Sync Audit® Tests

Tests can include:

Fast frequency and phase (TIE) measurements

Spot check or 24 x 7 (long term) monitoring

MTIE and TDEV Characterisation

Equipment and network limits testing for PRC, SSU and SEC outputs & PDH distribution outputs

Noise Generation testing for PRCs, SSUs and SECs

Input wander tolerance and noise transfer (with a suitable function generator)

Phase response during input reference switching and holdover

Frequency stability

Phase transients

Jitter testing Complex Standards tests are easily accomplished by combining key features of the Symmetricom TimeMonitor software, Pendulum WM11, Acterna ANT-20 and SyncWatch. In general, Chronos adheres to the guidelines for wander measurements given in Appendix II of O.172 (03/99). These include: Synchronised Wander Measurements In this test, the equipment under test is provided with the same reference clock as the sync test set. This enables wander generation of the equipment or Network to be analysed. Non-Synchronised Wander Measurements This test normally applies where there is a need to examine the short to medium term network performance. O.172 states that the stability of the two clocks has to be at least one order of magnitude better than the quality to be measured. Frequency difference between the two clocks can be seen as a slope on the TIE graph and can be removed with some types of post processing software.

Equipment Assessed Networks and equipment assessed and qualified for Standards compliance and interworking include Switching, Transmission, Wireless and Synchronisation products from many of the major manufacturers including: Alcatel-Lucent, Ascom Timeplex, Cisco, Cray, Datum, Ericsson, ECI Telecom, Fujitsu, Marconi, Motorola, NEC, NET, Newbridge Networks, Nokia-Siemens, Nortel, Oscilloquartz, PKI, Stratacom, Symmetricom, Tellabs, Teltrend. Chronos tailors each Sync Audit® to the specific requirements of the customer. Each Audit follows a similar phased procedure: Preliminary meeting to discuss the scope and objectives of the project. Testing period, normally determined through discussion (from a couple of days to a month or more). Report preparation and report presentation and results analysis with recommendations.

The final report will compare test results against the Standards and make recommendations regarding network planning, architecture and solutions for improving the transport quality and making the network more resilient. Chronos can also provide network planning advice and consultancy following the Sync Audit®. Worldwide Availability Chronos Sync Audit® have been conducted in Europe including the UK, Ireland, Denmark, Germany and Russia; and outside Europe in The Philippines, Malaysia, Latvia, Australia, Singapore, USA and Canada Chronos Sync Audit® test experts are able to travel to site at short notice ensuring a fast, efficient service, no matter where in the world you need us. Sync Audit® can either be carried out on a trouble-shooting or planned basis. Chronos also offers it as an annual or biannual Health Check. This is an excellent way of pre-empting possible fault conditions. Sync architecture must evolve as the network grows and changes and a regular sync Health Check will highlight changes necessary. The new challenge of integrating new technology into core and access network infrastructure means that there are many potential pit falls from a sync. perspective. The Sync Audit® consultancy testing service not only identifies problems, but offers solutions as well.

Pendulum WM-11

Case Study No 1 The Challenge - A large multi-national telecommunications Manufacturer has a major customer in a European country with significant problems in his private telecommunications network. Customer blaming Manufacturer, but the Manufacturer is pretty sure his equipment is okay. What does he do? The Solution - call in synchronisation experts Chronos Technology Limited who conduct a Sync Audit® at key locations in the network. The Sync Audit® is carried out to identify the quality of the synchronisation at various modes in the Customer’s network, particularly where leased lines are provided either at E1 or 64k rates from the local national carrier. The Result - comprehensive test report presented to the Carrier, where the Carrier admits that his network was not configured correctly, and synchronisation traceability was lost to the national primary reference clock. The SDH synchronisation activity was re-configured, and the Customer’s problem was solved. Case Study No 2 The Challenge - A large multi-national telecommunications Manufacturer has been experiencing problems in the field interfacing its equipment to the new generation of SDH telecommunications networks. The equipment uses a Phase Lock Loop (PLL) clock recovery circuit. This is going out of lock on an intermittent basis and causing frequent alarms on the central management system. Customers are concerned about the equipment behaviour, and are looking for a solution to stop the alarms. The Solution - Call in synchronisation experts Chronos Technology Limited who provided a Phase Lock Loop evaluation consultancy and SDH network effect simulations on the equipment. Tests were carried out to identify the behaviour of the various Phase Lock Loops based on the clock recovery circuits which receive their synchronisation from an incoming E1 2048 Mbit/s traffic carrying tributary. The Phase Lock Loop circuits were subjected to SDH pointer sequences and the resulting behaviour characterised. The Result - A comprehensive test report was presented showing evaluation of the different PLL circuits when subjected to wander, noise and pointer adjustment hits typical of telecom circuits, and as specified in relevant ETSI Standards. Manufacturer now able to establish a way forward to reduce sensitivity of the equipment to spurious effects evident in payload out of an SDH network. Case Study No 3 The Challenge - A large non-UK based global telecoms operator has grown its network around the world. It has installed and inherited different types of network equipment in many different countries. It already has a synchronisation platform in place, however, it wants a concise report examining the local architecture at each point of presence and its behaviour with regard to received and delivered sync. The Solution - Call in synchronisation experts Chronos Technology Limited who carried out a Sync Audit® at 11 sites around the globe. All the testing was completed within one continuous 4-week period by one of the Chronos experts moving from country to country. The Sync Audit® was carried out at each site. Tests were done on Switches, SDH transmission equipment and interconnects with other carriers. During the testing process, problems such as local architecture and sync loops were identified and cleaned up as the project progressed The Result - A comprehensive test report was prepared with local network diagrams including interconnection architecture for each site. Recommendations were made both for improvements on a local basis and strategically on a global basis. The report was presented to a panel including key management and directors at the operator's HQ outside the UK.

Sync Audit®

Standards Compliance The Sync Audit®, enables verification of Standards compliance on many key network elements. These include Primary Reference Clocks (PRCs), Synchronisation Supply Units (SSU) and Equipment Clocks in Switches - both electrical and optical, Cross Connects, Multiplexers and other communications equipment. The following are the main Standards which relate to synchronisation of telecom networks. The move to next generation network (NGN) technology has meant that new Standards must evolve. ITU Study Group 15/Q13 is working on a number of new Standards for packet based network synchronisation as are the IEEE with PTP Standard - 1588-2008 and the IETF with TICTOC BOF.

ETSI EN 300 462-1-1 Definitions and Terminology for Synchronisation Networks

EN 300 462-2-1 Synchronisation Network Architecture

EN 300 462-3-1 Control of Jitter and Wander Within Synchronisation Networks

EN 300 462-4-1 Timing Characteristics of Slave Clocks Suitable for Synchronisation

Supply to SDH and PDH Equipment

EN 300 462-5-1 Timing Characteristics of Slave Clocks Suitable for Operation in SDH Equipment

EN 300 462-6-1 Timing Characteristics of Primary Reference Clocks

EN 300 462-7-1 Timing Characteristics of Slave Clocks Suitable for Synchronisation Supply to Local Node Applications

ANSI T1.101-1999 Synchronisation Interface Standard

ITU-T G.811 Timing Characteristics of Primary Reference Clocks G.812 Timing Requirements of Slave Clocks Suitable for use as Node Clocks in Synchronisation Networks

G.813 Timing Characteristics of SDH Equipment Slave Clocks (SEC)

G.8251 Control of Jitter and Wander Within the Optical Transport Network (OTN)

G.8261 Timing and synchronisation aspects in packet networks propose Jitter and Wander limits as portions of the G.823 limits to be assigned to Circuit Emulation Islands. Most revolutionary proposal is for Synchronous Ethernet lockable to an external reference. Also proposes standard test scenario CES equipment

O.172 Jitter and Wander Measuring Equipment for Digital Systems which are Based on SDH

IEEE IEC 61588 IEEE1588 : Precision clock synchronisation protocol for networked measurements and control

systems

Synchronised Wander Measurement Test

INTRODUCTION Legacy PDH and NGN 1588-2008, PTP and SyncE equipment must inter-work with SDH transmission systems. Wireless Networks must utilise fixed network transport across electrical and optical networks. Synchronisation incompatibilities are common.

Networks evolve and technical personnel change; Synchronisation network design may no longer be optimised. It may be failing to deliver the synchronisation performance throughout the network.

To address equipment and network problems, Chronos Technology has developed Sync Audit®, a programme specifically designed to troubleshoot and characterise the Synchronisation performance of telecom networks and network elements. Chronos Technology have been actively engaged in carrying out sync audits for 15 years and have unrivalled expertise in this discipline. We deliver practical real world solutions and not just theoretical responses.

Using commercially available specialist test equipment and/or the Chronos’ SyncWatch Solution, our Sync Audit® experts conduct a thorough assessment which will pinpoint any problems. A Sync Audit® will analyse networks and equipment, verifies their compliance to Standards and locate problems. Recommended solutions are proposed providing the information necessary to achieve a quick and efficient fix.

Potential Clients Chronos has developed its Sync Audit® to be flexible, offering a number of specific applications suitable for either telecom equipment manufacturers, carriers or private network operators. Manufacturers

Testing of compliance to Equipment Standards Provides Test results to verify compliance with bid documentation Identification of design limitations Measurement of equipment noise transfer characteristics Equipment installation, commissioning and diagnostics testing

Carriers & Private Networks

Identify the link between service performance problems and poor network sync provision Verify your network conforms to the Standards Identify poor sync feeds from interconnect partners Identify problematic or noisy network elements Track down phase transients and non-systematic noise Evaluate manufacturers’ equipment in tenders Prioritise sync feeds at important nodes within the network Network planning support Equipment installation and commissioning testing Fault finding and sync loop tracking Resolve contention and interworking issues between different manufacturers’ equipment

D

ATA

SH

EE

T

KEY BENEFITS

Efficient and simple sync testing

Swift isolation of network or equipment problems

Delivers tangible evidence of synchronisation

Provides instant awareness of sync issue

Adaptable to multiple deployment and budget scenarios

Cost effective

TIMING & SYNCHRONISATION SOLUTIONS

Verifying the Sync Performance of Networks and Equipment

Chronos Technology Limited Stowfield House Stowfield Lydbrook GL17 9PD United Kingdom - +44 (0)1594 862200 www.chronos.co.uk sales@chronos.co.uk CTLcs038 r1.3— May12

TIMING & SYNCHRONISATION SOLUTIONS

Sync Audit®

Chronos Technology Limited Stowfield House Stowfield Lydbrook GL17 9PD United Kingdom - +44 (0)1594 862200 www.chronos.co.uk sales@chronos.co.uk