HP OMNIBER 718 37718A, 37718A OmniBER 718 User Manual

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HP 37718A

User’s Guide DSn/SONET Operation

OmniBER 718

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 Copyright HewlettPackard Ltd.1998

HP Part No. 37718-90022

First edition, 09/98 Second Edition, 12/98 Printed in U.K.

Warranty

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

Hewlett-Packardmakes no warranty of any kindwith regardtothis material, including, but not limited to, the implied warranties or merchantability and ﬁtness for a particular purpose.

Hewlett-Packard shall not be liable for errors contained herein or for incidental or consequentialdamages in connection with the furnishing, performance, or use of this material.

WARNING

Warning SymbolsUsed on the Product

The product is marked with this symbol when the user should referto 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 marked with this symbol to indicate that a laser is ﬁtted. The user should refer tothe laser safety information in the Calibration Manual.

Hewlett-Packard Limited Telecommunications Networks Test Division South Queensferry West Lothian, Scotland EH30 9TG

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User’s Guide DSn/SONET Operation

HP 37718A OmniBER 718

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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

• Testfeatures,forexample, theaddition oferrors andalarms to thetest

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.

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Contents

1 Setting the Interfaces

Setting DSn Transmit Interface 2 Setting SONET Transmit Interface 4 Setting Jitter Transmit Interface 7 Setting Wander Transmit Interface 9 Setting SONET THRU Mode 11 Using Smart Test 13 Setting DSn Receive Interface 15 Setting SONET Receive Interface 17 Setting Jitter Receive Interface 18 Setting Extended Jitter Receive Interface 19 Setting Wander Receive Interface 20

2 Selecting Test Features

Using Transmit Overhead Setup 22 Using Receive Overhead Monitor 24 Setting Overhead Trace Messages 26 Generating Overhead Sequences 27 Using Receive Overhead Capture 29 Adding Frequency Offset to SONET Signal 31 Adding Frequency Offset to the DSn Signal 33 Setting up Signaling Bits 34 Setting Transmit Structured Payload/Test Signal 37 Setting Receive Structured Payload/Test Signal 39 Setting Transmit N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal 40 Setting Receive N x 64 kb/s/N x 56 kb/s Structured Payload/Test Signal 42

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Contents

Inserting an External DSn Payload/Test Signal 43 Dropping an External Payload/Test Signal 46 Adding Errors & Alarms at the SONET Interface 49 Adding Errors & Alarms to the DSn Interface/DSn Payload 50 Using FEAC Codes 51 Setting DSn Spare Bits 53 Adding Pointer Adjustments 54 Using Pointer Graph Test Function 61 Stressing Optical Clock Recovery Circuits 63 Generating Automatic Protection Switch Messages 64 Inserting & Dropping Data Communications Channel 65

3 Making Measurements

Using Overhead BER Test Function 68 Test Timing 69 Making SONET Analysis Measurements 70 Making DSn Analysis Measurements 71 Measuring Frequency 72 Measuring Optical Power 73 Measuring Round Trip Delay 74 Monitoring Signaling Bits 76 Measuring Service Disruption Time 77 Performing a SONET Tributary Scan 80 Performing an SONET Alarm Scan 82 Performing a DSn Alarm Scan 83 Measuring Jitter 84 Measuring Extended Jitter 86 Measuring Wander 87 Measuring Jitter Tolerance 89

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Contents

Measuring Jitter Transfer 92

4 Storing, Logging and Printing

Saving Graphics Results to Instrument Store 98 Recalling Stored Graph Results 99 Viewing the Bar Graph Display 101 Viewing the Graphics Error and Alarm Summaries 103 Logging Graph Displays 105 Logging Results 107 Logging on Demand 110 Logging Jitter Tolerance Results 112 Logging Jitter Transfer Results 114 Logging Results to Parallel (Centronics) Printer 116 Logging Results to HP-IB Printer 117 Logging Results to Internal Printer 118 Logging Results to RS-232-C Printer 119 Printing Results from Disk 120 Connecting an HP 850C DeskJet Printer to a Parallel Port 121 Changing Internal Printer Paper 122 Cleaning Internal Printer Print Head 125

5 Using Instrument and Disk Storage

Storing Conﬁgurations in Instrument Store 128 Titling Conﬁguration in Instrument Store 129 Recalling Conﬁgurations from Instrument Store 130 Formatting a Disk 131

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Contents

Labeling a Disk 132 Managing Files and Directories on Disk 133 Saving Graphics Results to Disk 140 Saving Data Logging to Disk 142 Saving Conﬁgurations to Disk 143 Recalling Conﬁguration from Disk 144 Recalling Graphics Results from Disk 145 Copying Conﬁguration from Instrument Store to Disk 146 Copying Conﬁguration from Disk to Instrument Store 148 Copying Graphics Results from Instrument Store to Disk 150

6 Selecting and Using "Other" Features

Coupling Transmit and Receive Settings 154 Setting Time & Date 155 Enabling Keyboard Lock 156 Enabling Beep on Received Error 157 Suspending Test on Signal Loss 158 Setting Error Threshold Indication 159 Setting Screen Brightness and Color 160 Dumping Display to Disk 161 Running Self Test 163

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Contents

7 STS-1 SPE Background Patterns

8 ETSI/ANSI Terminology

ETSI/ANSI Conversion and Equivalent Terms 170

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Contents

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1 Setting the Interfaces

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

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Setting the Interfaces

Setting DSn Transmit Interface

Description DSn transmit interface settings should match 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 .

OTHER

SETTINGS CONTROL COUPLED

HOW TO: 1 Choose the required SIGNAL rate.

Rates of DS1, DS3, 2 Mb/s and 34 Mb/s are available.

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

CLOCK SYNC source - internally generated or recovered from the received DSn signal. If Jitter,Option 204, 205or 206, isﬁtted and SIGNAL is chosen a choice is added to the menu. This allows you to choose the

2M REF

synchronization source for the 2 Mb/s reference. The synchronization source is supplied from theSONET Clock module. It can be internally generated, derived from an external clock or recovered from the SONET received signal.

2 Mb/s

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Setting the Interfaces

Setting DSn Transmit Interface

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).

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

required LINE CODE. (At 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 33.

7 Choose the required PAYLOAD TYPE.

If is required must be chosen.

STRUCTURED

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

STRUCTURED

FRAMED

“Setting Transmit Structured Payload/Test Signal” page 37. 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.

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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 HP 37718A transmitter and receiver to the same

interface settings choose .

OTHER

SETTINGS CONTROL COUPLED

HOW TO: 1 Make your choice of SIGNAL rate.

If Option 106, DualWavelengthoptical module,is ﬁttedand an optical rate is chosen, choose the required wavelength (1550) or (1310). If STS-1 is chosen, choose the required interface level. Choose unless isrequired. If is chosen, see "Setting SONET THRU Mode " page 11.

2 Make your choice of CLOCK synchronization source. The RECEIVE

clocksynchronization choicedepends on theSONET ReceiveInterface choice.

EXTERNAL

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

Frequency Offset to SONET Signal” page 31.

INTERNAL THRU MODE THRU MODE

allows a choice of MTS, BITS or 10 MHz clocks.

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Setting the Interfaces

Setting SONET Transmit Interface

4 Choose FOREGROUND , BACKGROUND

B/G MAPPING

MAPPING and type of payload.

F/G MAPPING

Mapping may beselected from a pictorial display by moving thecursor to MAPPING and pressing .

SET

Use and to move betweenSTS Layer choice, VTLayer choice and Payload Layer choice. Use and to choose the mapping.

SET

Use to conﬁrm your choice and return to the

MAIN SETTINGS

display.

SONET

5 If VT-6 mapping is chosen, VT CONCATENATION selection is

enabled, choose or the tributary at which the concatenation

OFF

begins, VT6-2C through VT6-6C. The BACKGROUND, PATTERN IN OTHER VT-6’s 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 OFFSET value. See “Adding

Frequency Offset to SONET Signal” page 31

7 If FULL SPE, VT-6, VT-2or VT-1.5mapping is chosen, choose the test

tributary CHANNEL,including theSTS-3 for anOC-12/OC-48 signal.

8 Choose the payloadframing under PAYLOAD TYPEor VT PAYLOAD.

If is required must be chosen.

STRUCTURED

If is chosen, thePayload test signal must be set up.See

STRUCTURED

FRAMED

“Setting Transmit Structured Payload/Test Signal” page 37. If is chosen, see “Inserting an External DSn Payload/Test

INSERT

Signal” page 43.

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Setting the Interfaces

Setting SONET Transmit Interface

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

OTHER VT’s.

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Setting the Interfaces

Setting Jitter Transmit Interface

Description: You can add jitter to the transmitted DSn or SONET signal at 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.

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

interface. See Chapter “Setting DSn Transmit Interface”.

2 If you are adding jitter to the SONET signal, set up the SONET

transmit interface. See “Setting SONET Transmit Interface” page 4.

3 Choose JITTER/WANDER .

JITTER

If you wish to add wander to the DSn or SONET signal, See “Setting Wander Transmit Interface” page 9.

4 Choose JITTER .

If you wish to perform a Jitter Tolerance measurement, choose

AUTO TOLERANCE

. See “Measuring Jitter Tolerance” page 89.

If you wish to perform a Jitter Transfer measurement choose

TRANSFER FUNCTION

. See “Measuring Jitter Transfer” page 92.

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Setting the Interfaces

Setting Jitter Transmit Interface

5 Choose the modulation source.

If adding jitter to the DSn signal and is chosen, connect

EXTERNAL

the 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 SDH signal and is chosen, connect

EXTERNAL

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

6 Choose the JITTER MASK setting required.

You can choose the jitter range, jitter modulating frequency and jitter amplitude if is chosen. If youchoose , the HP 37718Awill "sweep" through the ITU-T

OFF

SWEPT

jitter mask (G.823 for DSn, G.958, G.825 or G.253 for SONET) adjusting the jitter amplitude according to the jitter frequency. If you choose , you can choose the "spot" jitter frequency. The

SPOT

jitter 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

SPOT

frequency to make closer examination of the problem.

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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.

HOW TO: DSn Wander (2 Mb/s)

1 ConnectREF OUT onthe SONETClock moduleto REF IN on theDSn

Jitter TX module (this provides the Wander Reference).

2 Setup the DSntransmit interface,chooseCLOCK SYNC and

select the SOURCE required from the menu. See “Setting DSn Transmit Interface” page 2.

3 Choose JITTER/WANDER .

Ifyou wishto addjitter tothe DSnsignal, See“Setting JitterTransmit Interface” page 7.

4 Choose WANDER . 5 Choose the modulation source.

If is chosen, connect the external source to the MOD IN

EXTERNAL

port of the DSn Jitter TX module. Up to 10 UI of external wander modulation can be added.

2M REF

WANDER

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Setting the Interfaces

Setting Wander Transmit Interface

6 Choose the WANDER MASK setting required.

You can choose the wander modulating frequency and wander amplitude if is chosen. If you choose ,you can choose the "spot" wander frequency. The

OFF

SPOT

wanderamplitude isadjusted andcontrolled accordingto yourwander frequency choice.

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

7 Set up the SONET transmit interface. See “Setting SONET Transmit

Interface” page 4.

8 Choose JITTER/WANDER .

WANDER

If you wish to add jitter to the SONET signal, see "Setting Jitter Transmit Interface " page 7.

9 Choose WANDER .

10 Choose the WANDER MASK setting required.

You can choose the wander modulating frequency and wander amplitude if is chosen. If you choose ,you can choose the "spot" wander frequency. The

OFF

SPOT

wanderamplitude isadjusted andcontrolled accordingto yourwander frequency choice.

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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. As THRU mode locks some user settings, you must set SIGNAL RATE, STS rate, STS-1 SPE CHANNEL (if appropriate) 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 eitheroverwrite is enabled the ENTIRE FRAME ERROR RATE

OFF

function is disabled.

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

You can substitutea 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.

HOW TO:

OC-12, OC-48

The overhead and payload may be overwritten for STS-3c SPE and AU3. PAYLOAD OVERWRITE is not available for STS-12C or STS-48C. TOH+POH CHANNEL overwrite is available for STS-12C and STS-48C.

1 Make the required SIGNAL RATE, MAPPING and CHANNEL

choices on the SONET and displays, See

TRANSMIT

RECEIVE

"Setting SONET Transmit Interface " page 4 and "Setting SONET

Receive Interface " page 17.

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Setting the Interfaces

Setting SONET THRU Mode

2 Make the PAYLOAD OVERWRITE choice required.

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

3 Make the TOH+POH CHANNEL OVERWRITE choice required.

You canonly modify those overhead bytes available under

SONET TEST FUNCTION SONET

: Errors & Alarms, Sequences,

TRANSMIT

Overhead BER, APS Messages and DCC Insert. The Section, Line and Path CVs are recalculated before transmission.

4 Ifyou wishto addjitterto theSTS-3, OC-3,OC-12 orOC-48signal, See

“Setting Jitter Transmit Interface” page 7.

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Setting the Interfaces

Using Smart Test

Description The SmartTest functioncan help speed-up conﬁguring theinstrument in

two ways. 1 A Smartsetup feature that will attempt to conﬁgure the instrument

to receive the incoming signal.

2 A series of “links” that provide quick access to some of the most

frequently used features of the instrument. Note that these tests are run with the instrument in its current conﬁguration, no attempt is made to set the instrument to the requirements of the test.

Smartsetup can help the user by attempting to identify the incoming signal structure and detect mixed payload signal structures.

HOW TO USE SMARTSETUP:

1 Connect the HP 37718A to the network and choose if necessary the

required SONET interface on the HP 37718A (Smartsetup will select DSn or SONET/SDH, but can not select between SONET and SDH).

2 Press .

The display will show the Smart Test menu above.

3 Press either or .

SMART TEST

SET

RECEIVE

SELECT

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Setting the Interfaces

Using Smart Test

4 In SONET mode the incoming signal will be identiﬁed on the top line

of the display, and under this the payload mappings, the J1 Trace and C2 byte indicators are displayed on the bottom lines.

5 Use the and keys to display the J1 Trace information for each

STS SPE. When the STS SPE of interest has been identiﬁed choose either or .

VIEW PAYLOAD PRBS SEARCH

6 Choosing will identify and display the payload

VIEW PAYLOAD

mapping of the TUG structured signal, as shown below. Choose the required tributary using and .

7 There are four choices available at this point:

SETUP RX

TROUBLE SCAN

tributary, exitsto the displayand starts

which sets the receiver to receive the selected tributary.

which sets the receiver to receive the selected

RESULTS

TROUBLE SCAN

gating.

VIEW LABELS

which displaysthe C2/V5/J1/J2 trace information for

the selected tributary.

TOP LEVEL

which returns the display to the STS SPE selection

window.

8 Choosing at Step 5 will prompt you for additional

information about patterns and which mapping to search. When the required data has been entered press .

9 When the search is complete a tributary display appears, with any

tributariescontaining the requiredPRBS indicatedwith a “P”.Choose the required tributary using and .

PRBS SEARCH

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Setting the Interfaces

Setting 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

OTHER

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.)

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

required LINE CODE. (At 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 the normal level. Choose the GAIN required to return the received signal to normal. Choose EQUALIZATION to compensate for cable losses if required.

MONITOR

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Setting the Interfaces

Setting DSn Receive Interface

5 Choose the PAYLOAD TYPE.

If is required must be chosen.

STRUCTURED

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

STRUCTURED

FRAMED

“Setting Transmit Structured Payload/Test Signal” page 37. 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.

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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 HP 37718A transmitter and receiver to the same

interface settings, choose .

OTHER

SETTINGS CONTROL COUPLED

HOW TO: 1 Choose the required SIGNAL source.

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 CONCATENATIONis 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 under CHANNEL.

4 Choose the payloadframing under PAYLOAD TYPE or VT PAYLOAD.

If is required must be chosen.

STRUCTURED

If is chosen the Payload test signal must beset up. See

STRUCTURED

FRAMED

“Setting Receive Structured Payload/Test Signal” page 39. If DROP is chosen, see “Dropping an External Payload/Test Signal” page 46.

5 Choose the PATTERN type and PRBS polarity.

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Setting the Interfaces

Setting Jitter Receive Interface

Description: Jitter and error measurements are made simultaneously when a jitter

option is ﬁtted. The measurements are made on the normal input to the DSn or SONET receiver and the interface selections are the normal Receiver selections. The jitter receive interface is selected with

PDH/DSn JITTER JITTER

or MEASUREMENT TYPE

RECEIVE

SONET

JITTER

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.

RECEIVE

HOW TO: 1 Choose MEASUREMENT TYPE .

2 Choose the RECEIVER RANGE - the jitter measurement range. 3 Choose the HIT THRESHOLD level - if the received jitter exceeds the

value chosen a jitter hit is recorded.

4 Choose the FILTER you wish to include in the peak to peak and RMS

jitter measurement.

JITTER

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Setting the Interfaces

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 or

RECEIVE

MEASUREMENT TYPE .

PDH/DSn JITTER

EXTENDED

RECEIVE

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.

SONET

JITTER

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

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Setting the Interfaces

Setting Wander Receive Interface

Description: You can measure Wander at all DSn and SONET rates. An external

timing reference should be selected on the or

SONET MAIN SETTINGS

display to ensure accurate Wander results.

TRANSMIT

PDH/DSn

HOW TO: 1 Choose an external timing reference on the

MAIN SETTINGS

display. See, “Setting SONET Transmit Interface”

page 4.

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

receive interface. See, “Setting DSn Receive Interface” page 15.

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

SONET receive interface. See, “Setting SONET Receive Interface” page 17.

4 Choose MEASUREMENT TYPE .

WANDER

5 Choose the wander HIT THRESHOLD - if the received wander

exceeds the value chosen a wander hit is recorded.

TRANSMIT

SONET

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2 Selecting Test Features

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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 overhead 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 4.

2 Choose the type of overhead to SETUP.

If OC-12 or OC-48 is chosen as the SONET interface, choose the STS3# and STS-1# you wish to set up. If STS-3 is chosen as the SONET interface, choose the STS-1# you wish to set up. DEFAULT - Use to set all overhead bytes to the standard values deﬁned by ITU-T. If a test function is active then the overhead bytevalue is determined by the choices made in the Test Function. If APS Messages is chosen, for example, K1K2 value is set by the APS Messages setup.

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Selecting Test Features

Using Transmit Overhead Setup

If (Transport Overhead) is chosen, choose the STS-1 to be

TOH

displayed.Many bytesin and areunlabeled as the

STS-1# 2 STS-1#3

other overhead functions have not yet been deﬁned. If is chosen, the hexadecimal value of all 81 bytes of the

STS-1# 1,2,3

STS-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 STS-3 in turn). The value of the bytes can be set

using .

If BYTE NAMES is chosen, the labels for the overhead

DECREASE DIGIT INCREASE DIGIT

STS-1# 1,2,3

bytes are 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 binary 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 26.

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

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Selecting Test Features

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 110.

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

“Setting SONET Receive Interface” page 17.

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. Manybytes in and areunlabeled becausetheother overhead functions have not yet been deﬁned. If is chosen, the hexadecimal value of all 81 bytes of

STS-1# 1,2,3

section overhead is 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 STS-3 in turn).The value of the bytes can be set using

INCREASE DIGIT

STS-1# 2 STS-1#3

DECREASE DIGIT

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Selecting Test Features

Using Receive Overhead Monitor

If BYTE NAMES is chosen, the labels for the overhead

STS-1# 1,2,3

bytes are displayed.

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 bits are monitored.

RING

LINEAR

TIP: If any abnormal behavior is observed on a particular path or section

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

RECEIVE

TEST FUNCTION

display of can be

OVERHEAD CAPTURE

used to "Zoom" in on the suspect byte or bytes on a frame by frame basis. See "Using Receive Overhead Capture " page 29.

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Selecting Test Features

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.

ChoosingLABELS in TRACEMESSAGES allowsthe settingof the S1 SYNC STATUS, STS PATH LABEL (C2) and VT PATH LABEL (V5).

Page 37

Selecting Test Features

Generating Overhead Sequences

Description You may insert a pattern 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 4.

2 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.

3 Choose the overhead type as required.

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

4 Choose the byte or bytes of overhead required. 5 Set up the required number of data patterns and the number of

frames in which each data pattern should appear. Yoursequence isderived fromupto 5blocks ofhexadecimal 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

Page 38

Selecting Test Features

Generating Overhead Sequences

6 Start the sequence by choosing .

START

NOTE When youstart thesequence illustrated, oneOut of Framealarm andone

Loss of Frame alarm should occur every eight seconds.

Page 39

Selecting Test Features

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 110.

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

“Setting SONET Receive Interface” page 17.

2 Choose the overhead type as required.

SOH- Section Overhead LOH- Line Overhead

POH- Path Overhead 3 Choose the Byte or bytes of overhead to be captured. Choose the TRIGGER to determine the start point of the capture.

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

OFF

provide a frame by frame monitor of the chosen byte or bytes.

-captures activity after your speciﬁed overhead state has occurred.

Can be used for transient detection from a speciﬁed expected state.

Page 40

Selecting Test Features

Using Receive Overhead Capture

ON NOT

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

4 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 and terminates when up to 16 records

START

havebeen captured.The capturecanbe terminatedearlier bypressing CAPTURE .

STOP

Page 41

Selecting Test Features

Adding Frequency Offset to SONET Signal

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

the payload 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 in1 ppmsteps using and . 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 be exceeded, the asynchronous payload is offset to prevent bit errors occurring and the maximum stuff rate is maintained. WhenFloating Byte 2Mb/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).

DECREASE DIGIT INCREASE DIGIT

Page 42

Selecting Test Features

Adding Frequency Offset to SONET Signal

Tributary Offset ±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 and .

DECREASE DIGIT INCREASE DIGIT

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 valueof SONETlinerate offsetand tributaryoffsetchosen issufﬁcient to causethe maximum stuffrate to beexceeded the payloadis offset to prevent bit errors occurring and the maximum stuff rate is maintained.

Page 43

Selecting Test Features

Adding Frequency Offset to the DSn Signal

Description You can add frequency offset to the interface DSn SIGNAL at all rates.

Frequency Offset can be added at preset ITU 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 34 Mb/s (E3) + 20 ppm −20 ppm DS-3 (44.736 Mb/s) + 20 ppm −20 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

frequency offset.(The amount of frequency offset can be varied while measurements are taking place.)

, , and to set the

Page 44

Selecting Test Features

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

DSn Operation

1 Choose on the display. 2 Choose SIGNAL and PAYLOAD TYPE or

PCM30CRC

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

the display.

MAIN SETTINGS

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

STRUCTURED SETTINGS

PDH/DSn

2 Mb/s PCM30

on the display.

TRANSMIT

MAIN SETTINGS

display.

Page 45

Selecting Test Features

Setting up Signaling Bits

SONET Operation

1 Choose on the display

SONET

2 Choose MAPPING or and VT

PAYLOAD or on the display.

PCM30 PCM30CRC

TRANSMIT

ASYNC 2Mb/s FL BYTE 2Mb/s

MAIN SETTINGS

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

the display.

MAIN SETTINGS

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

STRUCTURED SETTINGS

display.

HOW TO Transmit a DS1 payload signal with user-deﬁned signaling bits

DSn Operation

1 Choose on the display.

PDH/DSn

TRANSMIT

Page 46

Selecting Test Features

Setting up Signaling Bits

2 Choose SIGNAL or , and PAYLOAD TYPE

on the display

MAIN SETTINGS

3 Choose TEST SIGNAL or on the

SETTINGS

display.

DS1 DS3

56 kb/s Nx56 kb/s

STRUCTURED

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

required.

SONET Operation

1 Choose on the display.

SONET

2 Choose MAPPING or and VT PAYLOAD

STRUCTURED MAIN SETTINGS

on the display

3 Choose TEST SIGNAL or on the

SETTINGS

display .

TRANSMIT

ASYNC DS1

56 kb/s Nx56 kb/s

DS3

STRUCTURED

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

required.

Page 47

Selecting Test Features

Setting Transmit Structured Payload/Test Signal

Description Structured DSn Payload/Test Signal settings determine the SONET

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 HP 37718A transmitter and receiver to the same

Payload settings, choose .

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 Structured Payload/Test Signal " page 40.

2 Choose the PAYLOAD framing pattern.

If TEST SIGNAL 2Mb/s is chosen is added to the PAYLOAD menu.See "InsertinganExternal DSnPayload/TestSignal " page 43. If TEST SIGNAL DS1 is chosen is added to the menu. See "Inserting an External DSn Payload/Test Signal " page 43.

3 Choosethe testtributary inthe structuredpayload, under34Mb, 8Mb,

2Mb, 64 kb/s or DS2, DS1, 56 kb/s.

4 Choose the PATTERN type and PRBS POLARITY.

INSERT 2 Mb/s

INSERT DS1

Page 48

Selecting Test Features

Setting Transmit Structured Payload/Test Signal

5 Choose the B/G PATTERN.

The B/G PATTERN in the non test 56/64 kb/s timeslots is ﬁxed as NUMBERED,thatis, eachtimeslotcontains aunique numberto 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 34.

Page 49

Selecting Test Features

Setting Receive Structured Payload/Test Signal

Setting Receive StructuredPayload/Test Signal

Description Structured DSn Payload/Test Signal settings determine the SONET

payload or the DSn test signal to be tested.

TIP: If you wish to set the HP 37718A transmitter and receiver to the same

Payload settings, choose .

OTHER

STORED SETTINGS 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 Structured Payload/Test Signal " page 42.

2 Choose the Framing pattern of the PAYLOAD.

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

DROP 2 Mb/s

menu. See "Dropping an External Payload/Test Signal " page 46. If TEST SIGNAL DS1 is chosen, is added to the menu.

DROP DS1

See "Dropping an External Payload/Test Signal " page 46.

3 Choose the test tributary within the structured payload,under 34Mb,

8Mb, 2Mb, 64 kb or DS2, DS1, 56 kb/s.

4 Choose the PATTERN type and PRBS polarity.

Page 50

Selecting Test Features

Setting TransmitNx64kb/s/N x 56 kb/s Structured Payload/Test Signal

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

Description Wideband services such as high speed data links and LAN

interconnection 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 wideband signals are sent in a DS1/2 Mb/s frame by sharing the signal between multiple timeslots.

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

HOW TO: 1 Choose the required Test Signal rate.

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

DESELECT ALL DESELECT SELECT

timeslot is selected, an * marks the chosen timeslot. In the example above Timeslots 3, 5, 9, 21, 22, 23 are selected for test.

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

and softkeys. As each

Page 51

Selecting Test Features

Setting TransmitNx64kb/s/N x 56 kb/s Structured Payload/Test Signal

6 The B/G PATTERN in the non-test 56/64 kb/s timeslots is ﬁxed as

NUMBERED, that is, each timeslot contains a unique identiﬁcation number.

Signaling

7 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 34.

Page 52

Selecting Test Features

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

Description Wideband services such as high speed data links and LAN

interconnection 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 wideband signals are sent in a DS1/2 Mb/s frame by sharing the signal between multiple timeslots.

N x 64kb/s andNx56kb/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 Choose the Framing pattern of the 2M or DS1 PAYLOAD. 3 Choose the test timeslots within the structured payload using

DESELECT ALL DESELECT SELECT

timeslot is chosen an * marks the chosen timeslot. In the example above Timeslots 3, 5, 9, 21, 22, 23 are chosen for test.

4 Choose the PATTERN type and PRBS polarity.

and softkeys. As each

Page 53

Selecting Test Features

Inserting an External DSn Payload/Test Signal

Description You can insert a DSn signal from external equipment into the SONET

signal, or you can insert 2 Mb/s or DS1 into the structured DSn signal, as shown in the table below. DS3 and 34 Mb/s can only be inserted if SONET is chosen as the receive interface. 2 Mb/s or DS1 can be inserted from a structured or non-structured SONET payload and from a structured DSn signal.

RATE Availability Option

DS3 SONET 011 Only 34Mb/s SONET 010 and 011 2Mb/s DSn & SONET 010 and 011 DS1 DSn & SONET 011 Only

HOW TO: Insert 34 Mb/s & DS3

1 Connect the external payload to the 75Ω IN port of the PDH/DSn

receive module.

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

PAYLOAD or as required.

INSERT 34 Mb/s

INSERT DS3

Page 54

Selecting Test Features

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

Transmit module. If 2 Mb/s connect to 75ΩMUX port. If DS1 connect to 100Ω MUX port.

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

VT-1.5 MAPPING and VT PAYLOAD or .

INSERT 2 Mb/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 75ΩMUX port. If DS1 connect to 100Ω MUX port.

Page 55

Selecting Test Features

Inserting an External DSn Payload/Test Signal

Structured SONET Payload

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

Transmit Interface " page 4.

3 Set up the SONET structured payload. See "Setting Transmit

Structured Payload/Test Signal " page 37.

4 Choose 2M PAYLOAD/DS1 PAYLOAD or

INSERT DS1

INSERT 2 Mb/s

5 Choose the LINE CODE.

Structured DSn

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

Transmit Interface " page 2.

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

Structured Payload/Test Signal " page 37

8 Choose 2M PAYLOAD/DS1 PAYLOAD or

INSERT DS1

INSERT 2 Mb/s

9 Choose the LINE CODE.

Page 56

Selecting Test Features

Dropping an External Payload/Test Signal

Description You can drop a DSn signal from the received payload or drop 2 Mb/s or

DS1 from the structured DSn signal to external equipment as shown in the table below. DS3 and 34 Mb/s can only be dropped if SONET is chosen as the receive interface. 2 Mb/s or DS1 can be dropped from a structured ornon-structured SONET payload and froma structured DSn signal.

RATE Availability Option

DS3 SONET 011 Only 34Mb/s SONET 010 and 011 2Mb/s DSn & SONET 010 and 011 DS1 DSn & SONET 011 Only

HOW TO: Drop 34 Mb/s & DS3

1 Connect the 75Ω OUT port of the DSn Transmit module to the

external equipment.

2 Set up the receive SONET interface, and choose VT PAYLOAD ,

DROP 34 Mb/s

If is chosen, choose the DS3 output level.

DROP DS3

or .

DROP DS3

Page 57

Selecting Test Features

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 .

DROP 2 Mb/s

DROP DS1

3 Choose the required LINE CODE.

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 75Ω DEMUX port. If DS1 connect to 100Ω DEMUX port.

Page 58

Selecting Test Features

Dropping an External Payload/Test Signal

Structured SONET Payload

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

Receive Interface " page 17.

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

Structured Payload/Test Signal " page 39.

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 DSn Receive

Interface " page 15.

7 Set upthe DSnTest Signalinterface. See "Setting Receive Structured

Payload/Test Signal " page 39

8 Choose 2M PAYLOAD or DS1 PAYLOAD .

DROP 2 Mb/s

DROP DS1

9 Choose the LINE CODE.

Page 59

Selecting Test Features

Adding Errors & Alarms at the SONET Interface

Description Errors and alarms can be added to the SONET interface signal during

testing.

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

"Setting SONET Transmit Interface " page 4.

2 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 FRAMEand A1A2 FRAME, 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 theform of N errorsin T time period.N and T are both selectable.

3 Choose the ALARM TYPE

Errors and Alarms can be added at the same time.

Page 60

Selecting Test Features

Adding Errors & Alarms to the DSn Interface/DSn Payload

Adding Errors & Alarms to the DSn Interface/ DSn Payload

Description Errors and alarms can be added to the DSn interface/payload signal

during testing.

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

and payload required. See “Setting SONET Transmit Interface” page 4. If DSn interface is chosen, set up the DSn interface and payload required. See “Setting DSn Transmit Interface” page 2.

2 Choose the ERROR ADD TYPE and RATE on the Transmitter

TEST FUNCTION

The RATEcan be selectedfrom a ﬁxed valueor 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.

3 Choose the ALARM TYPE.

Errors and Alarms can be added at the same time.

display.

Page 61

Selecting Test Features

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 areembedded 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

2 Choose and ALARM TYPE .

TRANSMIT

DS3 CBIT

display.

TEST FUNCTION DS3 FEAC

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

BURST ON

TRANSMIT

Page 62

Selecting Test Features

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 .

ALL

If youchoose use theEDIT keysto select achannel from 1 to 28. Press when ﬁnished.

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

LOOPBACK

SINGLE CHANNEL

END EDIT

MESS, in the range 1 to 15.

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

ALARM/ STATUS

7 Choose TRANSMIT NEW CODE or to transmit the

selected FEAC message.

TIP: To View FEAC Messages

The received FEAC message can be viewed on the display.

BURST

RESULTS

Page 63

Selecting Test Features

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 4. If DSn interface is chosen, set up the DSn transmit interface and payload required. See "Setting DSn Transmit Interface " page 2.

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

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

Page 64

Selecting Test Features

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 4.

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

BURST - You determine the size of the burst by the number of PLACES chosen. If, for example, you choose 5 PLACES the pointer value will be stepped 5 times in unit steps e.g. 0 (start value), 1, 2, 3, 4, 5 (ﬁnal value). The interval between steps is as follows: For AU and TU-3, the minimum spacing between adjustments is 500 us. For VT the minimum spacing between adjustments is 2 ms. Choose ADJUST POINTER [ON] to add the chosen burst.

NEW POINTER - You canchoose apointer valuein the range0 to782 with or without a New Data Flag. The current pointer value is displayed for information purposes. Choose ADJUST POINTER [ON] to transmit the new pointer value.

Page 65

Selecting Test Features

Adding Pointer Adjustments

OFFSET - You can frequency offset the line rate or the SPE/VT rate, relative toeach other, thusproducing 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.

Pointer Type Line Rate SPE Rate VT Rate

SPE Constant Offset Tracks AU 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 Choosethe POLARITY, INTERVAL and PATTERN (whereapplicable)

for the selected sequence.

6 Choose POINTERSEQUENCES to generatethe selected

G.783 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 and OFFSET pointer movements described, the HP 37718A can also generate pointer 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:

Page 66

Selecting Test Features

Adding Pointer Adjustments

Non Periodic Sequence

Periodic Sequence

Initialization Sequence

Initialization

No Pointer Activity

Continuous Sequence

Cool Down

Sequence

Time

Measurement

Period

Note: SINGLE (A1), BURST (A2) and PHASE TRANSIENT(A3) are Non Periodic Sequences.

Initialization Period

ForSINGLE 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 periodwhich 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 HP 37718A displays a message indicating which phase (initialization, cool down or measurement) the transmitter is currently generating.

Page 67

Selecting Test Features

Adding Pointer Adjustments

NOTE The following conditions apply for pointer sequence generation:

The sequences can onlybe applied to the SPE pointer when the SPEdoes 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 example of a T1.105/GR-253, 87-3 Pointer Sequence.

T1.105 A4 and A5, 87-3 Pattern

No Pointer Adjustment

Pointer Adjustment

Start of Next 87-3 Pattern

Pointer Sequence

T1.105 A1 SINGLE GR-253 5-29

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

An Example of a Pointer Sequence

Description

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

Periodic bursts of 3 adjustments, all of the same polarity which is selectable. The interval between bursts is ﬁxed at approximately 30 seconds. The interval between adjustments within a burst is set to the minimum.

Page 68

Selecting Test Features

Adding Pointer Adjustments

Pointer Sequence

T1.105 A3 PHASE TRANSIENT GR-253 5031

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)

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

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

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

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).

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 to 200 ms, 500 ms, 1 s, 2 s, 5 s or 10 seconds.

Description

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

An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followedby 3 missing pointer movementswith an added pointer movement after the 43rd pointer. The spacing between the added adjustment and the previous adjustment is set to the minimum. Pointerpolarity 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.

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

Periodic Single adjustments, with selectable polarity and added adjustment (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.

Page 69

Selecting Test Features

Adding Pointer Adjustments

Pointer Sequence

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

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

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

Description

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. Theadded adjustment occurs 2 ms after the 13th pointer adjustment. Pointer polarity is selectable and the time interval between pointer adjustments programmable to 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.

An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followed by 3 missing pointer 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 Note1). Cancelled adjustments occur every 30 seconds or every repeat of the 87-3 pattern, whichever is longer.

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

GR-253 5-32(d) PERIODIC CANCEL (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. 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 adjustments occur every30 seconds or every repeat of the 26-1 pattern, whichever is longer.

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

30, 34 ms; 40 to 100 ms in 10 ms steps, 100 to 1000 ms in 100 ms steps 1, 2, 5, 10 seconds. ForVT pointers the sequence interval is selectable from: 200 ms, 500 ms, 1, 2, 5 and 10 seconds. ForSPEpointersthe minimumspacingbetween adjustmentsis500 us. For VT pointers the minimum spacing between adjustments is 2 ms.

Page 70

Selecting Test Features

Adding Pointer Adjustments

Table 1 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) PERIODIC NORMAL (26-1) A5 PERIODIC ADD (87-3) A5 PERIODIC ADD (Continuous) PERIODIC ADD (26-1) A5 PERIODIC CANCEL (g) 87-3 A5 PERIODIC CANCEL (Continuous) PERIODIC CANCEL 26-1

SPE VT6, VT2 VT1.5

✓✓✓ ✓✓✓ ✓✓✓ ✓ ✓✓✓

✓ ✓ ✓✓✓

✓

Page 71

Selecting Test Features

Using Pointer Graph Test Function

Pointer Graph shows the relative offset during the measurement period. This allows the time relationship of SPE or VT pointer movements to be observed. Up to4 days of storage allowslong 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 110.

TIP: The graph can also beviewed on the display

at the end of the measurement.

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

“Setting SONET Receive Interface” page 17.

2 Choose the CAPTURE INTERVAL required.

The capture interval determines the time between captures. Low values of capture interval should be chosen when a high degree of pointer movements is expected. High values ofcapture interval should be chosenwhen a low degree of pointer movements is expected, for example Wander over 1 day, use 5 MINS and Wander over 4 days, use 20 MINS.

RESULTS

SONET RESULTS

Page 72

Selecting Test Features

Using Pointer Graph Test Function

If, during a long term measurement (4 days), an event occurs at a particular time each day, a short term measurement can be made at the identiﬁed time to gain more detail of the event.

3 Choose the POINTER UNDER TEST type. 4 Press to start the measurement.

RUN/STOP

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

measurement can be made. 1 SEC - display window of approximately 5 minutes. 5 SECS - display 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.

Page 73

Selecting Test Features

Stressing Optical Clock Recovery Circuits

Description Ideally clock recovery circuits in the network equipment optical

interfaces should recover the clock even in the presence of long strings of 0’s. You can check the performance of your optical clock recovery circuits using the STRESS TEST test function.

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 4.

Choose the required STRESSING PATTERN. 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.

Page 74

Selecting Test Features

Generating Automatic Protection Switch Messages

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

Both LINEAR (ITU-T G.783) and RING (ITU-T G.841) topologies.

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

"Setting SONET Transmit Interface " page 4.

2 Choose the ITU-T TOPOLOGY required. 3 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, choosethe DESTINATION NODE ID, the SOURCE NODE ID, the type of PATH and the status code (K2 Bits 6>8) The currentTX and RX, K1and K2, values aredisplayed for reference only.

4 Choose to transmit the new K1/K2 values.

DOWNLOAD

Page 75

Selecting Test Features

Inserting & Dropping Data Communications Channel

Description The Data Communications Channel (DCC) of the regenerator and

multiplexer section overhead can be veriﬁed by protocol testing. The Insert and Drop capability provides access to the DCC via the RS-449 connector on the front panel of the Multirate Analyser module.

DCC INSERT is available on the , , display.

DCC DROP is available on the display.

HOW TO: 1 Connect the Protocol Analyzer to the DCC port on the Multirate

Analyzer module.

TRANSMIT

RECEIVE

SONET TEST FUNCTION

2 Choose the required DCC.

Page 76

Selecting Test Features

Inserting & Dropping Data Communications Channel

Page 77

3 Making Measurements

Page 78

Making Measurements

Using Overhead BER Test Function

Description You can perform a Bit Error Rate test on chosen bytes of the section, line

and path overhead bytes. You can access the transmit Overhead BER on the

TEST FUNCTION

display.

TRANSMIT

SONET

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

"Setting SONET Transmit Interface " page 4.

2 Set up the receive SONET interface and payload as required. See

"Setting SONET Receive Interface " page 17.

3 Choose the overhead byte to be tested on the

TEST FUNCTION

4 Choose the overhead byte to be tested on the

TEST FUNCTION

5 Press to start the test. 6 The PRBS pattern can be errored by pressing .

RUN/STOP

display.

RECEIVE

TRANSMIT

SINGLE

SONET

Page 79

Making Measurements

Test Timing

Description There are two aspects to test timing:

• Error results may be displayed as short term or cumulative over the measurement period.If short term error measurements are required, the short term period may be selected.

• The period of the test may be deﬁned or controlled manually.

HOW TO: 1 Choose on the display.

2 Choose the SHORT TERM PERIOD to the timing required for short

term results.

3 Choose the type of TEST TIMING required:

For manual control with choose . For a single timed measurement period started with , choose and choose the Test duration. Fora timed period starting at a speciﬁed time, choose , choose the Test duration and the test START date and time.

TIMING CONTROL

SINGLE

RUN/STOP

RESULTS

MANUAL

RUN/STOP

TIMED

Page 80

Making Measurements

Making SONET Analysis Measurements

MakingSONETAnalysisMeasurements

Description G.826, M.2101, M.2110 and M.2120 analysis results are provided for all

relevant SONET error sources. In addition the following results are provided:

Cumulative error count and error ratio Short Term error count and error ratio Alarm Seconds Frequency Pointer Values Pointer Graph

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

"Setting SONET Receive Interface " page 17.

2 If required set up the SONET transmit interface and payload. See

"Setting SONET Transmit Interface " page 4.

3 Press to start the measurement. 4 You can view the analysis results on the

ANALYSIS

TIP: The measurement will not be affected if you switchbetween the different

results provided.

RUN/STOP

display.

RESULTS

SONET

Page 81

Making Measurements

Making DSn Analysis Measurements

Description G.821, G.826, M.2100, M.2110 and M.2120 analysis results are provided

for all relevant DSn and DSn Payload error sources. In addition the following results are provided:

Cumulative error count and error ratio Short Term error count and error ratio Alarm Seconds SIG/BIT Monitor. See "Monitoring Signaling Bits " page 76.

HOW TO: 1 If SONET is chosen as the interface, set up the Receive Interface and

Payloadrequired.See "SettingSONET Receive Interface" page 17.If required set up the Transmit Interface and Payload. See "Setting SONET Transmit Interface " page 4.

2 If DSn ischosen as the interface, setup the DSn receive interface. See

"Setting DSn Receive Interface " page 15. If required set up the DSn

transmit interface. See "Setting DSn Transmit Interface " page 2.

3 Press to start the measurement. 4 If SONET is chosen as the interface, you can viewthe analysis results

on the display If DSn is chosen as the interface, you can view the analysis results on the display.

RUN/STOP

RESULTS

DSn PAYLOAD

DSn ERROR ANALYSIS

ERROR ANALYSIS

Page 82

Making Measurements

Measuring Frequency

Description The signal frequency and the amount of offsetfrom the standard rate can

be measured to give an indication of probability of errors.

HOW TO: 1 Connect the signal to be measured to the IN port of the DSN Receive

module or the IN port of the Multirate Analyzer module (SONET electrical) or the IN port of the Optical Interface module (SONET optical).

NOTE Frequency measurement is always available even if test timing is off.

Page 83

Making Measurements

Measuring Optical Power

Description Optical power measurement can be performed on the SONET signal

connected to the Optical module IN port.

HOW TO: 1 Connect the SONET optical signal to the IN port of the Optical

Interface module.

2 Choose the received input signal rate on the

RECEIVE

SONET

display.

NOTE Optical power measurement is always available even if test timing is off.

Page 84

Making Measurements

Measuring Round Trip Delay

Description: The time taken for voice trafﬁc to pass through the network is very

important. Excessive delay can make speech difﬁcult to understand. The Round Trip Delay feature of the HP 37718A measures thedelay in a 64 kb/s timeslot. A test pattern is transmitted in the 64 kb/s timeslot and a timer is set running. A loopback is applied to the network equipment to return the test signal. The received pattern stops the timer and the Round Trip Delay is calculated.

NOTE You can only measure Round Trip Delayon a 64 kb/s test signal obtained

from a 34 Mb/s or 2 Mb/s DSn interface or DSn payload signal.

HOW TO: 1 If measuringon an SONET interface,set up the SONET transmitand

receive interfaces and payloads required. See "Setting SONET Transmit Interface " page 4 and “Setting SONET Receive Interface” page 17.

2 If measuring on a DSn interface, set up the DSn transmit and receive

interfaces and payloads required. See “Setting DSn Transmit Interface” page 2 and “Setting DSn Receive Interface” page 15.

3 Connect a loopback to the network equipment.

Page 85

Making Measurements

Measuring Round Trip Delay

4 Choose ACTION to start the measurement.

If measuring on an SONET interface, the results are available on the

RESULTS

DSn PAYLOAD

display.

If measuring on a DSn interface, the results are available on the

display.

RESULTS

DSn

The Round Trip delay measurement range is up to 2 seconds. The resolution varies with the received interface signal rate:

2 Mb/s 1 microsecond 34 Mb/s 110 microseconds STS-1,STS-3 0.5 milliseconds

OC-12, OC-48 0.5 milliseconds

Page 86

Making Measurements

Monitoring Signaling Bits

Description The HP 37718A receiver can be used to monitor the state of signaling

bits in received 2 Mb/s signals with timeslot-16 CAS multiframing (PCM30 or PCM30CRC) and DS1 structured signals.

2.048 Mb/s Results

DS1 Results D4 and SLC-96 payloads

For 2 Mb/s signals with timeslot-16 CAS multiframing a table showing the values of A,B,C,D signaling bits in all 30 channels is given.

A table simultaneously showing the state of the A and B signaling bits in the 6th and 12th frames of a superframe is given. Each frame contains 24 timeslots. In SLC-96 mode A and B choices are 0, 1 or alternating. If you set bit A or B to alternate, the displayed bit changes to an A, to indicate that the bit is alternating from 1 to 0. The same signaling is transmitted in all channels.

ESF Payloads

A table simultaneously showing the state of the A, B, C and D signaling bits in the 6th, 12th, 18th and 24th frames of a superframe is given. Each frame contains 24 timeslots.

Page 87

Making Measurements

Measuring Service Disruption Time

Description: Protection switching ensures that data integrity is maintained and

revenue protectedwhen equipment failure occurs.The speed of operation of the protection switch can be measured.

The sequence of events involved in measuring the switching time is:

• Pattern Synchronization (no errors) is achieved.

• The protection switch is invoked - Pattern Synchronization is lost.

• The standby line is in place - Pattern Synchronization is regained.

The time interval between pattern sync loss and pattern sync gain is a measure of the disruption of service due to protection switching.

Service Disruption is chosen on the page except for the following conﬁguration:

• If you choose a DSn or SONET interface and an ANSI (DS1, DS3) framed, unstructured payload you must select Service Disruption on the Transmitter and Receiver display.

RESULTS

TEST FUNCTION

Page 88

Making Measurements

Measuring Service Disruption Time

NOTE At DS1 and DS3 Service Disruption results are only available for

Unstructured payloads.

Error Burst Deﬁnition

Error bursts start and ﬁnish with an error. Bursts of less than 10 us are ignored. Bursts are assumed to have completed when >2000ms elapses without any errors being received. The longest burst detected is 2 seconds.

Accuracy

300 us for DS1, 2Mb/s and 34Mb/s signals. 60 us for DS3 signals.

HOW TO: 1 If interfacing at SONET set up the SONET transmit and receive

interfaces and payloads required. See "Setting SONET Transmit Interface " page 4 and "Setting SONET Receive Interface " page 17.

2 If interfacing at DSn set up the DSn transmit and receive interfaces

and payloads as required. See "Setting DSn Transmit Interface " page 2 and "Setting DSn Receive Interface " page 15.

3 If you choose a DS1 or DS3 framed unstructured payload, choose

SERVICE DISRUPT

displays.

on the and

TRANSMIT

RECEIVE

TEST FUNCTION

Page 89

Making Measurements

Measuring Service Disruption Time

4 Press to start the measurement.

RUN/STOP

5 Invoke the protection switch. 6 View the results on the display.

RESULTS

SRVC DISRUPT

Results Displayed LONGEST - Longest burst of errors during measurement.

SHORTEST - Shortest burst of errors during measurement. LAST - Length of last burst of errors detected during measurement.

Page 90

Making Measurements

Performing a SONET Tributary Scan

Description Tributary Scan tests each tributary for error free operation and no

occurrence of Pattern Loss. A failure is indicated by highlighting the tributary in which the failure occurred. The

MAIN SETTINGS

, mapping setup determines the tributary structure.

TRANSMIT

The HP 37718A will conﬁgure the Transmitter to the Receiver and the PATTERN is forced to the payload it will ﬁll.

TIP: The SONET Tributary Scan display can be logged to the chosen logging

device. See "Logging on Demand " page 110.

SONET

HOW TO: 1 Set up the transmit and receive SONET interfaces and payload as

required. See "Setting SONET Transmit Interface " page 4 and

"Setting SONET Receive Interface " page 17.

2 Choose the required BIT ERROR THRESHOLD.

This determines the error rate above which a failure is declared.

3 Choose the required TEST TIMING.

The valueyou choose is thetest time for eachindividual tributary and not the total test time. For example, 28 VT-1.5 tributaries in an STS-1 SPE - the time taken to complete the Tributary Scan will be 28 X TEST TIMING choice.

Page 91

Making Measurements

Performing a SONET Tributary Scan

4 The Tributary Scan results can be viewed on the

SONET TRIBSCAN

The Scancan be started onthe display or the display by choosing START. If the Scan is started on the display, the HP 37718A changes to the display.

display.

RESULTS

TRANSMIT

SONET TEST FUNCTION

RESULTS

If a single path, for example, MAPPING is chosen, then Tributary Scan is disabled.

NOTE The keyboard is locked during tributary scan.

RESULTS

SONET TEST FUNCTION

STS-3c SPE

Page 92

Making Measurements

Performing an SONET Alarm Scan

Description SONET Alarm Scan tests each channel for alarm free operation and

identiﬁes and indicates any Unequipped channels. You can conﬁgure the Scan to check for the occurrence of any Path layer CV errors above a chosen threshold. The channel in which an alarm occurred is highlighted if any of the following alarms occur:

STS SPE: LOP-P, RDI-P, AIS-P, VT-1.5: LOP-P, AIS-P, RDI-P, H4 LOM, LOP-V, AIS-V, RDI-V

TIP: The SONET Alarm Scan display can be logged to the chosen logging

device. See "Logging on Demand " page 110.

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

“Setting SONET Receive Interface” page 17.

2 Choose on the display. 3 Choose AUTO or RX SETTINGS.

RX SETTINGS: The scan checks the structure set on the

SONET

AUTO: The scan checks the structure being received. This can be particularly useful when receiving mixed payloads.

4 Choose the CV error threshold. 5 Choose to start the Alarm Scan.

SONET ALM SCAN

display.

START

RESULTS

RECEIVE

Page 93

Making Measurements

Performing a DSn Alarm Scan

Description DSn Alarm Scan tests each channel for the following alarms:

Frame Loss RAI AIS

The channel in which an alarm occurs is highlighted.

HOW TO: 1 Setup thereceive DSninterface asrequired. See“SettingDSn Receive

Interface” page 15.

2 Choose to start the Alarm Scan.

Page 94

Making Measurements

Measuring Jitter

Description: Jitter and error measurements are made simultaneously when a jitter

option is ﬁtted. The measurements are made on the normal input to the DSn or SONET receiver and the interface selections are the normal DSn or SONET Receiver selections.

Cumulative and Short Term results of Jitter Amplitude and Jitter Hits are provided on the display.

RESULTS

Graph and Text results for Jitter Transfer and Jitter Tolerance are also provided.

JITTER

HOW TO: 1 If measuring Jitter on a DSn signal, set up the receive DSn interface

and the receive Jitter interface. See “Setting DSn Receive Interface” page 15 and “Setting Jitter Receive Interface” page 18.

2 If measuring Jitter on an SONET signal, set up the receive SONET

interfaceand the receive Jitter interface.See“Setting SONET Receive Interface” page 17 and “Setting Jitter Receive Interface” page 18.

Page 95

Making Measurements

Measuring Jitter

3 If performing a Jitter Tolerance measurement, See “Measuring Jitter

Tolerance” page 89. If performing a Jitter Transfer measurement, See “Measuring Jitter Transfer” page 92.

4 Press to start the measurement.

RUN/STOP

5 You can view the Jitter hits and Amplitude results on the

JITTER

display.

RESULTS

Page 96

Making Measurements

Measuring Extended Jitter

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.

When is chosen Jitter results are provided. Cumulative and

EXTENDED

Short Term results of Jitter Amplitude and Jitter Hits are provided on the display.

RESULTS

JITTER

HOW TO: 1 If measuring Extended Jitter on a DSn signal, set up the receive DSn

interface and the receive Jitter interface. See “Setting DSn Receive Interface” page 15 and "Setting Extended Jitter Receive Interface " page 19.

2 If measuring Extended Jitter on an SONET signal, set up the receive

SONETinterface andthe receiveJitter interface.See“Setting SONET Receive Interface” page 17 and "Setting Extended Jitter Receive Interface " page 19.

3 Press to start the measurement.

RUN/STOP

Page 97

Making Measurements

Measuring Wander

Description: Accurate Wander measurements require a Wander reference derived

from the SONET Clock module. Wander results are displayed in UI and nanoseconds and Jitter Amplitude and Jitter Hits results are available.

When wander is measured at 2 Mb/s, Estimated Bit and Frame slips are calculated and a Bar Graph shows the cumulative Wander over the measurement period.

HOW TO: Make the Measurement

1 To obtain the Wander reference from the DSn transmitter connect

REF OUT on the SONET Clock module to REF IN on the DSn Jitter TX module. Choose SIGNAL on the

MAIN SETTINGS

choose the SOURCE required from the menu. See “Setting DSn Transmit Interface” page 2.

2 To obtain the Wander reference from the SONET transmitter choose

the required reference from the CLOCK menu on the

MAIN SETTINGS

3 If measuring wander at a DSn rate set up the DSn receive interface.

See, “Setting DSn Receive Interface” page 15.

2 Mb/s

display, choose CLOCK SYNC and

TRANSMIT

WANDER REF IN

TRANSMIT

PDH/DSn

SONET

display. See, “Setting SONET Transmit Interface” page 4.

Page 98

Making Measurements

Measuring Wander

4 If measuring wander at a SONET rate set up the SONET receive

interface. See, “Setting SONET Receive Interface” page 17.

5 Choose MEASUREMENT TYPE . 6 Choosethe WANDER HITTHRESHOLD level-if thereceived wander

exceeds the value chosen a wander hit is recorded.

7 Press to start the measurement.

RUN/STOP

HOW TO: View the Results

WANDER

1 Choose on the display and choose thedisplay units

WANDER

RESULTS

required:

TIME displays the wander results in nanoseconds. UI displays the wander results in Unit Intervals If you are measuring wander at 2 Mb/s Estimated Bit slips and Estimated Frame slip results are provided and a choice is

GRAPH

added to the menu. If is chosen the cumulative wander results are displayed in

GRAPH

graphical form. The Graphs are additive and in the example shown above the Wander is -76.5 BITS.

NOTE Estimated Bit Slips signify the slippage from the start of the

measurement. One Estimated Frame Slip corresponds to 256 Bit Slips. Implied Frequency Offset is calculated from the Wander results.

Page 99

Making Measurements

Measuring Jitter Tolerance

Description: The jitter auto tolerance feature provides jitter tolerance measurements

within the relevant ITU-T mask, G.823 for DSn, G.958, G.825 and Bellcore GR-253 for SONET.

Jitter is generated at a range of frequencies within the mask and an error measurement is made. If no errors occur (PASS), the jitter amplitude at that frequency point is increased until errors occur (FAIL) or the maximum jitter amplitude is reached. The highest jitter amplitude at which PASS occurs is plotted on the graph as the Jitter Tolerance for that jitter frequency.

TIP: The transmitter and receiver can be set to different rates to allow testing

across multiplexers,for example transmitterset to STS-3 with embedded DS-3 and receiver set to DS-3.

HOW TO: Make the Measurement

1 Ifyou areperforming jittertoleranceon theDSn signal,setup theDSn

transmitand receiveinterfaces.See “SettingDSnTransmit Interface” page 2 and “Setting DSn Receive Interface” page 15.

Page 100

Making Measurements

Measuring Jitter Tolerance

2 If you are performing jitter tolerance on the SONET signal, set up the

SONET transmit and receive interfaces. See “Setting SONET Transmit Interface” page 4 and “Setting SONET Receive Interface” page 17.

3 If SONET is chosen as the interface, choose the SONET MASK.

TYPE A masks as per ITU-T G.958 have good jitter tolerance and the mask corner points are modiﬁed to compensate. TYPE B masks as per ITU-T G.958 have poorer jitter tolerance but a narrower jitter transfer function and the mask corner points are modiﬁed to compensate.

4 Choose the required test PATTERN. 5 Choose the NUMBER OF POINTSat which jitter is transmitted (3to

55)

6 Choose the DWELL TIME - the time jitter is generated at each jitter

frequency point (1 to 99.9 seconds).

7 Choose the DELAY TIME - the time delay between the jitter

frequency/amplitude being applied and the error measurement being made. This allows the network equipment to settle as jitter frequency is changed. (0 to 99.9 seconds).

8 Choose the ERROR THRESHOLD.

If ANY ERRORS is chosen, any BIP or BIT error will result in a FAIL. If BIT ERRORS is chosen, choose a value between 1 and 1,000,000 to determine the bit error threshold for the jitter tolerance PASS/FAIL decision. BER>= shows the bit error ratio calculated from the bit error threshold choice and the dwell time choice.

9 Press to start the jitter auto tolerance measurement.

The measurements progress can be monitored on the

RUN/STOP

TRANSMIT

display. At the end of the test the results can be viewed on the

or displays. The display is cleared

TRANSMIT

when is pressed but the results remain on the

TRANSMIT

RESULTS

TRANSMIT

RESULTS

display until the next jitter tolerance measurement is made.