Path: utzoo!telecom-request Date: Mon, 10 Jun 1991 13:10:13 EDT From: KATH MULLHOLAND Newsgroups: comp.dcom.telecom Subject: Re: Modification of Ringback Tone by Subscriber Apparatus Message-ID: Organization: TELECOM Digest 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 445, Message 1 of 12 Lines: 24 I think Tom Gray was right when he said if a PBX gives you a double ring you're paying for the call. I've asked three telecom CO people this question and all agreed -- the last CO through which the call passed passes the ringing tone. That is true even on DID connections. If you get a double ring from a PBX it is because the PBX returned answer supervision and is supplying its own ring. Yes, when you hear the phone ring, it rings twice, but we all know the ringing the caller hears is unrelated to the ringing the phone creates, don't we? :-} As I understand it, there are a few reasons you can get double ring from a phone company CO. 1) a party line of more than two parties. 2) a step office will supply a variety of wierd ringing and other tones. There may be others, as well. This is all second-hand, but what was coming in these messages didn't agree with my understanding of how our PBX related to TPC, so I started asking questions. Kath Mullholand UNH, Durham NH