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COMMUNICATIONS TEST & MEASUREMENT SOLUTIONS

WEBSITE: www.jdsu.com February 2011 1

IEEE 1588v2 PTP and Synchronous Ethernet: Synchronizing the Asynchronous

T-BERD®/MTS-6000A and 8000 MSAM Ordering Information

1588v2 PTP

– CTLS1588 (-U1) – IEEE 1588v2 PTP 10 Mbps to 1 Gbps test option

Synchronous Ethernet

– CTLSSYNCE (-U1) – SyncE 1G test option

– C10GSYNCE (-U1) – SyncE 10G test optionUse Case Turn-up and troubleshoot Ethernet networks using

synchronous timing standards

Intended Audience Carriers deploying, managing, and selling Ethernet Backhaul Services

• Designed for operations personnel who verify network synchronization, turn-up, fault analysis, and quality of service (QoS)

Carriers/NEMs designing and deploying network elements (NE) supporting TDM over IP services

• Designed for engineers and operations personnel involved with designing, installing, and troubleshooting TDM over IP services using Synchronous Ethernet and 1588v2 PTP technologies

Applications: Install, turn-up, troubleshoot, and ensure QoS on networks that support synchronous timing standards such as 1588v2 PTP and Synchronous Ethernet.

Solution DescriptionIEEE 1588v2 PTP is a test option for the T-BERD/MTS-6000A and 8000 Multi-Services Appllication MVodule (MSAM) that enables users to verify the connectivity, quality, and synchronization of networks using 1588v2 PTP. With this functionality, users can ensure proper network synchronization by emulating 1588v2 slave/master NEs and ensure network QoS by characterizing PTP messaging and packet delay variation (PDV) stability over time.

Synchronous Ethernet (SyncE) is a test option for the T-BERD/MTS-6000A and 8000 MSAM that provides real-time decodes of G.8264 sync status messages (SSM) on circuits up to 10 Gbps rates. With this feature, users can synchronize a circuit by verifying the propagation of the originating network clock source.

Value PropositionAs carriers continue to adopt carrier Ethernet, new standards such as Synchronous Ethernet and IEEE 1588v2 PTP have been developed to enable the high accuracy time synchronization of NEs, services, and networks. These new standards enable the successful transition of traditional TDM services to lower cost per bit Ethernet networks. Without synchronization, Ethernet networks cannot deliver services that require high accuracy synchronization, such as voice, video, and mobile backhaul. For example, mobile backhaul uses 1588v2 or SyncE to synchronize devices betweenthecellsiteandswitchingoffice.Withoutverifyingsynchronization,endusers may experience problems such as dropped calls or poor call quality.

The SyncE and 1588 test options on the T-BERD 6000A and 8000 MSAM helps users verify network synchronization, continuity, and quality of service. These advanced test options help solve issues associated with master/slave connectivity, synchronization stability, and continuity of the time synchronization chain.



Feature/Benefit Summary – 1588v2

Feature Description Advantage Benefit

Master/slave NE emulation

Emulate master/slave NEs through the support of 1588v2 PTP messaging

Verify NE connectivity, operation and provisioning

Enables users to sectionalize problems by isolating NEs with emulation capability

PTP frame link counts and stats

Measure and decode PTP messages on a circuit under test

Verify message connectivity and analyze diagnostic information in tables or graphs over time

Ensure that PTP messages are being routed correctly with end-to-end connectivity

Packet delay variation of PTP frames

Measure the packet delay variation associated with PTP handshaking between master/slave

Ensure high-accuracy time synchronization by measuring PDV (a.k.a. Jitter) on the sync source

Isolate problems associated with unstable network synchronization such as dropped calls

Supports multiple streams of data planetrafficandPTPmessages

Transmit up to four background trafficstreamsandPTP messages simultaneously

Ensure the prioritization of PTP messages versusdataplanetraffic

Ensure proper network synchronization under worst-case network load conditions

Capture and decode PTP messages

Perform deep packet inspection on PTP messages

Verify the correct handshaking of master and slave NEs

Resolve higher layer protocol issues with one instrument

Feature/Benefit Summary – SyncE

Feature Description Advantage Benefit

Measure SyncE frequency and offset

Measure the received frequency of the circuit under test; measure frequency offset from nominal in ppm

Verify proper frequency propagation throughout the SyncE network

Identify incorrect network operation and degraded QoS due to poor frequency synchronization

Test using recovered and external clock source references

Receiving and sourcing trafficrequiresrecovered or external clock synchronization by the test set

Test set frequency synchronization is mandatory in support of SyncE testing

Quickly test and verify proper SyncE network operation

Capture Ethernet Synchronization Messaging Channel (ESMC) messages

Capture ESMC messages at line rate for evaluation in Wireshark

Debug and verify potential issues associated with improper ESMC message content or formats

Identify network timing recovery issues quicker by evaluating ESMC communications

Sync Status Messages (SSM) decodes

Displays a decode of the timing source Quality Level (QL) driving the synchronization chain

Isolate issues associated with improperlyconfigurednetwork timing chains

Quickly identify issues associated with providing the incorrect reference clock to a NE



Use Case: Turn-up PTP Enabled Networks - 1588v2Networks such as 1588v2 PTP require that master/slave nodes establish time synchronization using 1588v2 PTP handshaking which occurs continuously on a constant basis and is required to maintain accurate synchronization. Failure to establish PTP message connectivity, makes achieving synchronization impossible and disables support for synchronized services. Technicians can use the T-BERD/MTS-6000A and 8000 MSAM to emulate slave/master NEs to verify the continuity and messaging across a 1588v2 network.

Master Slave

PTP Messaging

Announce

Sync

Follow_Up

Delay_Req

Delay_Resp

Use Case: Ensure Accurate Time Synchronization - 1588v2Time accuracy in a 1588v2 network relies on consistently received PTP messages betweenmaster/slaveelements.DataplanetrafficinanetworkcanaffectthetransitdelayofPTPmessagesbecausealltrafficsharesthesameNEprocessor.Therefore, a network with high utilization can affect the performance of end-to-end PTP messages and ultimately degrades synchronization. This issue can be identifiedbyperformingapacketdelayvariation(PDV)measurementonthePTPmessages exchanged between master and slave NEs. With the T-BERD/MTS 6000A and 8000 MSAM, users can verify the proper delivery of PTP messages by measuring PDV stability over time.

TDM Ethernet

PTP MessagingPrimary

ReferenceSource

MSAM -1588v2 Slave

Ethernet

Master

TDMCE IWF NTE NTEEthernet

Network

Sync Packet Delay Variation



Use Case: Troubleshooting of Connectivity - Perform Deep Packet Inspection – 1588v2During a 1588v2 network installation, PTP message connectivity problems can arise between the master and slave. Failure to establish PTP message connectivity makes achieving synchronization impossible and disables support for services. When troubleshooting these links, the T-BERD/MTS-6000A and 8000 MSAM can be used in Terminate mode to capture PTP messaging on both the transmit (Tx) and receive (Rx) test ports up to 1G. In this mode, the T-BERD/MTS-6000A and 8000 simultaneously generates, receives, and captures PTP messages on the circuit under test. Users can quickly identify higher layer protocol issues that may be associated with PTP messages and/or provisioning.

Use Case: Verify Link Quality in support of Accurate Timing - 1588v2Messagingwith1588/PTPisdesignedtoworkunderspecifiednetworkloadconditions. When NE processor utilization is high, it can affect PTP message processing and, therefore, forwarding. PDV in PTP messages will ultimately affect synchronization because it depends upon consistently timed message reception. TheT-BERD/MTS-6000Aand8000MSAMcanemulatedataplanetraffic(uptofour streams) and PTP messages simultaneously. Under these conditions, users can verify that 1588v2 PTP networks are operating properly under worst-case networkloadingscenariosandevenbeyondspecifiedlimits.

Stream #1Stream #2Stream #3Stream #4

PTP messages

Ethernet switchMaster

Slave

Sync PDV graph

PTP link counts/stats

Line rate capture of PTP messages

PTP decode with Wireshark



Use Case: Verify Network Reference Timing - Synchronous EthernetIn this scenario, the T-BERD/MTS-6000A MSAM is testing a Synchronous Ethernet circuit. The master clock (time reference) provides reference timing for the network, which ispropagatedthroughoutthenetworkviatheenhancedphysicallayerspecificationsofSyncEcircuits.Informationidentifyingthequalifylevel(QLmessage)ofthemasterclock driving the synchronization chain is passed through the network via sync status messages (SSM) in the Ethernet synchronization messaging channel (ESMC) that are contained in specialized Ethernet frames sent periodically, 1 per second. The T-BERD/MTS 6000A and 8000 MSAM enables users to verify that a SyncE circuit is correctly synchronized by decoding and displaying the SSM, capturing ESMC messages, and measuring the received frequency offset (ppm) of the circuit under test. In addition, duringEthernetserviceturn-up,testtrafficcanbegeneratedusinganexternalreferenceorrecoveredSyncEtimingtoensureproperSyncEtrafficpropagation.



Quick Demo Setup - 1588 PTP Link Stats, Link Counts, and Packet Delay VariationSelect the Layer 2 or 4 PTP/1588 term test for the intended interface. Select the PTP or graphs/major results category and the link stats/counts and graph to view results.

Quick Demo Setup - Ethernet Sync Status Messaging (E-SSM)SelectanyEthernetLayer2(orabove)application.WithintheEthernetmajorcategory,selecttheSSMresultscategorytoviewSSMresults.Receivedtrafficfrequencyoffsetislocatedatthetopofthescreen,whiletraffictimingsourceislocatedonthebottomnexttothelaserbutton.



FAQQ: How does the 1588v2 PTP functionality of the T-BERD/MTS 6000A and 8000 compare to the former JDSU CPO product the Calnex Paragon?

A:TheParagonismoreofalabtoolfocusedonNEdesignandverification.Anexample of this is support of the delay insertion function currently supported by theParagon.TheMSAMisfocusedonfieldoperationstaskedwithturningupandtroubleshooting 1588/SyncE networks.

Q: Can you perform one-way delay measurements between two tests using the 1588 protocol?

A: No, this feature is not currently supported, but it is under evaluation for a future release.

Q: Is this a software or hardware upgrade to existing units in the field?

A: Both features (SyncE and 1588v2) are software upgrades to existing units in the field.

Q: Are these features supported on the existing T-BERD/MTS 8000 transport module?

A: No, they are only supported on the MSAM for use with the T-BERD/MTS 8000 and 6000A.

Q: Are there pre-requisites for this feature?

A: Yes. Both of these options require Ethernet test interfaces. Keep in mind that the 1588v2 is supported up to 1 GigE rates, and Synchronous Ethernet is supported up to 10 GigE rates.

Q: Why would a provider deploy Synchronous Ethernet versus 1588v2?

A: Providers can deploy both technologies; in fact, some providers have expressed adesiretousebothtechnologiesonthesamenetworktorealizebenefitsfromboth.

Therefore, there are some fundamental differences between the technologies as follows.

• Synchronous Ethernet provides highly accurate frequency synchronization thatdependsontheenhancedphysicallayerspecificationsofSyncEcircuitsand, therefore, requires new NE hardware that can increase the overall cost of deployment.However,SyncEisnotaffectedbytheEthernet/IPtrafficloadingofanetwork.

• Primarily a software based-implementation, 1588v2 promises to decrease costs by working on existing carrier Ethernet networks. It also provides carriers a time ofday.However,oveeralltrafficloadingofthenetworkcanaffect1588v2PTPsynchronization accuracy.

Q: What are the similarities and differences of 1588v2 to the original 1588 version 1 protocol?

A: Version 1 of 1588 was originally developed for the synchronization of test equipment in LAN environments.

february 2011 1 - viavi solutions · pdf filecommunications test & measurement solutions...

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