[comp.dcom.telecom] Two CLASS Calling Services Questions

judice@sulaco.enet.dec.com (Lou Judice @KYO / DTN 323-4103) (02/25/90)

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

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.]

Ooops, more than two questions!


Thanks,
Lou Judice
Digital Equipment Corp.
Piscataway, NJ
(201 | 908) 562-4103


[Moderator's Note: Also please note the special issue Saturday on
CPID/ANI.  Although sending a blocking code can be done, as Vic Toth
points out, you are assuming one telco will *honor* the blocking code
sent by another telco. 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.  You
will be able to store it in your list of numbers you won't accept
calls from, but when you review the file of same, while other numbers
will be spoken to you, those that had blocked ID will be termed
'private entry'.  PT]

deej@bellcore.bellcore.com (David Lewis) (02/26/90)

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."

jhaller@cbnewsd.att.com (john.h.haller) (03/01/90)

I do not know what carriers will tariff, but I have a copy of the 5ESS
Switch Feature Handbook, AT&T select code 235-390-500.  The version I
am looking at is copyright 1988, so there may be a more recent
publication.  In the 5E6 generic, which is described as information
for planning purposes, not commitment to deliver any particular
features, there is a feature that allows selecting the caller ID
displayed to be either ANI (billing number) or calling party number,
either as the preferred or exclusive choice.  Note that 5E6 has not
been released yet.  Also listed under this feature is the capability
to block originating information on a per-call or per-subscriber basis
(for at least ISDN origination, it was not clear if both options are
supported on non-ISDN lines).

In order to have inter-LATA calling line ID, the end to end signalling
must be Signalling System 7.  For local calls to have calling # ID,
SS7 must be deployed locally.  I do not know how many, if any, local
switches are connected to long distance companies, which would prevent
inter-LATA Call ID.


John Haller jhh@ihlpl.att.com