Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!pprg.unm.edu!hc!lll-winken!netsys!vector!telecom-gateway From: goldstein%delni.DEC@decwrl.dec.com (Fred R. Goldstein dtn226-7388) Newsgroups: comp.dcom.telecom Subject: Re: Calling Party ID (questions answered) Message-ID: Date: 20 Mar 89 15:03:19 GMT Sender: news@vector.UUCP Lines: 44 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 9, issue 100, message 6 of 7 With regard to the capabilities of ISDN-provided CLID, here are what I think are answers to John Nagle's questions. >1. What happens when a call is originated from a PBX extension? Is > the number displayed just the identity of the outgoing PBX trunk? In many cases, PBX trunks today all give ANI for the listen DN of the PBX, not themselves. >Even assuming a PBX wants to cooperate and pass internal extension numbers > outward, is there a defined interface for this? Yes. There is provision for caller-provided ID, so that the PBX feeds the extension number into the public network. The public network may or may not screen this to see that it's a number belonging to that PBX. I think unscreened numbers are duly noted as such, though. (I don't recall.) >What happens when the > outgoing trunk has is outgoing only and has no telephone number, which > is not that unusual? No matter; some number is ANI'd. Typically the LDN but sometimes a different number. >2. What about inter-LATA calls? Which vendors pass the caller ID through, > or plan to? Will the FCC mandate that caller ID be passed across > long distance carriers? I doubt the FCC will mandate anything, but since AT&T already provides ANI and the others will have the capability, I'd expect it to be common among the facility-based carriers. >3. What about international calls? Eventually. Maybe, depending on country. No inherent reason why it's not possible, but regulatory concerns may exist. >4. Can the receiver distinguish "caller ID suppressed" from "caller ID > not known"? I _think_ that's possible, but I'm not sure. For example, if it is suppressed, there might be a notice in place of the number. >5. Is someone working on a modem that understands caller ID signals? I don't know about the current analog form, but in the ISDN world, it'll be the norm, since it's just another information element in the protocol (DSS1). fred [disclaimer: I speak for me. Sharing requires doctor's note.]