Path: utzoo!telecom-request Date: Sat, 4 May 91 00:06:57 GMT From: "Steven S. Brack" Newsgroups: comp.dcom.telecom Subject: Re: Caller*ID From US PBXs Reply-To: "Steven S. Brack" Message-ID: Organization: Nyx, Public Access Unix (sponsored by U. of Denver Math/CS dept.) Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 331, Message 4 of 10 Lines: 62 In article goldstein@delni.enet.dec.com (Fred R. Goldstein) writes: X-Telecom-Digest: Volume 11, Issue 301, Message 3 of 10 > In article , sbrack@isis.cs.du.edu > (Steven S. Brack) writes... >> (1) What will Caller*ID show as my number? >> (2) What does E911 get as my number? >> (3) What would an Ohio Bell trace show as my number? > In general, if you are behind a PBX, then the public network knows > only about the PBX trunk or group you're on. In some cases the trunk > will return a hunt pilot, in others its own number, depending upon how > it's set up. But none of the above three services can know your > extension number, even though it can be dialed directly. Extension > info is passed from the CO to PBX on incoming calls (DID service) > only. Ohio State's PBX is an NT SL100. It is possible to dial a 7D number from outside the system & reach my phone, or almost any other. I apologize if I wasn't clear about the system OSU uses. OSU actually bought Ohio Bell's old 42X- exchange CO, and uses it for both its switch and its offices. Funny seeing a windowless building with offices in it. From my conversation with their switch engineer, OSU has T1 to Ohio Bell, and a Litel POP. It's not your "typical" PBX system. > On Centrex, it would show the number for your extension. > Centrex-CU did deliver your extension number for billing purposes, > 911, etc. (If they had 911 back then!) This was done via a data link > from the switch to the CO, reporting which extension had seized which > trunk. > When the stepper went away, this service was made available to newer > PBX users, under the name "Automatic Identified Outward Dialing" > (AIOD). Many PBXs of the day, such as Dimension, supported it. > I'm not sure if modern PBXs even support AIOD. > AIOD would make caller*ID behave in the expected fashion. I know local services getting ANI don't get the "true" number, and (after much cajoling and pleading) the ONI read back to me by Sprint (we switched to them a few weeks ago -- Sprint has some network interface problems with our lines, but that "will be fixed in the next software upgrade") was for the trunk I was on, not my actual number. Our system occupies the entirety of the 292- & 293- prefixes, with about 1000 extra internal numbers not directly reachable from the Bell side. PS: I had an interesting tour of OSU's telecom facility. They have great plans for the future, including full ISDN and other goodies. Personally, I'm waiting for Ohio Bell to sue for "unfair competition" 8) 8) Steven S. Brack sbrack@nyx.cs.du.edu I am not speaking for the Ohio State University. Now, if only I could convince them of that 8)