Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!tut.cis.ohio-state.edu!VAX1.CC.UAKRON.EDU!neoucom.edu!wtm From: wtm@uhura.neoucom.EDU (Bill Mayhew) Newsgroups: comp.dcom.modems Subject: Re: T1000 Message-ID: <1991May14.021143.10585@uhura.neoucom.EDU> Date: 14 May 91 02:11:43 GMT References: <42.282CCC07@zswamp.uucp> Organization: Northeastern Ohio Universities College of Medicine Lines: 38 Here is another reason to disable modem-based error correction. I've had instances where MNP4 modems were besieged by a telco trunk line that had a framing error due to clock sync-slip. While there was no audible glitch on the line, it caused a regular phalanx of "~r" to march across the screen at approximately 1 second intervals at 1200 baud. Unfortunately, the distant site was equipped with a 1200 baud modem, so I had little choice in the matter. Apparently their end was unable for some unknown reason to be able to accept smaller than the default MNP packet size (though I tried on my end to use short packets). The result was that virtually every packet was guaranteed of receiving a noise hit, and thus the modems locked up with the very first packet being transmitted over and over again ad nausium. In this case, the uucp g protocol could have gotten that data through (and did). It seemed that every time I dialed that particular site I got the same horrible trunk connection from HELL. I tried to talk to the telco about the problem but was stonewalled. It was just about impossible to talk to an engineer. When I finally did get someone with some technical knowledge I (admittedly politely) told that if the line were could enough to carry an aural connection then the line was good enough; period, end of coversation. Both of our sites eventaully got TB+ modems which cirumvented the problem with the noisy trunk. I was quite surprised that the connection routinely carried 1350 cps or faster connections _without_ compression enabled. The reduction in connection time allowed the cost of the modems to be recouperated in about three months time. Bill -- Bill Mayhew NEOUCOM Computer Services Department Rootstown, OH 44272-9995 USA phone: 216-325-2511 wtm@uhura.neoucom.edu ....!uunet!aablue!neoucom!wtm via internet: (140.220.001.001)