When Traceback Reveals Illegal Calling
The industry uses a process called traceback to find the source of illegal calls. At present, the individual calls being traced are representative of the most prolific illegal calling campaigns. The notification sent to the provider usually includes a detailed description of the campaign, the type of telephone called (most often a mobile phone), whether the called party is on the federal Do-Not-Call list, indications of caller-ID spoofing, and an audio recording with the automated or pre-recorded announcement used by the caller. These elements confirm the variety of ways in which the caller is operating illegally.
Each call traced is typically indicative of one to two million similar calls.
Once a provider is made aware of this calling pattern, they can:
- Confer with their customer to have the calls brought into compliance or stopped.
- Pause service or restrict the calls-per-second, number of simultaneous calls, and/or allowable caller-ID while the matter is investigated.
- Flag the customer to industry and enforcement officials so that other providers can properly vet the customer before allowing their calls onto the network.
- Monitor the customer’s call records. Customers should not be permitted to continue generating large numbers of these types of calls without a compelling explanation:
- Lasting less than 30 seconds — this usually means that the called party did not want the call.
- Abandoned (where the calling party disconnects before the call is answered). This may be a “ring-once-and-cut” scam attempting to lure the customer into calling back a high-cost number, or it may be a denial-of-service or harassment attack.
- Using many different Caller-ID values.
These calls are made in such huge volume, they create mass annoyance for the public. Further, they can do serious damage if they perpetrate fraud or other types of abuse.
Note that because many of these calls are spoofed, merely “blocking the ANI” will not be effective. More proactive steps along the lines described above will be required.
It is imperative that providers act quickly. Effective mitigation should be put in place within 48 hours.
Next Step: Working with Upstreams