Path: utzoo!utgpu!watmath!clyde!att!osu-cis!killer!vector!nobody From: early%css.DEC@decwrl.dec.com (Bob Early CSS/NSG dtn 264-6252) Newsgroups: comp.dcom.telecom Subject: Re: Modem Noise Message-ID: Date: 12 Dec 88 13:30:05 GMT Sender: chip@vector.UUCP Lines: 52 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 199, message 5 >From: chen@cunixc.cc.columbia.edu (Bill Chen) >Subject: Modem noise >Date: 11 Dec 88 00:28:10 GMT >We've been having progressively worsening noise problems on our dial : : >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. Noise is just that. Random impulses being picked up by the telco lines as they pass through an 'electrically' noisy environment. Some such causes are elevator shafts; rotary machines (a such as motors, generators, and 'dynamos'), other wires such as HVAC transmission, poor grounding of the computer vequipment,; archaic telco equipment (step-and-select strowger swithches, etc). If you have the option of using MNP, use it. >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. With most telephone companies you must be persistent,and give the impression that you *know* it is in the central office, and they *must* fix it. (I personally had a defective phone service, and it took three months to get it fixed.) >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 This is a common problem with BELL 212A implementations. The "{{{" or 'curly bracket' isn't *really* the true character. The curly bracket is the modems interpretation of the noise impulses it is seeing, in much the same manner if you privide a string of randoms 'ones and zeros' to a computers operating system you will see many 'odd' charcters as the CPU attempts to 'parse' the charcters. >Bill Chen Bob Early "Long live the Scholar-Plus" [Moderator's note: The phone company seems to think their customers are all dumb. Remind me to tell you about the time I spent several days convincing Repair Service that a bummed out interoffice trunk between Chicago-Kenwood and Chicago-Wabash was not '...a problem with my instrument, which will require our representative to visit your premises a week from next Tuesday...'. I was finally able to sneak in through the 'back door' and speak to the supervisor in night plant about two in the morning. I held up the troubled trunk on one of my lines while he went in the frames, found me and busied it out. But should customers have to do this sort of thing for Bell? Pat Townson]