The fight against illegal robocalls continues to evolve, and in early 2025, the regulatory expectations for voice service providers — including small rural carriers — are becoming more complex and more urgent.
The FCC has made it clear that STIR/SHAKEN implementation is just one piece of a broader strategy that includes Know Your Customer (KYC) obligations, robocall mitigation plans, and enhanced tools to prevent and communicate call blocking.
So where do things stand today, and what do rural ILECs need to know?
Let’s break it down.
A Changing Enforcement Landscape
In February, the FCC proposed a $4.5 million fine against Telnyx LLC for allegedly allowing scam robocalls to pass through their network. The calls were particularly brazen — spoofed to look like government agencies and targeting FCC staff and their families. Telnyx actually detected and addressed the issue themselves, but the FCC still proposed a fine, citing failures in KYC procedures and inadequate robocall mitigation.
You can read the details here:
https://www.consumerfinancialserviceslawmonitor.com/2025/02/fcc-proposes-4-5-million-fine-against-telnyx-llc-for-alleged-robocall-violations/
The message is clear: good intentions and quick fixes aren’t enough. The FCC expects robust systems, proactive monitoring, and documented compliance.
STIR/SHAKEN: Where Things Stand
For most rural carriers, the STIR/SHAKEN story hasn’t changed dramatically in recent months, but the expectations continue to solidify.
- VoIP networks: If your network supports SIP, you are required to implement STIR/SHAKEN in the IP portions of your voice infrastructure.
- TDM networks: While technical limitations remain, the FCC still expects you to implement a robocall mitigation program for any non-IP traffic, and to continue filing certifications and updates in the Robocall Mitigation Database.
If you haven’t filed or updated your certification — or if you’re still relying on a temporary exemption — now is the time to revisit your setup.
More information: fcc.gov/call-authentication
Know Your Customer (KYC)
Alongside technical authentication, the FCC is leaning heavily on the idea that voice providers should know who’s using their network.
This includes:
- Vetting new and renewing customers
- Monitoring call patterns for suspicious behavior
- Proactively disconnecting bad actors
The Telnyx ruling signals that even if you catch the problem eventually, you may still be held responsible for allowing those calls to originate in the first place.
Two New Rules You Need to Know
In addition to the foundational STIR/SHAKEN and mitigation requirements, two new rules have recently been finalized that will affect your operations.
1. Do-Not-Originate (DNO) List Blocking
The FCC’s Eighth Report and Order mandates that all providers in the call path — originating, transit, and terminating — must block calls that appear to originate from numbers on a Do-Not-Originate (DNO) list.
What kinds of numbers are we talking about?
- Government agencies or inbound-only numbers that should never originate calls
- Private numbers that have been used in imposter scams
If someone is spoofing the IRS or a hospital billing department, these numbers may be added to a DNO list, and carriers are now required to block those calls at the network edge.
Each provider must use a “reasonable” DNO list — either a commercial list, an industry consortium, or a carefully maintained in-house version.
The rule takes effect 90 days after publication in the Federal Register.
More details: TransNexus blog
If you’re not sure how to implement this, or how to identify which numbers belong on the list, please reach out to us — we’re working on a plan to implement DNO compliance strategies and would be happy to assist.
2. SIP 603+ for Call Blocking Transparency
When a provider uses analytics to block a call (e.g., based on call patterns or blacklists), the FCC now requires that this be clearly communicated back to the originating party.
That’s where SIP 603+ comes in.
- This is a specific SIP response code defined in ATIS-1000099, indicating that a call was blocked due to suspicion of illegal robocalling.
- The response includes metadata describing the reason for the block, allowing the originating provider to respond or adjust.
This new rule goes into effect on March 25, 2026, giving the industry time to update systems and interfaces.
In the meantime, if you use analytics to block calls, it’s smart to review your SBC and routing infrastructure to confirm it can support SIP 603+ (and ISUP 21 for non-IP networks).
More here: TransNexus blog
What You Should Do Now
If you’re a rural ILEC or CLEC, here’s a checklist of actions to take:
- Ensure STIR/SHAKEN is deployed for all VoIP traffic
- Maintain and update your Robocall Mitigation Plan
- Implement DNO list-based call blocking
- Prepare your systems to handle SIP 603+ responses
- Strengthen your Know Your Customer processes
If you need help with any of these, particularly with DNO list management, TransNexus ClearIP integration, or STIR/SHAKEN via Metaswitch or TelcoBridges SBCs, we’d be happy to support you.
Disclaimer: This article is for informational purposes only and does not constitute legal advice. Award Consulting is not a law firm or regulatory consultancy. Please consult with qualified counsel or a regulatory expert to ensure your compliance approach meets FCC requirements.
