3CX Academy, Advanced Certification
In the criteria of the "Outbound Rules", "Calls from Extension(s)" having comma
separated values will allow multiple extension ranges to be defined - Answers -True
The Virtual Extension of the slave must match the master side virtual extension number
- Answers -True
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. - Answers -False
On outbound calls to external numbers, 3CX will process "Outbound Rules" in a "Best
Matching" way, depending on how many of the criteria match. - Answers -False
Wireshark can - without any additional Plugins Decode all Codecs including G711A,
G711U, GSM, G729, G726 - Answers -False
STUN extensions can be configured to connect to the tunnel port of 3CX instead of the
SIP port for more security. - Answers -False
The log files of 3CX are never cleaned even when you restart the 3CX Services -
Answers -False
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. -
Answers -False
Remote extensions may be provisioned using the HTTP or HTTPS URLs - Answers -
False
The default Voicemail PIN of an extension consist of 4 random alphanumerical
characters. - Answers -False
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. - Answers -True
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. - Answers
-True
, 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 - Answers -True
Your 3CX has only one SIP Trunk and receives a call from number 422033272020 and
you want it to be presented on the extension display as +44272020. You can do this
with a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 44(..)(..)(.*)
and "Replace Pattern" +44\3. - Answers -True
When selecting the option "I need a 3CX FQDN" an internal DNS is not mandatory -
Answers -True
The order of "Inbound Rules" is not important when you have DID and CID "Inbound
Rules", CIDs always have higher priority. - Answers -False
You have a Master Bridge with 3-digit extensions 1xxx and a Slave Bridge with 4-digit
extensions 2xxx. In the "Outbound Rules" you use to rote calls across the bridge, using
a prefix is mandatory. - Answers -False
You have run the 3CX "Firewall Checker" and comes up as Green, but you still have
audio issues and calls dropping on on outbound / inbound calls. Can SIP ALG be the
culprit? - Answers -True
An extension will be allowed up to 25 attempts (default) for authenticating successfully,
after what it will be blacklisted for the default blacklisting interval of 1800 minutes. -
Answers -False
The 3CX SIP port should be filtered by firewall ACL rules to maximize security and allow
only trusted IPs to reach it (VoIP providers or STUN extensions if any). - Answers -True
SRTP will secure calls so that a middle-man can't see the SIP traffic in plain-text. -
Answers -False
CID and DID "Inbound Rules" can both be configured to route calls differently
depending on the Office Hours. - Answers -True
"Prepend" will add digits to the end of the dialed number before sending hte call to the
destination defined in the "Route" - Answers -False
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. - Answers -False
In the criteria of the "Outbound Rules", "Calls from Extension(s)" having comma
separated values will allow multiple extension ranges to be defined - Answers -True
The Virtual Extension of the slave must match the master side virtual extension number
- Answers -True
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. - Answers -False
On outbound calls to external numbers, 3CX will process "Outbound Rules" in a "Best
Matching" way, depending on how many of the criteria match. - Answers -False
Wireshark can - without any additional Plugins Decode all Codecs including G711A,
G711U, GSM, G729, G726 - Answers -False
STUN extensions can be configured to connect to the tunnel port of 3CX instead of the
SIP port for more security. - Answers -False
The log files of 3CX are never cleaned even when you restart the 3CX Services -
Answers -False
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. -
Answers -False
Remote extensions may be provisioned using the HTTP or HTTPS URLs - Answers -
False
The default Voicemail PIN of an extension consist of 4 random alphanumerical
characters. - Answers -False
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. - Answers -True
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. - Answers
-True
, 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 - Answers -True
Your 3CX has only one SIP Trunk and receives a call from number 422033272020 and
you want it to be presented on the extension display as +44272020. You can do this
with a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 44(..)(..)(.*)
and "Replace Pattern" +44\3. - Answers -True
When selecting the option "I need a 3CX FQDN" an internal DNS is not mandatory -
Answers -True
The order of "Inbound Rules" is not important when you have DID and CID "Inbound
Rules", CIDs always have higher priority. - Answers -False
You have a Master Bridge with 3-digit extensions 1xxx and a Slave Bridge with 4-digit
extensions 2xxx. In the "Outbound Rules" you use to rote calls across the bridge, using
a prefix is mandatory. - Answers -False
You have run the 3CX "Firewall Checker" and comes up as Green, but you still have
audio issues and calls dropping on on outbound / inbound calls. Can SIP ALG be the
culprit? - Answers -True
An extension will be allowed up to 25 attempts (default) for authenticating successfully,
after what it will be blacklisted for the default blacklisting interval of 1800 minutes. -
Answers -False
The 3CX SIP port should be filtered by firewall ACL rules to maximize security and allow
only trusted IPs to reach it (VoIP providers or STUN extensions if any). - Answers -True
SRTP will secure calls so that a middle-man can't see the SIP traffic in plain-text. -
Answers -False
CID and DID "Inbound Rules" can both be configured to route calls differently
depending on the Office Hours. - Answers -True
"Prepend" will add digits to the end of the dialed number before sending hte call to the
destination defined in the "Route" - Answers -False
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. - Answers -False
