Tracing unwelcome calls

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In Canada and other countries, there is a legal requirement for CLECs (Competitive Local Exchange Carriers) to provide their subscribers with the Call Trace service. (http://www.crtc.gc.ca/eng/archive/2006/dt2006-52.htm#s10)

The Call Trace service permits end users to request a trace for threatening, harassing, or obscene phone calls in the event that they want to initiate an official investigation. PortaSwitch fully supports this functionality.

To initiate a call trace, an end user hangs up to end the call. Then they dial the Call Trace IVR access number and follow the voice-recorded instructions. The Call Trace IVR application marks the last incoming call attempt received by the end user as “traced.”

Only the last incoming call attempt can be traced. That is why it is important to dial the Call Trace IVR application immediately after a harassing call.

The SIP log for the traced call is then copied to a dedicated part of the database where it is stored for a preconfigured period of time. Upon request, an administrator retrieves this SIP log and provides it to law enforcement officials.

Call tracing

For example, end user John Doe receives a call from an anonymous caller. The caller says obscene things and makes threats to him. John Doe hangs up and immediately dials the Call Trace IVR access number. Depending on the Call Trace IVR configuration settings, John either is asked to press 1 to trace the call or immediately hears a recorded message informing him whether or not the trace was successful. Once John Doe has a successful call trace, he can contract a law enforcement agency and ask them to investigate the case.

An administrator uses the logs-extractor.pl utility to retrieve a SIP log for the traced call. They specify the account ID the call was addressed to and the billing environment ID to which the account belongs. To help narrow the search, the administrator can also indicate the time period during which the harassment call was received. The details of the trace are only revealed to law enforcement officials.

PortaSwitch can trace the last incoming call regardless of whether or not it was answered. Therefore, even if the caller hangs up before the end user picks up the phone, a call trace is still possible. The steps necessary for initiating a call trace are the same as for when a call is answered.

Service providers can offer the Call Trace service free of charge or assign a charge to it – either on a subscription basis or on a per call trace request. To do this, an administrator needs to configure a price for the UMTRACE destination in the customer tariff.

Call trace rate

With Call Trace functionality, service providers can help their customers identify a harassing caller and provide a law enforcement agency with evidence against the harassing caller.

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