by measuring time error, time interval error, and mean time interval error. Probes can monitor clocks and network paths passively by tapping signals or actively by exchanging precision time protocol messages. This allows operators to ensure synchronization quality and detect any issues to help meet new stringent time and phase requirements for next generation networks.
Field Measurement Options for Network Operators
- 1. Field Measurement Options for Network Operators Nir Laufer , ITSF 2013, Lisbon Portugal
- 2. Agenda • New Requirements – New Challenges • Sync SLA – Examples • Probing Slave Clock • Probing Boundary Clock • Probing the Network • Summary 2 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 3. New Requirement – New Challenges! Time/Phase requirement for NGN are much more stringent! • Frequency G.8261.1 Phase G.8271 16ppb +/- 1.5/1.1usec Even if all phase error is allocated to wander (no static phase error) , MTIE can’t exceed 3 usec 3 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 4. Why is „In Service“ Sync Assurance is Needed ? • Ensuring synchronization is working as designed is not a trivial task • Network PDV, asymmetry and environmental conditions can effect the synchronization quality • Some way to ensure proper synchronization should be integrated into Sync distribution/delivery functions or accompanied by cost effective Sync assurance tools • Lab test equipment is too expansive for “in service” installation in multiple locations • Other aspects such as power consumption and OSS should also be taken into consideration 4 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 5. Example #1 - Partitioning across Multiple Administrative Domains (G.8275 Appendix I) • Operators may purchase service from other operators in order to provide access to remote equipment or networks. • A boundary clock can be used to ensure a clean hand-off point to the second network operator. PRTC time reference, Tin GM BC Packet Slave Clock Tout + 1 test point Network Operator 1 Tout + Network Operator 2 Sync Probe Service Demarcation Boundary 5 © 2013 ADVA Optical Networking. All rights reserved. Confidential. 2 Network Operator 1 Sync Probe Service Demarcation Boundary
- 6. Example #2 - G.8271.1 Network Limits • Maximum absolute time error network limit applicable at the reference point C: max |TE| ≤ 1100 ns |TE|<1100nsec 6 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 7. Example #2 - G.8271.1 Network Limits Deployment Case 1 • Option A - Via 1PPS Physical Signal GPS Antenna Sync Probe • Option B - from the two-way PTP flow via a Passive PTP Probe Delay compensation (X) Sync Probe Tcombined_error ≈ (TM2 – T1 – T4 + TM3)/2 7 © 2013 ADVA Optical Networking. All rights reserved. Confidential. GPS Antenna
- 8. Example #2 - G.8271.1 Network Limits Deployment Case 1 – Option C • Option C- From the two-way PTP flow via an Active PTP Probe Sync Probe Tcombined_error ≈ (T2 – T1 – T4 + T3)/2 GPS Antenna 8 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 9. Example #3 - G.8261.1 Network Limit HMR1 150 usec • FPP : For any window interval of 200 seconds at least 1% of transmitted timing packets will be received within a fixed cluster, starting at the observed floor delay, and having a range of 150 µs (G.8260 floor delay packet population). 200s 9 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 10. Probing and Monitoring Slave Clock
- 11. Probing Slave Clock PRC/PRTC RNC RNC Slave Clock 11 Boundary Clock Transparent Clock Boundary Clock © 2013 ADVA Optical Networking. All rights reserved. Confidential. Grand Master
- 12. Probing Third Party Slave Clock Slave 1PPS and clock outputs can be monitored Vs. GPS/external reference Time Error , TIE and MTIE can be calculated and compared against target performance masks / metrics CLK TIE and 1PPS Time Error T-GM T1 T4 T3 Network T1 T4 Slave Clock T3 10MHz/BITS/Sync-E 1PPS GPS CLK and 1PPS MTIE Sync Probe (DUT) 12 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 13. Probing a Third Party Slave Clock • Probing the Slave Clock – Passive Probing • • • A Sync Probe is placed at a calibrated distance from the Slave Clock (system under test) The Sync Probe functions as passive PTP probe (fiber tapping or mirroring switch) The Sync Probe measure packet TE/TIE/MTIE of the tapped Slave port against a reference measurement timing signal Packet Time Error T-GM T1 T3 T4 Network Packet MTIE T3 T1 T4 Slave Clock (DUT) 13 GPS T3 Sync Probe © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 14. Slave Clock Self Monitoring The probing functions are integrated into the slave clock which deliver clock to the end application internal 1PPS and clock recovered from PTP can be self monitored Vs GPS/external reference as well as T3 generated by Slave Clock CLK TIE and 1PPS Time Error T-GM T1 T4 Network T1 T4 T3 Sync Probe + Slave Clock 14 CLK and 1PPS MTIE GPS 10MHz/BITS/Sync-E 1PPS © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 15. Probing and Monitoring Boundary Clock
- 16. Probing Boundary Clock PRC/PRTC RNC RNC Slave Clock 16 Boundary Clock Transparent Clock Boundary Clock © 2013 ADVA Optical Networking. All rights reserved. Confidential. Grand Master
- 17. Probing Third Party Boundary Clock A Sync Probe is used for assurance of third party Boundary Clock Boundary Clock 1PPS and clock outputs can be monitored Vs. GPS reference CLK TIE and 1PPS Time Error T-GM T1 T4 T3 GPS 10MHz/BITS/Sync-E Boundary Clock 1PPS (DUT) T1 T4 Sync Probe T3 Slave Clock 17 © 2013 ADVA Optical Networking. All rights reserved. Confidential. CLK and 1PPS MTIE
- 18. Boundary Clock Self Monitoring The probing functions are integrated into the Boundary Clock The internal BC 1PPS and clock recovered from PTP can be self monitored simultaneously CLK TIE and 1PPS Time Error T-GM T1 T4 T3 GPS Sync Probe + Boundary Clock T1 T4 10MHz/BITS/Sync-E 1PPS CLK and 1PPS MTIE T3 Slave Clock 18 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 19. Probing a Third Party Boundary Clock • Probing the Master side of a Boundary Clock – Active Probing • • The Sync Probe is placed at a calibrated distance from the Master port of an Third Party Boundary Clock (system under test) The Sync Probe functions as active probe GPS T-GM T1 T4 T3 T1 T4 Boundary Clock 10MHz/BITS/Sync-E (DUT) T4 Slave Clock 19 Sync Probe T3 T1 CLK TIE ,1PPS TE & Packet TE T3 CLK ,1PPS MTIE & Packet MTIE 1PPS Active Probing of PTP timing signal can combined with probing of 1PPS /CLK physical signals © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 20. Probing a Third Party Boundary Clock • Probing the Master/Slave side of a Boundary Clock – Passive Probing • • • The Sync Probe is placed at a calibrated distance from the Master/Slave port of a Third Party Boundary Clock (system under test) The Sync Probe functions as passive PTP probe (fiber tapping or mirroring switch) The Probe measure packet TE/TIE/MTIE of the tapped Master port against a reference measurement timing signal Packet Time Error T-GM T1 T3 T3 T4 GPS Boundary Clock Sync Probe T1 (DUT) T1 T4 T3 Slave Clock 20 © 2013 ADVA Optical Networking. All rights reserved. Confidential. Packet MTIE
- 21. Self Monitoring Network No GPS or external reference is needed! Each BC can compare next hope recovered clock Vs. his own recovered clock by compering T3 received form next hop against his own recovered clock which is used as reference. T-GM Packet Time Error T3 T1 T4 Sync Probe +BC SP-100 T1 T4 T3 Slave Clock (DUT) 21 © 2013 ADVA Optical Networking. All rights reserved. Confidential. Packet MTIE
- 22. Probing and Monitoring the Network
- 23. Probing the Network PRC/PRTC RNC RNC Slave Clock 23 Boundary Clock Network Boundary Clock © 2013 ADVA Optical Networking. All rights reserved. Confidential. Grand Master
- 24. Probing the Network • A Sync Probe can be used for testing the network connecting the master and Slave/BC Collect statistical information about the network (PDV, packet loss…) and can decide on network usability and KPI • Packet Counters (arrived, lost) • PD (Path Delay) , MPD (Mean Path Delay) ,Asymmetry • Network Usability (i.e. based on G.8261.1 FPP) Calculate PM statistics (i.e. 15min ,24hours) and TCAs in order to validate Sync SLA performance T-GM 24 ? © 2013 ADVA Optical Networking. All rights reserved. Confidential. BC/SC
- 25. PTP Network Active Probe Active Probe uses the internal Telecom slave packets exchanged The Sync Probe can probe the network and recover the clock simultaneously PTP network Probe Statistics and Usability Score T-GM T1 T4 Network (DUT) T1 T4 T3 GPS Sync Probe + Slave Clock 25 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 26. PTP Network Passive Probe Passive probe tap packet exchanged between master third party slave / boundary clock PTP network Probe Statistics and Usability Score T-GM T1 T3 T4 Network (DUT) GPS T1 T4 Slave Clock 26 T3 Sync Probe © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 27. Simultaneous Testing Simultaneously probing of the clock and the network can help in troubleshooting problems PTP network Probe Statistics and Usability Score T-GM T1 T4 CLK TIE ,1PPS TE & Packet TE T3 Network (DUT) GPS T1 CLK ,1PPS MTIE & Packet MTIE T3 T4 Slave Clock 10MHz/BITS/Sync-E (DUT) Sync Probe 1PPS 27 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 28. Summary • Time/Phase requirements for NGN are stringent • In services probing is needed in order to ensure proper synchronization • Monitoring the accuracy of the synchronization delivered is possible using Sync Probes which can be used for monitoring the clocks and/or the network FSP150 SP-100 28 © 2013 ADVA Optical Networking. All rights reserved. Confidential.
- 29. Thank you [email protected] 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.
Editor's Notes
- #5: Synchronization is a service which deliver Frequency/Phase/TimeLike other services , ways to monitor , test and analyze the quality of the service are neededClock Accuracy –Frequency ,phase and time accuracy measurement based on physical signals relative to referenceClock Analysis - Frequency and phase analysis based on packet timing signals measured relative to referencePTP Network Analysis - PTP path monitoring / testing
- #12: I think this slide is good however there are a few questions… (some of these are tricky)If there is an FSP 150 can they all provide SyncJack?If there is an FSP 150 would we also need to provide a SyncProbe?Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?
- #17: I think this slide is good however there are a few questions… (some of these are tricky)If there is an FSP 150 can they all provide SyncJack?If there is an FSP 150 would we also need to provide a SyncProbe?Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?
- #24: I think this slide is good however there are a few questions… (some of these are tricky)If there is an FSP 150 can they all provide SyncJack?If there is an FSP 150 would we also need to provide a SyncProbe?Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?