Path: utzoo!telecom-request Date: 8 Jun 91 03:22:43 GMT From: Dave Levenson Newsgroups: comp.dcom.telecom Subject: Re: Pet Peeve About Newer Modems (was Telephone Keypads) Message-ID: Organization: Westmark, Inc., Warren, NJ, USA 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 432, Message 6 of 7 Lines: 48 In article , forrette@cory.berkeley.edu (Steve Forrette) writes: > Since my switch will reliably take 36ms, I see no reason to not allow > me to dial at that speed. Anybody (Toby?) know why the newer modems > are handicapped/differently-abled in this manner? The noise picked up by a telephone mic, including some human voices, may contain brief bursts of energy that may be mistaken for touch tone signaling. Many touch tone signaling receivers are designed to reject tone signals shorter than 50 msec in an attempt to reduce their sensitivity to these false signals. Perhaps the modem makers are trying to prevent you from mis-dialing when using one of these switches. In article , jmason2@utcs.utoronto.ca (Jamie Mason) writes: > Also, I have heard of, but never heard officially, of a telco > tariff which requires that autodialers not retry the same number more > than ten times in a row automatically. This lead to: a) some > crippled terminal programs which won't do more than ten retries before > having to be restarted, and b) crippled hardware -- my DUoFone 195 (an > old Radio Shack gadget) has an auto redialer which keeps trying till > there's no more busy. But it will only try a maximum of ten times. > Of course, this is all obsolete now, in the days of Call Return, where > the Network does it for you. The reason they don't allow an autodialer to dial too many times or too rapidly is to prevent 'gridlock' in the network. If a bunch of people with auto-redial equipment are rapidly redialing each other and getting busy signals because the called party is also busy redialing, the network tends to block, and all with non-revenue calls! If your auto-redial equipment backs off a bit, it lets some of those calls reach you. Call*Return does not do its work by continually redialing, but by queueing a request in a database common to your switch and the called switch. This does not result in network blockage from busy attempts, as CPE rapid-dialing does. Dave Levenson Internet: dave@westmark.com Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave Voice: 908 647 0900 Fax: 908 647 6857