Synchronization security -Planning a robust timing ......G.8275.x PTP telecom profiles Profile...
Transcript of Synchronization security -Planning a robust timing ......G.8275.x PTP telecom profiles Profile...
Synchronization security - Planning a robust timing distribution architecture
Agenda
• Timing Standards Overview• PTP Distribution Architectures• Metro and National Phase Delivery Architecture
Structure of ITU-T Sync Requirements
LTE Services ToD/Phase Requirements
Basic Acronyms
• GM – Grand Master• PRC – Primary Reference Clock (Frequency)• ePRC – Enhanced Primary Reference Clock (Frequency)• PRTC – Primary Reference Time Clock (Phase/Time)• ePRTC – Enhanced Primary Reference Time Clock
(Phase/Time) – Clock combainer• BC – Boundary Clock Class A, B, C & D• TC – Transparent Clock
Equipment Clocks - Frequency
• Clocks for Frequency G.8262 Timing characteristics of Synchronous
Ethernet Equipment slave clock (EEC) G.8263 Timing Characteristics of Packet based
Equipment Clocks (PEC) and Packet based Service Clocks (PSC) G.8265.1 Precision time protocol telecom profile for
frequency synchronization.
Equipment Clocks – Time/Phase
• Clocks for Time/Phase G.8272 Primary Reference Timing Clock (PRTC)
specificationG.8272.1 enhanced Primary Reference Timing Clock
(ePRTC) specificationG.8273 Clock General Requirements G.8273.2 Telecom Boundary Clock specification G.8273.4 Timing characteristics of assisted partial timing
support slave clocks.
What is a PRTC (G.8272) ?
• PRTC is a function (not a “box”)• It specifies the performance (max|TE) of timing signal
from UTC to network interface (PTP output) • PRTC-A = +/-100nsec relative to UTC (specified 2012) • PRTC-B = +/-40nsec relative to UTC (value is
provisionally agreed 10-2017)
G.8272.1 ePRTC Functional Model
• Provides for highly accurate time of better than 30ns to UTC in combination with time reference
• Provides robust atomic-clock based time even during extended GNSS outages
• Long time constants can address diurnal effects such as those arising from variation in ionospheric delay of signals from GNSS satellites
“Autonomous primary reference clock” is a key component of the ePRTC
PRTC vs. ePRTC Time Accuracy and Stability
Time Error: <=100ns
MTIE
TDEV
PRTC Time Accuracy
Time StabilityMTIE is G.811 with 100 ns maximumTDEV is G.811 exactly
G.8272
G.8272.1
Time Error: <=30ns
ePRTC Time Accuracy
Time Stability
MTIE below G.8272 with 30 ns maximumTDEV below G.8272 and tau extended
MTIE
TDEV
G.8272.1 ePRTC Time Holdover
• ePRTC: Hold better that 100ns for 14 days of holdover “Class A” (PRTC time holdover not defined)
• ePRTC: Longer holdover under discussion “Class B” (100ns for 80 days under discussion)• ePRTC: The longer the holdover, the better the “autonomous primary reference” required
G.8273.2 High Performance BC Class C & DHigh accuracy (sub‐nano
second) optical time transferLayer 1 (lambda) or Layer 0
(physical) Optical Wave Division layer
(WDM,DWDM or CWDM) Ciena, Cisco, Infinera
High Performance BCSingle Clock Domain
From client to master portsG.8273.2
Class C & D (cTE < 10, Max|TE|low< 5 ns)
OCXO, Rb
Network RequirementsOptical Networks5G, eCPRI, cRAN
TE < +/‐130ns & beyond
Class A = 50nSClass B = 25nSClass C = 15nSClass D = 5nS
G.8275.x PTP telecom profiles
Profile Network Timing Support Transport Domain SyncE
G.8275.1 Full Path Multicast 24‐43 Must
G.8275.2 Partial Path Unicast 44‐63 Optional
PTP Telecom Profiles for Time and Phase synchronization – “Full Timing Support” (G.8275.1) – “Partial Timing Support” (G.8275.2)
PTP DISTRIBUTION NETWORK ARCHITECTURESDifferent architecture – Different performance – Different risk
GNSS Security for PNT Applications
GNSS sourcesGNSS sources
JAMMING, SPOOFING,WEATHER ANOMOLIES,ENVIRONMENT EFFECTS,SATELLITE ERRORS,GROUND STATIONMALFUNCTIONS,OTHERS…
POSITION
NAVIGATION
TIME
SecurePNT
Measurement, Monitoring,Analytics and Visualization
SecureSky
Reception
Atomic Clocks+
Timescale technology
VISIBILITY
DETECTION
RESILIENCY
GPS Spoofing and Jamming Vulnerabilities
• The vulnerability of GPS to interference is not a new phenomenon.
• GPS signals are extremely weak and highly vulnerable to jamming and spoofing resulting in partial or complete loss of GPS signal.
Microsemi BlueSKY GNSS Firewall
Current - Frequency PTP Deployments Typical Illustration
•Each GM has a local GPS•Each Chain considered an Island
•Low risk•Holdover duration 2 weeks
•Moderate Increase in dropped calls during handover between cells
GM
GM
GM
2G/3G/4G
2G/3G/4G
2G/3G/4G
Sync Quality NOT monitored
Simple Migration to Phase example
•Activate Phase at the eNB•While making no changes to the Timing source
•Assume backhaul supports Phase•Extreme High risk
•Holdover duration 15 minutes•Expected Large drop in Capacity , Bandwidth, Subscriber Numbers, Handover etc.
GM
GM
GM
4G/5G
4G/5G
4G/5G
Sync Quality NOT monitored
Simple Protection of Phase example – Protected
• Utilize another GM, deploy over the existing “MPLS” Network Backup PTP using APTS links to Aggregation Grand Masters
• Moderate risk• GM Holdover duration 1 week +
• Single backup Path
GM
GM
GM
5G
5G
5G
GM
Core Site ~10Km GM upgrade to support APTS required
Sync Quality monitored and Reported
PTP Using Assisted Partial Timing Support (APTS)
•APTS PRTC maybe placed at any point on the sync chain•It is expected that most deployment will be at points near to the eNB where the time error budget can be most easily controlled.
PRCFrequency ref
End Equipment
Time Slave Clock
T-SC
GNSS
Packet Network
PTP GM
PTP GM
• Customer A had a good IP network, carried over DWDM– Ran MPLS and syncE did not reach the edge.
• DWDM has large asymmetry– This example, had 27µS
APTS – Core Fed over DWDM Test
• APTS Calibrated the Path
• Provided splendid performance during 5 day test without GPS.
+/‐ 100nS Scale
Simple Protection of Phase – Absolute Accuracy
• Provide dedicated link between each site to make Timing Ring
• Time Quality is now Absolute• Removes all uncertainty of timing quality
• Low risk• Triple protected Phase input at each Aggregation Site.
GM
GM
GM
5G
5G
5G
GM
Same GM Hardware
Sync Quality monitored and Reported
Simple Protection of Phase – Protected with ePRTC
• Add one Caesium at any of the sites
• Share ePRTC with entire region• Provides Timing services, even with GNSS jamming or outage lasting “months”
• Lower risk• Triple backup Path • GNSS Independence
GM
GM
5G
GM
5G
5G
GM
Sync Quality monitored and Reported
Example Protected National Level
City 1
City 2
City 3
City 4
City 5
City 6
City 7
Sync Quality monitored and Reported Nationally
METRO AND NATIONAL PHASE DELIVERY ARCHITECTURE
Absolute accuracy with GNSS independence
High Accuracy Phase Delivery
•5g today requires 1.1uS , Future services will require much greater accuracy.
•GNSS can be expensive to deploy in Metro areas•Protection is needed from Jamming and Spoofing – city wide•ePRTC will provide long Holdover and better alignment to UTC
•Traditional PTP accuracy degrades when mixed with the voice and data traffic
High performance BC for “East-West” Use Case
Geographical RedundancyNo GNSS required in every location – Perfect for Urban
All Devices , are within 50nS of the original PRTC‐B
(Worst Case)
Precise Time from ePRTC or PRTC‐B at each end
Redundant time path for each 4100
Expansion of High Perf BC
Dedicated Dark Fibres, using Bi‐Di SFPFixed Offset is known and removed
Each 4100 is aligned within 5nS of its input
Separating Time from the Traffic ensures time has no variation or
uncertainty
GNSS for Monitoring Only
The only way to engineer a sub 100nS Network with
Redundancy
BlueSKY
ePRTCePRTC
BlueSKY
Architecture Summary• Data networks are excellent at transporting data• When PTP is mixed with voice and Data.. The Time quality is unknown• Sync equipment embedded in Routers and Switches may have drawbacks
– Often change in performance with FW updates.– Often has very low quality oscillator
• Separation of Data and PTP is the only way to be sure of the timing quality• A solution where data and PTP are mixed, is very localised , has uncertainty
– No Network Engineering - More Grand Masters - 1µS solution only• A solution where data and PTP are separate , can be national and is predictable
– Some Network engineering – Fewer Grand Masters - <50nS solution
TP4100 HPBC
TimePictra Monitoring and Management
GPS Receiver
GPS Receiver
TP4100 ePRTC
TimeCesium
TimeProvider 5000
IGM Indoor
IGM Outdoor
GNSS Firewall
GNSS FirewallTimePictra