Agilent 37718A User Guide

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 Copyright Agilent

Technologies 2000

Agilent Part No. 37718-90218

Printed in U.K. Sept ember

2000.

Warranty

The information co ntained in this document is subject to change without notice.

Agilent Technologies makes no warra n t y of any kind with regard to this material, including, but not limited to, the implied warranties or merchantab ility and fitness for a particular purpose.

Agilent T ec hno logies shall not be liable for errors contained here in or f or incidental or consequential damages in connection with the furnishing, performance, or use of this material.

WARNING

Warning Symbols Used on the Product

The product is marked with this symbol when the user should refer to the instruction manual in order to protect the apparatus against damage.

The product is marked with this symbol to indicate that hazardous voltages are present

The product is mar ked with this symbol to indicate that a laser is fitted. The user should refer to the laser safety information in the Verification Manual.

Agilent Technologies UK Limited Telecommunications Networks Test Divi sion South Queensferry West Lothian, Scotland EH30 9TG

2DRAFT

User Guide DSn/SONET/ATM/POS Operation

OmniBER 718 SONET User Guide

About This Book

This book tells you how to select the features that you want to use for your test.

The selections available are presented in the following groups:

• Transmit and receive interfaces

• Test features, for example, the addition of errors and alarms to the test signal

• Measurements including test timing

• Storing, logging and printing results with general printer information

• Using instrument and disk storage

• Using the “Other” features.

The selections available will depend on the options fitted to your instrument. The examples given in this book cover all options and therefore may include selections which are not available on your instrument.

1 Introduction

Product Description 14 Conventions 15 Connecting to the Network 16 Connecting Accessories 20 Front Panel Soft Recovery (Cold Start) 21 OmniBER 718 Option Guide 22

2 Setting the Interfaces

Setting PDH/DSn Transmit Interface (Option 012) 26 Setting DSn THRU Mode 28 Setting SONET Transmit Interface 29 Setting Jitter Transmit Interface 33 Setting Wander Transmit Interface 35 Setting SONET THRU Mode 37 Using Smart Test 40 Setting PDH/DSn Receive Interface 45 Setting SONET Receive Interface 47 Setting Jitter Receive Interface 48 Setting Extended Jitter Receive Interface 49 Setting Wander Receive Interface 50

3 Selecting Test Features

Using Transmit Overhead Setup 52 Using Receive Overhead Monitor 54

Contents

Setting Overhead Trace Messages 56 Setting Overhead Labels 57 Generating Overhead Sequences 58 Using Receive Overhead Capture 60 Adding Frequency Offset to SONET Signal 62 Adding Frequency Offset to the DSn Signal 64 Setting up Signaling Bits 65 Setting Transmit Structured Payload/Test Signal 68 Setting Receive Structured Payload/Test Signal 70 Setting Transmit N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal 71 Setting Receive N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal 73 Inserting an External DSn Payload/Test Signal 74 Dropping an External Payload/Test Signal 77 Adding Errors and Alarms at the SONET Interface 80 Adding Errors and Alarms to a DSn Signal 81 Using FEAC Codes 82 Setting DSn Spare Bits 84 Adding Pointer Adjustments 85 Using Pointer Graph Test Function 93 Stressing Optical Clock Recovery Circuits 95 Generating Automatic Protection Switch (APS) Messages 97 Inserting and Dropping the Data Communications Channel 102 Using DS1 LOOP Codes 103

4 Making Measurements

Using Overhead BER Test Function 108 Performing a Trouble Scan 109

Contents

Test Timing 111 Making SONET Analysis Measurements 112 Making DSn Analysis Measurements 113 Measuring Frequency 114 Measuring Optical Power 115 Measuring Round Trip Delay 116 Monitoring Signaling Bits 118 Measuring Service Disruption Time 119 Performing a SONET Tributary Scan 122 Performing a SONET Alarm Scan 125 Performing a DSn Alarm Scan 126 Measuring Jitter 127 Measuring Extended Jitter 129 Measuring Wander 131 Measuring Jitter Tolerance 134 Measuring Jitter Transfer 138 Measuring Pointer Adjustment (Tributary) Jitter 144

5 ATM Operation

Setting up the Transmitter for ATM Payloads 150 Setting up the Convergence Sublayer 153 Setting Foreground Traffic 155 Setting Background Traffic 157 Setting Foreground and Background Distributions 158 Transmitting ATM Alarms 161 Adding ATM Errors 163 Viewing ATM Results 165 Setting up the Receiver for ATM Payloads 166 Setting up the Receiver ATM signal 168

Contents

Policing ATM Traffic 170 Measuring ATM Delay Performance 172 Measuring ATM Alarms 175 ATM Service Disruption 176

6 Packet over SONET (POS)

POS Protocol Stack 180 Setting up the Transmitter for POS Payloads 181 Setting HDLC Framing, Scrambling and HDLC Frame Check Sequence 183 Setting IP Packet (Datagram) Length and Inter-Packet Gap 186 Setting IP Header 188 Setting IP Addresses 189 Setting IP Payload 190 Adding POS Alarms 191 Adding POS Errors 192 Setting up the Receiver for POS Operation 193 Setting up the Receiver POS signal 195 Viewing POS Results 196 POS Applications 197 Channelized Testing 198 Fully Exercising POS Hardware Architecture 200 Throughput Testing 204 Continuity Test 208 POS Service Disruption 211 HDLC Frame Stuffing 214 Jitter Tolerance Testing of POS Equipment 217

Contents

7 Storing, Logging and Printing

Saving Graphics Results to Instrument Store 222 Recalling Stored Graph Results 223 Viewing the Bar Graph Display 225 Viewing the Graphics Error and Alarm Summaries 227 Logging Graph Displays 229 Logging Results 231 Logging on Demand 241 Logging Jitter Tolerance Results 245 Logging Jitter Transfer Results 247 Logging Results to Parallel (Centronics) Printer 249 Logging Results to GP-IB Printer 250 Logging Results to Internal Printer 251 Logging Results to RS-232-C Printer 252 Printing Results from Disk 253 Connecting a Printer to a Parallel Port 254 Changing Internal Printer Paper 255 Cleaning Internal Printer Print Head 258

8 Using Instrument and Disk Storage

Storing Configurations in Instrument Store 260 Titling Configuration in Instrument Store 261 Recalling Configurations from Instrument Store 262 Formatting a Disk 263 Labeling a Disk 264 Managing Files and Directories on Disk 265 Saving a Screen Dump to Disk 272 Saving Graphical Results to Disk 274

Contents

Saving Data Logging to Disk 276 Saving Configurations to Disk 277 Recalling Configuration from Disk 278 Recalling Graphics Results from Disk 279 Copying Configuration from Instrument Store to Disk 280 Copying Configuration from Disk to Instrument Store 282 Copying Graphics Results from Instrument Store to Disk 284

9 Selecting and Using "Other" Features

Coupling Transmit and Receive Settings 288 Setting Time & Date 289 Enabling Keyboard Lock 290 Enabling Beep on Received Error 291 In-Band DS1 Loopcode 156MTS Compatibility 292 Suspending Test on Signal Loss 293 REI-L Result/Enable 294 AIS-L Result/Enable 295 Graph Storage Resolution 296 Setting Error Threshold Indication 297 Setting Screen Brightness and Color 298 To Generate a New Jitter Mask 299 To change the parameters of a User-defined jitter mask 301 Running Self Test 303 Trigger Output 306

Contents

10 STS-1 SPE Background Patterns

11 ETSI/ANSI Terminology

ETSI/ANSI Conversion and Equivalent Terms 312

12 Glossary of Terms

Contents

"Product Description " page 14 "Conventions " page 15 "Connecting to the Network " page 16 "Connecting Accessories " page 20 "Front Panel Soft Recovery (Cold Start) " page 21 "OmniBER 718 Option Guide " page 22

1 Introduction

Product Description

The OmniBER Communications Performance Analyzer provides all the test

capability you need to fully verify the performance of today’s high-capacity transmission systems and networks.

The main features of a dual standard (SDH/SONET) instrument are as follows:

• Multi-rate transmission testing from DS0 to OC-48.

• Supports concatenated payloads of VT 1.5 to STS-48c.

• Full PDH/T- carrier testing.

• Direct measurement of protection switching time.

• Powerful thru-mode testing for SONET ring turn-up.

• Comprehensive SONET overhead testing.

• Packet over SONET/SDH (POS) and ATM payloads up to 2.5 Gb/s.

• Fast access to key measurement tasks via Smart Test.

• Optical power and line frequency measurements.

• J0 section trace for DWDM testing

• J1 and J2 path trace for network path testing

• Optional integrated graphical printer.

• Transmit and Receive can be independently configured.

Conventions

The conventions used in this manual to illustrate instrument keys and display information are as follows:

TRANSMIT

PARALLEL

This is an example of a hardkey. Hardkeys (located to the right of the display) are used to give access to different sets of instrument settings, or select dedicated instrument functions. The key shown here displays the transmit settings.

This is an example of a softkey. Softkeys (located below the display) are used to select instrument settings. The values associated with softkeys change as you move the display cursor from one instrument setting to another.

These are the cursor control keys. They are used to move the display cursor from one instrument setting to another.

This is an example of a pop-up menu. Pop-up menus are an alternative way of selecting instruments settings (instead of using softkeys) . To access a pop-up menu, highlight an instrument setting, then use the key.

This symbol (when it appears next to settings on the display) indicates that there is a pop-up application associated with the instrument setting. To access a pop-up application, highlight the instrument setting which has this symbol, then use the

SET

key.

SET

This symbol appears at the bottom right of the display when an optical transmit module is fitted to the instrument. The symbol’s background changes from black to yellow when the optical output goes active.

Connecting to the Network

The network connectors are located on the modules at the side of the instrument. The connections available depend on the options fitted to your instrument.

Before Connecting, note the Warning and Caution information given.

Removing/Inserting Modules

Modules should only be removed or inserted by trained personnel.

All Connectors

CAUTION When connecting or disconnecting, ensure that you are grounded or,

make contact with the metal surface of the Mainframe with your free hand to bring you, the module, and the mainframe to the same static potential. Modules remain susceptible to ESD damage while the module is installed in the Mainframe Additional ESD information is required when servicing, see your Verification manual for further information.

Connecting to the Network

Optical Interface Connectors

For your protection, review all laser information given in this manual and th e Verification manual before installing or using the instrument.

WARN IN G To prevent personal injury, avoid use that may be hazardous to others, and

maintain the module in a safe condition En sure the information given below is reviewed before operating the module.

Laser Product Classification

All optical modules are classified as Class I (non-hazardous) laser product in the USA which complies with the United States Food and Drug Administration (FDA) Standard 21 CFR Ch.1 1040.10, and are classified as Class 1 (non-hazardous) laser products in Europe which complies with EN 60825 -1 (199 4).

T o avoid hazardous expo sure to laser radiation, it is recommen ded that the f ollowing practices are observed during system operation:

• ALWAYS DEACTIVATE THE LASER BEFORE CONNECTING OR DISCONNECTING OPTICAL CABLES.

• When connecting or disconnecting optical cables between the module and device-under-test, observe the connection sequences given below.

Connecting: Connect the optical cable to the input of the device-under-test

before connecting to the module’s Optical Out connector.

Disconnecting: Disconnect the optical cable from the module’s Optical Out

connector before disconnecting from the device-under-test. Always fit the fibre optic connector dust caps over the laser aperture.

• NEVER examine or stare into the open end of a b roken, severed, or disconn ected optical cable when it is connected to the module’s Optical Out connector.

• Arrange for service-trained personnel, who are aware of the hazards invo lved, to repair optical cables.

Connecting to the Network

CAUTION 1. Use of controls or adjustments or performance of procedures other than those

specified herein may result in hazardous radiation exposure.

2. Always fit the fibre optic connector dust caps on each connecto r when not in us e. Before connection is made, always clean the connector ferrule tip with acetone or alcohol and a cotton swab. Dry the connector with compressed air. Failure to maintain cleanliness of connectors is liable to cause excessive insertion loss.

Laser Warning Symbols The front p anel of the optical module has the following label: CLASS 1 LASER PRODUCT

NOTE CLASS 1 LASER PRODUCT translates as follows:

Finnish - LUOKAN 1 LASERLAITE

Finnish/Swedish - KLASS 1 LASER APPARAT

This label indicates that the radiant energy present in this instrument is nonhazardous.

OPTICAL IN Allows connection of an optical si gnal, wavelengt h 1200 to 1600 n m, at a maximum

input power level of -8 dBm. NEVER EXCEED +3 dBm. Accepts SONET signals OC-1, OC-3, OC-12 and OC-48 and SDH signals STM-0, STM-1, STM-4 and STM-16 depending on the instrument options fitted.

OPTICAL OUT Provides optical signals OC-1, OC-3, OC-12 or OC-48 at wavelength 1290 nm to

1330 nm, at a typical power level of +1 dBm. Also provides SDH signals STM-0, STM-1, STM-4 and STM-16 depending on the instrument options fitted.

Connecting to the Network

Cleaning Optical Connectors

It is recommended that the optical connectors be cleaned at regular intervals using the following materials:

Description Part Number

Blow Brush 9300-1131 Isopropyl Alcohol 8500-5344 Lens Cleaning Paper 9300-0761 Adhesive T ape Kit 15475-68701

CAUTION Do not insert any tool or object into t he IN or OUT port s of the instrum ent as damage

to or contamination of the optical fibre may result.

1 Recall Default settings (STORED SETTINGS 0) and remove the power from the

OmniBER 718.

2 Remove the adapters from the IN and OUT ports. Use an 11 mm spanner to

slacken the nut securing the adapter. On re-assembly tighten the nut using a torque spanner to 1.5 Nm.

3 Using the blow brush with the brush removed blow through the ferrule of the

standard flexible connector and the adapter.

CAUTION If the optical fibre of the fixed connector requires further cleaning this entails

disassembly of the modul e which should only be carried out by suitably trained service personnel.

4 Apply some isopropyl alcohol to a piece of the cleaning paper and clean the barrel

of the adapter. Us ing a new piece of cleaning paper , clean the face of the adapter . Repeat this operation, using a new piece of cleaning paper each time.

5 Lightly press the adhesive side of the tape provided against the front of the

adapter, then remove it quickly - repeat twice. This removes any parti cles of cleaning paper which may be present.

6 Replace the adapters on the flexible connector.

Connecting Accessories

LID Provides the output for the option 602 printer which is fitted in the cover (LID) of

the instrument.

VGA Provides the output for a display monitor.

HANDSET Allows connection of a telephone handset for communication across the network.

Printer HP-IB (GPIB), RS232, PARALLEL ONLY

Remote Control HP-IB (GPIB), RS232, 10 BASE -T

The port selected for external printer use is not available for remote control. See "Connecting a Printer to a Parallel Port " page 254.

Remote control connection is given in the Remote Control Manual. The port selected for remote control use is not available for an external printer.

10 Base-T Lan Connection Radiated Emissions

To ensure compliance with EN 55011 (1991) a category 5, STP patch lead, RJ45 cable should be used to connect the LAN port on the processor module marked "10 Base-T".

Front Panel Soft Recovery (Cold Start )

Front Panel Soft Recovery (Cold Start)

Use the following procedure if you need to perform a front panel soft recovery (i.e. cold start) of the instrument.

Soft Recovery Procedure

1 Switch off the instrument. 2 On the instrument front panel - press and hold so ftkeys 0 and 4 simultaneously

(the softkeys immediately below the display; key 0 is on the extreme left).

3 Power up the OmniBER 718 while holding the softkeys pressed. 4 When the LOS LED has flashed OFF and then ON again, the keys can be

released.

5 The LOS LED will flash OFF/ON again several times (7), followed by an audible

‘beep’ and the display indicating ‘Initializing Instrument’.

6 Once the initialization is complete the display will indicate:

‘Firmware Revision Update’ ‘Default settings assumed’ Hit any key to attempt restart’

7 Hit any key, then wait approximately 10 seconds. The instrument should return

to its default settings and normal operation.

OmniBER 718 Option Guide

This guide explains the features offered with each OmniBER Mainframe and its associated options. There are three mainframes as follows:

• The 37718A

• The 37718B

• The 37718C

The instrument test interfaces are:

2.5 Gb/s, 622 Mb/s, 155 Mb/s, 52 Mb/s, DS1 (1.5 Mb/s), DS3 (45 Mb/s), E1 (2 Mb/s), E2 (8Mb/s), E3 (34 Mb/s).

Mainframe test rate capability

Mainframe T est Rate Capability

37718A 2.5 Gb/s, 622 Mb/s, 155 Mb/s and 52

Mb/s 37718B 622 Mb/s, 155 Mb/s and 52 Mb/s 37718C 155 Mb/s and 52 Mb/s

Note that 52 Mb/s and 155 Mb/s electrical testing is included in the base mainframe.

SDH/SONET Interf a c e

Interface Option

SDH only 001

Dual standard SDH/SONET (ANSI/ITU-

002

OmniBER 718 Option Guide

Tributary test options

Option

PDH/T-carrier DS1, DS3, 2 Mb/s, 8 Mb/s, 34 Mb/s and 140 Mb/s

2 Mb/s into DS3 mapping (also requires option 012) 014 Replaces BNC connector with WECO 560 620

Optical interface

An optical interface must be ordered if an 37718A or 37718B is required.

Option

1310 nm only 104 1550 nm only 105 Dual wavelength 1310 nm/1550 nm 106 Replaces FC/PC adapters with SC 610 Replaces FC/PC adapters with ST 611

Jitter

Option

012

Adds jitter to all rates 200

OmniBER 718 Option Guide

ATM/POS

Option

ATM payloads (requires option

350)

POS payloads (requires option

350)

Advanced payload engine 350

Please note that in earlier versions of the OmniBER the list of AT M options included options 300, 301 and 302. These options have now been merged into one ATM option 300 (as listed above). A new Advanced payload engine option 350 has been added which must be ordered with an ATM or POS option.

Accessory options

Remote Omnibook controller 600 RS-232-C, GPIB and LAN remote control

interfaces 80-column in-lid printer 602

300

310

Option

601

“Setting PDH/DSn Transmit Interface (Option 012)” page 26 “Setting DSn THRU Mode” page 28 “Setting SONET Transmit Interface” page 29 “Setting Jitter Transmit Interface” page 33 “Setting Wander Transmit Interface” page 35 “Setting SONET THRU Mode” page 37 “Using Smart Test” page 40 “Setting PDH/DSn Receive Interface” page 45 “Setting SONET Receive Interface” page 47 “Setting Jitter Receive Interface” page 48 “Setting Extended Jitter Receive Interface” page 49 “Setting Wander Receive Interface” page 50

2 Setting the Interfaces

This chapter tells you how to set the instrument interfaces to match the network being tested.

Setting the Interfaces

Setting PDH/DSn Transmit Interface (Option 012)

Description DSn transmit interface settings should match network equipment settings of R ate,

Termination and Line Code and determine the Payload to be tested.

TIP: To set the Transmitter and Receiver to the same interface settings choose

SETTINGS CONTROL COUPLED

HOW TO: 1 Choose the required SIGNAL rate from 2 Mb/s, 8 Mb/s, 34 Mb/s, 140 Mb/s PDH,

plus DS1, DS3 T-carrier interfaces.

2 Choose the required CLOCK SYNC source, internally generated, externally

generated or recovered from the received PDH/DSn signal. If you select an external clock source, connect the external source to the appropriate port on the OmniBER clock module.

OTHER

3 If DS1 or DS3 is chosen, choose the required OUTPUT LEVEL. 4 If you have chosen 2 Mb/s as the SIGNAL rate, choose the required

TERMINATION. (At all other signal rates the impedance is fixed).

Setting the Interfaces

Setting PDH/DSn T ransmit Interface (Option 012)

5 If you have chosen 8 Mb/s, 2 Mb/s or DS1 as the SIGNAL rate, choose the

required LINE CODE. (At 140 Mb/s, 34 Mb/s and DS3 coding is fixed).

6 If required, choose the FREQUENCY OFFSET value.

See “Adding Frequency Offset to the DSn Signal” page 64.

7 Choose the required PAYLOAD TYPE.

If is required must be chosen.

STRUCTURED FRAMED

If is chosen the DSn test signal must be set up. See “Setting

STRUCTURED

Transmit Structured Payload/Test Signal” page 68. If you have chosen 2 Mb/s, DS1 or DS3 as the DSn SIGNAL rate, the Framed choice is expanded to provide a menu of framing types.

8 Choose the PATTERN type and the PRBS POLARITY.

Additional Patterns at DS1

9 If you select a DS1 SIGNAL , two 8-bi t pattern s and a 55 Octe t pat tern are ad ded

to the list of available patterns. The 8-bit patterns are as follows:

Table 1 8-Bit Patterns

Type Pattern

1-in-8 F01000000 2-in-8 F01100000

Note 1: F indicates the position of the framing bit with respect to the 8-bit pattern when the framed data is generated Note 2: Both 8-bit patterns and the 55 Octet pattern can only be selected as a payload for the whole DS1, i.e. they can not be selected as a pattern for an individual 64 kb/s channel. Note 3: Bit errors can be added to both 8-Bit and 55 Octet test patterns as with the other avai lable test pat terns.

The 55 Octet pattern uses the Daly pattern as per ANSI T1.403

Setting the Interfaces

RECEIVE

Setting DSn THRU Mode

Description THRU mode is used to non-intrusively monitor DSn lines where no protected

monitor points are available. Note that since THRU mode locks some user settings, you must set SIGNAL RATE (DS1 or DS3), before selecting THRU mode. Two modes of operation are possible:

Monitor Mode: This is when the Entire Frame Error Rate field is set to OFF. In this mode the received signal is passed through or transmitted unchanged, and the instrument monitors errors and alarms as normal DS1 operation.

Full Frame Overwrite Mode: In this mode any bit in the entire frame can be errorred at a user defined rate. The bit that is errorred can be any bit in the frame, including the frame bit (hence the title of “Full Frame Overwrite”). The error rates available are:

Data error rates: 1.0E-3, 1.0E-4, 1.0E-5, 1.0E-6, 1.0-E-7 and user programmable in 0.1 steps from 1.1E-3 to 1.0E-9

HOW TO: 1 Make the required SIGNAL RATE cho ice on the PDH/DSn

and displays.

2 Select THRU MODE as shown in the figure above. 3 Select an entire frame error rate from the choices given or us e the USER softkey

to program an error rate.

TRANSMIT

Setting the Interfaces

Setting SONET Transmit Interface

Payload Selection

One of the key features of the OmniBER 718 is the ability to test concatenated payloads. The following gives a brief des cri pti on of concatenat ed payl o ads , and the benefits of using them.

Concatenated Payloads

Bulk filled or contiguous payload structures e.g. (STS-48c) are designed for carrying broadband services. The entire payload area is used to carry the service with no structured mapping or channelization. In the case of a concatenated STS-48 (denoted STS-48c), the virtual container area is entirely filled by a single STS-48c SPE. This STS-48c SPE consists one Path Overhead and a single container capable of carrying a tributary signal operating at rates up to approximately 2.5 Gb/s. Once assembled a STS-48c SPE is multiplexed, switched and transported through the network as a single entity.

Benefits: Test the entire bandwidth in one go, and reduce test times. The following table illustrates the reduced test times using concatenated payloads.

Test Time (based on 100

errors)

Performance

test limit

10-

STS-48c SPE

payload

48 days >2 years

4.8 days 77 days

1 1.6 hou rs 7.7 days

1.2 hour 18.5 hour

7 minutes 1.9 hours

STS-3c SPE

payload

Setting the Interfaces

Setting SONET Transmit Interface

Description SONET transmit interface settings should match the network equipment settings of

Rate, Wavelength and Mapping, determine the payload to be tested and set background conditions to prevent alarms while testing.

TIP: If you wish to set the OmniBER 718 transmitter and receiver to the same interface

settings choose

OTHER

SETTINGS CONTROL COUPLED

Laser On/Off Control

If you wish to switch off the laser when connecting/disconnecting cables, set the field between the wavelength and INTERNAL selections to OFF. When the laser is on the laser symbol at the bottom right of the display is illumin a ted (yellow).

HOW TO: 1 Make your choice of SIGNAL rate.

If Option 106, Dual Wavelength optical module, is fitted and an optical rate is chosen, choose the required wavelength (1550 or 1310). If STS-1 is chosen, choose the required interface level. Choose unless is required. If is

INTERNAL THRU MODE THRU MODE

chosen, see "Setting SONET THRU Mode " page 37.

2 Make your choice of CLOCK synchronization source. The clock can be

internally sourced from the instrument, recovered from the signal at the optical RECEIVE port or externally sourced from the CLOCK REF IN ports (MTS 64 kb/s, BITS 1.5 Mb/s or 10 MHz REF).

Setting the Interfaces

Setting SONET Transmit Interface

3 If required choose the FREQUENCY OFFSET value. See “Adding Frequency

Offset to SONET Signal” page 62.

4 Choose the required and PAYLOAD TYPE, then

B/G MAPPING

F/G MAPPING

and BACKGROUND selection. The FOREGROUND selection is the channel that is chosen for test purposes. The BACKGROUND patterns are not used for test purposes and are either the same as the test channel or set to UNEQUIPPED.

Mapping may be selected from a pictorial display by moving the cursor to MAPPING and pressing .

SET

Use and to move between STS Layer choice, VT Layer choice and Payload Layer choice. Use and to choose the mapping.

SET

Use to confirm your choice and return to the

SONET MAIN SETTINGS

display. 5 If VT -6 map ping is chosen, VT CONCATENATION selection is enabled, choose

or the tributary at which the concatenation b e gins, VT6 -2C thr oug h VT6 -

OFF

6C. The BACKGROUND, PATTERN IN OTHER VT-6s is fixed at NUMBERED, that is, each VT-6 contains a unique number to allow identification in case of routing problems.

6 If required, choose DS1/2M/34M/DS3 O F FSET value. See “Adding Frequency

Offset to SONET Signal” page 62

Setting the Interfaces

Setting SONET Transmit Interface

7 If FULL SPE, VT -6, VT-2 or VT-1.5 mapp ing is chosen, choose the tes t tributary ,

including the STS-3 for an OC-12/OC-48 signal.

8 Choose the payload framing under PAYLOAD TYPE or VT PAYLOAD.

If is required must be chosen.

STRUCTURED FRAMED

If is chosen, the Payload test signal must be set up. See “Setting

STRUCTURED

Transmit Structured Payload/Test Signal” page 68. If is chosen, see “Inserting an External DSn Payload/Test Signal”

INSERT

page 74. If you have chosen 2 Mb/s, DS1 or DS3 under Mapping, the Framed choice is expanded to provide a menu of framing types.

9 Choose the PATTERN type and PRBS polarity.

10 Choose the mapping required in the background (non-test) STS’s. Refer to

Appendix A for a table of background patterns for STS-1 SPE.

11 If VT mapping is chosen for the test STS, choose the PATTERN IN OTHER

VT’s.

Setting the Interfaces

Setting Jitter Transmit Interface

Description: Option 200 required for jitter and option 012 for PDH/DSn.

HOW TO: 1 If you are adding jitter to the DSn signal, set up the DSn transmit interface. See

You can add jitter to the transmitted DSn or SONET signal at DS1, DS3, 2 Mb/s, 34 Mb/s, STS-3, OC-3, OC-12, and OC-48. You can source the jitter modulation internally or from an external source. Jitter measurement up to 2.5 Gb/s is available when ATM or POS is selected as a payload.

Chapter “Setting PDH/DSn Transmit Interface (Option 012)”.

2 If you are adding jitter to the SONET signal, set up the SONET tran smit interface.

See “Setting SONET Transmit Interface” page 29.

3 Choose JITTER/WANDER .

If you wish to add wander to the DSn or SONET signal, See “Setting Wander Transmit Interface” page 35.

4 Choose JITTER .

If you wish to perform a Jitter Tolerance measurement, choose

AUTO TOLERANCE

If you wish to perform a Jitter Transfer measurement choose

TRANSFER FUNCTION

JITTER

. See “Measuring Jitter Tolerance” page 134.

. See “Measuring Jitter Transfer” page 138.

Setting the Interfaces

Setting Jitter Transmit Interface

Choose the modulation source. If adding jitter to the DSn signal and is chosen, connect the

EXTERNAL

external source to the MOD IN port of the DSn Jitter TX module. Up to 10 UI of external jitter modulation can be added at the MOD IN port. If adding jitter to the SONET signal and is chosen, connect the

EXTERNAL

external source to the MOD IN port of the SONET Clock modu le. Up to 20 UI of external jitter modulation can be added at the MOD IN port.

5 If you have selected an Modulation Source, choose the JITTER

INTERNAL

CONTROL setting required. You can choose the jitter range, jitter modulating frequency and jitter amplitude if is chosen.

OFF

If you choose , the OmniBER 718 will "sweep" through the ITU-T jitter

SWEPT

mask (G.823 for PDH, GR-499 or G.824 for DSn, G.958, G.825 or GR-253 for SONET) adjusting the jitter amplitude according to the jitter frequency . With the

SWEPT

field selected, press SET on t he instrument front panel for a display of

the jitter mask sweep (an example is given below).

If you choose , you can choose the "spot" jitter frequency. The jitter

SPOT

amplitude is adjusted and controlled according to your jitter frequency choice.

TIP: If, when using the SWEPT MASK capability, a problem occurs around a certain

frequency, this may require closer examination. Stop the sweep at that point by choosing . You can then control the "spot" jitter frequency to make closer

SPOT

examination of the problem.

Setting the Interfaces

Setting Wander Transmit Interface

Description: You can add Wander to the 2 Mb/s DSn signal and the STS-3, OC-3,

OC-12 or OC-48 SONET signal. Wander is also available when you select an ATM or POS payload.

HOW TO: DSn Wander (2 Mb/s)

1 Set up the PDH transmit interface, choose CLOCK and select the SOURCE

required from the menu. If you select EXTERNAL connect the ex ternal source to the REF IN port on the CLOCK module. See “Setting PDH/DSn Transmit Interface (Option 012)” page 26.

2 Choose JITTER/WANDER .

If you wish to add jitter to the DSn signal, See “Setting Jitter Transmit Interface” page 33.

3 Choose WANDER . 4 Choose the WANDER MASK setting required.

You can choose the wander modulating frequency and wander amplitude if

is chosen.

OFF

If you choose , you can choose the "spot" wander frequen cy. The wander amplitude is adjusted and controlled according to your wander frequency choice.

SPOT

WANDER

Setting the Interfaces

Setting Wander Transmit Interface

SONET Wander (STS -3, OC-3, OC -12, OC-48)

5 Set up the SONET transmit interface. See “Setting SONET Transmit Interface”

page 29.

6 Choose JITTER/WANDER .

WANDER

If you wish to add jitter to the SONET signal, see "Setting Jitter Transmit Interface " page 33.

7 Choose WANDER .

8 Choose the WANDER MASK setting required.

You can choose the wander modulating frequency and wander amplitude if

is chosen.

OFF

If you choose , you can choose the "spot" wander frequen cy. The wander

SPOT

amplitude is adjusted and controlled according to your wander frequency choice.

Setting the Interfaces

Setting SONET THRU Mode

Description THRU mode is used to non-intrusively monitor SONET lines where no protected

monitor points are available. To enable THRU mode select the

MAIN SETTINGS

page. Select SIGNAL RATE before selecting THRU mode.

The entire frame can be errorred at a user defined rate if PAYLOAD OVERWRITE and TOH+POH CHANNEL OVERWRITE are both set to . If either overwrite is enabled the ENTIRE FRAME ERROR RATE f unctio n is disabled.

There are nominally three modes of operation as follows:

1. Transparent mode: This is the case when the PAYLOAD OVERWRITE field is set to OFF. The received signal is passed through the transmitter completely unchanged. The figure below illustrates the settings for this mode.

TRANSMIT

OFF

2. Hitless THRU Mode:

This mode enables you to change the channel under test and the payload mapping without causing errors in the line signal or any other payload channel, or having to switch out of THRU mode. When yo u select a Payload Overwrite choice ( other than OFF) an additional field is displayed which allows you to enable/disable Payload Overwrite. If Payload Overwrite is disabled the instrument remains transmitting while you select another channel/tributary (see figure on next page). In this mode any Section or Line CV errors are recalculated before transmission.

Setting the Interfaces

TRANSMIT

Setting SONET THRU Mode

3. Payload Overwrite: In this mode you can overwrite the payload as explained in the following text. Any Path CV errors are recalculated before transmission. Use the HOW TO procedure to setup your instrument for THRU Mode operation.

OC-1/STS-1, OC-3/STS-3

You can substitute a new payload, Section and Line Overhead (TOH) and Path overhead (POH) in the received OC-1/STS-1 or OC-3/STS-3 signal for testing.

OC-12, OC-48 The overhead and payload may be overwritten for STS-3c SPE and STS-1. PAYLOAD OVERWRITE is not available for STS-12C or STS-48C. TOH+POH CHANNEL overwrite is available for STS-12C and STS-48C.

HOW TO: 1 Make the required SIGNAL RATE choice, and select THRU MODE on the

SONET page 29.

2 Make the PAYLOAD OVERWRITE choice required.

Hitless Mode: The Payload Overwrite enable/disable field (next to the PAYLOAD OVERWRITE field) defaults to OFF.

If STS-3c SPE, STS-1 SPE, VT-6, VT-2 or VT-1.5 is chosen, the Section, Line and Path CVs are recalculated before transmission and the Mapping, Selected VT, VT Payload, Pattern, Tributa ry Offset and Pattern in other VT’s settings are displayed. To choose the settings in these, See "Setting SONET Transmit Interface " page 29, steps 4 through 10.

display, See "Setting SONET Transmit Interface "

Setting the Interfaces

Setting SONET THRU Mode

3 Switch the P AYLOAD OVERWRITE enable/disable field to ON. Test functions

are available whilst Payload Overwrite is enabled. Select the

TEST FUNCTION

folder and setup as required.

4 Make the TOH+POH CHANNEL OVERWRITE choice required.

The Section, Line and Path CVs are recalculated before transmission.

Setting the Interfaces

Using Smart Test

Smart Setup The Smart Setup feature simplifies instrument operation by:

• Allowing the instrument to auto-configure on the incoming signal. It will attempt

to identify signal structure, and detect mixed payload signal structures and alarms. The OmniBER 718 automatically displays all of the J 1 trace identifiers. Once the received signal has been identified you can select a channel of interest and explore further into the payload.

Smart Tests Allows you to quickly access the most commonly used instrument features such as:

• Signal quality

• Functional tests

• Jitter tests

• ATM tests

• POS tests

• Settings (stored, logging, Tx/Rx coupling and trigger output en able)

HOW TO: 1 Connect the 37718A to the network an d choose if necessary the required SONET

RECEIVE

SONET, but can not select between SDH and SONET).

2 Press .

interface on the 37718A (Smartsetup will select PDH or SDH/

SMART TEST

Setting the Interfaces

Using Smart Test

3 With Smartsetup highlighted, press to auto-discover information about

the receive signal.

Or press to exit Smart Tests.

CANCEL

START

An example of a typical display after choosing t o RUN Smartsetup is shown below. Note: The channel information displayed is the one obtained the last time a SCAN was performed. If you have changed the input signal since the last Smartsetup you must perform a RESCAN now. If you have selected a PDH/DSn interface and a PDH/DSn signal is received, a channel mapping display indicating the framing and status of each channel is given, see below.

Setting the Interfaces

Using Smart Test

SET UP RX

key If you select an individual channel using the cursor control keys, and then select

SET UP RX

, the instrument exits smartsetup and sets the receiver to the test

pattern detected in the selected channel.

To run a Smart Test (Signal Quality - Frequency Measurement):

1 Ensure a valid signal is connected to the instrument’s Receive port. 2 Press .

SMART TEST

3 Use the up and down cursor control keys to select Signal quality. 4 Use the left and right cursor control keys to access the tests. 5 Use the up and down cursor control keys to select Frequency Measurement.

6 Press

START

to display the frequency screen. Or press to exit Smart

CANCEL

Tests.

To run an ATM Smart Test

1 Ensure a valid signal is connected to one of the instrument’s Receive ports. 2 Press .

SMART TEST

3 Use the down cursor control key to select ATM payload setup or ATM tests. 4 Use the right cursor control key to access the setups/tests.

Setting the Interfaces

Using Smart Test

5 Use the down cursor control key to select required setup/test.

Note: It is not possible for OmniBER to find ATM in a PDH payload in Sm art setu p.

Setting the Interfaces

Using Smart Test

To run a POS Smart Test

1 Ensure a valid signal is connected to one of the instrument’s Receive ports. 2 Press .

SMART TEST

3 Use the down cursor control key to select POS Setup/Tests. 4 Use the right cursor control key to access the setups/tests. 5 Use the down cursor control key to select required setup/test. 6 Press

SELECT

to display the required S etup screen. Or press to exit

CANCEL

Smart Tests.

Setting the Interfaces

Setting PDH/DSn Receive Interface

Description DSn Receive interface settings should match the network equipment settings of

Rate, Termination and Line Code and determine the Payload to be tested.

TIP: To set the transmitter and receiver to the same interface settings choose

SETTINGS CONTROL COUPLED

HOW TO: 1 Choose the required SIGNAL rate.

2 If you have chosen 2 Mb/s as the SIGNAL rate, choose the required

TERMINATION. (At all other rates the impedance is fixed.)

OTHER

3 If you have chosen 8 Mb/s, 2 Mb/s or DS1 as the SIGNAL rate, choose the

required LINE CODE. (At 140 Mb/s, 34Mb/s and DS3 coding is fixed.)

4 If you are measuring at the network equipment monitor point, set the LEVEL

field to . In this case the received signal will be 20 to 30 dB below th e normal leve l. Choose the GAIN required to return the received signal to normal. Choose EQUALIZATION to compensa te for cable losses if required.

5 Choose the PAYLOAD TYPE.

MONITOR

Setting the Interfaces

Setting PDH/DSn Receive Interface

If is required must be chosen.

STRUCTURED FRAMED

If is chosen, the PDH/DSn test signal must be set up. See

STRUCTURED

“Setting Transmit Structured Payload/Test Signal” page 68. If you chose 2 Mb/s, DS1 or DS3 as the PDH/DSn SIGNAL rate, the FRAMED choice is expanded to provide a menu of framing types.

6 Choose the PATTERN type and the PRBS POLARITY required.

Additional Patterns at DS1

7 If you select a DS1 SIGNAL, two 8- bit pa tterns and a 55 Octet p attern are ad ded

to the list of available patterns. They are as follows:

Table 2 8-Bit Patterns

Type Pattern

1-in-8 F01000000 2-in-8 F01100000

The 55 Octet pattern uses Daly pattern as per ANSI T1.403.

Setting the Interfaces

Setting SONET Receive Interface

Description SONET Receive interface settings should match the network equipment settings of

Rate and Mapping, and determine the payload to be tested.

TIP: If you wish to set the OmniBER 718 transmitter and receiver to the same interface

settings, choose receiver to be configured to the same settings as the transmitter.

OTHER

SETTINGS CONTROL COUPLED

. This causes the

HOW TO: 1 Choose the required SIGNAL source either electrical or optical.

If STS-1 or STS-3 is chosen, choose the required LEVEL. If the LEVEL chosen is choose the required GAIN.

MONITOR

2 Choose mapping and type of payload. 3 If VT-6 mapping is chosen, and CONCATENATION is enabled, choose the

tributary at which the concatenation begins. If VT-6, VT-2 or VT-1.5 mapping is chosen, choose the test tributary, including the STS-3 for an OC-12/OC-48 signal.

4 Choose the payload framing under PAYLOAD TYPE or VT PAYLOAD.

If is required must be chosen.

STRUCTURED FRAMED

If is chosen the Payload test signal must be set up. See “Setting

STRUCTURED

Receive Structured Payload/Test Signal” page 70. If DROP is chosen, see “Dropping an External Payload/Test Signal” page 77 .

5 Choose the PATTERN type and PRBS polarity.

Setting the Interfaces

Setting Jitter Receive Interface

Description: Option 200 required for Jitter operation.

Jitter and error measurements are made simultaneously when a jitter option is fitted. Jitter measurement up to 2.5 Gb/s is also available when ATM or POS is selected as a payload. The jitter receive interface is selected with

JITTER

or MEASUREMENT TYPE .

RECEIVE

SONET JITTER JITTER

RECEIVE

PDH/DSn

The choices made on the jitter receive interface determine the jitter measurement range, the threshold level for determining a jitter hit and which filters are used in the jitter measurement.

HOW TO: 1 Choose the RECEIVER RANGE - the jitter measurement range.

2 Choose the HIT THRESHOLD level - if the received jitter exceeds the value

chosen a jitter hit is recorded.

3 Choose the FILTER you wish to inclu de in th e peak to peak and RMS jitter

measurement. The choices are: OFF, LP, HP1, HP2, 12kHz HP, LP+HP1, LP+HP2, LP+12kHz HP

4 If you have selected a PDH/DSn Receive Interface you can also select FILTER

VERSION, O.171 or O.172/GR-499. The selection is not available with a SONET Receive Interface.

Setting the Interfaces

JITTER

Setting Extended Jitter Receive Interface

Description: Extended Jitter measurements are made in a jitter bandwidth of 0.1 Hz to 25 kHz.

These measurements are made at the upper end of the standard wander frequency range and the lower end of the standard jitter frequency range. The extended jitter receive interface is selected with

SONET

MEASUREMENT TYPE .

RECEIVE

PDH/DSn JITTER

EXTENDED

The choices made on the jitter receive interface determine the threshold level for determining a jitter hit. The measurement Range and the Filters are not selectable.

RECEIVE

HOW TO: 1 Choose MEASUREMENT TYPE

2 Choose the HIT THRESHOLD level - if the received jitter exceeds the value

chosen a jitter hit is recorded.

EXTENDED

Setting the Interfaces

MAIN SETTINGS

Setting Wander Receive Interface

Description: You can measure Wan der at all DSn and SONET rates. An external timing r eference

should be selected on the or

TRANSMIT

display to ensure accurate Wander results.

PDH/DSn SONET

HOW TO: 1 Choose an external timing reference on the

SONET

MAIN SETTINGS

TRANSMIT

display . See, “Setting SONET Tran smit Interface” page 29.

2 If you intend to measure wander on a DSn signal, set up the DSn receive

interface. See, “Setting PDH/DSn Receive Interface” page 45.

3 If you intend to measure wander on a SONET signal, set up the SONET receive

interface. See, “Setting SONET Receive Interface” page 47.

4 Choose MEASUREMENT TYPE

WANDER

5 Choose the wander HIT THRESHOLD - if the received wander exceeds the value

chosen a wander hit is recorded.

“Using Transmit Overhead Setup” page 52 “Using Receive Overhead Monitor” page 54 “Setting Overhead Trace Messages” page 56 “Setting Overhead Labels” page 57 “Generating Overhead Sequences” page 58 “Using Receive Overhead Capture” page 60 “Adding Frequency Offset to SONET Signal” page 62 “Adding Frequency Offset to the DSn Signal” page 64 “Setting up Signaling Bits” page 65 “Setting Transmit Structured Payload/Test Signal” page 68 “Setting Receive Structured Payload/Test Signal” page 70 “Setting Transmit N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal”

page 71 “Setting Receive N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal” page 73

“Inserting an External DSn Payload/Test Signal” page 74 “Dropping an External Payload/Test Signal” page 77 “Adding Errors and Alarms at the SONET Interface” page 80 “Adding Errors and Alarms to a DSn Signal” page 81 “Using FEAC Codes” page 82 “Setting DSn Spare Bits” page 84 “Adding Pointer Adjustments” page85 “Using Pointer Graph Test Function” page 93 “Stressing Optical Clock Recovery Circuits” page 95 “Generating Automatic Protection Switch (APS) Messages” page 97 “Inserting and Dropping the Data Communications Channel” page 102 “Using DS1 LOOP Codes” page 103

3 Selecting Test Features

Selecting Test Features

Using Transmit Overhead Setup

Description You can set an overhead byte to a known static state to aid troubleshooting, for

example to quickly check for "stuck bits" in path ov erhead bytes. Transport Overhead, Path Overhead, Trace Messages and Labels can be set using this feature.

HOW TO: 1 Set up the SONET transmit interface and payload required. See "Setting SONET

Transmit Interface " page 29.

2 Choose the type of overhead to SETUP.

If OC-12 or OC-48 is chosen as the SONET interface, choose the STS-3# and STS-1# you wish to set up. If STS-3 is chosen as the SONET interface, choose the STS-1# yo u wish to set up. DEFAULT - Use to set all overhead bytes to the standard values defined by Bellcore/ANSI. If a test function is active then the overhead byte value i s determined by the choices made in the Test Function. If (Transport Overhead) is chosen, choose the STS-1 to be displayed.

TOH

Many bytes in and are unlabeled as the other overhead functions have not yet been defined.

STS-1# 2 STS-1#3

Selecting Test Fe atur es

Using Transmit Overhead Setup

If is chosen, the hexadecimal value of all 81 bytes of the STS-3

STS-1# 1,2,3

section & line overhead selected are displayed (all 324 bytes of an OC-12 or 1,296 bytes of an OC-48 are displayed 81 bytes at a time by selecting each STS3 in turn). The value of the bytes can be set using

INCREASE DIGIT

If BYTE NAMES is chosen, the labels for the overhead bytes are

DECREASE DIGIT

STS-1# 1,2,3

displayed.

3 If POH (Path Overhead) is chosen, choose the TYPE of overhead within STS-1

under test to be setup. J1 and J2 bytes can be set under Path Overhead or Trace Messages. H4 byte has a choice of sequences for VT-2, VT-1.5 and VT-6 mapping:

Full Sequence - 48 byte bi nary sequence . Reduced Sequence - Binary count sequence of 0 to 3 i.e. 111111(00 to 11). COC1 Sequence - Binary count sequence of 0 to 3 i.e. 110000(00 to 11).

H4 byte is transmitted as all zero’s for 34 Mb/s and DS3.

4 If TRACE MESSAGES is chosen, see "Setting Overhead Trace Messages "

page 56.

NOTE Any bit of an overhead byte which is displayed as x or s cannot be set at any time.

All other bits can be set to 0 or 1.

TIP: You can set all overhead bytes to the default state by selecting SETUP .

DEFAULT

You can set all overhead bytes and test functions to the default state by recalling Stored Settings [0] on the display.

OTHER

Selecting Test Fe atur es

Using Receive Overhead Monitor

Description When first connecting to a SONET network, a start up confidence check can be

made by viewing the behavior of all the overhead bytes. If the SONET network shows alarm indications, some diagnosis of the problem may be gained from viewing all the overhead bytes.The OVERHEAD MONITOR display is updated once per second (once per 8000 frames) approximately.

TIP: A snapshot of the received overhead can be logged to the chosen logging device.

See "Logging on Demand " page 241.

HOW TO: 1 Set up the receive SONET interface and payload as required. See “Setting

SONET Receive Interface” page 47.

2 Choose the type of overhead to MONITOR. 3 If (Transport Overhead) is chosen, choose the STS-3 # and

TOH

STS-1# to be displayed. Many bytes in and are unlabeled because the other overhead f unctions have not yet been de fined. If is chosen, the hexadecimal value of all 81 bytes of section

STS-1# 1,2,3

overhead is displayed (al l 324 bytes of an OC-12 o r 1, 296 by tes of an OC- 48 are displayed 81 bytes at a time by selecting each S TS-3 in turn). If BYTE NAMES is chosen, the labels for the overhead bytes are displayed.

STS-1# 2 STS-1#3

STS-1# 1,2,3

Selecting Test Fe atur es

Using Receive Overhead Monitor

4 If POH (Path Overhead) is chosen, choose the source of the overhead, SPE or

VTSPE. J1 and J2 bytes can be monitored under Path Overhead or Trace Messages

5 If TRACE MESSAGES is chosen, you can monitor a data message to verify

portions of the network. If the 16 byte CRC7 message structure is detected, the 15 characters within the message are displayed. If the CRC7 structure is not detected in J1, the 64 byte message format is assumed and displayed. If the CRC7 structure is not detected for J0 or J2, all 16 bytes are displayed.

6 If LABELS is chosen, the S1 sync status, STS path label (C2) and the VT Path

label (V5) are monitored.

7 If APS MESSAGES is chosen, choose the TOPOLOGY, (GR-253) or

(GR-1230). The K1 and K2 bytes are monitored.

RING

LINEAR

TIP: If an y abno rmal behavior is observed on a particular path or section overhead byte,

or an associated group of bytes (3XA1,3XA2; D1 - D3, D4 - D12), the

TEST FUNCTION

display of can be used to "Zoom" in

OVERHEAD CAPTURE

RECEIVE

on the suspect byte or bytes on a frame by frame basis. See "Using Receive Overhead Capture " page 60.

Selecting Test Fe atur es

Setting Overhead Trace Messages

Description You can insert a data message to verify portions of the network:

J0 verifies the section overhead. J1 verifies the STS-1 SPE or STS-3c SPE path connection. J2 verifies the VT SPE path connection.

HOW TO: 1 Choose the message for insertion in the chosen trace channel.

How to Edit User Messages

There are two ways you can edit a user message as follows;

• Use the edit keys at the bottom of the display JUMP , PREVIOUS CHAR, NEXT

CHAR and message or:

• Use

the POP UP alphanumerical keypad that is displa yed when you pres s the front

pane

l key. Detailed instructions on how to change instrument settings

SET

using the POP UP keypad is given in the Quick Start Guide (page 13) under the heading “Changing Instrument Settings”.

that are displayed when you position the cursor on a User

Selecting Test Fe atur es

Setting Overhead Labels

Description Choosing LABELS in TRACE MESSAGES allows the setting of the S1 SYNC

STATUS, STS PATH LABEL (C2) and VT PATH LABEL (V5).

How to Edit User Defined Labels

1 Choose the overhead label that you want to edit. 2 Edit the label using the softkeys at the bottom of the display. If you select USER,

use

the softkeys at the bottom of the display to edit the labe l key , or press , then use

the softkeys and pop- up keyp ad to edit t he label . Deta iled i nstru ctions on how to change instrument settings using the pop-up keypad is given in the Quick Start Guide (page 13) under the heading “Changing Instrument Settings”.

SET

Selecting Test Fe atur es

Generating Overhead Sequences

Description You may insert a sequence of patterns into a functional group of overhead bytes for

testing or troubleshooting purposes.

HOW TO: 1 Set up the SONET transmit interface and payload required. See “Setting SONET

Transmit Interface” page 29.

2 Select , SONET, SEQUEN CES as shown above.

TEST FUNCTION

3 Choose the type of sequence required.

SINGLE RUN - runs the sequence once and then stops. REPEAT RUN - runs the sequence repeatedly until STOPPED is chosen.

4 Choose the overhead type as required.

SOH- Section Overhead LOH- Line Overhead POH - Path Overhead

5 Choose the byte or bytes of overhead required. 6 Set up the required number of data patterns and the number of frames in which

each data pattern should appear. Your sequence is derived from up to 5 blocks of hexadecimal data. Each block can be transmitted in up to 64,000 frames. The data and the number of frames are set using

INCREASE DIGIT

DECREASE DIGIT

Selecting Test Fe atur es

Generating Overhead Sequences

7 Start the sequence by choos ing .

START

NOTE When you start the sequence illustrated, one Out of Frame alarm and one Loss of

Frame alarm should occur every eight seconds.

A1A2 Boundary Function

A1A2 provide a frame alignment pattern (A1=F6 H, A2=28 H). Use A1A2 to test the 6 framing bytes at the A1A2 boundary in the section overhead (see display on previous page). The 6 bytes across the boundary are:

STS-n

STS-3 channel: #n-2 #n-1 #n #1 #2 #3 Overhead byte: A1 #3 A1 #3 A1 #3 A2 #1 A2 #1 A2 #1

A network element, typically only uses three of these bytes (which ones are not defined in the standards, so will vary between manufacturers) to gain and maintain frame synchronization. In many cases the A1A2 bytes selected are those at the A1A2 boundary (i.e. the A1 bytes in the last STS-1 channel and the A2 bytes in the first STS-1 channel). Therefore, the ability to stress test across the boundary is necessary to verify a correct synchronization algorithm within a network element.

Selecting Test Fe atur es

Using Receive Overhead Capture

Description Section, Line and Path overhead provide network support functions, responding

dynamically to network conditions and needs. It is therefore useful to capture overhead activity on a frame by frame basis.

TIP: The Overhead Capture display can be logged to the chosen logging device. See

"Logging on Demand " page 241.

HOW TO: 1 Set up the receive SONET interface and payload as required. See “Setting

SONET Receive Interface” page 47.

2 Select , SONET, O/H CAPTURE as shown above. 3 Choose the overhead type as required.

4 Choose the Byte or bytes of overhead to be captured.

Choose the TRIGGER to determine the start point of the capture.

OFF

by frame monitor of the chosen byte or bytes.

used for transient detection from a specified expected state.

TEST FUNCTION

SOH- Section Overhead LOH- Line Overhead POH- Path Overhead

- starts immediately the capture is initiated. Can be used to provide a frame

-captures activity after your specified overhead state has occurred. Can be

Selecting Test Fe atur es

Using Receive Overhead Capture

ON NOT

- captures activity after the first occurrence of a deviation from your specified overhead state. Can be used for transient detection from a specified expected state.

5 Up to 16 records of overhead state are provided. Each record will represent

between 1 and 64,000 frames. A capture is started by pressing CAPTURE

START

can be terminated earlier by pressing CAPTURE .

and terminates when up to 16 records have been captured. The capture

STOP

Selecting Test Fe atur es

Adding Frequency Offset to SONET Signal

Description Frequency offset can be added to the SONET interface rate signal and to the payloa d

signal.

HOW TO: SONET Line Rate Offset

1 Choose the amount of frequency offset required.

You can set the Frequency Offset in the range -999 ppm to +999 ppm in 1 ppm steps using

SET

DECREASE DIGIT INCREASE DIGIT

for a pop-up numerical keypad. The amount of applied Frequency Offset can be varied while measurements are taking place. If the value of the SONET line rate offset chosen is sufficient to cause the maximum stuff rate to b e exceeded, the asynchronous pay load is offset to prevent bit errors occurring and the maximum stuff rate is maintained. When Floating Byte 2 Mb/s is chosen, in conjunction with SONET line rate offset, the chosen tributary will be offset as the line rate is offset. (No pointer movements).

and or press

Selecting Test Fe atur es

Adding Frequency Offset to SONET Signal

Tributary Offs et ±100 ppm

1 Choose the amount of tributary offset required.

You can set the Offset in the range -100 ppm to +100 ppm in 1 ppm steps using

DECREASE DIGIT INCREASE DIGIT SET

and or press for a pop-

up numerical keypad. The amount of applied Frequency Offset can be varied while measurements are taking place. Tributary offset affects the stuff rate but does not cause pointer movements and can be used to test mapping jitter. If the combined value of SONET line rate offset and tributary offset chosen is sufficient to cause the maximum stuff rate to be exceeded the payload is offset to prevent bit errors occurring and the maximum stuff rate is maintained.

Selecting Test Fe atur es

Adding Frequency Offset to the DSn Signal

Description Option 012 required.

You can add frequency offset to the interface DSn SIGNAL at all rates. Frequency Offset can be added at preset ITU-T/ANSI values or as User defined values in the range ±100 ppm. The preset values change with the SIGNAL rate chosen as shown:

DS-1 (1.544 Mb/s) ±32 ppm −32 ppm 2 Mb/s (E1) ±50 ppm −50 ppm 8 Mb/s ±30 ppm -30 ppm 34 Mb/s (E3) ±20 ppm −20 ppm DS-3 (44.736 Mb/s) ±20 ppm −20 ppm 140 Mb/s ±15 ppm -15 ppm

HOW TO: 1 Choose the FREQUENCY OFFSET required.

2 If you choose USER OFFSET, you can set the frequency offset to be between -

100 ppm and +100 ppm in 1 ppm steps. Select the field immediately below USER OFFSET and use

DECREASE DIGIT INCREASE DIGIT

offset.

(The amount of frequency offset can be varied while measurements are

, and to set the frequency

taking place.)

Selecting Test Fe atur es

Setting up Signaling Bits

Description When transmitting 2.048 Mb/s signals with timeslot-16 CAS (PCM30 or

PCM30CRC) multiframing the state of A,B,C,D signaling bits can be set. The signaling bits of all timeslots are set to the user-defined 4-bit value.

When transmitting a DS1 framed, structured signal the values of the A,B signaling bits for D4 and SLC-96 payloads, and A,B, C,D signaling bits for ESF payloads can be defined.

HOW TO Tran smit a DS1 payl oad signal with user-defined signaling bits

DSn Operation

1 Choose on the display.

Choose SIGNAL or , and PAYLOAD TYPE on the display

PDH/DSn

DS1 DS3 STRUCTURED

MAIN SETTINGS

2 Choose TEST SIGNAL

SETTINGS

display.

TRANSMIT

56 kb/s Nx56 kb/s STRUCTURED

or on the

3 Set the A,B bits (for D4 and SLC-96) and A,B,C,D bits (for ESF) as required.

SONET Operation

1 Choose

SONET

on the display.

TRANSMIT

2 Set MAPPING to VT-1.5. 3 Choose MAPPING

PAYLOAD on the

STRUCTURED MAIN SETTINGS

FL BYTE DS1 ASYNC DS1 DS3

, or and VT

display. If you choose

Selecting Test Fe atur es

Setting up Signaling Bits

FL BYTE DS1

4 Choose TEST SIGNAL

SETTINGS

proceed to step 5.

56 kb/s Nx56 kb/s STRUCTURED

display .

or on the

5 Set the A,B bits (for D4 and SLC-96) and A,B,C,D bits (for ESF) as required. 6 Floating Byte DS1 selection: Set th e ABC D bit s for NO-F-BIT or ESF framing

and/or the AB bits for D4 VT PAYLOAD framing as required.

HOW TO Transmit a 2 Mb/s signal with user-defined signaling bits

DSn Operation

1 Choose

PDH/DSn

2 Choose SIGNAL and PA YLOAD TYPE or on

the display.

MAIN SETTINGS

on the display.

2 Mb/s PCM30 PCM30CRC

TRANSMIT

3 If UNSTRUCTURED is chosen set the 2M CAS ABCD bits value on the

MAIN SETTINGS

display.

If STRUCTURED is chosen set the 2M CAS ABCD bits value on the

STRUCTURED SETTINGS

display.

Selecting Test Fe atur es

Setting up Signaling Bits

SONET Operation

1 Choose on the display.

SONET

TRANSMIT

2 Set MAPPING to VT-2. 3 Choose MAPPING or and VT PAYLOAD

PCM30 PCM30CRC MAIN SETTINGS

or on the

ASYNC 2Mb/s FL BYTE 2Mb/s

display.

4 If UNSTRUCTURED is chosen set the 2M CAS ABCD bits value on the

MAIN SETTINGS

display.

If STRUCTURED is chosen set the 2M CAS ABCD bits value on the

STRUCTURED SETTINGS

display.

Selecting Test Fe atur es

Setting Transmit Structured Payload/Test Signal

Setting Transmit St ructured Payload/Test Signal

Description Stru ctured DSn Payload/Test Signal settings determine the payload or the DSn test

signal to be tested and set any background (non test) conditions to prevent alarms while testing.

TIP: If you wish to set the OmniBER 718 transmitter and receiver to the same Payload

settings, choose .

Interested in International Gateway Testing?

If your instrument has option 014 fitted you can map an E1 or 2Mb/s signal into DS3 as shown below:

OTHER

SETTINGS CONTROL COUPLED

HOW TO: 1 Choose the required TEST SIGNAL rate. If Nx64 kb/s or N X 56 kb/s is chosen,

see "Setting Transmit N x 64 kb/s /N x 56 kb/s S truct ured P ayload/ Test Signal " page 71.

2 Choose the P AYLOAD framing pattern.

If TEST SIGNAL 2Mb/s is chosen is added to the PAYLOAD menu. See "Inserting an External DSn Payload/Test Signal " page 74. If TEST SIGNAL DS1 is chosen is added to the menu. See "Inserting an External DSn Payload/Test Signal " page 74.

3 Choose the test tributary in the structured payload, under 34Mb, 8Mb, 2Mb, 64

kb/s or DS2, DS1, 56 kb/s.

INSERT 2 M b/s

INSERT DS1

Selecting Test Fe atur es

Setting Transmit Structured Payload/Test Signal

4 Choose the PATTERN type and PRBS POLARITY.

5 Choose the B/G PATTERN. (background)

The B/G P ATTERN in the non test 56/64 kb/s timeslots is fixed as NUMBERED, that is, each timeslot contains a unique number to allow identification in case of routing problems.

Signaling

6 If a 2 Mb/s PAYLOAD with PCM30 or PCM30CRC framing, or 56 kb/s or

Nx56kb/s Test Signal is chosen. See, "Setting up Signaling Bits " page 65.

Selecting Test Fe atur es

Setting Receive Structured Payload/Test Signal

Description Stru ctured DSn Payload/Test Signal settings determine the payload or the DSn test

signal to be tested.

TIP: If you wish to set the OmniBER 718 transmitter and receiver to the same Payload

settings, choose

OTHER

SETTINGS CONTROL COUPLED

, .

HOW TO: 1 Choose the required Test Signal rate. If N x 64 kb/s or N x 56 kb/s is chosen, see

"Setting Receive N x 64 kb/s/N x 56 kb/s Structur ed Payload/Test Signal "

page 73.

2 Choose the Framing pattern of the PAYLOAD.

If TEST SIGNAL 2 Mb/s is chosen, is added to the menu. See

DROP 2 Mb/s

"Dropping an External Payload/Test Signal " page 77.

If TEST SIGNAL DS1 is chosen, is added to the menu.

DROP DS1

See "Dropping an External Payload/Test Signal " page 77.

3 Choose the test tribu tary within t he str uctured payl oad, u nder 34 Mb, 8Mb, 2Mb,

64 kb or DS2, DS1, 56 kb/s.

4 Choose the PATTERN type and PRBS polarity.

Selecting Test Fe atur es

Setting Transmit N x 64 k b / s /N x 56 k b /s Structured Paylo ad / Test Signal

Setting Transmit N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal

Description Wideband services such as hig h speed data l inks and LA N intercon nection require a

bandwidth greater than 56/64 kb/s but less than DS1/2 Mb/s for example 112 kb/s or 336 kb/s. These wide band signals are sent in a DS1/2 Mb/s frame by sharing the signal across multiple timeslots.

N x 64kb/s/N x 56 kb/ s structured payload allows a test pattern to be in serted across a number of timeslots even if the chosen timeslots are non-contiguous.

HOW TO: 1 Choose the required Test Signal rate.

2 If your instrument has option 014 fitted you can map an E1 or 2Mb/s signal into

DS3. Select DS1 or 2M as shown in the figure above.

3 Choose the Framing pattern of the 2M or DS1 PAYLOAD. 4 Choose the test timeslots within the structured payload usin g

DESELECT SELECT

* marks the chosen timeslot.

5 Choose the PATTERN type and PRBS polarity. 6 Choose the B/G PATTERN.

and softkeys. As each timeslot is selected, an

DESELECT ALL

Selecting Test Fe atur es

Setting Transmit N x 64 k b / s /N x 56 k b /s Structured Paylo ad / Test Signal

7 The B/G P A TTERN in the non-test 56/64 kb/s timeslots is fixed as NUMBERED,

that is, each timeslot contains a unique identification number.

Signaling

8 If a 2 Mb/s PAYLOAD with PCM30 or PCM30CRC framing, or 56 kb/s or

Nx56kb/s Test Signal is chosen. See, "Setting up Signaling Bits " page 65.

Selecting Test Fe atur es

Setting Receive N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal

Description Wideband services such as hig h speed data l inks and LA N intercon nection require a

bandwidth greater than 56/64 kb/s but less than DS1/2 Mb/s e.g. 112 kb/s or 336 kb/s. These wide band signals are sent in a DS1/2 Mb/s frame by sharing the signal across multiple timeslots.

N x 64kb/s and N x 56 kb/s structured payload/test signal allows the test Timeslots to be chosen for error measurement even when the Timeslots are non contiguous.

HOW TO: 1 Choose the required Test Signal rate.

2 If your instrument has option 014 fitted you can map an E1 or 2Mb/s signal into

DS3. Select DS1 or 2M as shown in the figure above.

3 Choose the Framing pattern of the 2M or DS1 PAYLOAD. 4 Choose the test timeslots within the structured payload usin g

DESELECT SELECT

marks the chosen timeslot. In the example above T imeslots 3, 5 , 9, 21, 22, 23 are chosen for test.

5 Choose the PATTERN type and PRBS polarity.

and softkeys. As each timeslot is chosen an *

DESELECT ALL

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TRANSMIT

Inserting an External DSn Payload/Test Signal

Description You can insert 2 Mb/s 34 Mb/s or 140 Mb/s into an STS-N line signal when option

012 is fitted. DS3, DS1, E3 and E1 can be inserted when option 014 is fitted.

RATE Availability Option

DS3 SDH & SONET 001, 012, 002 34Mb/s SDH & SONET 001, 012,002 2Mb/s PDH, SDH & SONET 001, 012, 002 DS1 DSn, SDH & SONET 001, 012, 002

HOW TO: Insert 34 Mb/s, 140 Mb/s & DS3

1 Press , select

SONET MAIN SETTINGS

and the page.

2 Set up the required transmit SONET interface, set appropriate MAPPING then

choose VT PAYLOAD

INSERT 140 Mb/s

, or

INSERT 34 Mb/s

INSERT DS3

as required. Connect your external source to the appropriate port as indicated on the instrument display (when you position the cursor on the PAYLOAD TYPE field and select INSERT).

Selecting Test Fe atur es

Inserting an External DSn Payload/Test Signal

Insert 2 Mb/s or DS1 (Unstructured SONET Payload)

1 Connect the external payload to the MUX port of the PDH/DSn T ransmit module.

If 2 Mb/s connect to 75

2 Set up the required transmit SONET interface, and choose VT-2 or

VT-1.5 MAPPING and VT PAYLOAD or .

Ω MUX port. If DS1 connect to 100Ω MUX port.

INSERT 2 M b/s

INSERT DS1

Insert 2 Mb/s or DS1 (Structured SONET Payload or Structured DSn)

1 Connect the external payload to the MUX port of the DSn Transmit module.

If 2 Mb/s connect to 75

Ω MUX port. If DS1 connect to 100Ω MUX port.

Selecting Test Fe atur es

Inserting an External DSn Payload/Test Signal

Structured SONET Payload

2 Set up the required transmit SONET interface. See "Setting SONET Transmit

Interface " page 29.

3 Set up the SONET structured payload. See "Set ting Transmit Structured

Payload/Test Signal " page 68.

4 Choose 2M PAYLOAD/DS1 PAYLOAD or .

INSERT 2 M b/s

INSERT DS1

5 Choose the LINE CODE.

Structured DSn

6 Set up, the required transmit DSn interface, See "Setting PDH/DSn Transmit

Interface (Option 012) " page 26.

7 Set up the DSn Test Signal interface. See "Setting Transmit Structured Payload/

Test Signal " page 68

8 Choose 2M PAYLOAD/DS1 PAYLOAD or .

INSERT 2 M b/s

INSERT DS1

9 Choose the LINE CODE.

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Dropping an External Payload/Test Signal

Description You can drop 2Mb/s 34 Mb/s or 140 Mb/s from an STS-N line signal when option

012 is fitted. DS3, DS1, E3 and E1 can be dropped when option 014 is fitted

HOW TO: Drop 34 Mb/s, DS3 and 140 Mb/s

1 Connect the 75

Ω OUT port of the DSn Transmit module to the external

equipment.

2 Set up the receive SONET interface, and choose PAYLOAD

DROP DS3

If is chosen, choose the DS3 output level.

DROP DS3

, or as required.

DROP 140 Mb/s

DROP 34 Mb/s

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Dropping an External Payload/Test Signal

Drop 2 Mb/s /DS1 (Unstructured SONET Payload)

1 Connect the DEMUX port of the DSn module to the external equipment. 2 Set up the required receive SONET interface, and choose VT-2 or

VT-1.5 MAPPING and VT PAYLOAD or .

3 Choose the required LINE CODE.

DROP 2 Mb/s DROP DS1

Drop 2 Mb/s/DS1 (Structured SONET Payload or Structured DSn)

1 Connect the DEMUX port of the Receive DSn module to the external equipment.

If 2 Mb/s connect to 75

Ω DEMUX port. If DS1 connect to 100Ω DEMUX port.

Selecting Test Fe atur es

Dropping an External Payload/Test Signal

Structured SONET Payload

2 Set up the required receive SONET interface. See "Setting SONET Receive

Interface " page 47.

3 Set up the SONET structured payload. See "Setting Receive Structured Payload/

Test Signal " page 70.

4 Choose 2M PAYLOAD or DS1 PAYLOAD .

DROP 2 Mb/s DROP DS1

5 Choose the LINE CODE.

Structured DSn

6 Set up, the required receive DSn interface, See "Setting PDH /DSn Receive

Interface " page 45.

7 Set up the DSn Test Signal interface. See "Setting Receive Structured Payload/

Test Signal " page 70

8 Choose 2M PAYLOAD or DS1 PAYLOAD .

DROP 2 Mb/s DROP DS1

9 Choose the LINE CODE.

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Adding Errors and Alarms at the SONET Interface

Description Errors and alarms can be added to an SONET signal during testing.

HOW TO: 1 Set up the SONET transmit interface and payload required. See "Setting SONET

Transmit Interface " page 29.

2 Select

TEST FUNCTION

, SONET, ERR & ALARM as shown above.

3 Choose the ERROR ADD TYPE and RATE required.

Errors can be added at preset rates and at USER programmable rate. With the exception of ENTIRE FRAME, A1A2 FRAME and BIT, errors can be added at ERROR ALL rate. If CV-L errors are chosen errors can be added to trigger an APS THRESHOLD. This takes the form of N errors in T time period. N and T are both selectable.

4 Choose the ALARM TYPE

Errors and Alarms can be added at the same time.

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Adding Errors and Alarms to a DSn Signal

Description Errors and alarms can be added to a DSn signal during testing.

HOW TO: 1 If SONET interface is chosen, set up the SONET transmit interface and paylo ad

required. See “Setting SONET Transmit Interface” page 29. If DSn interface is chosen, set up the DSn interface and payload required. See “Setting PDH/DSn Transmit Interface (Option 012)” page 26.

2 Select

TEST FUNCTION

, DSn PAYLD, ERR & ALARM as shown above.

3 Choose the ERROR ADD TYPE and RATE on the Transmitter

TEST FUNCTION

display. The RATE can be selected from a fixed value or is user programmable. If you select USER PROGRAM you can select the error rate before enabling the errors. This feature is useful for error threshold testing.

4 Choose the ALARM TYPE.

Errors and Alarms can be added at the same time.

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TRANSMIT

Using FEAC Codes

Description The third C-Bit in subframe 1 is used as a FEAC channel, where alarm or status

information from the far-end terminal can be sent back to the near-end terminal. The channel is also used to initiate DS3 and DS1 line loopbacks at the far-end terminal from the near-end terminal.

The codes are six digits long and are embedded in a 16 bit code word; the format is 0XXXXXX011111111. There are two types of code, Loopback and Alarm Status. Loopback provides a choice of two DS1 messages and two DS3 Messages . The DS1 Messages can be sent in ALL DS1 channels or in a SINGLE channel. The message can be repeated up to 15 times. Alarm Status provides 13 preset codes and a USER programmable code function. These codes can be transmitted continuously or in bursts.

The new code is transmitted by choosing or

HOW TO: Transmit an FEAC code

1 Choose SIGNAL and PAYLOAD TYPE on the

MAIN SETTINGS

DS3 CBIT

display.

2 Choose , DSn PAYLD and ALARM TYPE

DS3 FEAC

. When a FEAC code is not being transmitted, an all ones pattern is

transmitted.

TEST FUNCTION

BURST ON

TRANSMIT

Selecting Test Fe atur es

Using FEAC Codes

3 Choose the FEAC CODE TYPE. 4 Choose the MESSAGE from the choices displayed.

If you chose a DS1 message an additional field to the right of the DS1 MESSAGE is displayed. Position the cursor on this field and choose or

SINGLE CHANNEL

If you choose use the EDIT keys to select a channel from 1 to 28. Press when finished.

5 If is chosen, choose the REPEAT (TIMES) LOOP and MESS, in

LOOPBACK

SINGLE CHANNEL

END EDIT

ALL

the range 1 to 15.

6 If is chosen, choose the BURST LENGTH (TIMES).

ALARM/ STATUS

7 Choose TRANSMIT NEW CODE or to transm it the selected

FEAC message.

TIP: To View FEAC Messages

The received FEAC message can be viewed on the display.

BURST

RESULTS

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Setting DSn Spare Bits

Description Certain Spare Bits will cause the occurrence of a minor alarm when received as a

logical "0".: 8 Mb/s & 34 Mb/s - FAS Bit 12

2 Mb/s - NFAS Timeslot (timeslot 0 of NFAS frame) Bit 0

HOW TO: 1 If SONET interface is chosen, set up the SONET transmit interface and payload

required. See "Setting SONET Transmit Interface " page 29. If DSn interface is chosen, set up the DSn transmit interface and payload required. See "Setting PDH/DSn Transmit Interface (Option 012) " page 26.

2 Set the value of the spare bits required for testing.

If a BIT SEQUENCE is required, choose SEND SEQUENCE to transmit the sequence.

Selecting Test Fe atur es

Adding Pointer Adjustments

Introduction Pointers perform a critical role in the error free transmission of payload data

(subscriber data) through a SONET network. They also enable individual payload channels to be inserted or extracted from a high speed OC-n line signal (for example the functionality provided by ADMs).

Pointer adjustments are often necessary to compensate for asynchronous operation between different nodes within an SONET network.Th ese adjustments however can result in jitter being added to a DSn signal outpu t from a SONET network element.

Jitter caused by Pointer Adjustments

Pointer adjustments are the mechanisms within SONET to compensate for frequency and phase differences between STS-n SPE channels and the outgoing SONET frames. These pointer adjustments are byte wide and since they can occur randomly , they may caus e significant amounts of payload sign al jitter. It is therefore necessary to control the jitter on payload signals that is due to pointer adjustments.

Pointer adjustment activity within a network can be randomly spaced individual pointer adjustments, pointer bursts or periodic pointer adjustmen ts.

The Bellcore GR-253 and ANSI T1.105 standard s defines a set of poi nter seque nces to be used when evaluating an NE’s pointer adjustment jitter performance.

The OmniBER 718 generates a set of test sequences which can be used to simulate network pointer adjustment activity. This allows the amount of tributary jitter due to different types of pointer adjustment to be measured in the OmniBER 718.

Selecting Test Fe atur es

Adding Pointer Adjustments

Description The transmitted SPE or VT pointer value can be adjusted for testing purposes.

HOW TO: 1 Set up the SONET transmit interface and payload required. See "Setting SONET

Transmit Interface " page 29.

2 Choose the POINTER TYPE. 3 Choose the ADJUSTMENT TYPE required.

BURST - You determine the size of the burst by the nu mber of PLACES chosen. If, for example, you choose 5 PL ACES the poi nter val ue will be st epped 5 tim es in unit steps e.g. 0 (start value), 1, 2, 3, 4, 5 (final value). The interval between steps is as follows: For STS-SPE the minimum spacing between adjustments is 4 frames (500 us). For VT, the minimum spacing between adjustments is 4 multiframes (2ms). Choose ADJUST POINTER [ON] to add the chosen burst.

NEW POINTER - You can choose any pointer value in the defined range (0 to 782 For an STS-1 pointer) with or without a New Data Flag, and transmit it. The current pointer value is displayed for information purposes. Choose ADJUST POINTER [ON] to transmit the new pointer value.

OFFSET - You can frequency offset the line rate or the SPE/VT rate, relative to each other, thus producing pointer movements. If you offset the SPE pointer, an 87:3 sequence of pointer movements is generated. The available configurations are listed in the following table. If you are currently adding Frequency Offset to the SONET interface or payload, pointer OFFSET is not available.

Selecting Test Fe atur es

Adding Pointer Adjustments

Pointer Type Line Rate SPE Rate VT Rate

SPE Constant Offset Tra cks STS

Payload SPE Offset Constant Constant VT Constant Constant Offset VT Offset Tracks Line Rate Constant

T1.105/GR-253 - Provides pointer movements according to T1.105 and GR-253:

4 Choose the T1.105/GR-253 ADJUSTMENT TYPE. 5 Choose the POLARITY, INTERVAL and PATTERN (where applicable) for the

selected sequence.

6 Choose POINTER SEQUENCES to generate the selected

sequence and to stop the pointer sequences.

STOP INIT

START INIT

T1.105/GR-253 Pointer Sequences Explained

In addition to the BURST, NEW POINTER a nd OFFSET pointer movements described, the OmniBER 718 can also generate poin ter sequences (pointer movements) according to T1.105.03 and GR-253.

Before running a pointer sequence you can elect to run an initialization sequence, followed by a cool down period, and then run the chosen sequence. This is selected using the START INIT softkey shown in the display on the previous page. Initialized pointer sequences are made up of three periods : the Initialization Period, the Cool Down Period, and the Sequence (Measurement) Period, an example is given in the following figure:

Initialization SequenceNon Periodic Sequence

Periodic Sequence

Initialization

No Pointer Activity

Continuous Sequence

Cool Down

Note: SINGLE (A1), BURST (A2) and PHASE TRANSIENT(A 3) are Non Periodic Sequences.

Sequence

Time

Measurement

Period

Selecting Test Fe atur es

Adding Pointer Adjustments

Initialization Period

For SINGLE A1, BURST A2 and PHASE TRANSIENT A3 sequences the initialization sequence consists of 60 seconds of pointer adjustments applied at a rate of 2 adjustments per second and in the same direction as the specified pointer sequence.

Cool Down Period

A period following the initialization period which for SINGLE e), BURST f) and PHASE TRANSIENT sequences is 30 seconds long when no pointer activity is present.

Sequence (Measurement) Period

The period following the Cool Down period where the specified pointer sequence runs continuously.

Periodic Test Sequences

For periodic test sequences (for example PERIODIC ADD) both the 60 second initialization and 30 second cool down periods consist of the same sequence as used for the subsequent measurement sequence. If the product of the period T and the selected Optional background pattern (87+3 or 26+1) exceeds 60 seconds then the longer period is used for the initialization. For example, if T is set for 10 seconds then the initialization period may be extended to 900 seconds.

The OmniBER 718 displays a message indicating which phase (initialization, cool down or measurement) the transmitter is currently generating.

NOTE The following conditions apply for pointer sequence generation:

The sequences can only be applied to the SPE pointer when the SPE do es not contain a VT structure, otherwise it is applied to the VT pointer. Pointer sequence generation is not available when a frequency offset is being applied to the Line Rate.

The following figure gives an exam pl e of a T1 .10 5/ GR-2 53, 87-3 Pointer Sequence.

Selecting Test Fe atur es

Adding Pointer Adjustments

T1.105 A4 and A5, 87-3 Pattern

Pointer Adjustment

No Pointer Adjustment

Start of Next 87-3 Pattern

An Example of a Pointer Sequence

Pointer Sequence Description

T1.105 A1 SINGLE GR-253 5-29

T1.105 A2 BURST OF 3 GR-253 5-30

T1.105 A3 PHASE TRANSIENT GR-253 5031

Periodic Single adjustments, all of the same polarity which is selectable. Separation between pointer adjustments is fixed at approximat el y 30 seconds .

Periodic bursts of 3 adjustments, all of the same polarity which is selectable. The interval between bursts is fixed at approximately 3 0 seconds. The in terval between adjustments within a burst is set to the minimum.

Phase transient pointer adjustment burst test sequence. All adjustments are of the same polarity, which is selectable. The interval between bursts is fixed at 30 seconds. Each burst consists of 7 pointer movement. The first 3 in each burst are 0.25 s apart, and the interval between the 3 and 4 movement, and each remaining movement 0.5 seconds.

T1.105 A4 PERIODIC NORMAL (87-3 Pattern) GR-253 5-33(b)

T1.105 A4 PERIODIC NORMAL (Continuous Pattern) GR-253 5-34(b)

An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followed by 3 missing pointer movements. Pointer polar ity is selectable and the time interval between pointer adjustments settable.

Provides a continuous sequence of pointer adjustments . The polarity of the adjustments is selectable, and the time interval between adjustments can be set (see Note 1).

Selecting Test Fe atur es

Adding Pointer Adjustments

Pointer Sequence Description

GR-253 5-32(b) PERIODIC NORMAL (26-1 Pattern)

T1.105 A5 PERIODIC ADD (87-3 Pattern) GR-253 5-33(c)

T1.105 A5 PERIODIC ADD (Continuous Pattern) GR-253 5-34(c)

GR-253 5-32(c) PERIODIC ADD (26-1 Pattern)

This selection is only available if you have selected VT1.5 mapping. The sequence pattern is 26 pointer movements followed by 1 missing pointer movement. Pointer polarity is selectable and the time interval between pointer adjustments programmable t o 200 ms, 500 ms, 1 s, 2 s, 5 s or 10 seconds.

An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followed by 3 missing pointer movements with an added pointer movement after the 43rd pointer. The spacing between the added adjustment and the previous adjustment is set to the minimum. Pointer polarity is selectable. The time interval between pointer adjustments can be set (see Note 1). Added adjustments occur every 30 seconds or every repeat of the 87-3 pattern, whichever is longer.

Periodic Single adjustments, with selectable polarity and added adjustmen t (1 extra). The spacing between the added adjustment and the previous adjustment is set to the minimum, (see Note 2). The time interval between pointer adjustments can be set (see Note 1). Added adjustments occur every 30 seconds or every repeat of the 87-3 pattern, whichever is longer.

This selection is only available if you have selected VT1.5 mapping. The sequence pattern is 26 pointer movements followed by 1 missing pointer movement. The added adjustment occurs 2 ms after the 13th pointer adjustment. Pointer polarity is selectable and the time interval between pointer adjustments programmable t o 200 ms, 500 ms, 1 s, 2 s, 5 s or 10 s. Added adjustments occur every 30 seconds or every repeat of the 26-1 pattern, whichever is longer.

T1.105 A5 PERIODIC CANCEL (87-3 pattern) GR-253 5-33(d)

An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followed by 3 missing po in ter movements with a cancelled pointer movement at the 87th pointer. Pointer polarity is selectable, and the time interval between pointer adjustments can be set (see Note 1). Cancelled adjustments occur every 30 seconds or every repeat of the 87-3 pattern, whichever is longer.

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Adding Pointer Adjustments

Pointer Sequence Description

T1.105 A5 PERIODIC CANCEL (Continuous Pattern) GR-253 5-34(d)

GR-253 5-32(d) PERIODIC CANCEL (26-1 pattern)

NOTE For SPE pointers the sequence interval is selectable from 7.5 ms, 10, 20, 30, 34 ms;

Periodic Single adjustments, with selectable polarity and cancelled adjustment (1 less). The time interval between pointer adjustments can be set (see Note 1). Cancelled adjustments occur every 30 second s or every repeat of the 87-3 pattern, whichever is longer.

This selection is only available if you have selected VT1.5 mapping. The sequence pattern is 26 pointer movements followed by 1 missing pointer movement. The cancelled adjustment is the 26th pointer adjustment, that is the one before the regular gap of 1. Pointer polarity is selectable and the time interval between pointer adjustments programmable to 200 ms, 500 ms, 1 s, 2 s, 5 s or 10s. Cancelled adjustme nts occur every 30 seconds or every repeat of the 26-1 pattern, whichever is longer.

40 to 100 ms in 10 ms steps, 100 to 1000 ms in 100 ms steps, 1, 2, 5, 10 seconds. For VT pointers the sequence interval is selectable from: 200 ms, 5 00 ms, 1, 2, 5 and 10 seconds. For SPE pointers the minimum spacing between adjustments is 500 us. For VT pointers the minimum spacing between adjustments is 2 ms.

Table 3 Pointer Sequences Available with Selected

Mapping

MAPPING

POINTER SEQUENCE

A1 SINGLE A2 BURST OF 3 A3 PHASE TRANSIENT A4 PERIODIC NORMAL(87-3) A4 PERIODIC NORMAL

(Continuous)

SPE VT6, VT2 VT1.5

√ √ √ √ √ 3 √ √ √ √ √ √ √ √

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Adding Pointer Adjustments

Table 3 Pointer Seque nces Available with Selected

Mapping

MAPPING

POINTER SEQUENCE

PERIODIC NORMAL (26-1) A5 PERIODIC ADD (87 -3) A5 PERIODIC ADD

(Continuous) PERIODIC ADD (26-1)

A5 PERIODIC CANCEL (g) 873

A5 PERIODIC CANCEL (Continuous)

PERIODIC CANCEL 26-1

SPE VT6, VT2 VT1.5

√

√ √ √

√

√ √ √

√

Selecting Test Fe atur es

Using Pointer Graph Test Function

Pointer Graph shows the relative offset during the measurement period. This allows the time relationship of S PE or VT pointer movements to b e ob serv ed. Up to 4 days of storage allows long term effects such as Wander to be observed. If an alarm occurs during the measurement period, a new graph starts at the centre of the display (offset zero) after recovery from the alarm.

TIP: The Pointer Graph display can be logged to the chosen logging device. See

"Logging on Demand " page 241.

TIP: The graph can also be viewed on the

end of the measurement.

HOW TO: 1 Set up the receive SONET interface and payload as required. See “Setting

SONET Receive Interface” page 47.

2 On the RECEIVE Test Function page, select then choose the

CAPTURE INTERVAL required. The capture interval determines the time between captures. Low valu es of capture interval should be chosen when a high degree of pointer movements is expected. High values of capture interval should be chosen when a low degree of pointer movements is expected, for example W an der over 1 day , u se 5 MINS and Wander over 4 days, use 20 MINS. If, during a long term measurement (4 days), an event occurs at a particular time each day, then the instrument can be set to log the results graph of that event.

RESULTS

display at the

SONET RESULTS

PTR GRAPH

Selecting Test Fe atur es

Using Pointer Graph Test Function

3 Choose the POINTER UNDER TEST type. 4 Press

TIP: If the event occurs outside normal working hours, a Timed Start measurement can

be made. The values of capture interval available and the approximate total capture window is

as follows: 1 SEC - display window of approximately 5 minutes.

5 SECS - disp l ay window of approximately 25 minutes. 20 SECS - display window of approximately 1 hour 40 minutes. 1 MIN - display window of approximately 5 hours. 5 MIN - display window of approximately 1 day. 20 MIN - display window of approximately 4 days.

RUN/STOP

to start the measurement.

Selecting Test Fe atur es

Stressing Optical Clock Recovery Circuits

Description This test is essentially designed for testing optical clock recovery circuits in the

presence of long runs of zero’s or one’s (after scrambling). The test function page allows control of the test pattern and the block length. The maximum block length is 2 bytes less than the width of the SPE.

When the test is enabled, the instrument applies the selected pattern immedi ately after the first row of Section Overhead bytes after scrambling. The location of the start of the pattern is byte 4 at 52 Mb/s (i.e. after the first three bytes of overhead), byte 10 at 155 Mb/s, byt e 37 at 62 2 Mb/s an d byt e 145 at 2488 Mb/s. The remainder of the SPE will contain the signal structure and pattern as defined on the TRANSMITTER, MAIN SETTINGS page.

The payload is overwritten in such a way that the transmitted B1 and B2 values are correct.

When using this feature to test network equipment clock recovery, long runs of zero’s may be inserted at the input of the UUT (unit under test) and by monitoring B1 and B2 at the UUT output, error free transmission can be verified.

The stress test is available at all optical rates.

HOW TO: 1 Set up the SONET transmit interface and payload required. See "Setting SONET

Transmit Interface " page 29.

Selecting Test Fe atur es

Stressing Optical Clock Recovery Circuits

Choose the required STRESSING PATTER N. The G.958 test pattern consists of 7 consecutive blocks of data as follows: the first row of section overhead bytes, ALL ONES, a PRBS, the first row of section overhead bytes, ALL ZEROS, a PRBS and the first row of section overhead bytes.

2 If you choose ALL ONES or ALL ZEROS as the stressing pattern, choose the

number of bytes in the BLOCK LENGTH.

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Generating Automatic Protection Swi tch (APS ) Messag es

Generating Automatic Protecti on Switch (APS) Messages

Description You can program the K1 and K2 bytes to exercise the APS functions for both

LINEAR (GR-253) and RING (GR-1230) topologies. The APS Message types are:-

• PASSIVE

• ACTIVE

The following table shows the APS message type availability.

TX RX TOPOLOGY APS Message Types

SONET PDH/DSn LINEAR PASSIVE SONET PDH/DSn RING PASSIVE SONET SONET LINEAR PASSIVE or ACTIVE

GENERAL HOWTO:

SONET SONET RING PASSIVE

1 Set up the SONET transmit interface and payload required. See "Setting SONET

Transmit Interface " page 29.

2 Choose the TOPOLOGY required. 3 Follow the appropriate HOWTO, listed in the following pages.

Selecting Test Fe atur es

Generating Automatic Protection Swi tch (APS ) Messag es

PASSIVE APS HOWTO:

The default APS message type is PASSIVE. The APS message is only transmitted when the

key is pressed.

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Insert sonet_aps1.bmp

HOW TO: 1 Select PASSIVE APS message type.

NOTE This step does not apply t o RING TOPOLOGY.

2 Choose the message to be transmitted.

If LINEAR topology is chosen, choose the CHANNEL, the BRIDGED CHANNEL NO., the ARCHITECTURE and the RESERVED bits you require. If RING topology is chosen, choose the DESTINATION NODE ID, the SOURCE NODE ID, the type of PATH and the status code (K2 Bits 6->8) The current TX and RX, K1 and K2, values are displayed for reference only.

3 Choose to transmit the new K1/K2 values .

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Selecting Test Fe atur es

Generating Automatic Protection Swi tch (APS ) Messag es

Insert son_aps2.bmp

ACTIVE APS Message Type

This message type only applies to LINEAR topology. The ACTIVE APS message type gives real-time response to provide switching

keep-alive capability. The instrument will not initiate any changes, but will respond to change requests that appear on the input K1/K2 byte values.

The ACTIVE APS message type offers two modes:-

• UNIDIRECTIONAL

• BIDIRECTIONAL

The behavior for each mode is as shown in the following table.

APS MODE

RX K1 (b5-b8)

TX K1

(b1-b4)

TX K1

(b5-b8)

TX K2

(b1-b4)

TX K2

(b5)

TX K2 (b6-b8)

UNIDIRECTIONAL xxxx 0000 0000 xxxx user 100 BIDIRECTIONAL 0000 0000 0000 0000 user 101 BIDIRECTIONAL yyyy 0010 yyyy yyyy user 101

GR bit numbering convention

where:

xxxx = any 4-bit binary value. user = user programmable bit, corresponding to APS ARCHITECTURE.

Selecting Test Fe atur es

Generating Automatic Protection Swi tch (APS ) Messag es

yyyy = any non-zero 4-bit binary value.

Insert aps_3.bmp

HOW TO: 1 Select ACTIVE APS message type.

2 Select ACTIVE APS message mode.

Insert aps_4.bmp

100

Agilent 37718A User Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

1 Introduction

Product Description

Conventions

Connecting to the Network

Connecting Accessories

Front Panel Soft Recovery (Cold Start )

OmniBER 718 Option Guide

2 Setting the Interfaces

Setting PDH/DSn Transmit Interface (Option 012)

Setting DSn THRU Mode

Setting SONET Transmit Interface

Setting Jitter Transmit Interface

Setting Wander Transmit Interface

Setting SONET THRU Mode

Using Smart Test

Setting PDH/DSn Receive Interface

Setting SONET Receive Interface

Setting Jitter Receive Interface

Setting Extended Jitter Receive Interface

Setting Wander Receive Interface

3 Selecting Test Features

Using Transmit Overhead Setup

Using Receive Overhead Monitor

Setting Overhead Trace Messages

Setting Overhead Labels

Generating Overhead Sequences

Using Receive Overhead Capture

Adding Frequency Offset to SONET Signal

Adding Frequency Offset to the DSn Signal

Setting up Signaling Bits

Setting Transmit Structured Payload/Test Signal

Setting Receive Structured Payload/Test Signal

Setting Transmit N x 64 k b / s /N x 56 k b /s Structured Paylo ad / Test Signal

Setting Receive N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal

Inserting an External DSn Payload/Test Signal

Dropping an External Payload/Test Signal

Adding Errors and Alarms at the SONET Interface

Adding Errors and Alarms to a DSn Signal

Using FEAC Codes

Setting DSn Spare Bits

Adding Pointer Adjustments

Using Pointer Graph Test Function

Stressing Optical Clock Recovery Circuits

Generating Automatic Protection Swi tch (APS ) Messag es