Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!gatech!rutgers!netsys!vector!nobody From: chen@cunixc.cc.columbia.edu (Bill Chen) Newsgroups: comp.dcom.telecom Subject: Modem noise Message-ID: Date: 11 Dec 88 00:28:10 GMT Sender: chip@vector.UUCP Lines: 27 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 8, issue 198, message 3 We've been having progressively worsening noise problems on our dial up modem pool for our PBX. It seems to occur mainly at nights and consists mostly of "{" characters. These { comes periodically, about 1 every 30 secs to 2 minutes. Sometimes we get bursts of noise too. We have checked the modems, Racal Vadic VA4492Es and the PBX, IBM/ROLM 9751 and neither seem to be the cause. We don't run error correction such as MNP although our modems are equipped to do it. The noise seems to be generally one way, from the host side to the terminal side. Although recently, noise does seem to get to the host too. Telco people haven't been too helpful. Calling 611 is useless. Trying to talk to someone technical within the telephone company is next to impossible. Are there any people out there that may have seen this problem? I have been told by some people that there might be some notch filters that can cause this kind of noise. I don't know much about telephony things, but maybe someone out there in netland can shed some light. Thanks in advance. Bill Chen -- _____________________________________________________________________ William Chen chen@cunixc.cc.columbia.edu Network Planning 854-7593, 854-2455, 280-2455 Columbia University