Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!uunet!dialogic!paul From: paul@dialogic.UUCP (The Imaginative Moron) Newsgroups: comp.unix.i386 Subject: Re: uucico problem with flow control Keywords: uucico flow control 386ix Message-ID: <922@dialogic.UUCP> Date: 15 Aug 89 20:15:06 GMT References: <208@bulus3.BMA.COM> Reply-To: paul@dialogic.UUCP (The Imaginative Moron, aka Joey Pheromone) Organization: Dialogic Corp., Parsippany, NJ Lines: 57 In article <208@bulus3.BMA.COM> haugen@bulus3.BMA.COM (John M. Haugen) writes: >I recently have been having problems with uucico having problems receiving >large files from my news feed. When run with Uutry, I see bunches of >"alarm " messages and eventually the transfer fails. > >My suspicion is flow control is not being used/set up correctly by uucico. >This in turn is causing a loss of data. > > [ stuff about using XON/XOFF for flow control ] > >John M. Haugen Domain: haugen@BMA.COM >Bull Micral of America UUCP: ...!uunet!bulus3!haugen >1970 Oakcrest Ave. #300 ATT: 612-633-5660 >St. Paul, MN 55113-2624 OK, let's clear up a few misconceptions first, then get down to the nitty gritty.... uucp does not use xon/xoff. It has a number of internal packetizing protocols (most common being g-protocol) that use ACK/NACK and timeouts to re-send corrupted packets. Think about it - how can it use XON/XOFF ? Those charaters could be a legitimate part of the data stream. The problem you are having is because the standard ISC asy driver using regular PC serial ports cannot deal with prolonged bursts of 9600 (or even 4800) packets. It loses characters, thus causing both receiver and sender to pause; the sender waiting for an ACK, teh receiver waiting for more data (it has a packet size and counts). Eventually, the receiver times out, sends a NACK, and the sender re-tries. This holds true even when the Telebit is spoofing g-protocol. The fix is to change the asy driver and the serial card UART. We have a driver which we got via a reference from this group. You can get it from: Macro Computer Solutions 1-312-566-8910 Ask for the SDK serial driver for 386/ix. It's $50 for the driver - well worth it. With 16550 SIO chips in a standard PC serial card, it will do 19.2K easily. 16550 have a FIFO in them which the driver detects and enables. They are plug compatible with the more usual 16450 (I think that's the number ..). Try and get a card with one on. I've heard that National are discontinuing this chip, but have not had this confirmed. If 9600 is acceptable, you may be able to do it with a regular serial card and the new driver. Also, the above driver supports dumb multi-line cards such as the Digiboard COM8. Hope this helps. -- Paul Bennett paul@dialogic.UUCP, ..!uunet!dialogic!paul Dialogic Corp, 129 Littleton Road, Parsippany, NJ 07054 (201) 334-8450 x 194 "Englands Monarchy is how old ? 1000 years ? Jesus, you guys must have a hell of a lot of laws! " Anon. sysadmin