May 27, 2026
Know Your Upstream: How Downstream Provider Blocks Impact Your Calls
The FCC is continuing its crackdown on non-compliant carriers. When carriers don’t comply with regulations, they put the reputations of legitimate businesses at risk. The impacts of cracking down on these carriers, however, also reverberate across the telecom ecosystem. If you use a non-compliant service provider, your calls might get blocked or flagged.
As the FCC tries to bring carriers in line with regulatory standards, it becomes increasingly important for you to “Know Your Upstream” providers. Failing to do so could mean your calls aren’t facilitated reliably, and you might not reach your customers.
FCC Cracks Down On Carriers
Currently, the FCC is primarily focused on voice service providers that don’t comply with rules enacted to prevent illegal robocalls. The FCC uses a couple of tools designed to encourage compliance.
Belthrough Removed from RMD
The Industry Traceback Group started investigating Belthrough LCC, a voice service provider, in 2024. After a thorough investigation, the FCC had evidence showing that Belthrough was likely allowing illegal traffic through its gateway. In response, the FCC mandated that all voice service and intermediate providers must block calls coming from Belthrough, effectively disconnecting the company from the U.S. telecom system. Downstream providers have 30 days to comply with the FCC’s order.
Role of the Robocall Mitigation Database
The FCC also removed Belthrough from the Robocall Mitigation Database (RMD). To be included in the RMD, service providers must show evidence that they’ve taken steps to comply with the FCC’s robocall regulations. Companies that don’t comply can be fined $10,000 per violation.
Removal from the database also makes it incredibly difficult for companies to work with other service providers. It isn’t a perfect solution, but it helps the FCC, industry leaders, and other service providers identify non-compliant companies.
What Is a Downstream Service Provider?
In the telecom industry, service providers are responsible for facilitating calls. They’re categorized into three tiers based on the level of service they provide.
Tier 1 Providers (Upstream)
Tier 1 service providers include the telecom giants that manage the infrastructure that facilitates calls. These companies include household names like AT&T, Verizon, and T-Mobile. Since Tier 1 service providers own the fiber-optic lines and infrastructure, they provide essential services to downstream providers.
Tier 2 Providers (Downstream – Hybrid Providers)
Tier 2 service providers rent bandwidth from the Tier 1 providers. These companies include COX, Comcast, and Virgin. Although they rent bandwidth, they also own some of the country’s infrastructure. Service providers further downstream might choose to use a Tier 2 provider because they offer peering and lower costs.
Tier 3 Providers (Downstream – The Last Mile)
Tier 3 service providers manage “the last mile” of telecommunication. You might have heard of Tier 3 companies like Mint Mobile and Spectrum, but this category also includes much smaller providers that aren’t well-known. As last-mile service providers, Tier 3 providers rely on the infrastructure owned and managed by Tier 1 and Tier 2 providers. Even a Tier 3 provider can, however, own some local-level infrastructure.
Importantly, Tier 2 and Tier 3 service providers can experience local outages. A Tier 1 outage will also make it difficult or impossible for them to serve customers and clients.
How the Removal of RMD Affects Downstream Providers
The FCC can fine service providers for falling short of RMD requirements, but the government organization doesn’t always remove companies from the RMD. Full removal usually only happens when service providers demonstrate patterns of negative behavior that allow scammers to target consumers with robocalls.
When an RMD is removed, service providers are effectively disconnected from the calling ecosystem because all U.S. downstream providers must stop processing their calls until they come into compliance and the FCC adds them to the RMD.
Service providers that don’t stop processing calls can face consequences that include:
- Cease and desist letters that inform downstream providers that they must block the banned provider within two business days.
- Network isolation that blocks service providers from facilitating calls from downstream networks.
- Forfeiture and fines that can quickly reach millions of dollars. If a company refuses to comply, the government can step in to cease all operations.
Why “Know Your Upstream” Is Essential
The telecom ecosystem consists of many companies that provide various levels of service. If your ecosystem includes one bad actor, you could struggle to reach customers, clients, and leads. That’s why you must know your upstream providers. Even one non-compliant service provider could put your business at risk.
Partnering with respectable service providers certainly helps, but it’s difficult to know every provider connected to your ecosystem. That’s why you need objective insight into your numbers.
Caller ID Reputation provides phone number scoring that uses real-time data to show you when numbers get flagged or labeled. You can also use the STIR/SHAKEN Attestation Tester to ensure you have the A-Level Full Attestation needed to reach consumers.
Want to learn more about how Caller ID Reputation can help you succeed in today’s telecom ecosystem? Connect with an expert and find the right services for your brand.
