i3Forum’s analysis on the impact of VoLTE roaming, in relation with the need to validate international calls CLIs.
The growth of incoming calls with fake domestic CLIs which are used to abuse users with Spams and Scams are a domestic ramping problem that is spreading to incoming international calls.
The problem: International calls transited towards country A with a spoofed CLI of that country A to make it look like a trusted domestic call of that country.
The need: to validate the CLI of all international calls that have a CLI format of the destination country
The nature and size of the problem: A significant majority of international traffic with a CLI of the destination country is due to roaming travelers calling back their home country. The rest of that traffic is offshore Call Centers and remote offices DIDs.
i3Forum members Orange, Telefonica, and Vodafone, plus Deutsche Telecom, which represent a vast majority of European MNOs and a significant share of international MNOs, have come together to estimate the transition of International voice roaming calls towards VoLTE S8 HR, which by design removes the presence of international calls with a CLI of the destination country.
The absence of roaming calls over international IDD channels and the blocking of the remaining international fixed calls with a CLI of the destination country, removes the risk of unverified mobile calls with a CLI of the destination country over international wholesale carriers.
– use “is roaming” to verify roaming calls that are not yet on VoLTE S8 HR. This is the vast majority of calls that would need to be verified.
– Block all other international calls with a CLI of the destination country over standard international IDD routes
– Redirect legitimate “International calls with a CLI of the destination country” (such as Cloud DID numbers, offshore call centers) through dedicated channels back to the domestic network, for domestic CLI verification applicable in the domestic country of the number.
i3Forum concludes that there will be a very aggressive migration to VoLTE roaming and a steep decline of the amount of international roaming calls that would need to be verified.
Some complex CLI attestation solutions, such as STIR/SHAKEN, would require 16 to 24 months to be procured and put into production. These complex and therefore costly CLI attestation solutions face a challenging Return On Investment with volumes of calls to validate that will be small by the time the solution gets into production and will keep quickly declining towards zero as VoLTE roaming gets implemented by all MNOs.
The i3Forum members are committed to restore and ensure trust in the international voice industry. To do so, I3forum members recommend to implement solutions that are cost effective, efficient and quick to deploy to capture and safeguard the most voice calls in the immediate 24 months, and not have to wait 24 months for complex solutions.
I3FORUM recommends less complex solutions such as “is roaming query,” which validates legitimate roaming calls and allows the blocking of suspicious calls. Some European jurisdictions already recommend these “roaming status validation” and these solutions are already offered commercially by several vendors, which makes them quicker to deploy and quicker to bring trusted international calls CLI to all markets around the world.
i3Forum is planning to publish best practice recommendations to further speed up the adoption and efficiency of these “roaming status validation” solutions around the world.