Path: utzoo!utgpu!watserv1!watmath!att!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!van-bc!ubc-cs!nebulus!root
From: root@nebulus.UUCP (Dennis S. Breckenridge)
Newsgroups: comp.dcom.modems
Subject: Re: Error-correcting modems & uucp
Message-ID: <1990Apr13.012803.1639@nebulus.UUCP>
Date: 13 Apr 90 01:28:03 GMT
References: <963@frcs.UUCP> <967@frcs.UUCP> <1147@chinacat.Unicom.COM> <1990Apr12.002225.7496@imax.uucp>
Organization: Alchemy Mindworks, Vancouver, Canada
Lines: 27

dave@imax.uucp (Dave Martindale) writes:

>the modem's flow-control flag is irrelevant.  So, you don't need to do
>anything special to turn off flow control for incoming or outgoing uucp
>connections.

This may be true in some cases but if you run the modem locked at
19200 you ABSOLUTELY require flow control enabled. What happens is
uucico will ship a packet of data to the modem and the modem/serial
side is not ready, characters are dropped and the NAK is sent. This 
causes a retransmit, and so on and so on...
I have also found that the modem, when using hardware flow control,
will skid, (you 3B2 Eports guys know what this is!) and send a few
more characters out the serial port when you drop RTS. If your ports
card is true to nature it will lose it's mind, uucico will retransmit
the packet... The overall effect is TB works fine at 9600 baud, but
throughput decreases with 19200. The quick solution is to turn off all
flow control, the modem has a large buffer and try you luck. It works
on some sites namely Suns's, Consensys Powerports, AT&T IPC800's and
Computone AT8's. I have not verified this on the new series TB+ or 
TB2500's

-- 
-----------------------------------------------------------------------------
Dennis S. Breckenridge  (604) 277-7413   dennis@nebulus.uucp           VE7TCP
               EMACS: Eight Megabytes And Constantly Swapping!
-----------------------------------------------------------------------------