[VoiceOps] Calls coming up as spam on mobile carriers

Shawn L shawn at rmrf.us
Fri Jul 8 13:00:05 EDT 2022

We're having a strange one at $dayjob.  When one of our customers (in this
case a hospital) calls a patient back on a cell phone, the calls are coming
up with SPAM? in the caller id.  It seems to be happening with both Verizon
and AT&T.

We've checked the the DIDs in question have and are sending the proper
caller id, checked the Neustar database, etc. and can't find anything
that's missing.  These are TDM calls.  They come in over multiple TDM PRIs
and leave toward an AT&T tandem on a legacy TDM trunk group, so there's
really no way to do STIR/SHAKEN call attesting.

Our switch vendor (Ribbon / Genband / Nortel)  also mentioned that they've
had other clients with the issue and it seems to be limited to calls placed
to mobile carriers.  Another telco was able to find an AT&T portal to
register the numbers as legitimate, but it only lasted for about a month
before they had to do it again.

I haven't researched where at AT&T they might have entered the numbers, but
that doesn't seem like a valid option for a hospital with a thousand

Just wondering if others have seen this, and if anyone knows of a way to
resolve it.

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