1、#CiscoLive#CiscoLiveShahid Ajmeri,Sr.Product Manager,Provider Connectivity GroupBRKSPG-3050Network Based TimingSynchronizing 5G Mobile Networks 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveEnter your personal notes hereCisco Webex App Questions?Use Cisco Webex App to ch

2、at with the speaker after the sessionFind this session in the Cisco Live Mobile AppClick“Join the Discussion”Install the Webex App or go directly to the Webex spaceEnter messages/questions in the Webex spaceHowWebex spaces will be moderated by the speaker until June 9,2023.1234https:/ 2023 Cisco and

3、/or its affiliates.All rights reserved.Cisco PublicBRKSPG-30503 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicDisclaimer:Use of the terms“master”and“slave”in this presentation is ONLY in association with the official terminology used in industry specifications and standards(for ex

4、ample IEEE1588,ITU-T SG15/Q13 specifications,eCPRI,ORAN-Alliance and so forth),and in no way diminishes Ciscos commitment to promote diversity,equity,and inclusion.We will be sharing our efforts to remove this language from our products,content and culture at Cisco.If at any point you feel uncomfort

5、able,please feel free to exit the session for a couple of minutes and then rejoin.You can also reach out to us directly with questions,or requests for more information on our approach in a format that works for you.BRKSPG-30504 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoL

6、iveKey AbbreviationsAPTSAssisted Partial Timing Support(a)BMCA(alternate)Best Master Clock AlgorithmCACarrier AggregationCoMPCoordinated Multi-pointcTEConstant Time ErrordTEDynamic Time ErrorEECEthernet Equipment ClockeEECEnhanced EECESMCEthernet Synchronization Message ChanneleSyncEEnhanced SyncEFT

7、SFull Time SupportGNSSGlobal Navigation Satellite SystemMITMMan in the MiddleMTIEMaximum Time Interval ErrorO-CUOpen Centralized UnitO-DUOpen Distributed UnitO-RUOpen Radio UnitPRTCPrimary Reference Time ClockPTPPrecision Time ProtocolPTSPartial Time SupportSyncESynchronous EthernetT-BCTelecom Bound

8、ary ClockT-GMTelecom Grand MasterT-TCTelecom Transparent ClockT-TSCTelecom Time Slave ClockTAETime Alignment ErrorTDEVTime DeviationTETime ErrorTSNTime Sensitive NetworkingUTCUniversal Coordinated TimeBRKSPG-30505#CiscoLive 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicAgendaIntro

9、ductionNew Concepts and TechnologiesRedundancy,Resiliency and MonitoringPTP Security in 5G RANDesign GuidelinesSummaryBRKSPG-30506 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveDrivers of Precision TimingSyntonizationEnsuring two nodes are synchronized on correct rate or

10、 frequencyLocation Accuracy PositioningCorrelationBehavior and Event analysisControlBehavior and Event analysisSensor data processingEmergenciesAvoid CasualtiesEfficiencyImprove BandwidthChannel Processing,KPIsSecurity/TrustEvent DetectionPredict Future EventsTDM,Optical NetworksAR/VR/MR,V2V,Drones,

11、Aviation,AdvertisingIT Operations,Monitoring,Log analysisIOT,Smart Cities,Education,Healthcare 4G LTE/5G RadiosWiFI6/WiFi 7AI/ML MachinesEmergency response,Tracking,DefenseProving when event happened.Detection and ResponsePrecision and TraceabilityBRKSPG-30507 2023 Cisco and/or its affiliates.All ri

12、ghts reserved.Cisco Public#CiscoLiveTime Synchronization across ArchitecturesxHaulNetwork TimingPre-Agg/Agg3rdParty/Metro LinksBackup TimingPre-Agg/AggAPTSFeaturePerformance Measurement/Service AssuranceSR PM for accurate latency measurementWholesale ProvidersTiming as a ServiceTimingTimingRPDRPDRPD

13、Cable NetworkRPDRPDOLTResidentialGPONPublic or Private 5GMetro TransportCable/GPON TransportAPTS:Assisted Partial Timing SupportDU/CUDU/CUBRKSPG-30508DOCSISDOCSISOLT 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveTime Synchronization in 5G NetworksCell Synchronization Req

14、uirementsCoordinated Transmission and ReceptionApplication RequirementsTransmitter power ON/OFChange Transmit/Receive modesAir propagation timeetc.Increase throughput with Carrier Aggregation,Dual connectivityImprove performance with coordinate multipoint operation etc.Positioning and TrackingTime-s

15、ensitive networking:Robot control or Autonomous VehiclesExtended Realityetc.Intra Band Contiguous130ns FR2,LTE260ns FR1Intra Band Non-Contiguous 260ns(FR2,LTE)3us(FR1)Inter Band CA260ns(LTE)3us(NR)Frequency Band AFrequency Band BFrequency Band AFrequency Band AFrequency Band BFrequency Band BTDD TAE

16、 3sTX Diversity/NB-IoTTAE 65nsPositioningTAE 100nsTAE:Time Alignment Error3GPP TS 36.104,38.104BRKSPG-30509 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveTiming Distribution in Radio Access NetworkPRTC:Primary Reference Timing Clock,T-GM:Timing Grand Master,T-BC:Telecom

17、Boundary Clock,GNSS:Global Navigation Satellite SystemPRTC/T-GMPRTC/T-GMTransportNetworkGNSS per Cell SitePRTC/T-GMTransportNetworkNetwork Based TimingT-BCT-BCBRKSPG-305010 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveDeployment OptionsPTP AwareNetworkPTP AwareNetworkPT

18、P AwareNetworkPTP UnawareNetworkPTP UnawareNetworkPTP AwareNetworkPTP UnawareNetworkPTP UnawareNetworkPTP AwareNetworkT-BCT-BCT-BCT-BC-PT-BC-PT-BC-P/T-TSC-PT-BC-A/T-TSC-AG.8275.1 Full Path SupportG.8275.2Partial Timing SupportAssisted Partial Timing SupportPRTC Assisted TimingPRTC/T-GMPRTC/T-GMPRTC/

19、T-GMBRKSPG-305011 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLive5G Synchronization RequirementsRequirement 1:Absolute TimeRequirement 2:Relative TimeAt Network level:Phase Accuracy:1.1 s Frequency Accuracy:16pbb123N123N123NNaNbNca1a2b1b2b3c1c2c3abPRTC/T-GMT-BCT-TSC/gNBMa

20、x|TE|1.5s for entire chainTime Error accumulation up to node NMax|TE|260nsInside synchronizationClusterMax|TE|1.5s for entire chainAt Air interface Phase:TAE 3sFrequency:50pbbRelative Air Interface TAE within cluster130ns/260nsBRKSPG-305012 2023 Cisco and/or its affiliates.All rights reserved.Cisco

21、Public#CiscoLiveORAN Fronthaul Architecture OptionsC1C2C3C4TransportNetworkFronthaulNetwork Timing/SyncEBackupO-DUO-RUTransportNetworkFronthaulTiming/SyncETiming/SyncENetwork Timing/SyncEBackupO-DUO-RUTransportNetworkFronthaulTiming/SyncENetwork Timing/SyncEBackupO-DUO-RUTransportNetworkDark FiberTi

22、ming/SyncENetwork Timing/SyncEBackupO-DUO-RUBRKSPG-305013 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveTime Budget Example:ORAN C3 ArchitectureTransportNetworkFronthaulNetwork Timing/SyncEBackupO-RUO-DUO-RUA/BCPRTC/T-GM to O-DU 1.1sRelative Time Budget on Fronthaul Tran

23、sport100ns to 190nsRelative Air Interface TAE within cluster260nsT-TSCT-TSCa)Error at Radio Elements|TERE|=20nsb)Regular O-RU with Class B T-TSCT-TSC|maxTE|=cTE+dTE=60nsc)enhanced O-RU with Class C T-TSCT-TSC|maxTE|=15nsO-RU|maxTE|=|TERE|+T-TSC|TE|a)Regular O-RU=80nsb)enhanced O-RU=35ns1)Time Error

24、at Radio2)Time Error at UNI of O-RU260ns 2 x O-RU|maxTE|a)For Regular O-RU260ns 2x80=100ns i.e.50ns per linkb)enhanced O-RU260ns 2x35=190ns i.e.95ns per link3)Relative Time-budget on transportT-BCT-BCT-BCT-BCPRTC/T-GMBRKSPG-305014 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#Cis

25、coLiveType of Clocks and Network BudgetT T-BC/TBC/T-TSC/TTSC/T-TCTCcTEcTEdTE(MTIE)dTE(MTIE)Max|TE|Max|TE|dTE(high pass filter)dTE(high pass filter)Class A(with SyncE)50ns40ns100ns70nsClass B(with SyncE)20ns40ns70ns70nsClass C(with eSyncE)10ns10ns30ns(T-BC)Under study for T-TCUnder StudyClass D(with

26、eSyncE)*no T-TCUnder StudyUnder Study5 ns(low pass)*Under Study*Measured with first order filter of 0.1HzLink Asymmetric CompensationRandomNetworkVariationsShort TermHoldoverA/BCD 1.1s Network Budget 1.5s End-to-End Budget 250ns 380ns 200nsT-BC“1”T-BC“n”T-BC“21”20ns 20ns 20ns 100ns 150nsEnd Applicat

27、ionG.8271.1 Network Reference PointsClass B21 nodesClass C21 nodesPRTC-A 40nsPRTC-B 10ns 10ns 10ns 590ns 30nsePRTCBRKSPG-305015 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveRecommended Approach for 5GNetwork Based TimingPRTC/T-GMPRTC/T-GMTransportNetworkGNSS per Cell Si

28、te+100ns-100ns200ns error from PRTC alone200ns error from PRTC aloneCentralized PRTC provide better solution to meet relative time-errorIn theory,PRTC-A receivers at cell site will not meet relative time budget,PRTC-B or ePRTC may help.Network node with Class C T-BC performance are required.Provide

29、better Resiliency and RedundancyBMCA algorithms for best master selectionVirtual port:for GNSS receiver redundancyAssisted Partial Timing support(APTS),with backup PTP,for better accuracy and holdover on partial timing aware networksand so forthBetter antenna installations with clear satellite visib

30、ilityReduced costLess antenna and PRTC/GNSS installationsBetter operationsBMCA:Best Master Clock AlgorithmBRKSPG-305016New Concepts and TechnologiesTo meet 5G Synchronization Requirements 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveGNSS Receiver PerformanceImpacting Fa

31、ctorsIonosphereTroposphereTransmission delays and ErrorsIonospheric transmission delays and errorsSatellite visibility Antenna siting Cable delay correctionMulti-pathInterference(from other sources)Correction data available to the algorithmBRKSPG-305018 2023 Cisco and/or its affiliates.All rights re

32、served.Cisco Public#CiscoLiveIonosphere ErrorsThe biggest source of time error in PRTC-A receivers is disturbed signal propagation through the ionosphere which:Has 24 hours diurnal cycle depending on the rotation of earth,with minimum delay at night.Depends on space weather,resulting from changes in

33、 solar activity(11-year cycle)PRTC-AGNSS=100nsL1L1L1IonosphereSingle BandAntennaAntennaCableSolar activity is expected to be much higher in next 4 years,which will impact PRTC-A performanceBRKSPG-305019 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLivePRTC-A PerformanceNot

34、going to be accurate enough for 5G servicesAntenna installation are not always in open skies.Satellite visibility is limited in built-up areasSolar activity is expected to be more active,local and instantaneous errors could impact GNSS receiverSingle band limits anti-jamming/anti-spoofing capabiliti

35、esIllegal JammersOff the shelf JammersBRKSPG-305020 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLivePRTC-B ReceiversNecessary to meet 5G requirementsStabilityPRTC-BGNSS=40nsL1L1L1L2L2L2IonosphereDual BandAntennaAntennaCablePRTC-B receivers are Dual-band receivers Measures

36、ionospheric anomalies and models these effects better to improves overall stability of the clockBRKSPG-305021 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicPRTC-B BenefitsMulti-band support for better accuracyImproves traceability to UTC accuracyBetter security against Anti-Jammin

37、g and Anti-Spoofing attacksImproves overall network time-budget requirementsAddresses“Relative Time Budget”within cluster of radiosHelps meet stringent position tracking and location accuracy across Private 5G and Public 5G deploymentsPublic 5G:Carrier Aggregation,Dual Connectivity,CoMPEnterprise:TS

38、N,Power Grid,Factory Automation,Robotics,DroneMetaverse:AR/VR use casesAI/ML and AnalyticsCisco Solution 8000 Series platformsBRKSPG-305022 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveeSyncE/eEEC(G.8262.1)Mandatory for Class C Clocks and 5G RAN5x improvement 5x improve

39、ment to frequency synchronization performance Better phase/time synchronization performance for SyncE-assisted PTPHoldoverEEC(G.8262)eEEC(G.8262.1)Short term phase Transient Response Const Temp 120 ns 120 ns at Initial step10 ns 10 ns at Initial stepInitial response to loss of sync reference50 ns/se

40、c 50 ns/sec frequency offset,plus 1.16 X 10-4 ns/s2drift10 ns/sec 10 ns/sec frequency offset,plus 1.16 X 10-4 ns/s2driftStabilityEEC(G.8262)eEEC(G.8262.1)Wander GenerationMTIE:40ns MTIE:40ns 0.1sTDEV:3.2ns TDEV:3.2ns 0.1sMTIE:7ns MTIE:7ns 0.1sTDEV:0.64ns TDEV:0.64ns 0.1sImproved time noise transfer

41、performance Phase jump due to noise transfer from SyncE to PTP is low-pass filtered Noise Transfer FilteringEEC(G.8262)eEEC(G.8262.1)Clock Bandwidth1 1-10 Hz10 Hz1 1-3 Hz3 HzImproved holdover performance Longer chain or stable performance for long time 1.5us performanceMTIE:Maximum Time Interval Err

42、or,TDEV:Time DeviationBRKSPG-305023 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveESMC and Enhanced ESMC(G.8264)Enhanced ESMC Include new TLVs containing:Originator Clock-idNew SSM CodesSyncE steps removed from nearest SSU/PRCeSyncE steps removed from nearest SSU/PRCImpr

43、oves Solution:1.Allow higher accuracy clocks2.Separate counts of EEC/SEC and eEEC/eSEC hops from originator source3.Traceability and Monitoring4.Identify the source nodeDetect Timing LoopsPRTCPRCWhich Quality I shoulduse?QLQLQLESMC:Ethernet Synchronization Message ChannelBRKSPG-305024 2023 Cisco and

44、/or its affiliates.All rights reserved.Cisco Public#CiscoLiveESMC and Enhanced ESMC(G.8264)123451.New Hop Counters for EEC and eEEC clocksclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:1Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:2M

45、ixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:3Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:4Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:5Mixe

46、d EEC/eEEC:NoPartial chain bit:NoFlags:Is chain mix of SyncE and eSyncE=0=NOThe chain has non eESMC nodes =0=NO eEEC and eESMCEEC and eESMCEEC and ESMCExtended QL TLVOriginal QL TLV2.New flags helps in traceability:Do all nodes in the chain support eSyncE?Do all nodes in the chain support eESMC?Was

47、the TLV generated in the middle of the chain?BRKSPG-305025 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveESMC and Enhanced ESMC(G.8264)12345clockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:1Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC

48、clocks:0Count of eEEC clocks:2Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:1Count of eEEC clocks:2Mixed EEC/eEEC:YesPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:1Count of eEEC clocks:3Mixed EEC/eEEC:YesPartial chain bit:NoclockIdentity:Node1Count of EEC c

49、locks:1Count of eEEC clocks:4Mixed EEC/eEEC:YesPartial chain bit:NoFlags:Is chain mix of SyncE and eSyncE=1=YESThe chain has non eESMC nodes =0=NO EEC and eESMC1.New Hop Counters for EEC and eEEC clocks2.New flags helps in traceability:Do all nodes in the chain support eSyncE?Do all nodes in the cha

50、in support eESMC?Was the TLV generated in the middle of the chain?eEEC and eESMCEEC and eESMCEEC and ESMCExtended QL TLVOriginal QL TLVBRKSPG-305026 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveESMC and Enhanced ESMC(G.8264)12345clockIdentity:Node1Count of EEC clocks:0C

51、ount of eEEC clocks:1Mixed EEC/eEEC:NoPartial chain bit:NoclockIdentity:Node1Count of EEC clocks:0Count of eEEC clocks:2Mixed EEC/eEEC:NoPartial chain bit:NoNo Extended TLVNo Extended TLVclockIdentity:Node4Count of EEC clocks:1Count of eEEC clocks:1Mixed EEC/eEEC:YesPartial chain bit:YesclockIdentit

52、y:Node4Count of EEC clocks:1Count of eEEC clocks:2Mixed EEC/eEEC:YesPartial chain bit:YesFlags:Is chain mix of SyncE and eSyncE=1=YESThe chain has non eESMC nodes =1=YES ESMC,EEC1.New Hop Counters for EEC and eEEC clocks2.New flags helps in traceability:Do all nodes in the chain support eSyncE?Do al

53、l nodes in the chain support eESMC?Was the TLV generated in the middle of the chain?eEEC and eESMCEEC and eESMCEEC and ESMCExtended QL TLVOriginal QL TLVBRKSPG-305027 2023 Cisco and/or its affiliates.All rights reserved.Cisco PubliceSyncE and eESMCeSyncE is mandatory for Class C timingeSyncE provide

54、s better performance,stability and holdover to the clockEnhanced ESMC improves operations Avoid SyncE loops Provides hop counts improves traceability and MonitoringBRKSPG-305028 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveLinux PTP Project Status Check:Profile configur

55、ation is staticAny change require service restartImpacts radio operationsLimited or no support for Remote ManagementS-plane monitoringPhc2sys and ts2phc state monitoringOperations/Non-complianceNot fully compliant to ITU-T G.8275.1/G.8275.2Not compliant to G.8264 and G.781Doesnt comply to ORAN WG4 S

56、pecificationTest Cases Section 3.3 on S-plane complianceptp4l uses s0/s1/s2/s3 status instead of“locked”,“hold over”,“freerun”Doesnt update status in“announce”messagesNo Support for Primary to Backup switchingNo Support for profile interworkingNo support for APTS or Virtual Port no resiliency or red

57、undancy for timingCisco NCS540Compute Based TimingMost popular outdoor deployments are C1 architectureLinux PTP Project Timing NIC ptp4L:Synchronize clock using PTP protocol ts2phc:Synchronize clock to external signal e.g.1PPS phc2sys:synchronize NIC clock to system clock pmc:PTP management clientBR

58、KSPG-305029 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicCompute Based TimingIndustry needs to focus on contributing and improving Linux PTP projectFor 5G architecture,network-based timing provide most advanced solutionNetwork-based timing could help reduce complexity and cost on

59、 computeBRKSPG-305030Redundancy,Resiliency and Monitoring 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveRedundancy for Grand MasterUse Case:Relative Timing within Radio Cluster,Fronthaul and Private 5G Requirement:Set of RUs connected to a common DUAll radios and DUs nee

60、d to be synchronized by common PRTC for better accuracy and to manage relative timing within clusterSeamless network failover in case of PRTC failureO-DU200ns error 200ns error from PRTC from PRTC alonealoneT-GMT-GMBRKSPG-305032 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#Cisco

61、LiveSBCGNSSVPSGNSSVPSBCMRedundancy for Grand MasterApproach-Virtual Port(VP)Note:T-GM can only distribute clock(all ports are master ports),can not receiver it.But T-BC can.Virtual Port(G.8275.2 Annex B)provides electrical frequency and phase inputs to T-BCVirtual Port gives flexibility to configure

62、 node as”boundary clock”and run BMCA to select best time source Local GNSS or remote grandmasterRouter ARouter BRouter A has better clock qualityRouter B runs BMCA and selects router A as primary clock BRKSPG-305033 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveRedundanc

63、y for Grand MasterUse cases:Relative Timing within Radio Cluster,Fronthaul and Private 5GSolution:Configure Primary and Secondary PRTC priorityConfigure each node as T-BC with VP(virtual port)to select priority for local vs remote GNSSPrimary PRTC distributes clock to all nodes O-RUs,Routers,O-DUsIn

64、 case of Primary PRTC failure,BMCA will auto select secondary PRTCPrimarySecondaryO-DUT-BCwith VPT-BCwith VPCommon Common clock source clock source for all Radios for all Radios within a within a clusterclusterBRKSPG-305034 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveR

65、esiliency with backup PTPUse Case:Last mile over 3rdparty linksRequirement:Set of RUs connected over 3rdparty links/3rdparty network that doesnt support timing3rdPartyTransportO-DUG.8275.2PTP un-aware network doesnt guarantee timing performanceG.8275.2BRKSPG-305035 2023 Cisco and/or its affiliates.A

66、ll rights reserved.Cisco Public#CiscoLiveResiliency with backup PTPApproach:Assisted Partial Timing Support(APTS)MBCRouter ARouter BAPTS function allows T-BC to select local GNSS as the primary source;and continuously measures the time offset compared to that recovered from the back up PTP signal.In

67、 case of GNSS failure,T-BC will failover to back up PTP and removes the observed offset to maintain time accuracy during GNSS failure.APTS configuration requires Virtual Port(G.8275 Annex B)supportGNSSVPSBCSMeasure offset from backup PTP clock.In case of local GNSS failure,maintain clock accuracy wi

68、th backup signalBackup PTP from remote routerBRKSPG-305036 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveResiliency with backup PTPUse Case:Last mile over 3rdparty linksSolution:Connect local GNSS at each site to accurately synchronize RadiosUse back up PTP(G.8275.2)from

69、 network to maintain performance during local GNSS failureWhen local GNSS is down,accuracy and stability of the clock depends on PTP clock quality3rdPartyTransportG.8275.2PTP as backupO-DUAPTSAPTSAPTSG.8275.2BRKSPG-305037 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveATP

70、S Deployment GuidelinesAPTS is considered mainly for“Partial timing aware network”Backup Timing should be available as part of G.8275.2 profileG.8275.2 over partial aware network is not reliable.Please ensure G.8275.2 quality is good,to get max benefits of APTSAvoid multi-profile with APTSAPTS can c

71、orrect STATIC time error,dynamic error is still un-controlledOnly good for last measurementTimeTime Error(ns)Lock to local GNSSLocal GNSS is lost,clock goes into holdover and generates a first transientThe clock is in holdover within a short time,decided by BMCA algorithmThe clock selects the PTP re

72、ference,and changes from holdover to lock,and generates a second transientThe clock locks to the PTP reference,and the dTE is larger,and cTE could be also larger,due to the asymmetry caused by PTP unaware network.Although the clock can compensate it in advance,some remaining cTE could be still prese

73、nt.22 ns(transient for switching&residual PTP cTE)+15 ns(tranfser PTP gain)+X ns(generation XO PTP dTE)Lock to local GNSSGPS is restored and selected by the clockBRKSPG-305038 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveHoldover with SyncE AssistanceUse Case:Longer hol

74、doverLoss of PTP(11 mins)1.1 sReacquiredLoss of SyncE10 HoursZero ns5 HoursRealignedHoldover is either oscillator only,or assisted with external frequency(SyncE)Staying within 1.1 s is only possible for several hours when relying on local oscillatorBRKSPG-305039 2023 Cisco and/or its affiliates.All

75、rights reserved.Cisco Public#CiscoLiveNetwork Monitoring for Improved ResiliencyMonitoring Alternate Master Time InformationITU-T G.8275.1 Annex GUse Case 1:Passive port monitoring Master portUse Case 2:Master port monitoring Passive PortAllows PTP monitoring of alternate pathCalculates PTP offset b

76、etween PTP received from primary path and alternate linkIf offset crosses define threshold,monitoring alarm is generatedThis alarm doesnt trigger BMCAThe functionality helps monitors network healthFiber asymmetry between links,network failures and so forthBRKSPG-305040 2023 Cisco and/or its affiliat

77、es.All rights reserved.Cisco PublicRedundancy,Resiliency and MonitoringVP is for timing redundancy PRTC Redundancy G.8275.1 based full path support networksAPTS is for better timing resiliency Local GNSS for timing accuracy Backup PTP for maintain performance during GNSS failureHoldover with SyncE a

78、ssistanceImproves overall performanceCisco Solution support mature PTP monitoring and management solutionSNMP MIBs:CISCO-PTP-MIBCISCO-NETSYNC-MIBCISCO-GNSS-MIBYang/Telemetry SupportBRKSPG-305041PTP Security in 5G RAN 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveTiming S

79、ecurity AttacksAttackAttackImpactImpactAttacker TypeAttacker TypeFalse TimeAccuracy degradationDOSInternalExternalMITMPacket InjectorMITMPacket InjectorChanging Clock ParametersXXSpoofingXXXReplay AttackXXXRogue Master AttackXXXChanging and removing MessagesXXXXPacket Delay ManipulationXXXDOS attack

80、sXXXXXCryptography Performance attacksXXXXXGPS Spoofing/JammingXXXXXBRKSPG-305043 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveMACsec and Security for TimingMACsec is a L2 port-based security mechanismEither encryption+integrity checking OR only integrity checking(IEEE

81、802.1AE)Maybe mechanisms to choose whether to send secured/unsecured on a portEither asymmetry or dynamic time error can arise through:Difference in time to encrypt/decrypt messagesSelection of receive/transmission timestamping pointDifferences in time to encrypt/decrypt subsequent messagesMAC MAC D

82、ADAMACMACSASAEtherEther-typetypePayloadPayloadFCSFCSOriginal PacketEncrypted DataIntegrity ProtectedMAC MAC DADAMACMACSASASECSECTagTagEtherEther-typetypePayloadPayloadICVICVFCSFCSBRKSPG-305044 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLivePTP over MACSec Deployment Chall

83、enges1-Step Clock PHY based time-stamping doesnt work for 1-step clocks Timestamp can not be inserted into the“Sync”packet before it goes through the MACSec Encryption must always take same number of cycles(even after key rollover);any jitter can impact PTP performance.2-Step Clock Timestamp can be

84、generated by measuring“Sync”packet delay at the egress,and sub-sequent“Follow Up”message can carry it.PHY will not be able to differentiate encrypted PTP packets with other packets On receive side,decryption should take same time as encryption to avoid PDV from asymmetryPHYMACSecPTPPHYMACSecPTPPHY d

85、etects PTP packet and Provides Timestamp for“Follow Up”message”Timestamp is ideally done when packet hits wire at PHY.BRKSPG-305045 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLivePTP over IPSec Deployment ChallengesPHYIPSec EnginePTPPTP over IPSec IPSec is end-to-end and

86、introduces additional delay.IPSec Engine could be 1)Hardware based or 2)Software baseda.Hardware based IPSec EngineChallenges are similar to MACSecb.Software Based IPSec EngineTime-stamping in software increases delay variationsHardware based timestamping requires further considerationsIngress packe

87、ts has to be stored until corresponding PTP messages are decrypted and timestampedOutgoing packets should follow 2-step methodIngressEgressBRKSPG-305046 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveArchitectural Approach MACSec performs best with Full Path Support(FPS)a

88、nd ITU-T G.8275.1 profile IPSec is end to end(Client to Server)and doesnt align with G.8275.1 profile.5G timing requirements can not be met when PTP over MACSec is deployed on Partial Timing Support(PTS)networks with ITU-T G.8275.2PTPoMACSecPTPoMACSecT-BCT-BCT-BC IPSec is end to end-doesnt meet 5G p

89、erformance requirement Underlay network has no visibility to PTP packetsPTPoMACSecPTPoMACSecT-BCPTP unaware networkT-BCPTPoIPSecT-BCT-BCT-BCBRKSPG-305047 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveSecurity Mechanisms GuidelinesIEEE 1588-2019 Annex PProng A:PTP integra

90、ted security using TLVsProng B:External Security MechanismsL2 with MACSec i.e.Hop by hopL3 with IPSec i.e.End to EndProng C:Architecture GuidanceProng D:Monitoring and Management GuidanceBRKSPG-305048 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicPTP SecurityStatusMACSecMACSec wit

91、h ClearTag is being discussed,however it doesnt solve all issues.Inter-op will be biggest challengeIPSecNot suitable to meet 5G RAN timing requirementsIndustry is aligning towards supportingIEEE 1588-2019 prong A:PTP integrated security using TLVKey Exchange and Processing mechanisms to be finalized

92、 ITU-T-“Further Study”BRKSPG-305049Design Guidelines 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveNetwork DesignPhase SynchronizationDeploy G.8275.1 with physical frequency(SyncE/eSyncE)Reduce PDV(boundary clocks reset PDV back to zero)Reduce asymmetry(routing,link,node

93、,transport)-boundary clocks limit asymmetryLikely requires remediation of transport layerAvoid“PTP over Loopback”or”PTP over un-numbered”interfacesDeploy G.8275.1 in transport with bundle interfaces,avoid G.8275.2Frequency SynchronizationIf possible,use physical distribution(SyncE/eSyncE)not packet

94、for frequencyG.8265.1 interoperates with SONET/SDH&SyncE(some gaps with eESMC mapping)Packet distribution goal:reduce PDV(minimize hops as it disallows aware nodes)Asymmetry isnt an issue for frequency over packetBRKSPG-305051 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLi

95、veSelect the Correct ProfileFeatureFeatureG.8275.1 PTPoEG.8275.1 PTPoEG.8275.2 PTPoIPG.8275.2 PTPoIPTransportLayer 2 MulticastLayer 3(IP)UnicastNetwork ModelFull on-path supportPartial on-path supportIP RoutingNot applicableProblematic(rings,asymmetry)Transit trafficNot allowedProblematic(jitter,asy

96、mmetry)PerformanceBestVariableConfiguration ModelPhysical PortL3 devicePTP over BundlesNo issueBeing worked on(for BCs)AsymmetryReduced(T-BC on every node)T-BC good,not T-BC=badPDV/jitterTimestamping on wire(small)T-BC good,not T-BC=badBRKSPG-305052 2023 Cisco and/or its affiliates.All rights reserv

97、ed.Cisco Public#CiscoLiveRemediating Optical Transport“Smart”optical devices introduce buffering and/or complex processingOptical systems:separate channel for PTP(like Optical Service Channel)Cisco solution based on the NCS2K*Bi-directional fiber reduces asymmetryT T-BCBCT T-BCBCPRTC/T-GMBRKSPG-3050

98、53Summary 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicKey Take-a-ways1.Network based Time Synchronization is un-avoidable in 5G RANReduce compute complexity and costProvides Resiliency and Redundancy2.Advanced features matures 5G SynchronizationClass C Clock,PRTC-B Receivers eSy

99、ncE,eESMC VP and APTS3.PTP Security is not mature yet4.Follow Design Best Practices for predictive timing performance.BRKSPG-305055 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public“Synchronizing 5G Mobile Networks”Publisher:Pearsons/Cisco PresseBook&PrintPublished:June 2021https:/ I

100、nformationBRKSPG-305056 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicResources:Past Cisco Live Sessions5G Timing&SynchronizationBRKSPG-3050 Synchronizing 5G Mobile Networks Event:2023 AmsterdamBRKSPM-3295 5G Timing&Synchronization architecturesEvent:2020 BarcelonaBRKSPG-2557 5G S

101、ynchronization-Design,Testing and Deploying Timing to support 5G rollouts Event:2020 BarcelonaBRKSPG-305057Recommended Sessions on 5G 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveJune 4|2:00 pmTECSPGTECSPG-24322432New Adventures in Wireless:The Journey of WiFi6 and Priv

102、ate 5G Networks for the EnterpriseJune 5|8:30 amBRKSPGBRKSPG-20422042Architecting Private 5G for resiliency,security,and enterprise network convergenceJune 5|10:30 amBRKSPMBRKSPM-10061006The 5G System as a Spectrum Management SolutionJune 7|2:30 pmPSOGENPSOGEN-10331033Unlock business outcomes from c

103、onnectivity with a Private 5G solutionStartStartCisco Private 5G Learning Map59BRKSPG-3050June 5,|8:00 amBRKSECBRKSEC-20852085Architecting Enterprise Security in a Wi-Fi plus Private 5G WorldJune 5|11:00 amBRKENSBRKENS-29502950Is your Enterprise Network Ready for P5G June 8|09:30 amBRKSPGBRKSPG-2044

104、20445G Use Cases Flight Line of the Future and Smart Warehouse June 6|3:00 pmBRKEWNBRKEWN-20302030WiFi6 and Private 5G for the Enterprise a Better Together JourneyJune 8|1:00 pmBRKGENBRKGEN-20012001Cisco P5G-A Robust and Secure ArchitectureFinishFinishJune 8|01:00 pmIBOSPGIBOSPG-20072007Getting Star

105、ted with Private 5GJune 7|4:00 pmBRKSPGBRKSPG-30043004Monolithic or Polylithic packet cores?The case for specialized use-case-based mobile packet coresJune 5|11:30 amPSOSPGPSOSPG-10021002Leading Your Digital Transformation with Cisco Private 5G Network Offer 2023 Cisco and/or its affiliates.All righ

106、ts reserved.Cisco Public#CiscoLiveJune 4|9:00 amTECIOTTECIOT-25842584Designing IoT Wireless NetworksJune 5|1:00 pmBRKSPGBRKSPG-20632063Design,Deploy and Manage Transport Slicing using SDN Controller and AssuranceJune 5|1:00 pmBRKARCBRKARC-20942094Hiking the Band Canyon with 5G:New Use Cases,New Busi

107、ness Outcomes June 6|10:30 amBRKSPGBRKSPG-23152315Cloud-Ready Converged SDN TransportStartStartCisco 5G Learning Map60BRKSPG-3050June 5,|8:30 amBRKNWTBRKNWT-22032203Automation-first Approach to Network Infrastructure Modernization for 5G&BeyondJune 5|2:30 pmBRKSPGBRKSPG-10021002Dont Just Connect,Gro

108、w your IoT Business with Cisco IoT Cellular Connectivity ManagementJune 6|2:30 pmIBOSPMIBOSPM-203020305G Transport Design Considerations Combining Onsite and Cloud-Based DeploymentsJune 7|10:30 amBRKSPGBRKSPG-21332133Evolution of the Transport Network Architecture in the Context of 5G and Open RANJu

109、ne 6|4:00 pmBRKSPMBRKSPM-20272027Holistic Security in 5G DeploymentsJune 6|1:00 pmBRKSPGBRKSPG-24012401Cisco Secure Edge Protection Protecting the 5G Edge against DDoS AttacksJune 5|3:00 pmBRKIOTBRKIOT-11261126Connecting Moving Assets with Cisco IoT Solutions June 8|8:30 amBRKSPGBRKSPG-30503050Synch

110、ronizing 5G Mobile Networks 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveJune 8|10:30 amBRKNWTBRKNWT-23012301DevNetOps Automation Approach to Network Infrastructure Modernization for 5G and BeyondJune 8|1:00 pmBRKMERBRKMER-20012001Postcards from the 5G Edge:Meraki Cellu

111、lar GatewaysCisco 5G Learning Map61BRKSPG-3050June 8,|11:00 amBRKSPGBRKSPG-20402040Troubleshooting 5G ArchitecturesFinishFinishJune 8|9:30 amIBOSPGIBOSPG-20062006DISH Wireless,Worlds first 5G Network with a Hybrid Cloud 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicIF-1002 Learn h

112、ow Inclusive Language Can Positively Impact your Business Panel DiscussionDEVLIT-2761 Automating Language Bias out of CodeReference:Inclusion and DiversityBRKSPG-305062 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLiveFill out your session surveys!Attendees who fill out a m

113、inimum of four session surveys and the overall event survey will get Cisco Live-branded socks(while supplies last)!63BRKSPG-3050These points help you get on the leaderboard and increase your chances of winning daily and grand prizesAttendees will also earn 100 points in the Cisco Live Game for every

114、 survey completed.2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicContinue your educationVisit the Cisco Showcase for related demosBook your one-on-oneMeet the Engineer meetingAttend the interactive education with DevNet,Capture the Flag,and Walk-in LabsVisit the On-Demand Library f

115、or more sessions at www.CiscoL you#CiscoLive 2023 Cisco and/or its affiliates.All rights reserved.Cisco Public#CiscoLive66Gamify your Cisco Live experience!Get points Get points for attending this session!for attending this session!Open the Cisco Events App.Click on Cisco Live Challenge in the side menu.Click on View Your Badges at the top.Click the+at the bottom of the screen and scan the QR code:How:123466 2023 Cisco and/or its affiliates.All rights reserved.Cisco PublicBRKSPG-3050#CiscoLive