Evaluation of Incoming SIP Messages
Proceed as follows:
Separately for VoIP providers
Using the Configuration Manager (page Public switched tel. networks > Voice over IP (VoIP page) > Provider > Configure)
* Note: You can obtain the data for the settings either directly from the VoIP provider or from suitable lists in the Internet.
Requirements:
For entering a URL: configured DNS server
For using a STUN server: IP operating mode IPv4
PROVIDER
Select the provider to be displayed/configured.
The phone numbers of incoming VoIP calls listed in the call data list usually need to be converted before they can be used for callbacks.
* Note: To check these settings, direct incoming exchange line calls via this VoIP provider, e.g. using a mobile phone, and check the phone number sent along with the call in the call data list (in User Data > Call data list).
* Note: To identify the user-defined settings, select an incoming call under Monitoring > Network Data Stream and view it in the Wireshark programme. Select the options you require in the list fields under Search prioritisation (Wireshark term). The names ("terms") used for the search fields match the names used in Wireshark.
* Note: The phone number to be evaluated should be as canonical as possible (+445306.... or 00445306…). Otherwise it is not used for evaluation.
Internationalise unknown phone numbers
If phone numbers that are not in the standard canonical format are received: (e.g. +445306… or 00445306…), they are converted into this format.
Evaluate Connected Party Number (COPN)
Enabling this function prevents that a direct callback fails due to an incorrect depiction of the phone number when the call is answered.
Set prefix for the phone number
Sets a prefix for the country code before the phone number (maximum 10 characters).
Source for called number
Default
Selects an evaluation method for phone numbers which will work for most providers.
Request Line
Forces the phone number to be evaluated using the Request Line.
To Header
Forces the phone number to be evaluated using the To Header.
Analysis type
Default
Selects an evaluation method for phone numbers which will work for most providers.
Default (using the From Header as a Screened Number)
Selects an evaluation method for phone numbers which will work for most providers. The user provided number (unscreened number, corresponds to CLIP no screening) in the "From" header is transferred to the network provided number (screened number). The phone numbers can be used, for example, for Call Through via VoIP.
* Caution: As soon as you have enabled this option, your phone and PBX are open to attacks such as the transfer of manipulated phone numbers.