Path: utzoo!attcan!uunet!pyrdc!netsys!vector!nobody From: jhf@cblpe.att.com Newsgroups: comp.dcom.telecom Subject: DMS-100 problem Message-ID: Date: 8 Nov 88 14:06:00 GMT Sender: chip@vector.UUCP Lines: 31 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu (TELECOM Digest Coordinator) X-Administrivia-To: telecom-request@vector.uucp (USENET Telecom Moderator) X-TELECOM-Digest: volume 8, issue 174, message 2 I remember reading about a known problem with DMS-100s. It had to do with a synchronization problem with one of the cards in the switch. The manifestation of the problem is an "occasional" single bit error that makes it barely tolerable to use a 1200 baud modem over the line and nearly impossible to use a 2400 baud. Unfortunately, the error rate is so low that it's undetectable using the "standard" tests that the craftperson performs in response to noisy line complaints. Apparently it's quite easy for the craftperson to figure out that card in question is flakey *IF* you can tell them the particular card to check. Then, it's just a simple matter of a board swap and you're back in business at 2400 baud. A friend recently moved to a new exchange and found that his modem won't hold carrier for more than 5 minutes at 2400 baud and gets lots of curly brackets (another symptom of the DMS problem) at 1200 baud. Repeated calls to Ohio Bell about noisy lines have gotten him nowhere ("But sir, when our technician listened to the line, he didn't HEAR any noise.") except that he was told that the switch in question was a DMS-100. Any info would be appreciated. Thanks, Jeff --- Jeff Frontz Work: 614/860-2797 AT&T-Bell Labs (CB 1C-356) Cornet: 353-2797 att!cblpe!jhf jeff.frontz@attbl.att.com Home: 614/794-3986