AWAITING FEEDBACK Info on Sinch/Intelliquent/Onvoy

[morgondag]

I'm investigating these companies (Sinch is the owner of the others), which are accused of facilitating robocalls and spoofing for scammers ( https://commsrisk.com/scamhunters-b...-sinch-over-voip-numbers-for-callback-frauds/ ). If anyone has any additional relevant info about any of these companies, I'd be grateful if you could share it or point me to it.

 

[billsimon]

Sinch is a large public firm, not exactly some small operator working in the shadows. What kind of "additional relevant info" are you asking about? What kind of "investigation" are you doing? Perhaps leave it to the authorities?

 

[morgondag]

Without going into too much detail, it's for a Swedish media outlet. Any kind of useful info really.

 

[chris_c_]

I'm investigating these companies (Sinch is the owner of the others), which are accused of facilitating robocalls and spoofing for scammers ( https://commsrisk.com/scamhunters-b...-sinch-over-voip-numbers-for-callback-frauds/ ). If anyone has any additional relevant info about any of these companies, I'd be grateful if you could share it or point me to it.

Sinch, which acquired Inteliquent (formerly a major voice provider often associated with Onvoy), facilitates high-volume, automated calls by acting as a wholesale carrier that provides VoIP numbers, SIP trunking, and call routing services to businesses and other carriers. While providing legitimate services, their network infrastructure can be misused to transmit illegal robocalls, leading to regulatory scrutiny and accusations of enabling fraudulent traffic.

As wholesale providers, they offer SIP trunking, which allows customers to connect their own phone systems to the public telephone network to originate thousands of calls, a common method for robocall campaigns.

They provide large blocks of phone numbers (often in the Onvoy/Inteliquent network) that scammers use, allowing them to lease, discard, and change numbers frequently to evade detection.

They act as intermediate carriers (transit services), routing traffic from various, sometimes non-compliant, downstream providers to the final destination.

Inteliquent received a warning letter from the FTC in 2022 regarding the transmission of illegal, high-volume robocall traffic, including imposter and scam calls. https://en.wikipedia.org/wiki/Inteliquent

A 2025 Multi-state Task Force investigation highlighted that Inteliquent continues to transmit suspect traffic on behalf of customers. https://ncdoj.gov/wp-content/upload...E-Letter-to-INTELIQUENT-Issued-12-03-2025.pdf

Reports suggest that call centers, including those using VoIP for scams, use their numbers, and that they may be slow to cut off abusers. https://commsrisk.com/scamhunters-b...-sinch-over-voip-numbers-for-callback-frauds/

https://www.reddit.com/r/VOIP/comments/1ql5q7l/onvoy_llc_spam_calls

Despite these issues, Sinch and Inteliquent are involved in adopting STIR/SHAKEN protocols to authenticate calls and fight spoofing, alongside Neustar for robocall identification. https://www.t-mobile.com/news/press/tmobile-comcast-inteliqent

Sinch states they are a wholesale provider, generally lack direct information on the end-user, and must forward reports to their direct customer for investigation. They also have an Acceptable Use Policy that prohibits the use of their numbers for fraudulent activity. https://sinch.com/legal/report-scams-fraud/

 

[morgondag]

Thanks.

In your opinion, do you think the report I linked is too harsh against Sinch when they accuse them of being lax, perhaps even intentionally, against scam center customers? Do you think they more or less do what is realistically possible to detect and block such users?

 

[billsimon]

Do you think they more or less do what is realistically possible to detect and block such users?

How could one make an informed opinion about this without intricately knowing the operations of the company?

The AI barf that @chris_c_ pasted did point out one useful thing. They are largely providing transit for smaller operators. It is the responsibility of the operator that originates the call, not the transit operator, to know the customer, respond to fraud/scam complaints, etc. A comparison would be to blame internet transit providers for spam email that crosses the internet. It's not their problem. It's the email service's problem.

 

[chris_c_]

Thanks.

In your opinion, do you think the report I linked is too harsh against Sinch when they accuse them of being lax, perhaps even intentionally, against scam center customers? Do you think they more or less do what is realistically possible to detect and block such users?

EDITED:

Personally, I feel Sinch is slow-rolling their processing of complaints and shutdown of scam center customers.

Why? Because there's a conflict of interest.
A. Sinch's interest is in keeping customers, including scam centers, for as long as possible, because customers are their revenue source. Sinch would be happy to keep all customers including scam centers, and for scam center outbound calls to be blocked at the network level or at the user level by smarter Phone apps on users' smartphones.
B. The general public interest is in blocking scam centers by any and all means, in whichever ways are most reliable and effective. Deleting scam center customers from Sinch quickly is one of the best ways of derailing these scammers quickly.

One solution to this conflict of interest would be to separate the banning mechanism away from Sinch and bring it into the network level, similar to 10DLC operates for A2P (app to person) mass texting. Instead of the "Stop" command, the SIP calling network should track how many users flag a call as Scam, plus an optional AI score, and after a certain threshold, the SIP network itself (no Sinch or other VSPs) will block calls from that Sinch account on the basis of a substantial number of scam reports. The scamer calling account will be blocked from ringing user devices by the SIP network, effectively taken down in minutes or hours insteaf of days or weeks as is now the case, saving hundreds of potential victims from losing hundreds of thousands of dollars/pounds/euros.

Two things that would cut down on these scam calls at the level of the user smart phone/desk device/soft phone:
1. Require more KYC. Nobody, not even in 2nd and 3rd world nations, should be allowed to obtain VOIP service capable of calling into the US or Europe or any targeted country, without showing the VSP their ID, in case of future legal issues due to criminal activity.
2. The suspicious VOIP call headers must be exposed to users thru the Phone app and any calling app, when calls are live, and in call history records. When a call has a C-Level (Unverified) STIR/SHAKEN Attestation, it should byb default not ring and go straight to voicemail, and call history should show "C: Unverified" next to the name and number. Second, when spoofing, they put forged fake info in the SIP INVITE "From:" header, "Chase Bank <+1800....>", when it doesn't match the SIP "Contact:" header "<+1213....>" , the real name and number of the VOIP account from the "Contact:" header should be also shown, when calls are ringing/live, and in the Phone app's call history, so the user is warned of the scam caller and should not tap to call back.

 

[billsimon]

Sinch would be happy to keep all customers including scam centers

Fraud investigation departments and lawyers are expensive. I'm sure every carrier would be happier NOT to have fraudsters on their network. No matter how hard you or anyone tries to twist the situation into a "corporate greed" scenario, no one is getting rich from fraudsters except for fraudsters.