Viavi ComXpert CX100 User manual

CX100 ComXpert
Handheld Radio Test Set
Test and Measurement Guide

This page intentionally left blank.

VIAVI Solutions
1-844-GO-VIAVI
www.viavisolutions.com
CX100 ComXpert
Handheld Radio Test Set
Test and Measurement Guide
22144016 Rev 000
Part of CD 22144014

This page intentionally left blank.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 R - 1
Chapter Revision History
The following table contains a record of this manual’s revision history.
Table -1 Revision History
Doc Version Date Accepted by
Rev 000 October 30, 2022 Lance Woods

Chapter Revision History
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
R - 2 October 2022
This page intentionally left blank.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 i
Notice
Every effort was made to ensure that the information in this manual was accurate at the
time of release. However, information is subject to change without notice, and VIAVI
reserves the right to provide an addendum to this manual with information not available at
the time that this manual was created.
Copyright/Trademarks
© Copyright 2022 VIAVI Solutions, Inc. All rights reserved. No part of this guide may be
reproduced or transmitted, electronically or otherwise, without written permission of the
publisher. VIAVI Solutions and the VIAVI logo are trademarks of VIAVI Solutions Inc.
(“VIAVI”).
All other trademarks and registered trademarks are the property of their respective
owners.
Patent Information
Patented as described at www.viavisolutions.com/patents
Copyright Release
Reproduction and distribution of this guide is authorized for US Government purposes
only.
Terms and conditions
Specifications, terms, and conditions are subject to change without notice. The provision
of hardware, services, and/or software are subject to VIAVI’s standard terms and
conditions, available at www.viavisolutions.com/en/terms-and-conditions
Declaration of Conformity
VIAVI recommends keeping a copy of the Declaration of Conformity that shipped with the
unit with the test set at all times.
Warranty Information
Warranty information for this product is available on the VIAVI website at
https://www.viavisolutions.com/en-us/warranty-information
Low Voltage Directive Compliance
This product was tested and conforms to the Low Voltage Directive, 73/23/EEC as
amended by 93/68/EEC.

Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
ii October 2022
Japan Radio Law
The GITEKI Mark can be found on the meter in the “System -> File Browser -> Documents”
folder.
Federal Communications Commission (FCC) Notice
This device complies with part 15 of the FCC Rules. Operation is subject to the following
two conditions: (1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired
operation.
This equipment was tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy
and, if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications. Operation of this equipment in a residential
area is likely to cause harmful interference, in which case you will be required to correct
the interference at your own expense.
The authority to operate this equipment is conditioned by the requirements that no
modifications be made to the equipment unless the changes or modifications are expressly
approved by VIAVI.
ALERT
•To comply with FCC RF Exposure compliance requirements, a separation distance of at
least 20 cm must be maintained between the antenna of this device and all persons.
•This transmitter must not be co-located in conjunction with any other antenna or
transmitter.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 iii
Industry Canada Requirements
This device complies with Industry Canada's license-exempt RSSs. Operation is subject
to the following two conditions: 1) This device may not cause interference; and, 2) This
device must accept any interference, including interference that may cause undesired
operation of the device.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils
radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes: 1)
l'appareil ne doit pas produire de brouillage; et, 2) l'utilisateur de l'appareil doit accepter
tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en
compromettre le fonctionnement.
EU WEEE and Battery Directives
This product, and the batteries used to power the product, should not be disposed of as
unsorted municipal waste and should be collected separately and disposed of according
to your national regulations.
VIAVI has established a take-back processes in compliance with the EU Waste Electrical
and Electronic Equipment (WEEE) Directive, 2012/19/EU, and the EU Battery Directive,
2006/66/EC.
Instructions for returning waste equipment and batteries to VIAVI can be found in the
WEEE section of VIAVI’s Standards and Policies web page
If you have questions concerning disposal of your equipment or batteries, contact the
VIAVI WEEE Program Management team at [email protected]m
EU REACH
Article 33 of EU REACH regulation (EC) No 1907/2006 requires article suppliers to
provide information if a listed Substances of Very High Concern (SVHC) is present in an
article above a certain threshold.
For information on the presence of REACH SVHCs in VIAVI products, see the Hazardous
Substance Control section of VIAVI’s Standards and Policies web page
EU CE Marking Directives (LV, EMC, RoHS, RE)
This product conforms with all applicable CE marking directives. Please see EU
Declaration of Conformity for details.
EMC Directive Compliance
This product was tested and conforms to the EMC Directive, 2014/30/EU for
electromagnetic compatibility.

Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
iv October 2022
UK Declaration of Conformity
This product conforms with all applicable UKCA marking directives. Please request UK
Declaration of Conformity for further details.
China RoHS Materials Declaration
The China RoHS Materials Declaration is shipped with the product when required.
California Proposition 65
California Proposition 65, officially known as the Safe Drinking Water and Toxic
Enforcement Act of 1986, was enacted in November 1986 with the aim of protecting
individuals in the state of California and the state's drinking water and environment from
excessive exposure to chemicals known to the state to cause cancer, birth defects or
other reproductive harm.
For the VIAVI position statement on the use of Proposition 65 chemicals in VIAVI
products, see the Hazardous Substance Control section of VIAVI’s Standards and
Policies web page
Korea Certification
Ordering Information
This manual is a product of the VIAVI Technical Publications Department, issued as part
of the CX100 ComXpert Handheld Radio Test Set. The PDF format of this manual is
available and distributed with new equipment on a CD-ROM.
•The part number associated with the PDF form of this publication is 22144016
•The material number associated with the CD-ROM is 22144014
Class A Equipment (Industrial Broadcasting &
Communications Equipment).
This equipment is Industrial (Class A) electromagnetic wave suitability
equipment and seller or user should take notice of it, and this
equipment is to be used in the places except for home.

Software Notifications
22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 v
Contact Information
Contact the Technical Assistance Center (TAC) for technical support or with any questions
regarding this or other VIAVI products.
•Phone: 1-844-GO-VIAVI
•Email: Tech[email protected]
For the latest TAC information, go to:
https://www.viavisolutions.com/support/technical-product-support
Software Notifications
DFARS Statement
If software is for use in the performance of a U.S. Government prime contract or
subcontract, software is delivered and licensed as “Commercial Computer Software” as
defined in DFAR 252.227-7014 (Feb 2014), or as a “Commercial Item” as defined in FAR
2.101(a) or as “Restricted Computer Software” as defined in FAR 52.227-19 (Dec 2007) or
any equivalent agency regulation or contract clause. Use, duplication or disclosure of
Software is subject to VIAVI Solutions' standard commercial license terms, and non-DOD
Departments and Agencies of the U.S. Government will receive no greater than Restricted
Rights as defined in FAR 52.227-19(c)(1-2) (Dec 2007). U.S. Government users will
receive no greater than Limited Rights as defined in FAR 52.227-14 (June 1987) or DFAR
252.227-7015 (b)(2) (November 1995), as applicable in any technical data.
Open Source Disclaimer - IMPORTANT READ CAREFULLY
The CX100 ComXpert includes third party software licensed under the terms of separate
open source software licenses. By using this software you agree to comply with the terms
and conditions of the applicable open source software licenses. Software originated by
VIAVI is not subject to third party licenses. Terms of the VIAVI Software License different
from applicable third party licenses are offered by VIAVI alone.

Software Notifications
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
vi October 2022
This page intentionally left blank.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 TOC - i
Table of Contents
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-1
• Software Notifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Chapter 1 Getting Started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1 Device Controls and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.1.1 RF and Audio I/O Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.1.2 Front Panel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.2 Powering the Device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.2.1 AC Power Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.2.2 Connecting to an AC Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.2.3 Battery Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.2.4 Charging the Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.3 Power On/Off Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.4 Device Control and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.4.1 LCD User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.4.2 Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Chapter 2 Performing FM Transmitter Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.0.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.0.2 DUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.0.3 Equipment Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.0.4 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.0.5 Gathering Test Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Chapter 3 Performing AM Transmitter Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.0.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.0.1 DUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.0.2 Equipment Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.0.3 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Table of Contents
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
TOC - ii October 2022
3.0.4 Gather Test Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.0.5 Test DUT Power and Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.0.6 Test DUT Modulation Level and Distortion. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Chapter 4 Performing FM Receiver Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.0.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.0.1 DUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.0.2 Equipment Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.0.3 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.0.4 Configure the CX100 Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
4.0.5 Gather Test Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Chapter 5 Performing AM Receiver Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.0.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.0.1 DUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.0.2 Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.0.3 Configuring the Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.0.4 Configure CX100 Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
5.0.5 Gather Test Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Chapter 6 Performing VSWR and DTF Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.1 Performing VSWR/DTF Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.1.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.1.2 UUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.1.3 Equipment Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.1.4 Calibrate the CX100 Before VSWR Testing . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.1.5 To Perform VSWR Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
6.2 Performing Distance to Fault (DTF) Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
6.2.1 Scope of Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
6.2.2 UUT Parameters/Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
6.2.3 Equipment Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
6.2.4 Configuring the Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 LOF - i
List of Figures
Figure Title Chap/Page
Figure 1-1 . . . CX100 RF Input/Output Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Figure 1-2 . . . CX100 Controls and Buttons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 2-1 . . . FM Transmitter Test Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Figure 3-1 . . . AM Transmitter Test Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Figure 4-1 . . . FM Receiver Test Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Figure 5-1 . . . AM Receiver Test - Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Figure 6-1 . . . VSWR Calibration Setup Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Figure 6-2 . . . Calibration running and complete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Figure 6-3 . . . VSWR Test Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Figure 6-4 . . . DTF Test Setup Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Figure 6-5 . . . DTF (Distance to Fault) and Calibration . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Figure 6-6 . . . Return Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

List of Figures
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
LOF - ii October 2022
This page intentionally left blank.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 LOT - i
List of Tables
Table Number Table Title Page
Table A-1. . . . . Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Table 1 . . . . . . Document Revisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Table 2 . . . . . . Symbol Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Table 3 . . . . . . Text and Symbol Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Table 2-1 . . . . . FM Transmitter Test - DUT Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Table 2-2 . . . . . FM Transmitter Test - RF Receiver Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Table 2-3 . . . . . FM Transmitter Test - AF Function Generator Settings. . . . . . . . . . . . . . . . . . . 2-5
Table 3-1 . . . . . AM Transmitter Test - DUT Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Table 3-2 . . . . . CX100 Settings - RF Receiver Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Table 3-3 . . . . . AM Transmitter Test - AF Function Generator Settings . . . . . . . . . . . . . . . . . . 3-5
Table 4-1 . . . . . FM Receiver Test - DUT Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Table 4-2 . . . . . CX100 Settings - RF Generator Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Table 4-3 . . . . . FM Receiver Test- Modulation Generator Settings . . . . . . . . . . . . . . . . . . . . . . 4-4
Table 4-4 . . . . . FM Receiver Test - Meter Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Table 5-1 . . . . . AM Receiver Test - DUT Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Table 5-2 . . . . . AM Receiver Test - RF Generator Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Table 5-3 . . . . . AM Receiver Test - Modulation Generator Settings . . . . . . . . . . . . . . . . . . . . . 5-4
Table 5-4 . . . . . AM Receiver Test - Meter Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Table 6-1 . . . . . VSWR Test - Example Cable Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Table 6-2 . . . . . CX100 VSWR Test Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Table 6-3 . . . . . DTF Test - Example Cable Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Table 6-4 . . . . . DTF Test Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

List of Tables
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
LOT - ii October 2022
This page intentionally left blank.

22144016 CX100 ComXpert Test and Measurement Guide Rev 000
October 2022 Preface - i
Preface
This preface contains the following product information:
• Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
• Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
• Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
• Document History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii
• Symbols and Markings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
• Hypertext>Symbol Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
• Hypertext>Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Preface
Rev 000 CX100 ComXpert Test and Measurement Guide 22144016
Preface - ii October 2022
Purpose and Scope
This guide provides step by step instructions for using the CX100 to perform various tests
and measurements.
This guide should be used in combination with the CX100 ComXpert Operation Manual.
Refer to the CX100 ComXpert Operation Manual for information about device operation
and User Interface (UI) navigation.
Intended Audience
This manual is intended for personnel who are familiar with the use and operation of the
CX100 as well as with radio test systems and associated equipment and terminology.
Related Information
This document provides step by step instructions for using the CX100 to perform various
test and measurements.
Use this guide in conjunction with the following information:
• #22144015, CX100 ComXpert Operation Manual
The CX100 ComXpert Operation Manual contains product safety information,
installation and operational instructions and functional descriptions of the capabilities
supported by the CX100 ComXpert Handheld Radio Test Set.
Contact Information
Contact the Technical Assistance Center (TAC) for technical support or with any questions
regarding this or another VIAVI products.
•Phone: 1-844-GO-VIAVI
For the latest TAC information, go to:
http://www.viavisolutions.com/en/services-and-support/support/technical-assistance