HP OMNIBER 718 User Manual

HP 37718A OmniBER 718
User’s Guide DSn/SONET Operation
Copyright Hewlett­Packard Ltd.1998
All rights reserved. Reproduction, adaption, or translation without prior written permission is prohibited, except as allowed under the copyright laws.
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 kindwithregardto this 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
WarningSymbols Used on the Product
!
The product is marked with this symbol when the usershould 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 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
User’s Guide DSn/SONET Operation
HP 37718A OmniBER 718
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 andalarmsto 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.
iv
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
v
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
vi
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
vii
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
viii
Contents
7 STS-1 SPE Background Patterns
8 ETSI/ANSI Terminology
ETSI/ANSI Conversion and Equivalent Terms 170
ix
Contents
x
1

1 Setting the Interfaces

This chapter tells you how to set the instrument interfaces to match the network being tested.
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, 205 or206,is fitted andSIGNAL 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 theSONETClockmodule. It can be internally generated, derived from an external clock or recovered from the SONET received signal.
2
2 Mb/s
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.
3
Setting the Interfaces

Setting SONET Transmit Interface

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 Option106, Dual Wavelengthopticalmodule, isfittedand 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
clocksynchronizationchoice dependsonthe SONET ReceiveInterface choice.
EXTERNAL
3 If required choose the FREQUENCY OFFSET value. See “Adding
Frequency Offset to SONET Signal” page 31.
4
INTERNAL THRU MODE THRU MODE
allows a choice of MTS, BITS or 10 MHz clocks.
Setting the Interfaces
Setting SONET Transmit Interface
4 Choose FOREGROUND , BACKGROUND
B/G MAPPING
MAPPING and type of payload.
F/G MAPPING
Mapping may beselectedfroma pictorial display by moving the cursor to MAPPING and pressing .
SET
Use and to move betweenSTSLayer choice, VTLayerchoice 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-2orVT-1.5mapping is chosen, choose the test
tributary CHANNEL,including the STS-3foran OC-12/OC-48 signal.
8 Choose the payloadframingunder PAYLOAD TYPE or VTPAYLOAD.
If is required must be chosen.
STRUCTURED
If is chosen, thePayloadtestsignal must besetup. 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.
5
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.
6
Setting the Interfaces

Setting Jitter Transmit Interface

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 .
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
If you wish to perform a Jitter Transfer measurement choose
TRANSFER FUNCTION
ON
. See “Measuring Jitter Tolerance” page 89.
JITTER
. See “Measuring Jitter Transfer” page 92.
7
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 ofexternaljittermodulation 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 ofexternaljittermodulation 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 37718A will "sweep"throughthe 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.
8
Setting the Interfaces

Setting Wander Transmit Interface

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 ConnectREFOUT on theSONET Clockmoduleto REF INon the DSn
Jitter TX module (this provides the Wander Reference).
2 Setupthe DSntransmitinterface, chooseCLOCK SYNC and
select the SOURCE required from the menu. See “Setting DSn Transmit Interface” page 2.
3 Choose JITTER/WANDER .
Ifyouwish toadd jitter tothe DSnsignal,See “SettingJitter Transmit 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
ON
9
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 ,youcanchoosethe"spot"wander frequency. The
OFF
SPOT
wanderamplitude isadjustedand controlledaccordingto 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 .
ON
10 Choose the WANDER MASK setting required.
You can choose the wander modulating frequency and wander amplitude if is chosen. If you choose ,youcanchoosethe"spot"wander frequency. The
OFF
SPOT
wanderamplitude isadjustedand controlledaccordingto yourwander frequency choice.
10
Setting the Interfaces

Setting SONET THRU Mode

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 eitheroverwriteisenabled the ENTIRE FRAME ERROR RATE
OFF
function is disabled.
OC-1/STS-1, OC-3/STS-3
You can substituteanewpayload, 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 AU3. 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, MAPPING and CHANNEL
choices on the SONET and displays, See
"Setting SONET Transmit Interface " page 4 and "Setting SONET
Receive Interface " page 17.
TRANSMIT
RECEIVE
11
Setting the Interfaces
Setting SONET THRU Mode
2 Make the PAYLOAD OVERWRITE choice required.
If STS-3cSPE, STS-1 SPE,VT-6,VT-2or VT-1.5ischosen, 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 canonlymodify 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 Ifyouwish toadd jitterto theSTS-3,OC-3, OC-12or OC-48signal, See
“Setting Jitter Transmit Interface” page 7.
12
Setting the Interfaces

Using Smart Test

Using Smart Test
Description The SmartTest functioncanhelp speed-up configuring the instrument 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
SET
RECEIVE
SELECT
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
13
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 J1Traceand C2 byte indicators are displayed on the bottom lines.
5 Use the and keys to display the J1 Trace informationforeach
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, exitstothe displayandstarts
which sets the receiver to receive the selected tributary.
which sets the receiver to receive the selected
RESULTS
TROUBLE SCAN
gating.
VIEW LABELS
which displaystheC2/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
PRBS SEARCH
information about patterns and which mapping to search. When the required data has been entered press .
GO
9 When the search is complete a tributary display appears, with any
tributariescontainingthe required PRBSindicated with a“P”. Choose the required tributary using and .
14
Setting the Interfaces

Setting DSn Receive Interface

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 networkequipmentmonitorpoint,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
ON
15
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.
16
Setting the Interfaces

Setting SONET Receive Interface

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 CONCATENATIONisenabled, 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 payloadframingunder PAYLOAD TYPE or VTPAYLOAD.
If is required must be chosen.
STRUCTURED
If is chosen the Payload test signal must besetup. 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.
17
Setting the Interfaces

Setting Jitter Receive Interface

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. Thejitterreceiveinterfaceis 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 .
JITTER
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.
18
Setting the Interfaces

Setting Extended Jitter Receive Interface

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 .
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.
PDH/DSn JITTER
EXTENDED
RECEIVE
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
19
Setting the Interfaces

Setting Wander Receive Interface

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.
20
TRANSMIT
SONET
2

2 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 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 byte value 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.
22
Selecting Test Features
Using Transmit Overhead Setup
If (Transport Overhead) is chosen, choose the STS-1 to be
TOH
displayed.Manybytes in and areunlabeledas 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 ofanOC-48are displayed 81 bytes at a time by selecting each STS-3 in turn). The value of the bytes can be set
using .
DECREASE DIGIT INCREASE DIGIT
If BYTE NAMES is chosen, the labels for the overhead
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
23
Selecting Test Features

Using Receive Overhead Monitor

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,somediagnosisoftheproblem 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 becausethe other 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 isdisplayed(all 324 bytes of anOC-12or1,296 bytes of an OC-48 are displayed 81 bytes at a time by selecting eachSTS-3 in turn).The value of the bytes can be set using
INCREASE DIGIT
24
STS-1# 2 STS-1#3
DECREASE DIGIT
.
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.
25
Selecting Test Features

Setting Overhead Trace Messages

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.
ChoosingLABELSin TRACE MESSAGESallows the settingof the S1 SYNC STATUS, STS PATH LABEL (C2) and VT PATH LABEL (V5).
26
Selecting Test Features

Generating Overhead Sequences

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 isderivedfrom upto 5blocksof hexadecimaldata. 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
27
Selecting Test Features
Generating Overhead Sequences
6 Start the sequence by choosing .
START
NOTE When youstart the sequenceillustrated,one Out ofFramealarm andone
Loss of Frame alarm should occur every eight seconds.
28
Selecting Test Features

Using Receive Overhead Capture

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.
ON
Can be used for transient detection from a specified expected state.
29
Selecting Test Features
Using Receive Overhead Capture
ON NOT
- captures activityafterthe first occurrence of adeviationfrom 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.Thecapture canbe terminatedearlierby pressing CAPTURE .
STOP
30
Selecting Test Features

Adding Frequency Offset to SONET Signal

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 in1ppm stepsusing 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. WhenFloatingByte 2 Mb/sischosen, 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
31
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 valueofSONETlinerate offsetand tributaryoffset chosenis sufficient to causethe maximum stuff ratetobe exceeded thepayloadis offset to prevent bit errors occurring and the maximum stuff rate is maintained.
32
Selecting Test Features

Adding Frequency Offset to the DSn Signal

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
33
Selecting Test Features

Setting up Signaling Bits

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
PDH/DSn
2 Mb/s PCM30
on the display.
TRANSMIT
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.
34
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
35
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
DS1 DS3
56 kb/s Nx56 kb/s
display.
STRUCTURED
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.
36
Selecting Test Features

Setting Transmit Structured Payload/Test Signal

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 "Insertingan External 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 Choosethetest tributaryin the 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
37
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,that is,each timeslotcontains auniquenumber toallow 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.
38
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 menu. See "Dropping an External Payload/Test Signal " page 46. If TEST SIGNAL DS1 is chosen, is added to the menu. See "Dropping an External Payload/Test Signal " page 46.
3 Choose the test tributary within the structured payload,under34Mb,
8Mb, 2Mb, 64 kb or DS2, DS1, 56 kb/s.
4 Choose the PATTERN type and PRBS polarity.
DROP 2 Mb/s
DROP DS1
39
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.
40
and softkeys. As each
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.
41
Selecting Test Features

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

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.
42
and softkeys. As each
Selecting Test Features

Inserting an External DSn Payload/Test Signal

Inserting an External DSn Payload/Test Signal
Description You can insert a DSn signal from external equipment into the SONET
signal, or you can insert2Mb/sor 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 75 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
43
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 75MUX 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 75MUX port. If DS1 connect to 100Ω MUX port.
44
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.
45
Selecting Test Features

Dropping an External Payload/Test Signal

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-structuredSONETpayload and from astructuredDSn 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 75 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
46
or .
DROP DS3
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 75DEMUX port. If DS1 connect to 100Ω DEMUX port.
47
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 DSn TestSignal interface.See "Setting ReceiveStructured
Payload/Test Signal " page 39
8 Choose 2M PAYLOAD or DS1 PAYLOAD .
DROP 2 Mb/s
DROP DS1
9 Choose the LINE CODE.
48
Selecting Test Features

Adding Errors & Alarms at the SONET Interface

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 theexceptionof ENTIRE FRAME and A1A2FRAME,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 ofN errors in T timeperiod. N and T are both selectable.
3 Choose the ALARM TYPE
Errors and Alarms can be added at the same time.
49
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 selected from afixedvalue or is userprogrammable. 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.
50
display.
Selecting Test Features

Using FEAC Codes

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
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
51
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 keys toselecta channel from 1 to 28. Press when finished.
5 If is chosen, choose the REPEAT (TIMES) LOOP and
LOOPBACK
SINGLE CHANNEL
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
ON
RESULTS
52
Selecting Test Features

Setting DSn Spare Bits

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.
ON
53
Selecting Test Features

Adding Pointer Adjustments

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- Youcanchoose apointer value inthe range 0to 782 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.
54
Selecting Test Features
Adding Pointer Adjustments
OFFSET - You can frequency offset the line rate or the SPE/VT rate, relative toeachother,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.
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 ChoosethePOLARITY,INTERVAL andPATTERN (whereapplicable)
for the selected sequence.
6 Choose POINTERSEQUENCES to generate the 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:
55
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
ForSINGLEA1,BURSTA2and 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 periodwhichforSINGLE 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.
56
Selecting Test Features
Adding Pointer Adjustments
NOTE The following conditions apply for pointer sequence generation:
The sequences can onlybeappliedto the SPE pointer when the SPE does 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
87
3
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.
57
Selecting Test Features
Adding Pointer Adjustments
Pointer Sequence
T1.105 A3 PHASE TRANSIENT GR-253 5031
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)
GR-253 5-32(b) PERIODIC NORMAL (26-1 Pattern)
T1.105 A5 PERIODIC ADD (87-3 Pattern) GR-253 5-33(c)
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.
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.
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.
An 87-3 pattern is selected. The sequence pattern is 87 pointer movements followedby3missing pointer movements with anadded pointer movement after the 43rd pointer. The spacing between the added adjustment and the previous adjustment is set to the minimum. Pointerpolarity is selectable. Thetimeinterval 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.
Description
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.
58
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)
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. Theaddedadjustmentoccurs 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).Cancelledadjustments 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 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.
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 every30secondsor every repeat of the 26-1 pattern, whichever is longer.
Description
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. ForVTpointers the sequence interval is selectable from: 200 ms, 500 ms, 1, 2, 5 and 10 seconds. ForSPEpointerstheminimumspacingbetweenadjustmentsis500us. For VT pointers the minimum spacing between adjustments is 2 ms.
59
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
✓✓✓ ✓✓✓ ✓✓✓ ✓ ✓✓✓
✓ ✓ ✓✓✓
✓ ✓ ✓✓✓
60
Selecting Test Features

Using Pointer Graph Test Function

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 to4days of storage allows long termeffectssuchas Wander to be observed. If an alarm occursduringthemeasurementperiod, 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 beviewedonthe 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 ofcaptureinterval should be chosen when alowdegree 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
61
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.
62
Selecting Test Features

Stressing Optical Clock Recovery Circuits

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.
63
Selecting Test Features

Generating Automatic Protection Switch Messages

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, choosetheDESTINATIONNODE ID, the SOURCE NODE ID, the type of PATH and the status code (K2 Bits 6­>8) The currentTXand RX, K1 and K2,valuesare displayed for reference only.
4 Choose to transmit the new K1/K2 values.
64
DOWNLOAD
Selecting Test Features

Inserting & Dropping Data Communications Channel

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.
2 Choose the required DCC.
TRANSMIT
RECEIVE
SONET TEST FUNCTION
SONET TEST FUNCTION
65
Selecting Test Features
Inserting & Dropping Data Communications Channel
66
3

3 Making Measurements

Making Measurements

Using Overhead BER Test Function

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
display.
RECEIVE
SONET
4 Choose the overhead byte to be tested on the
TEST FUNCTION
5 Press to start the test.
RUN/STOP
display.
6 The PRBS pattern can be errored by pressing .
TRANSMIT
SINGLE
68
SONET
Making Measurements

Test Timing

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.
TIMING CONTROL
RESULTS
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 .
RUN/STOP
MANUAL
For a single timed measurement period started with , choose and choose the Test duration.
SINGLE
Fora timed period starting at a specified time, choose , choose the Test duration and the test START date and time.
RUN/STOP
TIMED
69
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
TIP: The measurement will not be affected if you switchbetweenthedifferent
results provided.
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RUN/STOP
ANALYSIS
display.
RESULTS
SONET
Making Measurements

Making DSn Analysis 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 "Setting SONETReceive Interface" page 17. If required set up the Transmit Interface and Payload. See "Setting SONET Transmit Interface " page 4.
2 If DSn ischosenas the interface, set up the DSnreceiveinterface. 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.
RUN/STOP
4 If SONET is chosenasthe interface, you can view the analysis results
on the display
RESULTS
DSn PAYLOAD
ERROR ANALYSIS
If DSn is chosen as the interface, you can view the analysis results on the display.
RESULTS
DSn ERROR ANALYSIS
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Making Measurements

Measuring Frequency

Measuring Frequency
Description The signal frequencyandthe amount of offset from thestandardrate 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.
72
Making Measurements

Measuring Optical Power

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
display.
NOTE Optical power measurement is always available even if test timing is off.
RECEIVE
SONET
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Making Measurements

Measuring Round Trip Delay

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 the delay 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 Delayona64kb/stestsignalobtained
from a 34 Mb/s or 2 Mb/s DSn interface or DSn payload signal.
HOW TO: 1 If measuringonan SONET interface, set uptheSONET transmit and
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.
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Making Measurements
Measuring Round Trip Delay
4 Choose ACTION to start the measurement.
ON
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
75
Making Measurements

Monitoring Signaling Bits

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.
76
Making Measurements

Measuring Service Disruption Time

Measuring Service Disruption Time
Description: Protection switching ensures that data integrity is maintained and
revenue protectedwhenequipment failure occurs. The speedofoperation 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
77
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
on the and
TRANSMIT
RECEIVE
TEST FUNCTION
displays.
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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.
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Making Measurements

Performing a SONET Tributary Scan

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 valueyouchoose is the testtimefor each individual 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.
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Making Measurements
Performing a SONET Tributary Scan
4 The Tributary Scan results can be viewed on the
SONET TRIBSCAN
The Scancanbe started on the 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
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
81
Making Measurements

Performing an SONET Alarm Scan

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.
SONET ALM SCAN
RESULTS
3 Choose AUTO or RX SETTINGS.
RX SETTINGS: The scan checks the structure set on the
SONET
display.
RECEIVE
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.
START
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Making Measurements

Performing a DSn Alarm Scan

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 Setupthe receiveDSn interfaceasrequired. See“Setting DSnReceive
Interface” page 15.
2 Choose to start the Alarm Scan.
ON
83
Making Measurements

Measuring Jitter

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.
Graph and Text results for Jitter Transfer and Jitter Tolerance are also provided.
RESULTS
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
interfaceandthe receiveJitterinterface. See“Setting SONET Receive Interface” page 17 and “Setting Jitter Receive Interface” page 18.
84
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
85
Making Measurements

Measuring Extended Jitter

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 Short Term results of Jitter Amplitude and Jitter Hits are provided on the display.
HOW TO: 1 If measuring Extended Jitter on a DSn signal, set up the receive DSn
EXTENDED
RESULTS
interface and the receive Jitter interface. See “Setting DSn Receive Interface” page 15 and "Setting Extended Jitter Receive Interface " page 19.
JITTER
2 If measuring Extended Jitter on an SONET signal, set up the receive
SONETinterfaceand thereceive Jitterinterface. See“Setting SONET Receive Interface” page 17 and "Setting Extended Jitter Receive Interface " page 19.
3 Press to start the measurement.
86
RUN/STOP
Making Measurements

Measuring Wander

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
display, choose CLOCK SYNC and 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
display. See, “Setting SONET Transmit Interface” page 4.
3 If measuring wander at a DSn rate set up the DSn receive interface.
See, “Setting DSn Receive Interface” page 15.
2 Mb/s
TRANSMIT
WANDER REF IN
TRANSMIT
PDH/DSn
SONET
87
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 ChoosetheWANDERHIT THRESHOLDlevel- ifthe receivedwander
exceeds the value chosen a wander hit is recorded.
7 Press to start the measurement.
RUN/STOP

HOW TO: View the Results

1 Choose on the display and choose thedisplay units
WANDER
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 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.
WANDER
RESULTS
GRAPH
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.
88
Making Measurements

Measuring Jitter Tolerance

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 allowtesting
across multiplexers,for example transmitter set toSTS-3with embedded DS-3 and receiver set to DS-3.

HOW TO: Make the Measurement

1 Ifyouareperformingjitter toleranceon theDSn signal,setup theDSn
transmitandreceiveinterfaces.See“SettingDSn TransmitInterface” page 2 and “Setting DSn Receive Interface” page 15.
89
Making Measurements
Measuring Jitter Tolerance
2 If you are performing jitter toleranceontheSONET 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.958havegood 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 POINTSatwhichjitter is transmitted (3 to
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.
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