When reviewing robocall mitigation reports, the numbers in the report should be investigated to understand why they are being reported as a potential robocall.
Collect Information
There are many reasons why a number might show up in the robocall mitigation reports.
To start the investigation, information can be collected by asking these questions:
- Did the call come in from a subscriber line or SIP trunk? Check whether the caller has the capability to modify their calling number.
- Is the calling number an owned calling numbers? If the call came in from a trunk, does it use a calling number that was assigned for use by the specific customer?
- Was the call forwarded out of the network? ClearIP only recognizes calls as forwarded if the Diversion header is present in the SIP Invite. If present, the Forwarded field is set to Yes for that call in the SIP Messages page.
Here are a few possible scenarios that can cause unfamiliar calling numbers to appear in the robocall mitigation report.
- The PBX or switch forwards the call but does not set the Diversion header.
- The caller is spoofing the calling number.
- The switch receives an inbound call to a phone number that is not in the switch, but the service provider owns the number block. Since the number is not assigned to a subscriber, the switch may check the routing for outbound calls and send the call to ClearIP as the first choice route.
View SIP Messages
The robocall mitigation reports only display the calling number that was flagged as a robocall number, but the reports do not provide information about the called number or the timestamp when calls occurred. This information can be viewed on the SIP Messages page.
The Asserted Calling Number shown in the SIP Report can be copied to look for that number in the SIP Messages page. In the SIP Messages page, click on the Columns button and select the Robocall Mitigation option. Then can enter the copied number into the Asserted Calling Number column filter to view details about the individual calls received from that calling numbers.
The call records on the switch should also be checked to obtain additional information about where the call came from.
Make a Decision
Once the situation is better understood, a decision can be made. If it is detemrined that a subscriber’s call patterns may resemble robocall activity, it can be decided that the subscriber should be contacted about their activity, the robocall data within ClearIP should be ignored, or the subscriber should be notifited on steps to get their number corrected from being mislabeled as spam.
It is not required to use ClearIP to automatically block any subscriber’s outbound calls. ClearIP notifies of potential robocall activity within outbound calls and allows for the decision to be mad eon how to respond.
Remove Calling Number from Future Reports
If it is decided that a calling number is not a robocall, the number can be removed from appearing in any future reports. If the calling number shows up in the SIP Report for Calling Numbers with Reputation Score Above 0, turn off the reputation lookup service for the specific calling number.
In the Reputation Policies page, create a rule, set the Status field to Disabled and set the Calling Number field to the calling number found in the SIP Report. The other fields can be left as the default settings.
If the calling number appears in the Invalid or High Risk Number Report, disable the Inbound Shield lookup by creating a similar rule to disable the service for the specific calling number
Correct SPAM Mislabeling
If it is suspected that a customer’s phone number is wrongfully being labelled as robocall or spam, there is a process to improve the number’s reputation by contacting the relevant reputation data provider.
There are many different reputation data providers, so who is contaced to resolve spam labelling depends on the exact provider that labeled the call as spam.
If a subscriber’s number is flagged as spam by one of the large wireless carriers, the subscriber can fill out a form at https://www.freecallerregistry.com/fcr/ to request vetting and potential whitelisting of their number in the relevant reputation databases.