Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!wuarchive!mit-eddie!uw-beaver!sumax!halcyon!ralphs From: ralphs@halcyon.wa.com (Ralph Sims) Newsgroups: comp.dcom.modems Subject: Re: USR HST troubles Keywords: old hst uucp Message-ID: Date: 29 Aug 90 21:52:43 GMT References: <2256@sud509.ed.ray.com> Organization: The 23:00 News Lines: 46 heiser@tdw201.ed.ray.com writes: > I know this isn't the optimal modem for this application .. but I can't > afford a Telebit right now (and they have big problems with low-speed > modems trying to connect). Ahem. I believe it's the low-speed modems that have the problems. I find that some EVEREX 1200's, PROMETHEII (whatever the plural is of PROMETHEUS), and AVATEK's generally have difficulties. A few things can make life a bit easier. If the Telebit answers with its PEP tones first, some modems get confused by the sequence and disconnect; this can be overcome by having the calling modem use S9=20 and S10=20 (*). These settings hold them online for 20 seconds when carrier drops, which may be what they think is happening. setting S7 in excess of 45 seems to help at times. USR's (and maybe some others) may have a register that allows the modem to detect a 'voice' call. Don't believe it! The Telebit's PEP tones are far from a 'voice' (unless you're Bill the Cat) and those that use this scheme will hang up on it (maybe an X7 register for the USR HST?). This 'feature' should be against the law :-) . Aside from the strange answering sequences, another thing gets in the way: MNP. Yep, that thing that we like to use for error-correction at times. Again, referencing the above-mentioned modems, the MNP 'handshake' routine can throw things for a loop. Turn MNP off for low-speed connects, especially if your users are mainly interested in reading text and not file transfers. I have a ZOOM PC2400 that performs flawlessly when I do these things and craps out when I don't. Data communications is a black art. > Any suggestions would be welcome. If it won't work, I'll just lock it > at 2400 and forget about 9600-HST ... and get a Telebit as soon as I > can (anyone have one for sale at a good price?) Contact uunet for their prices--I don't think many can beat them. Larry Snyder (nstar) and I tried HST's for UUCP and I gave it up as a lost cause (although U.S. Sprint loved it!). ~345cps was not my idea of a good time, especially at ~US$6.00/hr. with a backbone feed. (*) I also use these settings on the Telebit to take care of things like call-waiting on the other end, etc. This trick also does a good job of defeating call-waiting on outdial, but both ends need to co-operate. -- No matter who you elect, the Government still gets in.