flash@clmqt.marquette.Mi.US (Gary Bourgois) (08/15/89)
I have a modem problem that is driving me insane. I operate one of two USENET sites in Marquette, Michigan. I have a friend in Hamburg, West Germany, with whom I have been communicating over various networks for 7 years. We determined that the most cost effective method of communication is for him to call my system directly to transfer mail. The problem is that at 1200 or 2400 baud he can _not_ get a reliable connection. In fact, _nothing_ but garbage. My system is user-supported so we cut corners, using donated (or the cheapest possible) hardware. I thus have three different brands of modems, but all yield the same results. At our sister site, a similar situation exists. However, one of the other site's modems (a rather inexpensive CMS-2400BX) provided error free communication between Marquette and Hamburg. When the other site switched things around and put the CMS on another of his phone lines, my German friend found the good modem on his own before we could tell him about the swap. This arrangement involved forwarding mail across town, workable but not ideal. My friend decided on his own that he would purchase the CMS modem, and we would reinstall it on my machine, and the other site would install a NEW CMS modem to replace the old one. To my consternation, after I installed the CMS modem on one of my lines, my German friend tried calling in and the result was THE SAME TOTAL GARBAGE on the modem that worked flawlessly across town. Thinking that the problem has to do with audio level, I called the phone company. While they said they would come here and run level checks, I was informed that since I am only 4 blocks from the central office, while the OTHER site is three miles from the CO, and that the DMS-100 switch they use automatically compensates, audio level is the unlikely cause of the error rate. The problem seems peculiar to Germany. I did have a user call from Amsterdam, with no problems. We have heard about an "echo barrier breaker" tone (1200hz) which is supposed to be issued from some modems to stop the "confusing" echos caused by propagation delays. Why this modem worked across town, even when swapped from one line to another, and does not work here is a total mystery. I am wondering if anyone out there runs 2400 baud between the Federal Republic and the USA, and what hardware they use. He can connect fine to MCI-MAIL, and other USA commercial services. Yeah, I know. "cheap modems"... I thought that also, but why the thing only works three miles west of here (farther from the CO)... Well, that is the PERPLEXING MYSTERY of the week. Any help would be appreciated, please email to the address below. Thanks! -- ------------------------------------------------------------------- | Gary Bourgois, ...rutgers!sharkey!lopez!flash (flash@lopez.UUCP) | | Nationwide Amateur Radio NIGHTLY after 0200z on 3950 KHz | -------------[ WB8EOH = The Eccentric Old Hippie ]-----------------