Path: utzoo!attcan!uunet!cs.utexas.edu!uwm.edu!bionet!hayes.ims.alaska.edu!accuvax.nwu.edu!nucsrl!telecom-request From: barefoot@hobbes.ncsu.edu (Heath Roberts) Newsgroups: comp.dcom.telecom Subject: Re: Advice on ANI Hardware Wanted Message-ID: <13827@accuvax.nwu.edu> Date: 20 Oct 90 16:20:56 GMT Sender: news@accuvax.nwu.edu Reply-To: Heath Roberts Organization: NCSU Computing Center Lines: 70 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 747, Message 6 of 7 >> Any switch on the face of >> the planet can be adapted for ANI. >Then why haven't they? Why haven't they offer ANI service as >they have done with call-waiting, call-forwarding, and etc? First, this statement should be qualified to read "any digitally- controlled switch..." After all, there are still some step and crossbar switches out there. The problem isn't so much with individual switches. It's with connecting all these switches together. Call forwarding can be done to any number from your local CO -- it just out-dials the number your phone is forwarded to on a trunk line (unless it handles the line the call is forwarded to directly) and the call is completed like any other. The switch just connects the incoming call with the outgoing trunk. Call-waiting is not available in all areas, only those that support it. Supporting it generally means that both serving switches, regardless of manufacturer, have SS7 (Signalling System 7), which defines a protocol for one switch to say "tell me when number XXX-XXXX is available, I have a call waiting on XXX-XXXX. When the line becomes free, the second switch calls back and says "Yo: that call you had waiting? I can complete it now. Please ring your party..." Likewise with CLID: instead of a switch just saying "this call is for XXX-XXXX", SS7 defines a protocol like "I have a call for XXX-XXXX from XXX-XXXX (or maybe from "calling number blocked") and the caller's name is so-and-so (or once again, maybe "the caller asked me not to identify him"). So if the switches your call is routed through don't support this kind of signalling protocol, it's not going to work... Availability of a common protocol is the primary technical reason ANI/CLID doesn't work everywhere, but another big reason is that individual state PUC's are not allowing such service to be provided. Here in North Carolina, the State Attorney General has declared that CLID is illegal... >> CLASS, on the other hand, is relatively new technology requiring SS#7 >> signaling between participating offices. Among its many features is >> the infamous Caller-ID. >Could you please elaborate on CLASS? Common Local Area Signalling System defines features like Call waiting, Ring-again, Call forwarding, Calling line ID, etc ... The features are not themselves new, nor it the standard, but it's just now being implemented across networks. >> While there has been some interchanging of these terms on this forum, >> it would be well to realize that ANI and Caller-ID are not one and the >> same. >What's the difference between ANI and Caller-ID? From my understanding, ANI is not always available in real time. I think originally this was available on incoming WATS (800) lines so businesses could see where their calls were coming from, and showed up on the bill at the end of the month. Caller ID occurs in the first half-second or so when the called phone starts to ring. Of course, ANI has been improved somewhat, and does work in real-time now, but only from switches that support SS7. Heath Roberts NCSU Computer and Technologies Theme Program barefoot@catt.ncsu.edu