3CX ACADEMY PRACTICE EXAMINATION - ALIGNED WITH THE 3CX BASIC CERTIFICATION
CURRICULUM
3CX Basic Certification Exam
2026/2027 Update | Questions and Verified Answers | A Grade
Current for 3CX v20 feature changes | Aligned with 3CX Academy official practice exam scope
100 6 A-D 30/50/20
Questions, exactly and Coverage sections across the Multiple choice options, one Cognitive mix: recall / application
sequentially numbered exam domains correct answer / analysis
Examination Instructions and Document Guide
Each question carries exactly one correct answer. The correct choice is marked inline with the [CORRECT] tag,
followed by a verified answer line and a comprehensive administration rationale explaining why the correct option works
and why each distractor fails.
Question style follows the certification blueprint: approximately 75 percent scenario-based administration and
troubleshooting cases, and 25 percent direct recall items. Distractors represent common 3CX pitfalls, including port
confusion, codec misuse, SIP ALG misconceptions, registration error misdiagnosis, license feature misunderstanding and
remote connectivity configuration errors.
Coverage sections: Section 1 System Fundamentals, Installation and Requirements (Q1-20); Section 2 Networking,
Firewall and Port Configuration (Q21-35); Section 3 SIP Trunking and VoIP Fundamentals (Q36-55); Section 4
Extension Management and Call Routing (Q56-75); Section 5 Security, Maintenance and Troubleshooting (Q76-85);
Section 6 3CX Apps, Remote Connectivity and SBC (Q86-100).
Content reflects the 2026/2027 update of the 3CX Basic Certification curriculum, including v20 platform requirements,
verified port maps, licensing tiers (Free, Standard 16 SC, Pro 64 SC, Enterprise) and current remote connectivity tooling.
Emphasis throughout is on practical administration, troubleshooting and real-world deployment scenarios.
SECTION 1 | QUESTIONS 1-20
System Fundamentals, Installation and Requirements
OS Requirements, FQDN, Deployment Models, License Types and Virtualization
Q1: A managed service provider is preparing a brand-new 3CX v20 installation for a 25-seat legal office and
wants the vendor-validated baseline platform to guarantee full update paths and support coverage. Which
operating system is the primary supported platform for 3CX v20 installations?
A. Windows Server 2016 Standard (64-bit)
B. Ubuntu Server 22.04 LTS (64-bit)
C. Debian 11 (64-bit) [CORRECT]
D. CentOS Stream 9 (64-bit)
Correct Answer: C
Rationale: Debian 11 (64-bit) is the primary supported platform for 3CX v20 and is the operating system shipped with
the official 3CX ISO image, so it receives validated update paths and full vendor support. Windows Server 2019 or newer
can host 3CX, but it is a secondary option rather than the primary baseline, and Windows Server 2016 is not supported.
Ubuntu and CentOS are 64-bit Linux distributions, but they are not validated by 3CX for v20 and fall outside supported
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 1
,3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
troubleshooting scope. Selecting the primary platform from the start avoids migration effort and ensures the installation
behaves exactly as tested by 3CX.
Q2: Which hardware architecture requirement applies to every host system used for a 3CX v20 installation?
A. 64-bit only [CORRECT]
B. 32-bit or 64-bit, both fully supported
C. 32-bit only, for maximum compatibility
D. ARM-based processors only
Correct Answer: A
Rationale: 3CX v20 is published exclusively as a 64-bit product, and both the Debian-based ISO and the Windows
installer require a 64-bit capable host. There is no 32-bit build, so attempting to install on a 32-bit operating system fails at
the first step. ARM processors are not a supported architecture for running the PBX itself. Administrators must verify
64-bit support in the CPU, the hypervisor settings and the operating system before starting an installation.
Q3: A company with strict Microsoft standardization policies insists on running 3CX v20 on a Windows Server
host. The infrastructure team is reviewing three spare servers with different Windows licenses. Which is the
minimum Windows Server version that 3CX supports for v20?
A. Windows Server 2012 R2
B. Windows Server 2008 R2
C. Windows Server 2016
D. Windows Server 2019 [CORRECT]
Correct Answer: D
Rationale: Windows Server 2019 or newer is the supported Windows platform range for 3CX v20 installations. Windows
Server 2016 and older releases such as 2012 R2 and 2008 R2 are not supported, so 3CX will not assist with
troubleshooting on those hosts. When a Windows host is chosen, the administrator must still install the required
prerequisites and must avoid installing conflicting software. In most cases the Debian 11 appliance remains the
recommended baseline, with Windows Server 2019+ reserved for organizations that require Windows.
Q4: Which of the following sets lists virtualization platforms that are officially supported for production 3CX
deployments?
A. VirtualBox, Parallels Desktop, Hyper-V and KVM
B. Hyper-V, VMware ESXi, KVM and XenServer [CORRECT]
C. Docker containers, ESXi, Hyper-V and Proxmox
D. VMware Workstation, XenServer, KVM and VirtualBox
Correct Answer: B
Rationale: 3CX supports running as a virtual machine on Hyper-V, VMware ESXi, KVM and XenServer, which are the
server-grade hypervisors validated for production telephony. Desktop virtualization products such as VirtualBox, Parallels
Desktop and VMware Workstation are not supported because they lack the reliability and timing precision a PBX
requires. Container platforms such as Docker are likewise not a supported deployment method for the PBX. Choosing a
supported hypervisor ensures that audio timing, network throughput and vendor support expectations are all met.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 2
,3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
Q5: A Windows administrator plans to deploy 3CX v20 on a server that already runs Microsoft SQL Server for a
billing application and a DNS server role for the branch office. The server has 32 GB of RAM, so resource
pressure is not a concern. What is the correct guidance?
A. The installation is fully supported because ample RAM eliminates conflicts
B. Do not install 3CX on a host running Exchange, MS SQL, DNS or VPN software; 3CX must have a
dedicated server [CORRECT]
C. The installation is supported only with a Pro license or higher
D. The installation is supported if MS SQL is used only for logging purposes
Correct Answer: B
Rationale: 3CX must be installed on a dedicated host, and software such as Exchange, MS SQL, DNS services and VPN
products must not run on the same server regardless of RAM capacity. These applications create port conflicts, service
dependencies and security exposure that lead to unpredictable telephony failures that are hard to diagnose. DNS is
specifically discouraged because name resolution problems directly break SIP routing and certificate validation. The
administrator should either move 3CX to a dedicated machine or relocate the other roles, since co-existence is not a
licensing question at all.
Q6: Which web browsers are supported for using the 3CX Web Client?
A. Safari and Opera only
B. Internet Explorer 11 and legacy Edge
C. Google Chrome only
D. Chrome, Edge and Firefox [CORRECT]
Correct Answer: D
Rationale: The 3CX Web Client is a native HTML5 and JavaScript application that is validated on Google Chrome,
Microsoft Edge and Mozilla Firefox. Internet Explorer and the legacy Edge engine lack the modern APIs the client
depends on, and Safari or Opera are not in the supported set for administration and call handling. Because no plugin is
required, any of the three supported browsers can be used immediately after login. Administrators should also keep
browsers current, since the web client ships new functionality with each 3CX update.
Q7: A growing logistics company wants IVR voice menus so callers can reach departments, together with
time-based routing that behaves differently during and outside office hours. According to the 3CX licensing
structure, which is the minimum license edition that provides these features?
A. Pro edition [CORRECT]
B. Free edition
C. Standard edition
D. Enterprise edition only
Correct Answer: A
Rationale: Voice menus and time-based routing require the Pro edition at minimum, so the company must purchase a
Pro license to build the requested IVR and schedule behavior. The Free edition only provides basic calling functionality
and cannot satisfy the requirement. The Standard edition also does not unlock these features in the licensing model
covered by this certification, and Enterprise is not required because Pro is already sufficient. Planning the license around
required features first, then simultaneous call capacity second, prevents costly license upgrades after deployment.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 3
, 3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
Q8: A reseller is sizing a 3CX Standard edition license for a customer and needs to explain the simultaneous call
model. How many simultaneous calls (SC) does a Standard edition license include?
A. 4 SC
B. 8 SC
C. 16 SC [CORRECT]
D. 64 SC
Correct Answer: C
Rationale: The Standard edition license includes 16 simultaneous calls, which is the licensed concurrency ceiling rather
than a count of extensions or users. The Pro edition includes 64 simultaneous calls, so 64 SC is a Pro figure and not a
Standard figure. Options such as 4 SC or 8 SC correspond to smaller tiers and will undersize a Standard deployment.
When sizing, the administrator counts every active conversation, including internal calls, so the SC value must cover peak
concurrent conversations.
Q9: During a pre-installation review, the IT director asks the junior technician which network prerequisites must
be satisfied before 3CX can be installed and activated. Which answer is correct?
A. A static PPPoE connection provisioned by the ISP
B. An internal-only DNS server with no external records
C. A site-to-site VPN tunnel to the license portal
D. A publicly resolvable FQDN and proper firewall configuration [CORRECT]
Correct Answer: D
Rationale: Every 3CX installation requires a Fully Qualified Domain Name that is resolvable on the public internet,
together with correct firewall configuration, before the system can be installed, activated and operated. An internal-only
hostname breaks certificate issuance, remote provisioning and app connectivity, so it is not acceptable. PPPoE, VPN
tunnels and internal DNS servers are not substitutes for these two prerequisites. The FQDN is what the license,
certificates and remote clients are all bound to, which is why it is validated at activation time.
Q10: An administrator prefers not to manage TLS certificates manually and asks what the 3CX-managed FQDN
option actually provides. Which statement is correct?
A. It requires purchasing a commercial certificate each year
B. It only resolves on the internal network
C. It provides a subdomain such as pbxname.3cx.com with an automatically maintained Let's Encrypt
certificate [CORRECT]
D. It disables HTTPS provisioning for security reasons
Correct Answer: C
Rationale: When the administrator selects a 3CX-managed subdomain such as pbxname.3cx.com, 3CX handles DNS for
that name and provisions and renews a Let's Encrypt certificate automatically. This removes the most common causes of
expired-certificate outages and simplifies remote provisioning. A custom domain is still available as the alternative mode,
but then the administrator owns the DNS records and must keep public resolution working. The managed mode certainly
does not disable provisioning; on the contrary, it makes secure HTTPS provisioning straightforward.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 4
CURRICULUM
3CX Basic Certification Exam
2026/2027 Update | Questions and Verified Answers | A Grade
Current for 3CX v20 feature changes | Aligned with 3CX Academy official practice exam scope
100 6 A-D 30/50/20
Questions, exactly and Coverage sections across the Multiple choice options, one Cognitive mix: recall / application
sequentially numbered exam domains correct answer / analysis
Examination Instructions and Document Guide
Each question carries exactly one correct answer. The correct choice is marked inline with the [CORRECT] tag,
followed by a verified answer line and a comprehensive administration rationale explaining why the correct option works
and why each distractor fails.
Question style follows the certification blueprint: approximately 75 percent scenario-based administration and
troubleshooting cases, and 25 percent direct recall items. Distractors represent common 3CX pitfalls, including port
confusion, codec misuse, SIP ALG misconceptions, registration error misdiagnosis, license feature misunderstanding and
remote connectivity configuration errors.
Coverage sections: Section 1 System Fundamentals, Installation and Requirements (Q1-20); Section 2 Networking,
Firewall and Port Configuration (Q21-35); Section 3 SIP Trunking and VoIP Fundamentals (Q36-55); Section 4
Extension Management and Call Routing (Q56-75); Section 5 Security, Maintenance and Troubleshooting (Q76-85);
Section 6 3CX Apps, Remote Connectivity and SBC (Q86-100).
Content reflects the 2026/2027 update of the 3CX Basic Certification curriculum, including v20 platform requirements,
verified port maps, licensing tiers (Free, Standard 16 SC, Pro 64 SC, Enterprise) and current remote connectivity tooling.
Emphasis throughout is on practical administration, troubleshooting and real-world deployment scenarios.
SECTION 1 | QUESTIONS 1-20
System Fundamentals, Installation and Requirements
OS Requirements, FQDN, Deployment Models, License Types and Virtualization
Q1: A managed service provider is preparing a brand-new 3CX v20 installation for a 25-seat legal office and
wants the vendor-validated baseline platform to guarantee full update paths and support coverage. Which
operating system is the primary supported platform for 3CX v20 installations?
A. Windows Server 2016 Standard (64-bit)
B. Ubuntu Server 22.04 LTS (64-bit)
C. Debian 11 (64-bit) [CORRECT]
D. CentOS Stream 9 (64-bit)
Correct Answer: C
Rationale: Debian 11 (64-bit) is the primary supported platform for 3CX v20 and is the operating system shipped with
the official 3CX ISO image, so it receives validated update paths and full vendor support. Windows Server 2019 or newer
can host 3CX, but it is a secondary option rather than the primary baseline, and Windows Server 2016 is not supported.
Ubuntu and CentOS are 64-bit Linux distributions, but they are not validated by 3CX for v20 and fall outside supported
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 1
,3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
troubleshooting scope. Selecting the primary platform from the start avoids migration effort and ensures the installation
behaves exactly as tested by 3CX.
Q2: Which hardware architecture requirement applies to every host system used for a 3CX v20 installation?
A. 64-bit only [CORRECT]
B. 32-bit or 64-bit, both fully supported
C. 32-bit only, for maximum compatibility
D. ARM-based processors only
Correct Answer: A
Rationale: 3CX v20 is published exclusively as a 64-bit product, and both the Debian-based ISO and the Windows
installer require a 64-bit capable host. There is no 32-bit build, so attempting to install on a 32-bit operating system fails at
the first step. ARM processors are not a supported architecture for running the PBX itself. Administrators must verify
64-bit support in the CPU, the hypervisor settings and the operating system before starting an installation.
Q3: A company with strict Microsoft standardization policies insists on running 3CX v20 on a Windows Server
host. The infrastructure team is reviewing three spare servers with different Windows licenses. Which is the
minimum Windows Server version that 3CX supports for v20?
A. Windows Server 2012 R2
B. Windows Server 2008 R2
C. Windows Server 2016
D. Windows Server 2019 [CORRECT]
Correct Answer: D
Rationale: Windows Server 2019 or newer is the supported Windows platform range for 3CX v20 installations. Windows
Server 2016 and older releases such as 2012 R2 and 2008 R2 are not supported, so 3CX will not assist with
troubleshooting on those hosts. When a Windows host is chosen, the administrator must still install the required
prerequisites and must avoid installing conflicting software. In most cases the Debian 11 appliance remains the
recommended baseline, with Windows Server 2019+ reserved for organizations that require Windows.
Q4: Which of the following sets lists virtualization platforms that are officially supported for production 3CX
deployments?
A. VirtualBox, Parallels Desktop, Hyper-V and KVM
B. Hyper-V, VMware ESXi, KVM and XenServer [CORRECT]
C. Docker containers, ESXi, Hyper-V and Proxmox
D. VMware Workstation, XenServer, KVM and VirtualBox
Correct Answer: B
Rationale: 3CX supports running as a virtual machine on Hyper-V, VMware ESXi, KVM and XenServer, which are the
server-grade hypervisors validated for production telephony. Desktop virtualization products such as VirtualBox, Parallels
Desktop and VMware Workstation are not supported because they lack the reliability and timing precision a PBX
requires. Container platforms such as Docker are likewise not a supported deployment method for the PBX. Choosing a
supported hypervisor ensures that audio timing, network throughput and vendor support expectations are all met.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 2
,3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
Q5: A Windows administrator plans to deploy 3CX v20 on a server that already runs Microsoft SQL Server for a
billing application and a DNS server role for the branch office. The server has 32 GB of RAM, so resource
pressure is not a concern. What is the correct guidance?
A. The installation is fully supported because ample RAM eliminates conflicts
B. Do not install 3CX on a host running Exchange, MS SQL, DNS or VPN software; 3CX must have a
dedicated server [CORRECT]
C. The installation is supported only with a Pro license or higher
D. The installation is supported if MS SQL is used only for logging purposes
Correct Answer: B
Rationale: 3CX must be installed on a dedicated host, and software such as Exchange, MS SQL, DNS services and VPN
products must not run on the same server regardless of RAM capacity. These applications create port conflicts, service
dependencies and security exposure that lead to unpredictable telephony failures that are hard to diagnose. DNS is
specifically discouraged because name resolution problems directly break SIP routing and certificate validation. The
administrator should either move 3CX to a dedicated machine or relocate the other roles, since co-existence is not a
licensing question at all.
Q6: Which web browsers are supported for using the 3CX Web Client?
A. Safari and Opera only
B. Internet Explorer 11 and legacy Edge
C. Google Chrome only
D. Chrome, Edge and Firefox [CORRECT]
Correct Answer: D
Rationale: The 3CX Web Client is a native HTML5 and JavaScript application that is validated on Google Chrome,
Microsoft Edge and Mozilla Firefox. Internet Explorer and the legacy Edge engine lack the modern APIs the client
depends on, and Safari or Opera are not in the supported set for administration and call handling. Because no plugin is
required, any of the three supported browsers can be used immediately after login. Administrators should also keep
browsers current, since the web client ships new functionality with each 3CX update.
Q7: A growing logistics company wants IVR voice menus so callers can reach departments, together with
time-based routing that behaves differently during and outside office hours. According to the 3CX licensing
structure, which is the minimum license edition that provides these features?
A. Pro edition [CORRECT]
B. Free edition
C. Standard edition
D. Enterprise edition only
Correct Answer: A
Rationale: Voice menus and time-based routing require the Pro edition at minimum, so the company must purchase a
Pro license to build the requested IVR and schedule behavior. The Free edition only provides basic calling functionality
and cannot satisfy the requirement. The Standard edition also does not unlock these features in the licensing model
covered by this certification, and Enterprise is not required because Pro is already sufficient. Planning the license around
required features first, then simultaneous call capacity second, prevents costly license upgrades after deployment.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 3
, 3CX Basic Certification Exam | 2026/2027 Update Questions and Verified Answers | A Grade
Q8: A reseller is sizing a 3CX Standard edition license for a customer and needs to explain the simultaneous call
model. How many simultaneous calls (SC) does a Standard edition license include?
A. 4 SC
B. 8 SC
C. 16 SC [CORRECT]
D. 64 SC
Correct Answer: C
Rationale: The Standard edition license includes 16 simultaneous calls, which is the licensed concurrency ceiling rather
than a count of extensions or users. The Pro edition includes 64 simultaneous calls, so 64 SC is a Pro figure and not a
Standard figure. Options such as 4 SC or 8 SC correspond to smaller tiers and will undersize a Standard deployment.
When sizing, the administrator counts every active conversation, including internal calls, so the SC value must cover peak
concurrent conversations.
Q9: During a pre-installation review, the IT director asks the junior technician which network prerequisites must
be satisfied before 3CX can be installed and activated. Which answer is correct?
A. A static PPPoE connection provisioned by the ISP
B. An internal-only DNS server with no external records
C. A site-to-site VPN tunnel to the license portal
D. A publicly resolvable FQDN and proper firewall configuration [CORRECT]
Correct Answer: D
Rationale: Every 3CX installation requires a Fully Qualified Domain Name that is resolvable on the public internet,
together with correct firewall configuration, before the system can be installed, activated and operated. An internal-only
hostname breaks certificate issuance, remote provisioning and app connectivity, so it is not acceptable. PPPoE, VPN
tunnels and internal DNS servers are not substitutes for these two prerequisites. The FQDN is what the license,
certificates and remote clients are all bound to, which is why it is validated at activation time.
Q10: An administrator prefers not to manage TLS certificates manually and asks what the 3CX-managed FQDN
option actually provides. Which statement is correct?
A. It requires purchasing a commercial certificate each year
B. It only resolves on the internal network
C. It provides a subdomain such as pbxname.3cx.com with an automatically maintained Let's Encrypt
certificate [CORRECT]
D. It disables HTTPS provisioning for security reasons
Correct Answer: C
Rationale: When the administrator selects a 3CX-managed subdomain such as pbxname.3cx.com, 3CX handles DNS for
that name and provisions and renews a Let's Encrypt certificate automatically. This removes the most common causes of
expired-certificate outages and simplifies remote provisioning. A custom domain is still available as the alternative mode,
but then the administrator owns the DNS records and must keep public resolution working. The managed mode certainly
does not disable provisioning; on the contrary, it makes secure HTTPS provisioning straightforward.
3CX Basic Certification Exam | 2026/2027 Update | Questions and Verified Answers Page 4
