3CX ACADEMY, ADVANCED
CERTIFICATION|| LATEST UPDATE
2025
In the criteria of the "Outbound Rules", "Calls from Extension(s)" having comma
separated values will allow multiple extension ranges to be defined - ANSWERTrue
The Virtual Extension of the slave must match the master side virtual extension number
- ANSWERTrue
For extensions that are registered over multiple site-to-site VPNs, by default 3CX
delivers the audio between phones if they are on different subnets. - ANSWERFalse
On outbound calls to external numbers, 3CX will process "Outbound Rules" in a "Best
Matching" way, depending on how many of the criteria match. - ANSWERFalse
Wireshark can - without any additional Plugins Decode all Codecs including G711A,
G711U, GSM, G729, G726 - ANSWERFalse
STUN extensions can be configured to connect to the tunnel port of 3CX instead of the
SIP port for more security. - ANSWERFalse
The log files of 3CX are never cleaned even when you restart the 3CX Services -
ANSWERFalse
Once Secure SIP has been configured in 3CX, Secure SIP certificates will need to be
deployed manually in phones and softphones OS so that they can communicate. -
ANSWERFalse
Remote extensions may be provisioned using the HTTP or HTTPS URLs -
ANSWERFalse
The default Voicemail PIN of an extension consist of 4 random alphanumerical
characters. - ANSWERFalse
Your 3CX has only one SIP Trunk and receives a call from number 8135791691. If you
have a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 813(...)(.*)
and "Replace Pattern" \1\2, the extension that receives the call will see "5791691" as
the caller ID on its display. - ANSWERTrue
When 3CX has been installed without a FQDN from 3CX and in split DNS mode, the
DNS server must not be installed on the same machine as the phone system. -
ANSWERTrue
, Your Local IP Phone loses the registration to 3CX and you want do troubleshoot the
issue. You should start a Wireshark Capture on the 3CX Server, reboot the phone, and
then apply the Filter sip.Cseq.Method==REGISTER in order to see if registrations are
reaching 3CX - ANSWERTrue
"Prepend" will add digits to the end of the dialed number before sending hte call to the
destination defined in the "Route" - ANSWERFalse
Your Local IP Phone loses the Registration to 3CX and you want to troubleshoot the
issue. You should start a Wireshark Capture on the 3CX Server, reboot the phone, and
then apply the Filter sip.Cseq.Method==SUBSCRIBE in order to see if registrations are
reaching 3CX. - ANSWERFalse
The "Server Activity Log" will provide information for: Phone Registrations, Gateway and
SIP Trunk Interactions, All Related Calls - ANSWERTrue
Each extension gets a default password which is always the same and should be
changed for more safety. - ANSWERFalse
You are debugging an audio issue using wireshark by analysing the RTP streams.
While using the RTP Stream analysis tools you see that the MAX Delta of packages
from the Provider to 3CX is 8-- MS while the Max Delta for the reverse direction is 20
Ms. The issue is located at the provider end and not 3CX end. - ANSWERTrue
If you want to check 3CX routing of a call then only a Wireshark capture is needed, -
ANSWERFalse
Knowing only the FQDN/port of 3CX and the MAC address of a phone I could guess its
provisioning URL. - ANSWERFalse
An outbound call is routed through the VoIP Provider. This "Route" of the "Outbound
Rule" has "Strip Digits" set as 0 and has no values in the "Prepend" field. A user dials
004433272020. 3CX will send the call to the provider exactly as dialed - ANSWERTrue
You can use the same VoIP Provider in all of the Outgoing Routes of a rule -
ANSWERTrue
If you want to decode audio in wireshark without any plugins, your calls will need to be
using either G711A or G711U - ANSWERTrue
If you want to check the internal PBX routing of a call, the most reliable way is through
the use of the Binary Log Viewer, or which you must know some information about the
call you are investigating, like the Caller ID, the time of the call, etc. - ANSWERTrue
CERTIFICATION|| LATEST UPDATE
2025
In the criteria of the "Outbound Rules", "Calls from Extension(s)" having comma
separated values will allow multiple extension ranges to be defined - ANSWERTrue
The Virtual Extension of the slave must match the master side virtual extension number
- ANSWERTrue
For extensions that are registered over multiple site-to-site VPNs, by default 3CX
delivers the audio between phones if they are on different subnets. - ANSWERFalse
On outbound calls to external numbers, 3CX will process "Outbound Rules" in a "Best
Matching" way, depending on how many of the criteria match. - ANSWERFalse
Wireshark can - without any additional Plugins Decode all Codecs including G711A,
G711U, GSM, G729, G726 - ANSWERFalse
STUN extensions can be configured to connect to the tunnel port of 3CX instead of the
SIP port for more security. - ANSWERFalse
The log files of 3CX are never cleaned even when you restart the 3CX Services -
ANSWERFalse
Once Secure SIP has been configured in 3CX, Secure SIP certificates will need to be
deployed manually in phones and softphones OS so that they can communicate. -
ANSWERFalse
Remote extensions may be provisioned using the HTTP or HTTPS URLs -
ANSWERFalse
The default Voicemail PIN of an extension consist of 4 random alphanumerical
characters. - ANSWERFalse
Your 3CX has only one SIP Trunk and receives a call from number 8135791691. If you
have a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 813(...)(.*)
and "Replace Pattern" \1\2, the extension that receives the call will see "5791691" as
the caller ID on its display. - ANSWERTrue
When 3CX has been installed without a FQDN from 3CX and in split DNS mode, the
DNS server must not be installed on the same machine as the phone system. -
ANSWERTrue
, Your Local IP Phone loses the registration to 3CX and you want do troubleshoot the
issue. You should start a Wireshark Capture on the 3CX Server, reboot the phone, and
then apply the Filter sip.Cseq.Method==REGISTER in order to see if registrations are
reaching 3CX - ANSWERTrue
"Prepend" will add digits to the end of the dialed number before sending hte call to the
destination defined in the "Route" - ANSWERFalse
Your Local IP Phone loses the Registration to 3CX and you want to troubleshoot the
issue. You should start a Wireshark Capture on the 3CX Server, reboot the phone, and
then apply the Filter sip.Cseq.Method==SUBSCRIBE in order to see if registrations are
reaching 3CX. - ANSWERFalse
The "Server Activity Log" will provide information for: Phone Registrations, Gateway and
SIP Trunk Interactions, All Related Calls - ANSWERTrue
Each extension gets a default password which is always the same and should be
changed for more safety. - ANSWERFalse
You are debugging an audio issue using wireshark by analysing the RTP streams.
While using the RTP Stream analysis tools you see that the MAX Delta of packages
from the Provider to 3CX is 8-- MS while the Max Delta for the reverse direction is 20
Ms. The issue is located at the provider end and not 3CX end. - ANSWERTrue
If you want to check 3CX routing of a call then only a Wireshark capture is needed, -
ANSWERFalse
Knowing only the FQDN/port of 3CX and the MAC address of a phone I could guess its
provisioning URL. - ANSWERFalse
An outbound call is routed through the VoIP Provider. This "Route" of the "Outbound
Rule" has "Strip Digits" set as 0 and has no values in the "Prepend" field. A user dials
004433272020. 3CX will send the call to the provider exactly as dialed - ANSWERTrue
You can use the same VoIP Provider in all of the Outgoing Routes of a rule -
ANSWERTrue
If you want to decode audio in wireshark without any plugins, your calls will need to be
using either G711A or G711U - ANSWERTrue
If you want to check the internal PBX routing of a call, the most reliable way is through
the use of the Binary Log Viewer, or which you must know some information about the
call you are investigating, like the Caller ID, the time of the call, etc. - ANSWERTrue
