[cisco-voip] Caller ID.

[Mark R. Lindsey]

On Mar 2, 2005, at 1:03 AM, John Osmon wrote:
> It turns out that we'd been sending calls without tagging them
> as 'national'.  A Verizon tech sent me an SS7 trace that showed
> the "Nature of Address Indicator" was set to 'spare' and said that
> their Lucent gear couldn't deal with that -- even though the proper
> phone number for the caller-id info was available...

"Spare" means that you were sending the number without fully specifying
what format the number was encoded in -- i.e., you sent a code for NAI
that didn't have a defined meaning. It'd be something like sending an IP
packet without specifying a defined value in the 8-bit protocol part of
the header, then just hoping the receiving equipment figure out that you
meant TCP.

Sure, they could have made a guess that you were sending the national 
number
party, and kept going -- but that's asking a lot. In a sense, they did 
just keep
going -- they could have just rejected the call altogether.

> was I in the wrong for not tagging the calls?  If so,
> why did everyone else (apparently) assume it was a 'national' number?

You were sending signaling that was malformed. It's possible that some 
of
the other equipment was reading only the numbering plan (NP), and wasn't
even using the NAI part to make the translations/routing decision. The 
Lucent
gear was probably running in a "safer" mode where it validated every 
field.

It may have nothing to do with any telco's policy, and more to do with 
the
programming standards of the guy that wrote that chunk of the caller-ID 
handling
code for Lucent.