Caller ID numbers that start with '1' [telecom]

Lately, I've been having numbers show up on my cell phone's caller ID where the local exchange begins with 1. I thought 1, when it is used as the first digit in a phone number in the NANP denotes that the digits that follow are to be routed long distance. Has this changed?

Reply to
Alan Smithee, A.S.C.
Loading thread data ...

A dialing plan is different from a numbering plan.

The world numbering plan assigns prefix 1 for NANP numbers, so a number that shows up with a leading 1 is just a full phone number.

The dialing plan in North America is (oversimplifying a bit) 1+10 means a ten digit NANP number, while 7D is an NANP number where the first three are the same as yours.

I've noticed the same thing, that CLID often has the leading 1, which makes sense since on calls from other countries, it starts with whatever the country code is, like 44 for calls from the UK. My telco also sometimes sends CLID that starts 1011-1NXX and is truncated, which I think is just a bug in the switch programming.

Reply to
John Levine

That's not quite how I read his post. From "the local exchange begins with 1", I thought he was saying that the calling number displays as NXX-1XX-XXXX instead of the expected NXX-NXX-XXXX. If so, I it could just as well be Caller ID spoofing by a junk caller.

Bob Goudreau Cary, NC

Reply to
Bob Goudreau

Teleslime with the right equipment can send whatever CID they like.

For example, a few days ago I got a call where my CID showed "123 456 7809". I didn't answer and it hung up on my answering machine.

Reply to
Rich Greenberg

In Message-ID: , Mark Smith asked:

Answer: No. In the North American Numbering Plan, both the area code (NPA) and the central office code are of the form NXX -- where "N" represents any digit except zero or one ("X" represents any decimal digit).

No legitimate North American phone number will have a 1 at the beginning, whether it is a ten digit number or a seven digit number.

Reply to
Michael D. Sullivan

I believe that 1XX-XXXX numbers have been used to identify dedicated circuits, but none of those can make POTS calls.

Reply to
John Levine Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.