3CX Basic Certification Exam Prep |
Complete Question Bank & Study Guide |
2026/2027 Edition
Section 1: System Fundamentals & Requirements
Q1: Which of the following is a mandatory prerequisite for installing a 3CX system with
remote-phone capabilities?
A) A static internal IP address for the server
B) A publicly resolvable Fully Qualified Domain Name (FQDN) and proper firewall
configuration
C) A dedicated Windows Server operating system
D) A supported IP phone on-site before installation
Correct Answer: B
Rationale: A publicly resolvable FQDN is mandatory for remote STUN/RPS provisioning
and SSL-certificate functionality, which are core to remote operations. While a static IP
(A) is recommended, it is not strictly mandatory because DHCP reservations can be
used. 3CX can be installed on various OSs, not just Windows Server (C). Phones (D) can
be provisioned after installation.
Q2: The 3CX Session Border Controller (SBC) is primarily used to:
,A) Provide voicemail-to-email transcription
B) Tunnel VoIP traffic securely between remote sites and the 3CX PBX
C) Replace the need for SIP trunks
D) Act as a DHCP server for IP phones
Correct Answer: B
Rationale: The SBC brokers RTP and SIP traffic over a single, secure TCP port (default
5060 outbound), eliminating NAT issues at remote sites. It does not perform voicemail
transcription (A), still requires SIP trunks (C), and does not hand out DHCP leases (D).
Q3: Which TCP/UDP ports MUST be open on the firewall for a standard 3CX Cloud PBX
to register remote extensions using the 3CX Tunnel (SBC)?
A) 80, 443, 5060, 10000-10999
B) 443, 5001, 5090 (TCP) and 10000-10999 (UDP)
C) 22, 53, 443, 5060
D) 443, 5060-5061, 7000-7999
Correct Answer: B
Rationale: Port 443 (HTTPS provisioning), 5001 (Tunnel), 5090 (HTTPS tunnel) and the
10 K-11 K UDP range for RTP are compulsory. Option A mixes legacy ports; C lists
SSH/DNS which are unrelated; D omits the tunnel port.
Q4: Choose the minimum supported operating system for a fresh on-premise 3CX v20
installation:
,A) Windows Server 2016 64-bit
B) Debian 11 (Bullseye) 64-bit
C) Ubuntu 18.04 64-bit
D) Windows 10 Pro 32-bit
Correct Answer: B
Rationale: 3CX v20 ships as a Debian 11 appliance or ISO; 64-bit is mandatory. Windows
Server 2019+ is supported only as app install inside supported Debian; Ubuntu 18.04 (C)
is too old; 32-bit (D) is rejected by installer.
Q5: Which FQDN mode does the 3CX setup wizard create if you select “I want 3CX to
manage my domain”?
A) A subdomain under 3cx.net
B) A sub-domain under 3cx.eu (or .us/.com) with Let’s Encrypt certificate
C) A standalone .local domain
D) A customer-owned domain with manual DNS
Correct Answer: B
Rationale: The “3CX-managed” option auto-creates <pbxname>
Q6: The 3CX “Web Client” runs:
A) Only inside the Management Console
B) Natively in any modern browser without plug-ins
, C) Inside the 3CX Windows desktop app exclusively
D) Requires Java Runtime Environment
Correct Answer: B
Rationale: The Web Client (user portal) is pure HTML5/JavaScript; no plug-ins, Java, or
local app required. The desktop app (C) embeds the same interface but is optional.
Q7: A customer wants to use voice menus and time-based routing. Which 3CX license
level is the MINIMUM required?
A) Free edition (8 SC)
B) Small (16 SC)
C) Pro (64 SC)
D) Enterprise (1024 SC)
Correct Answer: A
Rationale: Digital Receptionist (IVR) and time-routes are included even in the free 8-call
edition. Pro/Enterprise add queues, call-center reports, etc., but NOT basic IVR.
Q8: The default web access URL for the 3CX Management Console on a local network
is:
A) https://<server-ip><fqdn><server-ip><server-ip>
Correct Answer: A
Complete Question Bank & Study Guide |
2026/2027 Edition
Section 1: System Fundamentals & Requirements
Q1: Which of the following is a mandatory prerequisite for installing a 3CX system with
remote-phone capabilities?
A) A static internal IP address for the server
B) A publicly resolvable Fully Qualified Domain Name (FQDN) and proper firewall
configuration
C) A dedicated Windows Server operating system
D) A supported IP phone on-site before installation
Correct Answer: B
Rationale: A publicly resolvable FQDN is mandatory for remote STUN/RPS provisioning
and SSL-certificate functionality, which are core to remote operations. While a static IP
(A) is recommended, it is not strictly mandatory because DHCP reservations can be
used. 3CX can be installed on various OSs, not just Windows Server (C). Phones (D) can
be provisioned after installation.
Q2: The 3CX Session Border Controller (SBC) is primarily used to:
,A) Provide voicemail-to-email transcription
B) Tunnel VoIP traffic securely between remote sites and the 3CX PBX
C) Replace the need for SIP trunks
D) Act as a DHCP server for IP phones
Correct Answer: B
Rationale: The SBC brokers RTP and SIP traffic over a single, secure TCP port (default
5060 outbound), eliminating NAT issues at remote sites. It does not perform voicemail
transcription (A), still requires SIP trunks (C), and does not hand out DHCP leases (D).
Q3: Which TCP/UDP ports MUST be open on the firewall for a standard 3CX Cloud PBX
to register remote extensions using the 3CX Tunnel (SBC)?
A) 80, 443, 5060, 10000-10999
B) 443, 5001, 5090 (TCP) and 10000-10999 (UDP)
C) 22, 53, 443, 5060
D) 443, 5060-5061, 7000-7999
Correct Answer: B
Rationale: Port 443 (HTTPS provisioning), 5001 (Tunnel), 5090 (HTTPS tunnel) and the
10 K-11 K UDP range for RTP are compulsory. Option A mixes legacy ports; C lists
SSH/DNS which are unrelated; D omits the tunnel port.
Q4: Choose the minimum supported operating system for a fresh on-premise 3CX v20
installation:
,A) Windows Server 2016 64-bit
B) Debian 11 (Bullseye) 64-bit
C) Ubuntu 18.04 64-bit
D) Windows 10 Pro 32-bit
Correct Answer: B
Rationale: 3CX v20 ships as a Debian 11 appliance or ISO; 64-bit is mandatory. Windows
Server 2019+ is supported only as app install inside supported Debian; Ubuntu 18.04 (C)
is too old; 32-bit (D) is rejected by installer.
Q5: Which FQDN mode does the 3CX setup wizard create if you select “I want 3CX to
manage my domain”?
A) A subdomain under 3cx.net
B) A sub-domain under 3cx.eu (or .us/.com) with Let’s Encrypt certificate
C) A standalone .local domain
D) A customer-owned domain with manual DNS
Correct Answer: B
Rationale: The “3CX-managed” option auto-creates <pbxname>
Q6: The 3CX “Web Client” runs:
A) Only inside the Management Console
B) Natively in any modern browser without plug-ins
, C) Inside the 3CX Windows desktop app exclusively
D) Requires Java Runtime Environment
Correct Answer: B
Rationale: The Web Client (user portal) is pure HTML5/JavaScript; no plug-ins, Java, or
local app required. The desktop app (C) embeds the same interface but is optional.
Q7: A customer wants to use voice menus and time-based routing. Which 3CX license
level is the MINIMUM required?
A) Free edition (8 SC)
B) Small (16 SC)
C) Pro (64 SC)
D) Enterprise (1024 SC)
Correct Answer: A
Rationale: Digital Receptionist (IVR) and time-routes are included even in the free 8-call
edition. Pro/Enterprise add queues, call-center reports, etc., but NOT basic IVR.
Q8: The default web access URL for the 3CX Management Console on a local network
is:
A) https://<server-ip><fqdn><server-ip><server-ip>
Correct Answer: A
