3CX Academy, Advanced Certification Study Guide 2023

In the criteria of the "Outbound Rules", "Calls from Extension(s)" having comma separated values will allow multiple extension ranges to be defined - True The Virtual Extension of the slave must match the master side virtual extension number - 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. - 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. - False Wireshark can - without any additional Plugins Decode all Codecs including G711A, G711U, GSM, G729, G726 - False STUN extensions can be configured to connect to the tunnel port of 3CX instead of the SIP port for more security. - False The log files of 3CX are never cleaned even when you restart the 3CX Services - 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. - False Remote extensions may be provisioned using the HTTP or HTTPS URLs - False The default Voicemail PIN of an extension consist of 4 random alphanumerical characters. - False Your 3CX has only one SIP Trunk and receives a call from number 1. If you have a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 813(...)(.*) and "Replace Pattern" 12, the extension that receives the call will see "" as the caller ID on its display. - 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. - 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 - True Your 3CX has only one SIP Trunk and receives a call from number 020 and you want it to be presented on the extension display as +. You can do this with a "Inbound CID Reformatting" rule on the Trunk with "Source Pattern" 44(..)(..)(.*) and "Replace Pattern" +443. - True When selecting the option "I need a 3CX FQDN" an internal DNS is not mandatory - True The order of "Inbound Rules" is not important when you have DID and CID "Inbound Rules", CIDs always have higher priority. - 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. - 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? - 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. - 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). - True SRTP will secure calls so that a middle-man can't see the SIP traffic in plain-text. - False CID and DID "Inbound Rules" can both be configured to route calls differently depending on the Office Hours. - True "Prepend" will add digits to the end of the dialed number before sending hte call to the destination defined in the "Route" - 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. - False The "Server Activity Log" will provide information for: Phone Registrations, Gateway and SIP Trunk Interactions, All Related Calls - True