Check out Nir Laufer's guidelines on making phase delivery possible 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.