How the UBlocker Works with First-Ring Suppression


When a call comes in from a number on the Blacklist, the UBlocker requires 2–3 seconds to read the Caller ID (name and number) and communicate with our server before disconnecting the call. During this process, the phone will usually ring once before the call is blocked.


At HQTelecom, we understand that even a single ring from a blocked call can be a nuisance. Our team has been searching for a solution to fully suppress these rings. While many products have claimed to do this, none worked effectively, except one — the Panasonic Model KX-TG994SK (and newer model KX-TGF973) series with base unit model KX-TGF970 includes a feature called “One Ring Scam” suppression. This feature eliminates the first one to two rings on all incoming calls. 


Our engineers at HQTelecom have tested the KX-TGF970 base units and confirmed that it successfully suppresses the first 1–2 rings when paired with UBlocker WiFi/LAN models running on Raspberry Pi 3B and 3B+. This short delay provides just enough time for the UBlocker to disconnect blacklisted calls (both user and global lists) before your phone ever rings.


Note: There are at least 2 variations of these Panasonic phone systems.  


Important Note for Older UBlocker Models
If you are using an older UBlocker WiFi or LAN unit, you may still experience a partial ring on some blacklisted calls—even with the Panasonic KX-TGF970 system. If this happens, please contact us for upgrade options to ensure full compatibility.


[ Click here to purchase a Panasonic Base Unit Model KX-TGF970 (refurbished) from our website ]


Why Use Panasonic KX-TGF970 Base Unit + Ultimate Call Blocker Together 
The Panasonic KX-TGF970 includes built-in call blocking features such as:

  • A database of 14,000 pre-loaded scam numbers

  • Storage for up to 2,000 additional blocked numbers

While helpful, these features cannot compare to the UBlocker’s advanced technology, which includes:

  • A Global Blacklist of over 500,000 pre-recorded scam numbers

  • Unlimited capacity for user-defined blacklists

  • Advanced options such as Whitelist Mode and partial name/number blocking

In summary: For the best protection against unwanted calls, we recommend combining Panasonic’s first-ring suppression feature with the powerful call blocking capabilities of the UBlocker.