Power Matters
Comparison of On-path Support to Other Methods for Precision Timing Protocol Adam Wertheimer Microsemi Corporation +1-613-270-7235 [email protected]
© 2013 Microsemi Corporation 1
Power Matters.
Delivery of Frequency via Synchronous Ethernet Methods for delivering phase
• Phase over Unaware networks • Phase over Partially aware network • Phase over Aware networks Comparison of results using different methods
Introduction
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Power Matters.
Fully approved in ITU-T G.8262 Advantages
• Synchronous Ethernet extends the SONET/SDH timing model to Ethernet
• Meets all existing frequency requirements via the bit rate of the Ethernet physical layer – Independent of packets and loading
Disadvantages • Need to upgrade Ethernet equipment in the Ethernet packet chain to
support SyncE • Need unbroken chain of SyncE equipment from frequency source to
end application – May use SONET or PDH to add timing to Ethernet at some intermediate
point in the network (i.e. at egress from SONET over packet network to Ethernet network)
Use case – SyncE for frequency distribution
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Power Matters.
SyncE Syntonization
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BITS/SSU PRS/PRC
G.812 Type I SSU
G.811 PRC
G.8262 EEC
Option 1 End
Application
End Application
Transition from Frequency to Frequency and Phase
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Power Matters.
Aware • Addition of Boundary clock at each node in the network
– According to ITU model current under study • Split up the network in to smaller pieces • Needed for end-to-end time of day performance
Terminology: Aware networks
6
From IEEE Std 1588-2008 page 32
© 2013 Microsemi Corporation
Power Matters.
Unaware networks • No processing of the PTP packets at intermediate nodes by Boundary
Clocks Partially Aware
• Some Boundary Clocks in the network but not at every node • May be needed for existing networks during transition • May allow phase transfer without upgrading all network elements in
network Aware Networks
• All nodes in the network have Boundary Clocks
Terminology: Network Types
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Power Matters.
Network Types
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Unaware
Partially Aware
Aware
Power Matters.
Unaware No On-Path Support
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Telecom Slave /BC (IEEE1588)
PRS/PRC
PRTC
IEEE1588 Server
G.8272 PRTC
G.8273.1 PTM T-GM
G.812 Type I SSU
G.811 PRC
G.8262 EEC
Option 1
“G.82xx” PEC-B
BITS/SSU
Power Matters.
Test Setup
10
1PPS
IP Traffic
Scope
sync, delay_resp delay_req
Grand Master
GPS
Ext. Ref
Network Emulator
5 or 10 GE Switches
1PPS
Slave
IP Traffic
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Power Matters.
Results – 5 switch network
5 Gigabit Ethernet switch network Passed frequency mask for DS1 and E1 network
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Test Case Traffic Model Phase (30 min from start-up)
Minimum [ns]
Maximum [ns]
Absolute [ns]
TC12 - Static TM2 -92 5 92
TC13 – Square (50min from start)
TM2 -220 90 220
TC13 – Square (70min from start)
TM2 -180 102 180
TC14 - Ramp TM2 -140 30 140
TC15 - Outage 10 & 100 s.
TM2 -62 25 62
TC16 - Cong. 10 & 100 s.
TM2 -52 -5 52
TC17 – Re-route 3 Sw 200us.
TM2 -65 63 65
Power Matters.
Results – 10 switch network
10 Gigabit Ethernet switch network Passed frequency mask for DS1 and E1 network
© 2013 Microsemi Corporation 12
Test Case Traffic Model Phase (30 min from start-up)
Minimum [ns]
Maximum [ns]
Absolute [ns]
TC12 - Static TM2 -220 +150 220
TC13 – Square (50min from start)
TM2 -200 +285 285
TC13 – Square (70min from start)
TM2 -330 +280 330
TC14 - Ramp TM2 165 +265 265
TC15 - Outage 10 & 100 s.
TM2 165 +232 232
TC16 - Cong. 10 & 100 s.
TM2 115 +260 260
TC17 – Re-route 3 Sw 200us.
TM2 190 +285 285
Power Matters.
Network Types
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Unaware
Partially Aware
Aware
Power Matters.
Currently under study in standards Too many network types and configurations Need unaware phase profile May be possible in a managed network
• Single carrier with careful engineering of link utilization and routing
Use case Phase over Partially aware networks
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Power Matters.
Partially Aware Network Partial On-Path Support without SyncE Syntonization
15 © 2013 Microsemi Corporation
Telecom Slave /BC (IEEE1588)
PRS/PRC
PRTC
IEEE1588 Server
G.8272 PRTC
G.8273.1 PTM T-GM
G.812 Type I SSU
G.811 PRC
G.8262 EEC
Option 1
“G.82xx” PEC-B
BITS/SSU
BC (optional)
Power Matters.
Test Setup
16
1PPS
IP Traffic IP Traffic
1PPS
Scope
sync, delay_resp delay_req
Grand Master Modified BC
GPS
Ext. Ref
Network Emulator
10 GE Switches
sync, delay_resp delay_req
Ext. Ref
Network Emulator
10 GE Switches IP Traffic
1PPS
Slave
IP Traffic
© 2013 Microsemi Corporation
64/16 64/16
Power Matters.
Results - Frequency
Passed frequency mask for DS1 and E1 network
Test Case Traffic Model ITU-T G.8261 PEC Deployment Case 2
ITU-T PEC Deployment Case 1 / EEC Option 1 / ITU-T G.823 SEC
G.823 Traffic CES MTIE TDEV
BC: TC12 – TC17 TM2
Slave: TC12 – TC17 TM2
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Test Case Traffic Model
ITU-T G.8261 PEC Deployment Case 2 G.824
DS1
G.824 Traffic (TDEV) G.824 Traffic CES
BC: TC12 – TC17 TM2
Slave: TC12 – TC17 TM2
Power Matters.
Results - Phase
Passed phase mask of 1 microsecond over the 20 switch network Network: 10 GE switches – modified BC – 10 GE switches Used combined PDV file with 7 test cases
© 2013 Microsemi Corporation 18
Test Case Traffic Model
Phase
Min Max Abs
BC: TC12 – TC17 TM2 -550 ns 334 ns 550 ns
Slave: TC12 – TC17* TM2 -939 ns 297 ns 939 ns
Power Matters.
Partially Aware Network Partial On-Path Support with SyncE Syntonization
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Telecom Slave Clock (IEEE1588 & SyncE)
PRS/PRC
PRTC
IEEE1588 Server
G.8272 PRTC
G.8273.1 PTM T-GM
G.812 Type I SSU
G.811 PRC
G.8262 EEC
Option 1
“G.82xx” PEC-B
BITS/SSU
BC (optional)
Power Matters.
Network Types
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Unaware
Partially Aware
Aware
Power Matters.
Aware Network Full On-Path Support without SyncE Syntonization
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G.8272 PRTC
G.8273.1 PTM T-GM
G.8273.2 T-BC
G.811 PRC
G.8262 EEC
Option 1
G.8273.4 T-TSC
PRTC
IEEE1588 Server Telecom Slave Clock
(IEEE1588)
PRS/PRC BITS/SSU
Power Matters.
Test Setup
Master, 10 Boundary Clock nodes, Slave Expect phase alignment of 150-200 ns
• Based on noise accumulation along the chain at 16/16
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1588 CLK & PPS (measure)
T-BC #10
S M
T-BC #9
S M
T-BC #8
S M
T-BC #7
S M
T-BC #6
S M
T-BC #5
S M
T-BC #4
S M
T-BC #3
S M
T-BC #2
S M
T-BC #1
S M
T-GM #0
M
PRTC (GPS or Rb)
T-TSC #11
S
1000 Mbps Copper
IEEE 1588 Time Domain
SyncE Frequency Domain
1588 CLK & PPS (measure)
Power Matters.
Aware Network Full On-Path Support with SyncE Syntonization
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G.8272 PRTC
G.8273.1 PTM T-GM
G.8273.2 T-BC
G.811 PRC
G.8262 EEC
Option 1
G.8273.4 T-TSC
PRTC
IEEE1588 Server Telecom Slave Clock
(IEEE1588 & SyncE)
PRS/PRC BITS/SSU
Power Matters.
Test Setup/Results
Master, 10 Boundary Clock nodes, Slave • SyncE distribution reference chain Phase (at slave)
• FFO < +/- 3 ppb • MTIE < 30 ns • Time Error < 70 ns
– Note: Packet rate of 16/16
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1588 CLK & PPS (measure)
T-BC #10
S M
T-BC #9
S M
T-BC #8
S M
T-BC #7
S M
T-BC #6
S M
T-BC #5
S M
T-BC #4
S M
T-BC #3
S M
T-BC #2
S M
T-BC #1
S M
T-GM #0
M
PRTC (GPS or Rb)
T-TSC #11
S
1000 Mbps Copper
IEEE 1588 Time Domain PRC/ PRS (Rb) SyncE Frequency Domain
SyncE Clock
(measure)
1588 CLK & PPS (measure)
SyncE Clock
(measure)
Generic Switch/Router
Clock Filtering
Ethernet/IPSyncE/SONET/SDH
Line Cards
Ethernet/IPSyncE/SONET/SDH
Line Cards
Telecom-BCG.8273.2
L2/L3 Sync Network
L1 SyncNewtork
SyncE/SONET/SDHLine Card
Recovered Clock
Ethernet/IPLine Card
With MAC/PHY TImestamping
Ingress Packets /
Timestamps
EECG.8262
Ethernet/IPSyncE/SONET/SDH
Line Cards
L1 SyncNetwork
L2/L3 Sync Network1588 Clock
1588 PPS
SyncE Clock
L1 SyncNetwork
L2/L3 Sync Network
FilteredSyncEClock
1588 ToD
Power Matters.
Summary
© 2013 Microsemi Corporation 25
Phase transfer results for various networks as shown in this presentation The use of aware network with SyncE support give the best
performance The use of SyncE provides improvement in the partially
aware case SyncE and IEEE-1588 together gives the best performance
Phase transfer (ns) Partially Aware Aware
No SyncE Support Good Better
With SyncE Support Good Best