Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!cornell!uw-beaver!tikal!sigma!uw-nsr!john
From: john@uw-nsr.UUCP (John Sambrook)
Newsgroups: comp.mail.uucp
Subject: Re: 4800 > 9600 ?
Message-ID: <1202@uw-nsr.UUCP>
Date: 10 Jan 88 18:10:33 GMT
References: <426@taux01.UUCP> <2337@mandrill.CWRU.Edu>
Reply-To: john@uw-nsr.UUCP (John Sambrook 548-4386)
Organization: UW-Bioengineering, Seattle, WA
Lines: 40

In article <2337@mandrill.CWRU.Edu> rynes@mandrill.CWRU.Edu (Edward M. Rynes  Esq.) writes:

>  We have the same problem connecting a Vax to a Data General over a
>serial line.  After much confusion and too many hours of debuging I
>came to the conclusion that one or both machines could not keep up
>with the conversation at 9600 baud and some of the data was lost.
>There does not seem to be any flow control between the two systems.
>The master sends a packet then waits for a reply from the slave. 
>(usualy about 10 seconds) if no reply is received it resends the
>packet.  The first few packets seem to go OK but after that buffers
>start to fill and eventualy a packet will get lost.  A lost packet
>will cause the slave to not respond causing the master to wait.  The
>wait allows the buffers on the slave to empty out allowing the next
>few packets to get through.  At 4800 baud both systems seem to keep
>up with the flow of data thus no lost packets and no waiting.
>
>   This may or may not be the problem you are having but the results
>are the same.  Good luck.

I have also run into this problem on a Data General system.  UUCP
on Data General systems has always been a problem for our group and,
I believe, for Data General as well.  

In the past the release notices for both MV/UX and DG/UX have included
disclaimers to the effect of "The ability to handle UUCP at speeds
greater than 4800 baud is a function of machine loading."  Note that 
this is not a direct quote, but I think it is close.

The good news is that DG/UX will be using HoneyDanBer UUCP starting
with revision 4.00.  At least that is what our local office claims.
I can't say whether or not this will help throughput problems.  I don't
know if MV/UX will support it or not.  

I have also noticed that if I want to use Kermit to send a file to 
our DG MV/10000 I have to do so at 4800 baud or less.  Any faster and
I get lots and lots of packet errors.  

-- 
John Sambrook                        Internet: john@nsr.bioeng.washington.edu
University of Washington RC-05           UUCP: uw-nsr!john
Seattle, Washington  98195               Dial: (206) 548-4386