Do Not Originate (DNO) Filtering
Stop illegal spoofing and protect your customers with real‑time DNO enforcement.
How DNO Filtering Works
Call Arrives
Every inbound call is intercepted and the calling number is extracted for instant screening.
DNO Lookup
The calling number is checked against our aggregated DNO list, updated continuously from multiple authoritative sources.
Block or Allow
Flagged numbers are rejected instantly with a SIP 603 Decline. Clean calls pass through normally.
Under the Hood
- DNO list is aggregated from ITG, T‑Mobile, and Hiya.
- Lookups happen in real time with sub‑millisecond latency.
- Rejected calls return
SIP 603 Declinewith a descriptive reason header. - All lookup results are logged for audit and compliance reporting.
Trusted Data Sources
ITG
Industry Traceback Group – the official US telecom traceback consortium providing verified DNO entries from across the industry.
T‑Mobile
One of the largest US carriers, contributing their own verified DNO entries based on network‑level call analysis.
Hiya
A leading call protection and reputation service, providing real‑time intelligence on spoofed and fraudulent numbers.
What's Covered
The combined DNO list covers thousands of numbers from high‑trust entities that never originate calls:
One‑Click Configuration
1. Go to Settings
Navigate to your Account Settings page and locate the Call Filtering section.
2. Toggle DNO On
Flip the "Enable DNO Filtering" switch. No configuration files needed.
3. Instant Protection
All calls through our STIR/SHAKEN and routing APIs are now screened. Changes take effect immediately.
Benefits
Subscriber Protection
Block scam calls that impersonate trusted organisations before they reach your subscribers.
Reduced Complaints
Fewer consumer complaints and reduced regulatory exposure from illegal spoofing on your network.
Improved Call Completion
Block fraudulent traffic early so legitimate calls complete faster and more reliably.
Zero Additional Cost
Included with your STIR/SHAKEN service at no extra charge. No per‑lookup fees.
Always Up‑to‑Date
The DNO list is continuously refreshed from all three sources. You never need to manage it manually.
Full Audit Trail
Every DNO lookup and rejection is logged with timestamp, calling number, and reason for compliance reporting.
Ready to block spoofed calls?
Enable DNO filtering in your account settings and start protecting your network today.