I have two landline telephone numbers available here. One is thru Time Warner, the other is a netTalk VoIP line. Also a cell phone, which I have had for a number of years (with the same number).
Very seldom I call myself! But a week ago as a demo I called the TW number from the cell phone, and found, while the number displayed was correct, a name was displayed that I have never heard of. Normally, I would expect on a call from a cell phone to have possible something like the city and state for the phone.
Today I reran the test, and the display name is still screwed up on the TW number. However, in calling the netTalk number, it displays "WIRELESS CALLER" -- which is what I would expect.
Where might this information get corrupted? (Or, where should I direct a complaint?)
Oh, I also realize that I can (on some phones) enter a name in the phone's directory, and have it override the provided name for incoming calls. That is not the case here!
Welcome to the wonderful world of CNAM lookup. The CNAM data doesn't transfer along with a call, only the calling number does.
Basicly, each telco keeps a database of lookups of CNAMs. When a call connects and the telco terminating the call needs to send callerID data, they need to do a database dip out of a variety of sources to get the proper data.
The ILECs probably are the most correct, as they have a huge database of their own CNAM data, and are willing to pay the CNAM database dip fee from a CLEC or other ILEC to find the CNAM data to feed along. (wholesale rates of these are on the order of $0.002 to $0.006 a database dip).
Now, a CLEC may not feel like paying for the database dip, so they may just look at the flag on the # if it is a mobile number or not, and display "WIRELESS CALLER" and figure that nobody on mobile cares about caller ID delivery, because everybody has their contact books all setup for anybody they care about.
Or, they may cache old database dip data they got ages ago and stored away so they didn't have to pay for new lookups on the number.
Or a CLEC may cheap out by going to something like listyourself.net, which takes some public info, some user submitted data, to give data out of questionable value.
There is no "central" database of CNAM data, unlike some of the other telco style data that LECs have to subscribe to. But the terminating telco may do a variety of things, from ILEC style full-proper lookups to tossing up random data.
As to fixing up things. You could figure out where your such-and-such telco gets its CNAM data, and try to contact that company to see if you can get your data updated there properly. Or maybe your LEC can do that for you. Ie. I'd expect the CLEC I use to go out and do that for me, but that is just how they operate. I would expect an ILEC to do so, but only after explaining myself 20 times trying to get to the right person that can do it.
If you want to confirm what a dip will return for a given number, I'd suggest opening an account with
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They require a minimum deposit of US$10 to open an account, and charge only $0.004 per dip (so $10 buys 2500 dips).
If the dip returns different info than what TW showed, you'll know they are at fault (for not doing a dip). If it returns the same info you know that your cell provider is at fault.
One can find a number of other similar providers via a net search, but they required the smallest initial outlay the last time I searched.
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