Check the calling party's number against the Open CNAM database (use a command line utility like c URL on Linux/OS X as shown, or Invoke-Web Request in Power Shell on Windows).If the data is accurate, there's not much you can do because the carrier on the far end is doing it wrong.Unsurprisingly, I did find that the ANI was defaulting to the dialing device's internal DN (Call Manager), so I programmed the external phone number mask for the line appearances where it was missing, but the issue did get me thinking.
Obviously, the called party doesn't see the Caller ID text presented by the calling party's carrier, the database dip always occurs on the far end. It's not like I'm going to ask for LOA from the called party. Is it just a crapshoot and different for every carrier?That scenario should be covered by pulling from public CNAM data.The Wikipedia article on E911 makes it sound like ALI databases and MSAG are separate databases, but sorta joined at the hip. Each telco will use this data to keep their information in check but also overwrite it in cases.And each ILEC/CLEC is responsible for maintaining their own. E911 does this because a company could have PRIs at one main branch and extend those across the state.So the teleco will overwrite the ALI information and correct for that change. The originator and their carrier do not send the CNAM, only the CID.
It is up to the called party's carrier to do a lookup of the CNAM that matches the CID - if they choose to do it.
(I'm assuming that the number is the CID and the text is the CNAM, but I didn't know that differentiation until I read your post : P)There are some cases where we do pass it along to the telco we hand off to on SS7 but it still isn't guaranteed it'll be at the term telco or that they'll use it.
I just know what I see on our SS7 IAM messages out. The Caller ID Name look-up is done by receiving carrier.
Go to Online and enter in your URL in this format (looks like E.164 addressing): If there is an entry in CNAM, your response will have a "Response Body" with the result from the database. If there was no response, you'll only get a header back containing an HTTP 404 Not Found.
There could be emergency services implications of CNAM not being uptodate too if they cannot locate your address via the database.
Our experience is the receiving carrier does not always use CNAM lookup services either.