Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!texbell!vector!telecom-gateway From: fmsystm!macy@hal.uucp Newsgroups: comp.dcom.telecom Subject: Re: Special Information Tones Message-ID: Date: 28 Sep 89 09:05:41 GMT Sender: news@vector.Dallas.TX.US Reply-To: macy@fmsystm.UUCP (Macy Hallock) Organization: F M Systems Medina, Ohio USA Lines: 51 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 418, message 10 of 11 In article kitty!larry@uunet.uu.net (Larry Lippman) writes: >X-TELECOM-Digest: volume 9, issue 412, message 1 of 9 >In article carroll1!dtroup@uunet.uu. >net (Dave Troup) writes: >> Does anyone know what the recording alert tones are? You know-those >> dee-doo-DOO, "The number you have reached..." What are the frequencies >> to them. Ive NEVER been able to find out what those are. > These tones are called SIT (Special Information Tones). Their >purpose is to permit an automatic Call Disposition Analyzer (CDA) to >differentiate between a human voice and a recorded announcement, and >to categorize the type of recorded announcement. SIT Tone information follows: Special Infomation Tones (SIT) are a series of three tones at the beginning of intercepted call. These tones are used by call processing equipment to automatically identify the type of intercept the call has reached. SIT Tone type and usages Period Frequency Designation SSL LLL IC - Intercept - Vacant No. or AIS or etc. LLL LLL NC - No Circuit (Inter-LATA carrier) LSL HLL VC - Vacant Code SLL HLL RO - Reorder Announcement (Inter-LATA Carrier) LSS LHL #1 - Add'l Reserved Code SLL LHL RO - Reorder Announcement SSL HHL #2 - Add'l Reserved Code LLL LLL NC - No Circuit, Emergency or Trunk Blockage Where: Period-Duration: S=Short 274 msec L=Long 380 msec Frequency: L=Low 913.8 hz 1370.6 hz 1776.7 hz H=High 985.2 hz 1428.5 hz This information taken from a central office recorder/announcer installation manual ca. 1983. I believe SIT's are specified by Bellcore and/orr CCITT. I have heard SIT's used on international calls to several countries. Macy Hallock fmsystm!macy@NCoast.ORG F M Systems, Inc. hal!ncoast!fmsystm!macy 150 Highland Dr. uunet!hal.cwru.edu!ncoast!fmsystm!macy Medina, OH 44256 Voice: 216-723-3000 X251 Disclaimer: My advice is worth what you paid for it. Alt.disclaimer: Your milage may vary. Biz.disclaimer: My opinions are my own. What do I know?