kmcvay@icgnu.UUCP (Ken McVay [1B Systems Management]) (08/10/90)
I've been banging my head against the wall here, trying to make two T2500's behave themselves.... The modems are on each end of a leased phone line, and they have never really performed reliably. I'm unfamiliar with the differences in operation when using leased lines instead of dialup, and would appreciate some pointers, particularly concerning flow control. The modem at this end is set as default AECM, with the following exceptions: S07=255 S41=002 S50=255 S51=005 S55=003 S101=001 S105=000 S110=001 S111=030 S255=000 Given the present performance (ie nearly useless most of the time) I have no problem starting over at both ends.... The systems are running SCO Xenix 2.3.2, and both are using Wyse smart port cards (don't know which ones just yet - I'm new around here). Any and all helpful suggestions gratefully accepted!
bob@semantic.UUCP (08/10/90)
Ken McVay writes: > I've been banging my head against the wall here, trying to make two T2500's > behave themselves. The modems are on each end of a leased phone line. > I'm unfamiliar with the differences in operation when using leased lines > instead of dialup, and would appreciate some pointers, particularly > concerning flow control. > The systems are running SCO Xenix 2.3.2, and both are using Wyse smart port > cards Well I'm not familiar with leased lines but I am familiar with T2500s, SCO Xenix 2.3.2 and smart cards. Since your running Xenix I assune you are using some kind of 386 or 486 PC clone. Probably a Wyse? These usually come configured with a stand PC RS232-C serial port. Every good clone should. My first suggestion is to try running your modems off of these serial ports rather than the smart ports. This will eliminate a whole level of guessing and flow control! UUCP uses XON/XOFF characters in its protocol and the modem uses it for flow control; this creates a conflict. However the TBITs know this and work with it. But your smart card is sitting there in the middle! And it can't figure out what the heck is going on. So first off; Get off the stupid smart card for a while until you get everything else worked out. I am also currently running SCO Xenix 2.3.2, with a T2500 on my (dumb) serial card and the default (XON/XOFF) flow control works fine. (Except when doing UUCP with slow modems; but that's a different story) > I'm unfamiliar with the differences in operation when using leased lines Now this sounds like there would be a few basic registars to set and I bet Telebit Tech Support could tell you what they are. However here is my standard dialup configuration (For T2000s & T2500s): (The ones with stars(*) I think are applicable) * &f Reset Modem * e0 Echo off; Don't need a getty on our case. * q6 Be quiet, unless your asked x14 Notice when the line is in use 38=20 Standard delay before disconnect * 45=255 Enable remote access * 48=1 Use eight bit comparison * 51=5 19200 baud Interface speed 52=2 Reset on disconnect * 54=3 Standard break interpertation 61=25 Low speaker volume * 66=1 Lock interface speed 92=1 PEP tones last * 110=1 Enable data compression * 111=30 Use UUCP protocol * 131=1 Data carrier detect when data carrier detected * &w Save in NVRAM A few notes on your current configuration: S07=255 (The default of 40 should be sufficient, See S101 description) S41=002 (This is a leased line, why bother with an inactivity timer?) S50=255 (Correct) S51=005 (Correct) S55=003 (Worried about +++ in the data stream?) S101=001 (The other is set to 2, right?) S105=000 (I don't understand the purpose of this) S110=001 (Correct) S111=030 (Correct) S255=000 (This is the default) -- Good Luck! -- Robert A. Gorman (Bob) bob@rsi.com Watertown MA US -- -- Relational Semantics, Inc. uunet!semantic!bob +1 617 926 0979 --
det@cimcor.mn.org (Derek Terveer) (08/15/90)
Ken McVay writes: > [...] UUCP uses > XON/XOFF characters in its protocol and the modem uses it for flow control; Er, don't you mean that xon/xoff are not treated in any special way, i.e., for flow control, and that they are valid data bytes. The telebits may be set (by changing the values of specific registers) to use a variety of flow control methods, including rcs/cts and xon/xoff. It is typically set to xon/xoff by default for non-uucp users. > this creates a conflict. However the TBITs know this and work with it. Huh? > I am also currently running SCO Xenix 2.3.2, with a T2500 on my (dumb) > serial card and the default (XON/XOFF) flow control works fine. > (Except when doing UUCP with slow modems; but that's a different story) I don't believe that this is true. Most likely you are either not sending binary files or your uucp is sending and resending a lot of packets. Change to hardware flow control if you can. What kind of throughput are you getting with xon/xoff flow control enabled? > However here is my standard dialup configuration (For T2000s & T2500s): > (The ones with stars(*) I think are applicable) > > * &f Reset Modem > * e0 Echo off; Don't need a getty on our case. > * q6 Be quiet, unless your asked > x14 Notice when the line is in use > 38=20 Standard delay before disconnect > * 45=255 Enable remote access > * 48=1 Use eight bit comparison > * 51=5 19200 baud Interface speed I wouldn't recommend this unless you are really sure your serial port can handle 19200 without dropping characters. > 52=2 Reset on disconnect > * 54=3 Standard break interpertation > 61=25 Low speaker volume > * 66=1 Lock interface speed > 92=1 PEP tones last > * 110=1 Enable data compression I wouldn't recommend this unless you are sending a lot of UNcompressed files. derek -- temporarily: derek@cimcor.MN.ORG as soon as i get my pc back: det@hawkmoon.MN.ORG
larry@nstar.uucp (Larry Snyder) (08/16/90)
We run all our modems locked at 19.2 kbaud with hardware flow control only
and have no problem with any tranfers (uucp, zmodem, ymodem, sealink, etc..)
--
Larry Snyder, Northern Star Communications, Notre Dame, IN USA
uucp: iuvax!ndmath!nstar!larry -or- larry@nstar
Public Access Unix Site (219) 289-0282 (5 lines/PEP/HST/Hayes-V)datri@convex.com (Anthony A. Datri) (08/16/90)
>Change to >hardware flow control if you can. Many say this; none say how to do it. . -- beak is beak is not
ralphs@halcyon.wa.com (Ralph Sims) (08/16/90)
larry@nstar.uucp (Larry Snyder) writes: > We run all our modems locked at 19.2 kbaud with hardware flow control only > and have no problem with any tranfers (uucp, zmodem, ymodem, sealink, etc..) I'll have to second this (all of my _one_ modems). The machines I'm dialing in to are using 9600 DTE rates (or are floating the baudrate--not sure how you *nix-er's do things), and I get ~770cps with batched news and around that for zmodem transfers. I'd expect to get higher throughputs with their ports opened to 19.2. Would it be a good guess that uucico enjoys an 80% effective throughput (20% overhead with 3 windows?)? Couple that with phone line degradation and ~1100cps may be max. Remember the days when we tried uucico with USR HST's at 38.4? ~340cps with a tailwind (my phone bill STILL hasn't recovered. :-) -- Of all the things I've lost, I miss my mind the most...