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From: nvuxr!deej@bellcore.bellcore.com (David Lewis)
Newsgroups: comp.dcom.telecom
Subject: Re: Two CLASS Calling Services Questions
Message-ID: <4464@accuvax.nwu.edu>
Date: 26 Feb 90 15:09:24 GMT
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X-Telecom-Digest: Volume 10, Issue 130, Message 8 of 9


In article <4345@accuvax.nwu.edu>, judice@sulaco.enet.dec.com (Lou Judice 
@KYO  DTN 323-4103) writes:
 
> How exactly does the Caller*ID box behave when calls are received from
> outside the area code and/or exchanges that do not transmit the ANI
> information?

Lessee... a little background.

For the uninitiated, the pertinent geographic division is a LATA, a
Local Access and Transport Area.  Within LATAs, local exchange
carriers (LECs) are permitted to carry and switch calls; across LATA
boundaries (with some minor exceptions), calls must be routed through
an interexchange carrier (IC).

Therefore, the signaling information, which includes the calling party
number used by the CLASS features, must also be routed through an IC
for inter-LATA calls.

Currently, there is no implemented common channel signaling
interconnection between LECs and ICs (although I just read of a trial
down in SWBT/BellSouth lands).  Therefore, any interLATA call will not
have available the calling party number, and the box displays a code
which means "calling party number unavailable".

> Eventually, will Caller*ID work across area codes???

Again, the pertinent area is really "across LATAs", and the answer is
"yes, eventually".  Technical requirements and possibly standards for
common channel signaling interconnection need to be worked out, and a
whole slew of business arrangements have to be negotiated.

> For those states with per-call Caller*ID blocking, is the Caller*ID
> box display disabled or is the ANI not transmitted at all? Ie., is
> Call*Trace and Return*Call disabled as well???  [If not, then it would
> seem easy to get the caller's # by returning their call, and checking
> the number on your next bill.]

As far as I know, the blocking feature (as the moderator stated) sets
a privacy indicator in the common channel signaling message.  The
calling party number is still sent.  If the terminating end office
sees the privacy indicator sent, it doesn't send the calling party
number to the CPE.  It does, however, still have the number, and call
trace and call return should work.  Yes, you could return the call and
note the number on your next bill, provided it's an itemized call and
not an unlimited usage call or a message unit call.

> [Moderator's Note: ...  And the word we are getting from Illinois Bell
> is that (once CLASS is implemented later this year) if the number is
> otherwise unavailable then attempts to 'return call' will fail.]

If the calling party number is not sent to the terminating end office,
yes (as seems obvious), you won't be able to use "return call" or
"call trace".  If the calling party number is sent, but the privacy
indication is set, I believe you can still return and trace calls, but
I'm not certain.


David G Lewis					...!bellcore!nvuxr!deej
	(@ Bellcore Navesink Research & Engineering Center)
			"If this is paradise, I wish I had a lawnmower."